rule s for classification offshore units

RULES FOR CLASSIFICATION

Offshore units

DNV-RU-OU-0101 Edition July 2021

Offshore drilling and support units

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The PDF electronic version of this document available at the DNV website dnv.com is the official version. If thereare any inconsistencies between the PDF version and any other available version, the PDF version shall prevail.

DNV AS

FOREWORD

DNV rules for classification contain procedural and technical requirements related to obtaining andretaining a class certificate. The rules represent all requirements adopted by the Society as basisfor classification.

© DNV AS July 2021

Any comments may be sent by e-mail to [email protected]

This service document has been prepared based on available knowledge, technology and/or information at the time of issuance of thisdocument. The use of this document by other parties than DNV is at the user's sole risk. Unless otherwise stated in an applicable contract,or following from mandatory law, the liability of DNV AS, its parent companies and subsidiaries as well as their officers, directors andemployees (“DNV”) for proved loss or damage arising from or in connection with any act or omission of DNV, whether in contract or in tort(including negligence), shall be limited to direct losses and under any circumstance be limited to 300,000 USD.

CHANGES – CURRENT

This document supersedes the July 2020 edition of DNVGL-RU-OU-0101.The numbering and/or title of items containing changes is highlighted in red.

Changes July 2021, entering into force 1 January 2022

Topic Reference Description

Ch.1 Sec.2 [1.1.2],Former App.A

Deleted App.A and replaced text with reference to DNV-RU-SHIP Pt.1 Ch.1 App.A in Ch.1 Sec.2 [1.1.2].

Ch.1 Sec.2 [2.6.3],Ch.1 Sec.2 [2.6.4],Ch.1 Sec.2 [2.6.5]

New subsections with updated documentation requirements.

Ch.1 Sec.2 [2.7.6] New subsection with updated requirements for handling of ISMdeficiencies.

Ch.1 Sec.2 [4.1.7] New subsection for MARPOL Annex VI certification.

Ch.1 Sec.3 [2.9] Deleted class notation R for restricted service.

Ch.1 Sec.3 Table 6,

Ch.2 Sec.7 [29],

Ch.2 Sec.7 [30],

Ch.2 Sec.7 [31],

Ch.2 Sec.7 [32]

Removed subsection Special features notations and movedtext into separate subsections. No change in requirements.

Ch.1 Sec.4 [1.4.1] Clarified requirement for documentation submitted for re-approval.

Former Ch.2 Sec.7 Deleted subsection Summary of reference documents foradditional class notations.

Miscellaneous changes

Ch.2 Sec.7 [32] Renamed 'performance standards' to 'safety andenvironmental critical elements' (SECE).

Loading computer system Ch.1 Sec.3 Table 6,Ch.2 Sec.7 [13]

Updated description for additional class notation LCS, andmade qualifier (DC) optional.

Ch.1 Sec.3 Table 6 Added class notations Smart, D-INF, DDV, and REW.

Former Ch.1 Sec.3[2.8.4],Ch.2 Sec.7 [25]

Deleted descriptive notation Smart and replaced withadditional class notation Smart for operations based on digitalor environmentally friendly solutions.

Ch.2 Sec.7 [26] New class notation D-INF for data collection infrastructure.

Ch.2 Sec.7 [27] New class notation DDV for data-driven verification.

Data-driven notations

Ch.2 Sec.7 [28] New class notation REW for remote witnessing.

Operation with closed bus-tie Ch.2 Sec.7 [5] New class notations DPS(3-CBS) and DYNPOS(AUTRO-CBS) for closed bus-tie systems with built-in test functionality.

Greenhouse gas emissionabatement

Ch.2 Sec.7 [33] New class notation Abate to address greenhouse gas emissionreduction measures.

Changes - current

Rules for classification: Offshore units — DNV-RU-OU-0101. Edition July 2021 Offshore drilling and support units

DNV AS


Performance standard forprotective coating

Ch.2 Sec.7 [34] New class notation COAT-PSPC for protective coatings.

Rebranding to DNV All This document has been revised due to the rebranding of DNVGL to DNV. The following have been updated: the companyname, material and certificate designations, and references toother documents in the DNV portfolio. Some of the documentsreferred to may not yet have been rebranded. If so, please seethe relevant DNV GL document.

Editorial correctionsIn addition to the above stated changes, editorial corrections may have been made.

Changes - current


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CONTENTS

Changes – current............................................................3

Chapter 1 Principles and procedures for classification.... 15Section 1 Introduction....................................................................................................... 15

1 Introduction....................................................................................................... 15

1.1 General.......................................................................................................... 15

1.2 Scope and application......................................................................................15

1.3 Organisation................................................................................................... 15

1.4 References......................................................................................................16

1.5 Definitions and abbreviations............................................................................17

Section 2 Classification principles..................................................................................... 24

1 General...............................................................................................................24

1.1 The Society.................................................................................................... 24

2 The classification concept.................................................................................. 24

2.1 Introduction....................................................................................................24

2.2 Main class and class notations.......................................................................... 24

2.3 Conditions and assumptions involving other parties............................................. 25

2.4 Interactions with flag administrations and statutory requirements..........................25

2.5 Applicable rules...............................................................................................26

2.6 Documentation and information........................................................................ 27

2.7 Disclosure of information..................................................................................28

2.8 Access............................................................................................................28

2.9 Calibration of equipment.................................................................................. 29

2.10 Service suppliers........................................................................................... 29

3 Appeals.............................................................................................................. 29

3.1 Decisions taken by the Society......................................................................... 29

4 Statutory certification........................................................................................ 29

4.1 General.......................................................................................................... 29

4.2 Service suppliers............................................................................................. 30

Section 3 Classification scope and notations.....................................................................31

1 Scope of classification....................................................................................... 31

1.1 General.......................................................................................................... 31

1.2 Rule parts...................................................................................................... 31

1.3 Rule particulars...............................................................................................31

2 Class notations...................................................................................................32

2.1 General.......................................................................................................... 32

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2.2 Construction symbols.......................................................................................32

2.3 Main class notation..........................................................................................32

2.4 Structural design notations...............................................................................33

2.5 Service notations............................................................................................ 33

2.6 Class notations related to battery and fuel cell installations.................................. 34

2.7 Optional class notations related to special equipment and systems........................ 34

2.8 Optional class notations related to cold climate operation..................................... 36

2.9 Service restrictions.......................................................................................... 36

2.10 Compliance with coastal state legislation.......................................................... 36

2.11 Descriptive notation....................................................................................... 37

2.12 Combination of notations................................................................................37

Section 4 Assignment of class........................................................................................... 38

1 Assignment of class – new units....................................................................... 38

1.1 General.......................................................................................................... 38

1.2 Requirements for builder or designer.................................................................38


1.4 Plan approval..................................................................................................40

1.5 Survey during construction...............................................................................40

1.6 Installation of machinery, systems and equipment...............................................41

1.7 Testing and commissioning...............................................................................41

2 Assignment of class – existing units..................................................................42

2.1 General.......................................................................................................... 42


2.3 Design approval.............................................................................................. 42

2.4 Class entry survey.......................................................................................... 42

3 The class certificate........................................................................................... 42

3.1 General.......................................................................................................... 42

3.2 Late commissioning......................................................................................... 43

4 The register of vessels.......................................................................................43

4.1 General.......................................................................................................... 43

Section 5 Retention of class.............................................................................................. 44

1 General...............................................................................................................44

Section 6 Certification of materials, components and systems..........................................45

1 General...............................................................................................................45

1.1 Introduction....................................................................................................45

1.2 Requirements for manufacturer.........................................................................45

2 The Society's involvement................................................................................. 45

2.1 General.......................................................................................................... 45

2.2 Plan approval..................................................................................................46

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2.3 Type approval................................................................................................. 46

2.4 Survey........................................................................................................... 47

2.5 Manufacturing survey arrangement....................................................................47

3 Suspension and withdrawal of certificates.........................................................48

3.1 General.......................................................................................................... 48

Chapter 2 Design and construction provisions................ 49Section 1 Design and construction requirements for main class....................................... 49

1 General...............................................................................................................49

1.1 Introduction....................................................................................................49

1.2 Technical reference documents..........................................................................49

1.3 General assumptions....................................................................................... 50

2 Safety principles and arrangement.................................................................... 50

2.1 General.......................................................................................................... 50

2.2 Design principles............................................................................................. 50

2.3 Arrangement...................................................................................................50

2.4 Escape and communication.............................................................................. 50

3 Materials............................................................................................................ 50

3.1 Technical requirements.....................................................................................50

3.2 Supplementary classification and certification requirements.................................. 51

4 Structural design................................................................................................51

4.1 Scope............................................................................................................ 51


5 Fabrication and testing of offshore structures................................................... 52



6 Stability and watertight/weathertight integrity.................................................52


7 Mooring and towing........................................................................................... 53

7.1 General.......................................................................................................... 53

7.2 Temporary mooring......................................................................................... 53

7.3 Towing........................................................................................................... 53


8 Marine and machinery systems and equipment................................................. 54



9 Electrical systems and equipment......................................................................55


10 Instrumentation and telecommunication systems............................................55

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10.1 Technical requirements...................................................................................55

10.2 Supplementary classification requirements........................................................55

11 Fire protection................................................................................................. 56


11.2 Supplementary classification and certification requirements................................ 56

12 Preparation for surveys and inspections on location........................................56

12.1 General........................................................................................................ 56

13 Summary of technical reference standards......................................................57

Section 2 Supplementary requirements for drilling units.................................................. 59

1 General...............................................................................................................59

1.1 Introduction....................................................................................................59

1.2 Scope............................................................................................................ 59


2.1 General.......................................................................................................... 59

2.2 Arrangement...................................................................................................59

2.3 Area classification............................................................................................59

2.4 Emergency shutdown.......................................................................................59



3.1 General.......................................................................................................... 60

4 Fire protection................................................................................................... 60

4.1 General.......................................................................................................... 60

4.2 Supplementary technical requirements...............................................................60

5 Temporary mooring............................................................................................60

6 Summary of requirements................................................................................. 61

Section 3 Supplementary requirements for well intervention units................................... 62

1 General...............................................................................................................62

1.1 Introduction....................................................................................................62

2 General requirements........................................................................................ 62

2.1 Structural design.............................................................................................62

2.2 Position keeping.............................................................................................. 63

3 Requirements for Well intervention unit(1).......................................................63

3.1 General.......................................................................................................... 63

3.2 Supplementary requirements............................................................................ 63

4 Requirements for Well intervention unit(2).......................................................64

4.1 General.......................................................................................................... 64

4.2 Arrangement...................................................................................................64

4.3 Area classification............................................................................................64


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4.6 Fire protection................................................................................................ 65

Section 4 Supplementary requirements for accommodation units.....................................66

1 General...............................................................................................................66

1.1 Introduction....................................................................................................66



3 Structural strength.............................................................................................66

3.1 General.......................................................................................................... 66

3.2 Design loads...................................................................................................66

3.3 Containerised modules..................................................................................... 66

3.4 Gangways.......................................................................................................67

4 Electrical systems and equipment......................................................................67

4.1 Emergency source of power and emergency installation....................................... 67

5 Position keeping................................................................................................ 67

Section 5 Supplementary requirements for crane units.....................................................68

1 Introduction....................................................................................................... 68

1.1 Objective........................................................................................................68

1.2 Safety principles – emergency shutdown............................................................68


2.1 General.......................................................................................................... 68


3 Stability and watertight integrity.......................................................................68

4 Crane with substructure.................................................................................... 68

4.1 Certification.................................................................................................... 68

4.2 Substructure................................................................................................... 68

Section 6 Supplementary requirements for wind turbine installation units....................... 69

1 General...............................................................................................................69

1.1 Introduction....................................................................................................69

2 General requirements........................................................................................ 69

2.1 Structural strength.......................................................................................... 69

2.2 Stability and watertight....................................................................................69

2.3 Position keeping.............................................................................................. 69

3 Crane installations............................................................................................. 69

Section 7 Additional class notations..................................................................................70

1 Introduction....................................................................................................... 70

1.1 General.......................................................................................................... 70

1.2 Technical reference documents..........................................................................70

1.3 General assumptions....................................................................................... 70

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2 Enhanced systems..............................................................................................70

2.1 General.......................................................................................................... 70


2.3 Certification of materials and components.......................................................... 71

3 Position mooring equipment.............................................................................. 71

3.1 General.......................................................................................................... 71


3.3 Certification requirements................................................................................ 71

4 Position mooring system....................................................................................72

4.1 General.......................................................................................................... 72

4.2 Application......................................................................................................72



5 Dynamic positioning systems.............................................................................73

5.1 General.......................................................................................................... 73



6 Drilling facilities.................................................................................................76

6.1 General.......................................................................................................... 76



6.4 DRILL(US).................................................................................................... 78

6.5 Modular drilling systems.................................................................................. 78

7 Helicopter decks.................................................................................................78

7.1 General.......................................................................................................... 78



8 Well testing facilities......................................................................................... 79

8.1 General.......................................................................................................... 79



9 Temporary oil storage facilities......................................................................... 80

9.1 General.......................................................................................................... 80



10 Crane installations........................................................................................... 81

10.1 General........................................................................................................ 81


10.3 Certification.................................................................................................. 83

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10.4 Testing......................................................................................................... 83

11 Offshore gangways.......................................................................................... 84

11.1 General........................................................................................................ 84


11.3 Certification of materials and components........................................................ 84

12 Additional fire protection................................................................................. 84

12.1 General........................................................................................................ 84



13 Loading computer............................................................................................ 85

13.1 Introduction.................................................................................................. 85

13.2 Scope...........................................................................................................85

13.3 Application.................................................................................................... 85

13.4 Class notations..............................................................................................85



14 Periodically unattended machinery space........................................................ 86

14.1 General........................................................................................................ 86



15 Well intervention system................................................................................. 87

15.1 General........................................................................................................ 87



15.4 Modular well systems.....................................................................................88

16 Hull monitoring system....................................................................................88

16.1 General........................................................................................................ 88


17 Fatigue methodology specification...................................................................88

17.1 General........................................................................................................ 88


18 Hull fabrication................................................................................................ 89

18.1 General........................................................................................................ 89


19 Noise, vibration and comfort rating notations................................................. 90

19.1 General........................................................................................................ 90


19.3 Certification requirements...............................................................................91

20 Cold climate notations..................................................................................... 91

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20.1 General........................................................................................................ 91

20.2 Structural strength........................................................................................ 91

20.3 Winterized.................................................................................................... 93

21 Environmental notations.................................................................................. 94

21.1 General........................................................................................................ 94

21.2 Objective...................................................................................................... 94


22 Enhanced system verification.......................................................................... 95

22.1 General........................................................................................................ 95



23 Integrated software dependent systems......................................................... 96

23.1 General........................................................................................................ 96



24 Cyber security.................................................................................................. 97

24.1 General........................................................................................................ 97


24.3 Documentation requirements.......................................................................... 98

25 Smart unit........................................................................................................98

25.1 Introduction.................................................................................................. 98

25.2 Objective...................................................................................................... 98

25.3 Scope...........................................................................................................98

25.4 Application.................................................................................................... 98

25.5 Class notations..............................................................................................99


26 Data collection infrastructure.......................................................................... 99

26.1 Introduction.................................................................................................. 99

26.2 Objective...................................................................................................... 99

26.3 Scope...........................................................................................................99

26.4 Application.................................................................................................. 100

26.5 Class notations............................................................................................ 100

26.6 Technical requirements................................................................................. 100

27 Data-driven verification................................................................................. 100

27.1 Introduction................................................................................................ 100

27.2 Objective.................................................................................................... 101

27.3 Scope......................................................................................................... 101

27.4 Application.................................................................................................. 101

27.5 Class notations............................................................................................ 101

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28 Remote witnessing.........................................................................................103

28.1 Introduction................................................................................................ 103

28.2 Objective.................................................................................................... 103

28.3 Scope......................................................................................................... 103

28.4 Application.................................................................................................. 104

28.5 Class notations............................................................................................ 104


29 Non-self-propelled..........................................................................................104

29.1 Objective.................................................................................................... 104

29.2 Scope......................................................................................................... 104

29.3 Application.................................................................................................. 105

30 Tailshaft monitoring.......................................................................................105

30.1 Objective.................................................................................................... 105

30.2 Scope......................................................................................................... 105

30.3 Application.................................................................................................. 105


31 Built for in-water survey................................................................................105

31.1 Objective.................................................................................................... 105

31.2 Scope......................................................................................................... 105

31.3 Application.................................................................................................. 105


32 Barrier management notation........................................................................ 105

32.1 Introduction................................................................................................ 105

32.2 Objective.................................................................................................... 106

32.3 Scope......................................................................................................... 106

32.4 Application.................................................................................................. 106


32.6 Development of unit specific performance standards........................................ 113

33 Abate..............................................................................................................113

33.1 Introduction................................................................................................ 113

33.2 Objective.................................................................................................... 114

33.3 Scope......................................................................................................... 114

33.4 Application.................................................................................................. 114

33.5 Technical Requirements................................................................................ 114

34 Performance standard for protective coatings............................................... 116

34.1 Introduction................................................................................................ 116

34.2 Scope......................................................................................................... 116

34.3 Application.................................................................................................. 116

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34.4 Class notations............................................................................................ 117


Appendix A Introduction to offshore classification........1181 Introduction........................................................................................ 1182 The classification system.................................................................... 1182.1 The classification process and its limitations.........................................1182.2 Who needs classification?...................................................................1182.3 Recognition of DNV........................................................................... 1192.4 Responsibility for safety at sea........................................................... 1192.5 Classification of newbuildings............................................................. 1192.6 Classification in the operational phase................................................. 1202.7 Owner's duties..................................................................................120

3 Remuneration......................................................................................1214 Classification support..........................................................................1214.1 General............................................................................................1214.2 Pre-contract support..........................................................................1214.3 In-service support.............................................................................1214.4 Limitations....................................................................................... 121

Changes – historic........................................................122

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CHAPTER 1 PRINCIPLES AND PROCEDURES FORCLASSIFICATION

SECTION 1 INTRODUCTION

1 Introduction

1.1 GeneralThis publication presents DNV rules for classification of offshore units, Drilling and support units, the termsand procedures for assigning classification, including listing of the applicable technical references to beapplied for classification.

Guidance note:

A more extensive introduction to offshore classification is given in App.A.

---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---

1.2 Scope and applicationThis document covers classification of mobile offshore units of the following structural design types:

— ship-shaped units— column-stabilised units— cylindrical units

for the following services:

— drilling— well intervention— accommodation— heavy-lifting— wind turbine installation— general offshore support.

Guidance note:

Self-elevating units for the above mentioned services are covered by DNV-RU-OU-0104.


This document provides classification principles, procedures, design and construction requirements for theservices and structural design types included in the scope.Principles, procedures and requirements for retention of class during operation of the unit are covered byDNV-RU-OU-0300.

1.3 OrganisationThis document is divided into two main chapters as follows:

— Ch.1: providing general information about classification principles and procedures— Ch.2: providing design and construction requirements for the newbuilding phase.

The content is completed with the following appendixes:

— App.A: Introduction to offshore classification.

Chapter 1 Section 1


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1.4 ReferencesThis document includes references to other DNV documents and recognised codes and standards which shallbe used in conjunction with the requirements given in this document for assignment of class.Table 1 lists DNV references used in this document. See Sec.2 [2.5] for applicable editions.

Table 1 DNV references

Document code Title

DNV-CG-0172 Allowable thickness diminution for hull structure

DNV-CG-0264 Autonomous and remotely operated ships

DNV-CG-0508 Smart vessel

DNV-CG-0550 Maritime services - terms and systematics

DNV-CG-0557 Data-driven verification

DNV-CP-0338 DNV type approval scheme

DNV-OS-A101 Safety principles and arrangement

DNV-OS-B101 Metallic materials

DNV-OS-C101 Design of offshore steel structures, general – LRFD method

DNV-OS-C102 Structural design of offshore ship-shaped and cylindrical units

DNV-OS-C103 Structural design of column-stabilised units – LRFD method

DNV-OS-C104 Structural design of self-elevating units – LRFD method

DNV-OS-C201 Structural design of offshore units – WSD method

DNV-OS-C301 Stability and watertight integrity

DNV-OS-C401 Fabrication and testing of offshore structures

DNV-OS-D101 Marine and machinery systems and equipment

DNV-OS-D201 Electrical installations

DNV-OS-D202 Automation, safety, and telecommunication systems

DNV-OS-D301 Fire protection

DNV-OS-E101 Drilling plant

DNV-OS-E201 Oil and gas processing systems

DNV-OS-E301 Position mooring

DNV-OS-E401 Helicopter decks

DNV-RP-C210 Probabilistic methods for planning of inspection for fatigue cracks in offshore structures

DNV-RP-C302 Risk based corrosion management

DNV-RU-OU-0102 Floating production, storage and loading units

DNV-RU-OU-0104 Self-elevating units, including wind turbine installation units and liftboats

DNV-RU-OU-0294 Modular systems for drilling and well

Chapter 1 Section 1


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Document code Title

DNV-RU-OU-0300 Fleet in service

DNV-RU-SHIP DNV rules for classification of ships

DNV-SI-0003 Verification for compliance with United States regulations on the outer continental shelf

DNV-SI-0166 Verification for compliance with Norwegian shelf regulations

DNV-SI-0167 Verification for compliance with United Kingdom shelf regulations

DNV-ST-0378 Standard for offshore and platform lifting appliances

Table 2 lists other references used in this document. See Sec.2 [2.5] for applicable editions.

Table 2 Other references

Document code Title

IACS Rec 47 International Association of Classification Societies, Shipbuilding and Repair Quality Standard,see www.iacs.org.uk

ISO 9001 Quality management systems – Requirements

1.5 Definitions and abbreviations

1.5.1 Definition of verbal formsThe verbal forms defined in Table 3 are used in this document.

Table 3 Definition of verbal forms

Term Definition

shall verbal form used to indicate requirements strictly to be followed in order to conform to the document

should verbal form used to indicate that among several possibilities one is recommended as particularly suitable,without mentioning or excluding others

may verbal form used to indicate a course of action permissible within the limits of the document

1.5.2 Definition of termsThe terms defined in Table 4 are used in this document.

Table 4 Definition of terms

Term Definition

alteration change that does not affect the basic character or structure of the unit it is applied to

assessment act of assessing, appraising or evaluating a condition of a product, process or system

builder party contracted to build a unit in compliance with the Society's rules

certificate compliance document referring to a standard that is ratified or accepted by agovernment, and issued by a third party organisation, see DNV-CG-0550 Sec.3

Chapter 1 Section 1


DNV AS

http://www.iacs.org.uk

Term Definition

class class is assigned to and will be retained for Units, which the Society has found to be incompliance with applicable requirements of the Society's rules

class certificate class certificate is a certificate targeting an asset and referring to the Society's rules forclassification, see DNV-CG-0550 Sec.3

class entry assignment of class to an existing unit

class notation abbreviation or keyword expressing a specific feature relating to a unit or its machinery,systems and equipment, or service area while referring to specific requirements in therules

classification service which comprises the development and maintenance of independent technicalstandards for units – class rules and standards, and to verify compliance with the rulesand standards throughout the unit's lifeThe extent of and methods for verifying compliance will be decided by the Society toestablish reasonable assurance that the relevant rules are complied with.

commissioning process of assuring that components, equipment and the systems are functioning inaccordance with the functional requirements

compliance document document stating that the issuing organisation has established reasonable assurance thatthe target complies with all or selected requirements of the standard editions referred to,see DNV-CG-0550 Sec.3

contract for construction contract between the prospective owner and the builder to build a unit, see Sec.4 [1.3.2]

conversion change that substantially alters the dimensions, carrying capacity or the type of the unit

critical structural areas areas that have been identified from calculations to require monitoring or from theservice history of the subject unit or from similar or sister units to be sensitive tocracking, buckling or corrosion which would impair the structural integrity of the unit

customer any person and/or company which has requested the Society's service and/or hasentered into a contract for services directly with the Society

declaration document stating that the issuing organisation has established reasonable assurance thatthe target complies with all or selected requirements of the standard editions referred to,see DNV-CG-0550 Sec.3

deficiency failing or shortcoming with respect to applicable requirements

designer party who created or developed documentation which is submitted to the Society forapproval or information

documentation drawings, descriptions, calculations, reports, procedures, certificates and similarinformation describing e.g. the design, installation, testing, operation, maintenance orstatus of an object

emergency towing towing related to an emergency situation normally caused by failure of the Units ownpropulsion (compare with normal towing)

flag administration government of the state whose flag the unit is entitled to fly

guidance notes additional information containing advice which is not required for the assignment orretention of class, but with which the Society, based on experience, advises compliance

Chapter 1 Section 1


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Term Definition

hybrid twin for structural condition monitoring, hybrid twin is considered as a design model coveringstructural details of potential critical areas, and where design environment has beenreplaced by encountered environment captured by measured structural response andfrom environment/weather data

IACS International Association of Classification Societies

Independent tank self-supporting tank which does not form part of the unit's hull and does not contributeto the hull strength

Independent gravity tank tank with design vapour pressure not exceeding 0.7 bar

Interpretation norms for fulfilling the associated principal requirements as defined by other regulatorybodies on matters which are left to the satisfaction of the flag administration or arevaguely wordedThese do not preclude the use of other alternative solutions, but these shall bedocumented and approved for compliance to the principal requirement equivalent to theoriginal interpretation.

main character of class characters showing compliance with a defined set of classification rules for hull and/ormachinery

main functions in the context of these rules for classification:

— structural strength— stability, watertight integrity and weathertightness— drainage and bilge pumping— ballasting— power generation— propulsion (as applicable)— steering (as applicable)— position keeping (as applicable) 1)

Guidance note:1) Including jacking systems as applicable.


main hoisting system all major lifting equipment directly involved in lifting pipe, riser etc. into and out of thewell, such as drawworks, hydraulic cylinders, top drive, links, elevators etc.Pipe handling equipment used for making up and breaking out pipe/stands are notconsidered main hoisting systems.

manufacturer organisation that manufactures the material or product, or carries out part productionthat determines the quality of the material or product, or does the final assembly of theproduct

mechanical completion verification that the components, equipment and the systems are constructed, installedand tested in accordance with applicable drawings and specifications and are ready fortesting and commissioning in a safe manner

memorandum to owner information related to the unit, its machinery, systems and equipment or applicablerequirementsA memorandum to owner will be issued in relation to information that does not requireany corrective action or survey.

Chapter 1 Section 1


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Term Definition

mobile offshore unit buoyant construction engaged in offshore operations including drilling, production,storage or support functions, not intended for service at one particular offshore location,and which can be relocated without major dismantling or modification

newbuilding new unit under construction at a builder

numerical twin for structural condition monitoring, a numerical twin is considered as a design modelcovering structural details of potential critical areas, and where design environment hasbeen replaced by encountered environment/weather data

offshore installation buoyant or non-buoyant construction engaged in offshore operations including drilling,production, storage or support functions, and which is designed and intended for use atone particular location for an extended period

owner registered owner and/or manager of the Unit and/or any other organisation and/or person who has assumed the responsibility for operation of the unit and who onassuming such responsibility has agreed to take over all the duties and responsibilitiesrelated to the unit

patrolling independent and unscheduled check that the applicable processes, activities andassociated documentation of the building functions continue to comply with the rules andstatutory requirements

performance standard statements which can be expressed in qualitative or quantitative terms, of theperformance required of a system or item of equipment, used as the basis for managinga hazard of the unit

plan approval systematic and independent examination of drawings, design documents or records bythe Society in order to verify compliance with the Rules or statutory requirements whereauthorised by the flag administrationThe extent and method of plan approval will be decided at the discretion of the Society.

plan approval staff personnel authorized to carry out plan approval and to conclude whether or notcompliance with the rules or statutory instruments has been met

position mooring anchoring system for position keeping at the unit's working location

ressure vessel tank with design gas or vapour pressure exceeding 0.7 bar

procedural requirements requirements for the process of assessing compliance with technical requirementsProcedural requirements cover:

— basis for design assessment, i.e. information or documentation requirements— requirements for certification of products— requirements for surveys to assign, maintain and retain class.

product declaration declaration relating to and identifying a product, issued by the manufacturer and basedon examination and/or testing performed upon the product itself, see DNV-CG-0550Sec.3

quality audit systematic and independent examination to determine whether established workprocesses and quality systems are adhered to

quality system quality management system and established procedures for production and control

Chapter 1 Section 1


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Term Definition

quality survey plan plan that systematically identifies activities related to the classification project (e.g.construction, installation, testing, mechanical completion, pre-commissioning, testingand commissioning) and the extent of involvement each party (i.e. yard's QC, yard's QA,DNV and owners (if desired)) will undertakeSuch a plan needs to be submitted to the Society for approval prior to commencement ofclassification projects.

reliability ability of a component or a system to perform its required function under givenconditions for a given time interval

representative tanks those tanks which are expected to reflect the condition of other tanks of similar type andservice and with similar corrosion protection systemsWhen selecting representative tanks account shall be taken of the service and repairhistory on board and identifiable critical and/or suspect areas.

retroactive requirement requirement in the rules or a statutory requirement that will enter into force for certainunits in operation and under construction at a given date or at an upcoming surveyThe retroactive requirement will specify the required actions to be taken in order toretain class or statutory certification.

RR related to statutory certification will be issued only if the Society has been authorisedto carry out statutory certification on behalf of the flag administration.

rules independent standard that consist of all requirements, technical and procedural,adopted by the Society as the basis for classification. and published in DNV's rules forclassification and referred documents

society DNV AS and its affiliates carrying out classification and statutory certification

safety systems systems, including required utilities, which are provided to prevent, detect/warn of anaccidental event/abnormal conditions and/or mitigate its effects

Interpretation:The following should be considered as safety systems:

— ESD, including blowdown where relevant— PSD— fire and gas detection— PA/GA— fire-fighting systems— BOP incl. control system— safety systems for essential or important services— safety systems are normally considered as 'on-demand' functions.

---e-n-d---o-f---i-n-t-e-r-p-r-e-t-a-t-i-o-n---

spaces separate compartments including holds and tanks

statement of compliance compliance document that is issued by a third party organisation, and is not a certificate,see DNV-CG-0550 Sec.3

statutory certification service with the intention of confirming compliance with regulatory codes andregulations, in agreement with relevant flag administrations

survey systematic and independent assessment of a unit, materials, components or systems inorder to verify compliance with the rules and/or statutory requirements

Surveys will be carried out at the discretion of the Society, which also decides the extentand method of survey.

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Term Definition

surveyor personnel authorised to carry out Surveys and to conclude whether or not compliancehas been met

technical requirements requirements for design and construction of a unit, system or component, and theminimum requirements they shall meet during the operational lifetime

temporary conditions design conditions not covered by operating conditions, e.g. conditions during fabrication,mating and installation phases, and dry transit phases

temporary equipment equipment intended for use on board for a period not exceeding 30 months and whichis covered by class, requires hook-up to systems covered by class and/or is a significantdeck load and/or may pose a risk for fire, explosion and escape routes

temporary mooring anchoring in sheltered waters or harbours exposed to moderate environmental loads

tentative rules and standards provisional rules or standards to which DNV reserves the right to make immediate and/orretroactive adjustments in order to obtain the purpose intended

(normal) towing drawing or pulling the unit by a chain or line using a tug boatNormally towing is performed for units without any propulsion for (re-)location (comparewith emergency towing).

transit conditions all wet unit movements from one geographical location to another

unit in the context of these rules signifies a mobile offshore unit

verification service that confirms through the provision of objective evidence (analysis, observation,measurement, test, records or other evidence) that specified requirements have beenmet

vessel any object designed for transportation or special operations on water

witnessing attendance of tests or measurements with the intention of verifying compliance withagreed test or measurement procedures

1.5.3 AbbreviationsThe abbreviations described in Table 5 are used in this document.

Table 5 Abbreviations

Term Description

A availability

API American Petroleum Institute

BAT best available technology

BOP blow out preventer

BS British Standard (issued by British Standard Institution)

CCR central control room

CMC certification of materials and components

CMMS computerised maintenance management system

CTF coating technical file

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Term Description

DDV data-driven verification

ECC emergency control centre

EDP drilling equipment planned maintenance system

ESD emergency shut down

FMEA failure modes effects analysis

IACS International Association of Classification Societies

IEC International Electrotechnical Commission

IMO International Maritime Organization

HMI human machine interface

HVAC heating, ventilation and air-conditioning

ISO International Organisation for Standardization

LRFD load and resistance factor design

MACC marginal abatement cost curve

MC mechanical completion

MO memorandum to owner

MOU mobile offshore unit

NDT non-destructive testing

OEM original equipment manufacturer

PFP passive fire protection

QSP quality survey plan

RR retroactive requirement

SAE Society of Automotive Engineers

SECE safety and environmental critical elements

SQ system qualification

TS target system

VM verification method

VSD variable speed drive

WHRU waste heat recovery unit

WSD working stress design

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SECTION 2 CLASSIFICATION PRINCIPLES

1 General

1.1 The Society

1.1.1 DNV is an organisation with the objective of safeguarding life, property, and the environment. DNVoperates through the limited company DNV AS, which is registered in Norway and operates through aworldwide network of affiliates and offices.DNV carries out classification, certification and other verification services related to mobile offshore units,facilities, systems, materials and components and performs research in connection with these functions.Moreover, provided its integrity is not impaired, DNV may perform assignments which utilise its knowledge orwhich contribute to develop knowledge that will be required for the performance of these tasks.

1.1.2 The DNV general terms and conditions (T&C), see DNV-RU-SHIP Pt.1 Ch.1 App.A, for classificationservices, are an integral part of the rules in their latest version. In case of any ambiguities or contradictionsbetween the T&C and other parts of the rules, the provisions of the T&C shall prevail.

2 The classification concept

2.1 Introduction

2.1.1 The classification concept consists of the development and application of rules and referred offshorestandards with regard to design, construction and survey of mobile offshore units.

2.1.2 In general, the rules and standards cover requirements for:

— availability of main functions and the safety of installations supporting the main functions— the structural strength and integrity of essential parts of the unit's hull and its appendages— the safety of machinery, systems and equipment supporting non-main functions that constitute possiblehazards to personnel and unit

— safety levels and availability beyond that of main class, (see [2.2.2]).

2.1.3 Class may be assigned to a unit when the Society has established reasonable assurance that the rulesare complied with.

2.1.4 The assignment of class is documented by the issuance of a class certificate or an interim classcertificate and the entry of the unit's main particulars and details of class in the Society's register, (see Sec.4[4]).

2.1.5 Class is maintained during the service period provided applicable requirements are observed andsurveys carried out. The class will be retained on the condition that the requirements applicable for retentionof class are complied with. Retention of class is confirmed by annual endorsements and renewal of the classcertificate at 5-year intervals.

2.2 Main class and class notations

2.2.1 The class notations are based on the following structure:

— main class notations

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— structural design notations— service notations— additional class notations related to special equipment and systems— additional class notations related to cold climate operations— service restrictions.

Applicable class notations are provided in Sec.3.

2.2.2 Mandatory class notations stipulate requirements for:

— availability of main functions and the safety of installations supporting the main functions— structural strength and integrity of essential parts of the unit's hull and its appendages— the safety of machinery, systems and equipment supporting non-main functions that constitute possiblehazards to personnel and unit.

2.2.3 Class notations are assigned to a unit in order to determine applicable requirements in the rules forassignment and/or retention of that class notation.

2.2.4 Additional class notations include requirements to safety levels and availability beyond that of mainclass and mandatory class notations.

2.2.5 Upon consideration, class notations as found in other rule books published by the Society may beassigned to a unit complying with these class notations.

2.3 Conditions and assumptions involving other parties

2.3.1 Classification is performed on the basic assumption that other parties involved fulfil their individualobligations, including ensuring compliance with the rules. Classification does not substitute the role and/orrelease the obligations of other parties.

2.3.2 Nothing contained in these rules or in any certificate, report or document issued in connection withor pursuant to these rules, shall relieve any customer, designer, engineer, builder, manufacturer, yard, seller,supplier, owner, operator, unit management or any other party from any obligations or consequences ofdefault whatsoever.

2.3.3 Compliance with the rules does not imply that a unit is considered seaworthy. The acceptance andcommissioning of a unit is the exclusive responsibility of the owner.

2.4 Interactions with flag administrations and statutory requirements

2.4.1 The unit's arrangement and equipment shall comply with the requirements given by its flagadministration, as applicable.Such compliance is a prerequisite for class. Compliance shall be demonstrated by possession of theapplicable convention certificates issued according to [4]. The Society will not verify compliance with theserequirements unless authorised by the flag administration.

2.4.2 If the Society has not been authorised to undertake statutory certification on behalf of a flagadministration, the Society assumes the right to refuse to issue, or withdraw class for such units. The Societydecides the extent of authorization found necessary in order to retain class.

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2.5 Applicable rules

2.5.1 The rules lay down technical and procedural requirements related to obtaining and retaining a classcertificate.

2.5.2 The rules stipulate requirements for the design, construction, survey and testing of mobile offshoreunits.

2.5.3 The rules stipulate requirements for structures, materials, machinery, systems and equipment.

2.5.4 The rules cover in some areas requirements also stipulated by IMO conventions and codes.Guidance note:

For issuance of statutory certificates, compliance with the statutory instruments will prevail where the rules and IMO conventionsand codes differ, see [2.5.1].


2.5.5 The rules and amendments to the rules accepted by the Society will enter into force on a date decidedby the Society. Unless stated otherwise, the entry into force date shall be six (6) months after the date ofpublication.Unless stated otherwise, the coming into force date for DNV documents referenced by this document astechnical basis for classification shall be six (6) months after the date of publication.

Guidance note:

The date on which changes to the rules come into force is shown on page 3 of new/revised chapters of the rules.

Requirements for retaining class are given in DNV-RU-OU-0300, latest edition in force.


2.5.6 In the case where service experience and/or theoretical findings show that unacceptable risks mayexist in connection with items covered by the existing rules, the Society may, at any time, decide to lay downsupplementary or amended requirements concerning the assignment and retention of class.

2.5.7 If an amendment to the rules is made mandatory to units already contracted (see Sec.4 [1.3.3] ) orto units that have already been assigned class, this will be especially stated.

2.5.8 The Society may consider the use of risk based assessments as a means of documenting compliancewith requirements in the rules.

Guidance note:

The assessment may be carried out using the format presented in IMO MSC-MEPC.2/Circ.12 Revised guidelines for formal safetyassessment (FSA) for use in the IMO rule-making process. An alternative is provided in DNV-CG-0121 Classification based onperformance criteria determined from risk assessment methodology.


2.5.9 Alternatives to detailed requirements in the rules may be accepted when the overall safety andreliability level is found to be equivalent or better than that of the rules.

Approval may be revoked if subsequent information indicates that the chosen alternative is not satisfactory.

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2.5.10 If detailed requirements are not prescribed in the rules, the Society may consider the safety andreliability level of a proposed solution, or require clarification to resolve the issue. The Society reserves theright to accept or reject proposed solutions without justification.

2.5.11 The approval as described in [2.5.10] shall be based on an agreed scheme of analysis that isseparately worked out and approved.

Guidance note:

For new technology, recommended practice DNV-RP-A203 can be a suitable basis for such scheme.


2.5.12 Upon request by the customer, DNV may consider the use of other recognised codes and standardsas part of the basis for classification. Such agreed alternative arrangements shall be specified in the classagreement.

2.5.13 The Society reserves the exclusive right to interpret, decide equivalence or make exemptions to theRules.

2.5.14 The rules are an integral part of the Society's classification service. The safety objectives inherentin the rules are achieved in conjunction with this classification service. Using the rules without thecorresponding classification services may have the result that safety objectives are not met.

2.5.15 The rules are under the sole ownership rights and copyrights of the Society. It is prohibited byanyone else than the Society to offer and/or perform classification services, wholly or partly, on the basis ofand/or pursuant to these rules without the Society's prior written consent. The Society is not responsible forthe consequences arising from any use of the rules by others.

2.6 Documentation and information

2.6.1 All documentation and information that may influence the judgement, decisions and requirementsof the Society for the purpose of classification, shall be made available to the Society. It is the customer'sresponsibility to document and/or demonstrate compliance with the rules. Information may be madeavailable by submitting documents to the Society or by permitting surveys performed by the Society at thecustomer's premises, onboard the unit or at the premises of the customer's sub-contractors.

2.6.2 Documentation requirements are stated in the rules and in lists of documentation requirementssupplied by the Society. Documentation shall be submitted to the Society by the customer in accordance withDNV-CG-0550 Sec.6. If additional documentation and/or information are required, the Society will ask forthis specifically.

2.6.3 The submitted documentation, which forms the basis for classification shall, at all times, reflectthe true status. In this respect, any revisions of documents required for plan approval shall therefore besubmitted to the Society.

2.6.4 The supply of information should take place electronically and on a continuous basis in a formataccepted by the Society, e.g. by online access to the Society's data bases, see DNV-CG-0550.

2.6.5 The customer warrants that he/she has the necessary rights to disclose relevant documentation andinformation to the Society.

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2.7 Disclosure of information

2.7.1 The Society will not disclose any information received or reports made in connection with classificationto any other party than those entitled thereto (see IACS PR03) or those having been given the right toreceive information by legislation, court decision or written permission from the owner of the information.

2.7.2 The Society will not disclose information that can be considered as the property of another partyexcept when permission is given in writing by that party.

2.7.3 Internal communication, notes and calculations produced within the Society in connection withclassification will not be disclosed to other parties.

2.7.4 Notwithstanding [2.7.1] to [2.7.3], the following parties will have access to such information:

— authorised representatives of the flag administration— authorised audit teams performing audits in connection with certification of the Society.

2.7.5 Notwithstanding [2.7.1] and [2.7.3], the Society may disclose information requested by a court order,governmental body (including regional bodies) or other public investigation bodies that are authorised by adecree.

2.7.6 When deficiencies, possibly affecting the implementation of the International Safety Management(ISM) Code on board, are identified during any survey, a report will be completed. The Society may, at itsdiscretion, release this report to the organisation responsible for the safety management system audit onboard. See also IACS PR17.

2.7.7 Information recorded in the Society's register of vessels, which encompass the status of classificationand statutory surveys and certificates issued by the Society, overdue conditions, class suspensions,withdrawals and reinstatements, will be published and/or released to any interested party e.g. throughEquasis according to IACS PR16.

2.7.8 The Society may at its discretion release information to other classification societies concerningrelevant technical information on serious structural, machinery and system failures for the purpose ofimproving safety and protection of the marine environment. The owner will be informed accordingly. See alsoIACS PR02A and PR02B.

2.8 Access

2.8.1 For the purpose of verifying compliance with the rules, the customer shall provide the Society'ssurveyors with safe access to the unit and/or to their premises.The premises and objects to be surveyed shall as agreed be cleaned and prepared for survey.

2.8.2 The customer shall provide flag administration and authorised audit and/or inspection teams with safeaccess to the unit and/or to their premises in order to audit the Society's compliance with applicable rules,regulations and quality standards.

2.8.3 The Society reserves the right to decline to perform a requested service when inadequate access isprovided or the safety of its surveyors may be compromised.

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2.9 Calibration of equipmentMeasuring and test equipment used by customers, the result of which may form the basis for the surveyor'sdecisions, shall have a calibration status to an appropriate accuracy according to the rules or as accepted bythe surveyor.

2.10 Service suppliersSuppliers providing services on behalf of the customer, such as measurements, tests and maintenance ofsafety systems and equipment, the result of which may form the basis for the surveyor's decisions, shall beapproved by the Society, according to criteria established by the Society.

3 Appeals

3.1 Decisions taken by the SocietyThe customer may request in writing that a decision made by the Society shall be taken up forreconsideration. The expenses incurred shall be paid by the customer. However, if the earlier decision isrevoked, the Society’s expenses will be covered by the Society.

4 Statutory certification

4.1 General

4.1.1 The Society undertakes statutory certification on behalf of flag administrations when and to the extentthe Society has been authorised to do so by the individual flag administration.Statutory certification includes inter alia approval, survey and the issuance of statutory certificates.When the Society acts on behalf of a flag administration, the Society follows international statutoryinstruments, IACS unified interpretations and DNV statutory interpretations, and generally follows guidanceissued by IMO in circulars etc. unless the flag administration has instructed the Society otherwise.

4.1.2 It is assumed by the Society that required statutory Surveys for units classed by the Society will becarried out by the Society or by officers of the flag administration itself and that statutory certificates willbe issued by the Society or by the flag administration with the exceptions mentioned in [4.1.3] to [4.1.6].The Society assumes the right to withdraw class if statutory certificates are not issued as described in thisparagraph.

4.1.3 The Society may accept that Safety Management Certificates (ISM code) are issued by a third partythat has been authorised by the flag administration and complies with the Code for Recognized Organisations(RO Code), adopted by Resolution MSC.349(92).

4.1.4 The Society may accept that International Ship Security Certificates (ISPS code) are issued by a thirdparty that has been authorised by the flag administration and complies with MSC/Circ.1074.

4.1.5 The Society may accept that Maritime Labour Certificates are issued by a third party that has beenauthorised by the flag administration and complies with MLC, 2006.

4.1.6 The Society may accept that Cargo Ship Safety Radio Certificates (SOLAS) are issued by a third partythat has been authorised by the flag administration.

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4.1.7 The Society may accept that Statements of Compliance - Fuel Oil Consumption Reporting (ref. MARPOLAnnex VI) are issued by a third party that has been authorised by the flag administration.

4.1.8 For a dually classed unit, where the Society has not been authorised by the flag administration to issuestatutory certificates, the Society may accept that such certificates are issued by the other class society asauthorised by the flag administration.

4.2 Service suppliersWhere surveyors use the services of service suppliers in making decisions affecting statutory requirements,the suppliers shall be approved by either:

— the relevant flag administration— a duly authorised organisation acting on behalf of the flag administration— an equipment supplier when explicitly described by IMO conventions, resolutions or circulars, or— the Society.

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SECTION 3 CLASSIFICATION SCOPE AND NOTATIONS

1 Scope of classification

1.1 GeneralThe rules and referred standards define acceptance criteria for design, construction, survey and testingof offshore units, their marine and machinery installations, systems and equipment, applicable to thenewbuilding and operational phase.

1.2 Rule partsThese rules states terms and procedures for assigning class for offshore drilling and support units, as wellas listing the applicable technical reference documents stipulating technical requirements for classification.These may be DNV offshore standards, other DNV standards and internationally recognised codes.

Guidance note:

Rules for maintaining class in operation are given in DNV-RU-OU-0300.


1.3 Rule particularsThe rules with reference standards give requirements in the following areas:

Table 1 Hull and main structure

Hull and main structure

— strength— materials and welding— corrosion protection— constructional fire protection— weathertight and watertight integrity— stability and floatability— tank arrangement.

Table 2 Marine and machinery installations and equipment

Marine and machinery installations and equipment

Machinery installations and equipment, including their related auxiliary functions, with respect to strength andperformance as applicable to the following main functions:

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Marine and machinery installations and equipment

— power generation— position keeping— propulsion (as applicable)— steering (if applicable)— fire and flammable gas detection, fire protection and extinguishing— drainage and bilge pumping— ballasting— emergency shutdown systems (as applicable).

Other machinery installations, regardless of their contribution to the main functions stated above, when located inenclosed hull compartments below the damage water line.

Other installations stated in the rules.

2 Class notations

2.1 GeneralAll units classed with the Society may be assigned:

— construction symbol— main class notation— structural design notation— service notation— special equipment and systems notations (as applicable)— special feature notations (as applicable)— descriptive notation (as applicable).

2.2 Construction symbols

2.2.1 The symbol will be assigned to units built under the supervision of the Society.

2.2.2 The construction symbol will be assigned to units built under the supervision of a classificationsociety recognized by the Society and later assigned class with the Society. For such units the class notationswhich the Society considers to have the equivalent intent will be assigned.

2.2.3 Units other than those described in [2.2.1] and [2.2.2] will not be assigned a construction symbolwhen classed with the Society.

2.3 Main class notation

2.3.1 The notation 1A will be assigned to units with hull, machinery, systems and equipment found to be incompliance with applicable rule requirements as given in this section.

2.3.2 The main class notation 1A will also be assigned to units designed and constructed in accordance withthe rules of another classification society, and later assigned class with the Society.

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2.4 Structural design notationsThe structural design notation indicates the type of structural design. The notations currently in use are givenin Table 3.

Table 3 Class notations related to structural design

Class notation Description Design requirements

Column-stabilised A structure dependent on the buoyancy of widely spaced columnsfor floatation and stability in all modes of operation

Ch.2 Sec.1

Ship-shaped Monohull ship and barge structures having displacement hulls withor without propulsion machinery

Ch.2 Sec.1

Cylindrical A cylindrical shaped displacement hull with or without machinery Ch.2 Sec.1

Mobile offshore A structure not properly characterised by the above notations Ch.2 Sec.1

Guidance note:

Self-elevating units are described in DNV-RU-OU-0104.


2.5 Service notations

2.5.1 Units constructed according to rules for offshore classification, arranged for a particular service andfound to be in accordance with the relevant requirements for such service, will be given a correspondingservice notation.

2.5.2 Service notations currently in use are defined in Table 4.

Table 4 Class notations related to service


Accommodation unit Unit's purpose accommodation Ch.2 Sec.4

Crane unit Unit's purpose crane operation Ch.2 Sec.5

Drilling unit Unit's purpose drilling Ch.2 Sec.2

Offshore support unit Unit's purpose offshore support N/A

Well intervention unit Unit's purpose well intervention, defined with qualifier 1 or 2 Ch.2 Sec.3

Wind turbine installationunit

Unit's purpose installation of fixed and floating wind powerequipment

Ch.2 Sec.6

Guidance note:

Classification services related to hydrocarbon production, storage and loading are presented in DNV-RU-OU-0102.


2.5.3 The service notations in Table 4 shall be considered mandatory for the relevant types of units exceptfor Well intervention 1, see Ch.2 Sec.3 for further details.

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2.5.4 Units intended for multiple services shall comply with all the applicable design requirements for these.In case of conflicting requirements, the most stringent requirement will prevail.

Guidance note:

Units intended for both drilling and production service (FDPSO) shall comply with the requirements for production units in DNV-RU-OU-0102 and for drilling units in this document.


2.6 Class notations related to battery and fuel cell installationsTable 5 list class notations covering battery and fuel cell installations. The notations may be mandatory asdescribed in Ch.2 Sec.1.

Table 5 Class notations related to battery and fuel cell installations

Class notation Qualifier Purpose Design requirements

Power Battery installations for propulsionBattery

Safety Battery installations used as anadditional source of power

Power Fuel cell installationsFC

Safety Fuel cell installations where the fuelcell power is not used for essential,important or emergency users

Ch.2 Sec.1 [8]

2.7 Optional class notations related to special equipment and systemsUnits having special equipment or systems found to satisfy specified class requirements will be given acorresponding additional class notation. Notations currently in use are given in Table 6.

Table 6 Class notations related to equipment and systems


Abate Abatement of green house gases Ch.2 Sec.7 [33]

Barrier Safety barrier management system Ch.2 Sec.7 [32]

BIS Built for in-water survey Ch.2 Sec.7 [31]

BWM Ballast water management Ch.2 Sec.7 [21]

Clean Arrangements for controlling and limiting operationalemissions and discharges

Ch.2 Sec.7 [21]

COAT-PSPC Performance standard for protective coating Ch.2 Sec.7 [34]

COMF-MOU Comfort class Ch.2 Sec.7 [19]

Crane-offshore Onboard crane which may comprise offshore and platformcranes

Ch.2 Sec.7 [10]

Cyber secure Requirements to cyber security for a unit Ch.2 Sec.7 [24]

DDV Data-driven verification Ch.2 Sec.7 [27]

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D-INF Data collection infrastructure that standardise data andmetadata

Ch.2 Sec.7 [26]

DPS Dynamic positioning system Ch.2 Sec.7 [5]

DRILL Drilling plant Ch.2 Sec.7 [6]

DYNPOS Dynamic positioning system Ch.2 Sec.7 [5]

E0 Periodically unattended machinery space Ch.2 Sec.7 [14]

ECO Machinery centralised operated Ch.2 Sec.7 [14]

ES Enhanced systems Ch.2 Sec.7 [2]

ESV Enhanced system verification Ch.2 Sec.7 [22]

F Additional fire protection Ch.2 Sec.7 [12]

FAB Fabrication specification Ch.2 Sec.7 [18]

FMS Fatigue methodology for ship-shaped units Ch.2 Sec.7 [17]

HELDK Helicopter deck Ch.2 Sec.7 [7]

HMON Hull monitoring system Ch.2 Sec.7 [16]

Inert Inert gas system DNV-RU-SHIP Pt.6 Ch.5Sec.8

ISDS Integrated software dependent system Ch.2 Sec.7 [23]

LCS Loading computer system Ch.2 Sec.7 [13]

ME Position mooring equipment Ch.2 Sec.7 [3]

Non-self-propelled Towing assistance will be required during transit Ch.2 Sec.7 [29]

POSMOOR Position mooring system Ch.2 Sec.7 [4]

Recyclable Inventory of hazardous materials part 1 Ch.2 Sec.7 [21]

REW Remote witnessing Ch.2 Sec.7 [28]

Smart Operations based on digital or environmentally friendlysolutions

Ch.2 Sec.7 [25]

TEMPSTORE Temporary storage of oil Ch.2 Sec.7 [9]

TMON Tailshaft monitoring Ch.2 Sec.7 [30]

VCS Vapour control systems Ch.2 Sec.7 [21]

VIBR Vibration level criteria for machinery, components,equipment and structure

Ch.2 Sec.7 [19]

Walk2work Certified offshore gangway installed with related unitrequirements

Ch.2 Sec.7 [11]

WELL Well intervention system Ch.2 Sec.7 [15]

WELLTEST Well test system Ch.2 Sec.7 [8]

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2.8 Optional class notations related to cold climate operation

2.8.1 Units designed or strengthened for operation within particular geographical or environmental areasfound to be in accordance with relevant class rule requirements may be assigned a corresponding optionalclass notation.

2.8.2 Optional class notations related to cold climate service are given in Table 7.

2.8.3 Further details on notation qualifiers and application for different unit types is given in Ch.2 Sec.7 [20].

Table 7 Class notations related to cold climate


DAT Design ambient air temperature for material selection suitablefor regular service during winter to Arctic or Antarctic waters

Ch.2 Sec.7 [20]

Ice Structural strength for navigation in ice Ch.2 Sec.7 [20]

PC Polar class – structural strength for navigation in ice-infestedpolar waters

Ch.2 Sec.7 [20]

Winterized Systems designed for operation in cold climate Ch.2 Sec.7 [20]

2.9 Service restrictions

2.9.1 Units not approved for unrestricted service will have relevant service restrictions stated in the appendixto the classification certificate.

2.9.2 Other service restrictions or operational limits included in the design assumptions of a unit will bestated in the appendix to the classification certificate, and/or on special signboards onboard.

2.9.3 Service restrictions and deviations from the rule requirements shall be addressed in a memo forowners (MO) informing them about the assumption for the class notation if the Unit shall be operated outsidethe geographical areas or other boundaries agreed in the classification contract.

2.10 Compliance with coastal state legislation

2.10.1 When DNV is requested to carry out verification in accordance with coastal state regulations for thecomplete unit or parts of the unit, an additional notation may be assigned to the relevant class designations,consisting of the relevant coastal state code and the issue of coastal state regulations used as basis forverification in brackets, e.g.:DRILL(N).

2.10.2 Coastal state code notations currently in use, are listed in Table 8.

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Table 8 Notations for coastal state verification

Notation Description

Accommodation unit(N)

Drilling unit(N)

Well intervention unit(N)

DRILL(N)

HELDK(S, H, N)/HELDK(S,H, F, N)

Crane-offshore(N)

COMF-MOU(N)

Verified for compliance with DNV’s interpretation of relevant Norwegian coastal staterequirements.

DRILL(US) Verified for compliance with DNV's interpretation of relevant US outer continental shelf

UKVS Verified for compliance with DNV’s interpretation of relevant UK coastal staterequirements.

2.10.3 For further information on procedures and scope of verification for coastal state requirements, seeDNV statutory interpretations for coastal state regulations listed in Sec.1 Table 1.

2.11 Descriptive notation

2.11.1 For a unit with purpose, function or feature not covered by existing notations, this may be recognizedby assignment of a descriptive notation.

2.11.2 The descriptive notation may be assigned upon request to the class society.

2.11.3 There are no class requirements associated with a descriptive notation.

2.11.4 The descriptive notation will be identified by use of square brackets [.…].

2.12 Combination of notations

2.12.1 Class notations shall be combined as follows:<construction symbol> <main class notation> <structural design notation> <service notations><additional notations> <special feature notations> <service restriction, if any>.Example: 1A Column-stabilised Drilling unit POSMOOR Non-self-propelled.

2.12.2 In accordance with Sec.2 [2.2.5] optional class notations from the Society's other rule books may,upon special consideration, be assigned to a vessel complying with those rules.

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SECTION 4 ASSIGNMENT OF CLASS

1 Assignment of class – new units

1.1 GeneralA request for classification of a new mobile offshore unit shall be submitted in writing by the customer. TheSociety reserves the right to decline a request for classification.

1.2 Requirements for builder or designer

1.2.1 Builders or designers unfamiliar to the Society shall provide the Society with evidence of theircapability to successfully manage classification projects.

Guidance note:

Evidence may incorporate successful outcome of classification projects carried out for another classification society or successfuloutcome of design projects of similar nature.


1.2.2 Builders or designers shall instruct their subcontractors and suppliers of materials, machinery systemsand equipment that the Society's rules apply and that the Society's certificate shall be provided as and whenrequired by the rules.

1.2.3 Welding of important structures, machinery installations and equipment shall be carried out byapproved welders, with approved welding consumables, following approved welding procedures and, ifapplicable, at welding shops approved by the Society. Requirements for approval of welding shops, welders,manufacturers of welding consumables, welding consumables, and welding procedures are given in DNV-OS-C401 and by a series of detailed approval programmes.

1.2.4 The following documentation from the builder or designer (workshop and yard) and fromsubcontractors shall be submitted when requested by the Society:

— information related to the builder’s or designer’s quality control and quality management system— information related to the builder's procedures for managing materials that are excluded from use onboard by class and/or statutory requirements

— an 'Asbestos Free Declaration' confirming that structures, machinery, systems and equipment on boardare asbestos free and meets the requirements set forth in SOLAS Reg. II-1/3-5.2

— list of relevant subcontractors to the builder— list of relevant subcontractors to the manufacturer of systems and components to be delivered for theproduct, if applicable.

1.2.5 To assess compliance with the rules the Society may require additional documentation and carry out anassessment of yard's processes, systems and personnel related to classification projects. The results of theassessment shall be used as a basis to decide on the extent of the involvement of surveyors of the Society.The extent of the involvement of the surveyors shall be clearly reflected in a quality survey plan (QSP) orequivalent inspection and test plan (ITP), and shall be approved by the Society.

Guidance note:

A generic version of a QSP issued by the Society can be used as a model to develop an appropriate QSP for specific classificationprojects that should be submitted to the Society for approval before commencing activities in the project.


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1.2.6 Calculations specified in the requirements shall be carried out by computer programs supplied by,or recognised by the Society. Programmes applied where reliable results have been demonstrated to thesatisfaction of the Society are regarded as recognised programmes. Generally valid approvals for computerprograms are, however, not given by the Society.

1.3 Applicable rules

1.3.1 The rules that apply for assignment of class to a new unit are generally those in force at the date of'contract for construction'.The Society may upon special consideration and in agreement with the parties involved decide on the rules tobe applied.

1.3.2 The term date of 'contract for construction' shall be construed as follows:

1) The date of 'contract for construction' of a unit is the date on which the contract to build the unit issigned between the prospective owner and the builder. This date and the construction numbers (i.e. hullnumbers) of all the units included in the contract are to be declared to the classification Society by theparty applying for the assignment of class to a newbuilding.

2) The date of 'contract for construction' of a series of units, including specified optional units for which theoption is ultimately exercised, is the date on which the contract to build the series is signed between theprospective owner and the builder.units built under a single contract for construction are considered a 'series of units' if they are built tothe same approved plans for classification purposes. However, units within a series may have designalterations from the original design provided:

a) such alterations do not affect matters related to classification, orb) if the alterations are subject to classification requirements, these alterations are to comply with the

classification requirements in effect on the date on which the alterations are contracted betweenthe prospective owner and the builder or, in the absence of the alteration contract, comply withthe classification requirements in effect on the date on which the alterations are submitted to theSociety for approval.

The optional units will be considered part of the same series of units if the option is exercised not laterthan 1 year after the contract to build the series was signed.

3) If a contract for construction is later amended to include additional units or additional options, the dateof 'contract for construction' for such units is the date on which the amendment to the contract, is signedbetween the prospective owner and the builder. The amendment to the contract is to be considered as a'new contract' to which 1 and 2 above apply.

4) If a contract for construction is amended to change the unit type, the date of 'contract for construction'of this modified unit, or units, is the date on which revised contract or new contract is signed betweenthe owner, or owners, and the builder.

(IACS PR 29 Rev.0)

1.3.3 For a unit in a series of identical units under construction to the class of, or of a design previouslyapproved by another classification society, the Society may accept the design approved by that classificationsociety.

1.3.4 For a unit where the flag administration undertakes approval and surveys of items covered by thestatutory instruments which are also covered by the rules, the Society may accept their decisions as basis forassigning class, provided the Society's remaining requirements for main class and mandatory class notationsare complied with. Necessary documentation, such as copies of approved plans, reports and other particularsapproved by the flag administration shall be submitted.

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1.3.5 For a unit intended to be permanently moored on location for production and/or storage ofhydrocarbons, the Society may accept decisions by the national administration with jurisdiction over thewaters in which the unit shall operate (the coastal state) as basis for assigning class.

1.3.6 When class is assigned on the basis of a design approved by another classification society, the flagadministration or according to flag administration requirements or decisions by national authorities accordingto [1.3.4], [1.3.5] or [1.3.6], information to this effect shall be included in the appendix to the classificationcertificate (see [3.1.5]).In case of class being assigned on the basis of flag administration requirements according to [3.1.5] anmemorandum to owner shall also be issued.

1.4 Plan approval

1.4.1 Documentation shall be submitted as specified in the rules and according to lists of documentationrequirements supplied by the Society.Any documents submitted for re-approval shall be especially marked to identify revised parts.

1.4.2 Where subcontractors and suppliers are involved, the customer shall co-ordinate the submission ofrequired documentation, as well as co-ordinate any approval comments given by the Society.

1.4.3 Documents subject to plan approval will be assessed by and at the discretion of the Society. Theresults of the assessment will be stated in a letter of approval. Comments, conditions and limitations may bestated in the letter of approval or on the plans returned.

1.4.4 The plan approval may be revoked at any time if subsequent information indicates that the solutionwas contrary to the rules.

1.5 Survey during construction

1.5.1 When a unit is built under the supervision of the Society, the Society will survey:

— that the construction and scantlings comply with the requirements of the rules and the approved plans,and that the required materials are used

— that the materials, components and systems have been certified in accordance with the rules— that the work is carried out in compliance with the applicable rules and acceptable standards— that satisfactory tests are carried out to the extent and in the manner prescribed by the rules.

The construction survey shall include all relevant parts irrespective of sub-contracting and geographicallocation of manufacturing of e.g modules, legs, pontoons.

Guidance note:

IACS Recommendation No. 47 Shipbuilding and Repair Quality Standard – Part A: for new construction – is regarded as anexample of an acceptable standard.


1.5.2 The scope of survey is decided by the Society. The scope has been established utilising knowledgeacquired from, amongst other, operational experience with risk based methods and experience feedback frominternal and external sources.

1.5.3 The Society may increase the scope based on observed quality during construction.

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1.5.4 The Society may base its verification methods on the quality system as implemented in the builder'sfabrication processes and as accepted by the Society. The surveys at the builder's premises may consistof a combination of visual inspection, review of records and witnessing of manufacturers' tests andmeasurements.

1.5.5 The customer shall submit to the Society certificate for materials, components and systems installedin the unit and as required by the rules.

1.5.6 The extent of participation in the mechanical completion activities by the Society shall be clearlyidentified in the QSP submitted by the customer and approved by the Society. The extent of participationshall be limited to ensuring compliance with the requirement of classification rules and applicable statutoryrequirements.

1.6 Installation of machinery, systems and equipment

1.6.1 All machinery, systems and equipment covered by the rules shall in general be new.Guidance note:

If second hand equipment complies with applicable rules for the newbuilding, it may upon special consideration by the Society beinstalled, provided the owner has given a written acceptance.


1.6.2 The extent of participation in the mechanical completion activities by the Society shall be clearlyidentified in the QSP submitted by the customer and approved by the Society. The extent of participationshall be limited to ensuring compliance with the requirement of classification rules and applicable statutoryrequirements.

1.7 Testing and commissioning

1.7.1 Where specified by the rules, testing shall be carried out in the presence of a surveyor, and relatedrequirements for test programmes shall be observed.

1.7.2 A test programme shall be prepared by the customer and accepted by the Society. The programmeshall specify systems and components to be tested, and the testing procedure.The Society may, in order to verify compliance with the rules, request additional tests and/or data to berecorded.

1.7.3 Procedures for pre-commissioning, testing and commissioning for all the systems onboard that arecovered by the scope of classification shall be prepared by the customer and accepted by the Society.

1.7.4 The tests shall give evidence as to satisfactory operation and performance in accordance with therules. When testing control and safety systems, failure modes shall be simulated as realistically as possible.

1.7.5 The extent of participation by the Society shall be clearly identified in the QSP submitted by thecustomer and approved by the Society, and shall be limited to ensure compliance with the requirement ofclassification rules and applicable statutory requirements.

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2 Assignment of class – existing units

2.1 GeneralA request for class entry of an existing unit shall be submitted in writing by the customer. The Societyreserves the right to accept or decline an application for class entry.

2.2 Applicable rulesFor units built under the supervision of a classification society recognized by the Society, the rules in force atthe same date as those enforced by the other society will be applied. If such date is not known, the Society 'srules in force at the date of 'contract for construction' will be applied.

2.3 Design approval

2.3.1 Before a unit, which has not been built under the supervision of the Society, is surveyed forassignment of class, the information required in [1.4.1] shall, in general, be submitted for plan approval.For a unit classed with a recognised classification society, the submitted information may be reduced to plansshowing the main scantlings and arrangements of the actual hull and machinery installations.

2.3.2 The extent of plan approval for a unit, which has not been classed, or which was previously classedwith a classification society not covered by [2.3.1], will be specified in each case.

2.3.3 For a unit that has been built under the supervision of another classification society, the Society mayon the basis of an overall consideration and survey, exempt the unit from requirements in the rules.

2.4 Class entry survey

2.4.1 Prior to assigning class to an existing unit, that unit shall undergo the surveys pertaining to the ageand type of the unit as a minimum.The scope of survey will in each separate case be decided by the Society.

2.4.2 Before assigning class, the flag administration will be notified about the class entry. The flagadministration may decide that an extended scope of surveys has to be carried out.

3 The class certificate

3.1 General

3.1.1 The Society will issue a class certificate as proof of assignment of class.

3.1.2 Class may be assigned with conditions of class.

3.1.3 The class certificate is valid provided conditions for retention of class are complied with, as follows:

— for a new unit: to a date not exceeding five (5) years from the date of class assignment— for an existing unit: to a date not exceeding five (5) years from the expiry date of the existing certificate— for an existing unit taken into class: to a date not exceeding five (5) years from the date of classassignment or, if the Society accepts the periodical surveys credited by the previous classification society,until the expiry date of the class certificate of the previous classification society

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— for an interim class certificate: to a date not exceeding 15 months from assignment of class.

3.1.4 Upon request, statements confirming compliance with the rules may be issued for hull, machinery orspecific class notations provided the Society's class has been assigned.

3.1.5 An appendix to the class certificate will be issued stating assumptions for the assignment of class andrestrictions regarding the use of the unit which were established or assumed at the time of assignment ofclass.

3.2 Late commissioningIf the unit is not immediately commissioned upon delivery, but is laid up for a period, the unit may beaccepted for entry into service upon application by the owner. The unit may be subject to a condition surveybefore entering into service.The extent and scope of survey will depend on the time period laid up and conservation measures taken.Provided the hull, machinery, systems and equipment are found in all respects free from deterioration,subsequent periodical surveys will date from the time of the condition survey.

4 The register of vessels

4.1 General

4.1.1 When a unit has been assigned class, its main particulars and details of the class assigned will beentered in the Society’s 'Register of Vessels'. In addition to the class notations, appropriate data related toidentification, flag, ownership and other particulars will also be entered.

4.1.2 The class assignment date is entered in the 'Register of Vessels'. For units built under the supervisionof the Society, the due date for the periodical surveys will be calculated from this date. For units built underthe supervision of another classification society, the due date for the periodical surveys will depend upon theexisting periodical survey schedule defined by the previous classification society.

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SECTION 5 RETENTION OF CLASS

1 GeneralFor principles and procedures related to retention for class of units in operation, see DNV-RU-OU-0300 Ch.1.

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SECTION 6 CERTIFICATION OF MATERIALS, COMPONENTS ANDSYSTEMS

1 General

1.1 Introduction

1.1.1 The scope of classification requires that specified materials, components and systems intended for theunit are certified according to the rules. The objective of certification is to ensure that materials, componentsand systems used in units to be classed by the Society comply with the rule requirements.Certification normally includes both plan approval and survey during production and/or of the final product,see [2.2] and [2.3].

1.1.2 Ch.2 and the referred offshore standards define the extent of the certification that is required for class.Guidance note:

Subcontracted parts of a newbuilding like modules, legs, pontoons etc. are not regarded as part of the materials, components andsystems certification described in this section, but are considered as part of the newbuilding process as described in Sec.4.


1.1.3 When the Society issues a certificate to document compliance with requirements as described in thissection, the certificate will normally be in an electronic format that will be signed digitally. The electronicversion of the digitally signed certificate represents the original of the certificate and any paper version is acopy.

1.2 Requirements for manufacturer

1.2.1 Manufacturers of materials, components and systems of categories not covered by Sec.4 [1.2] shall beconsidered for approval according to criteria established by the Society, as applicable.

1.2.2 Quality control of materials, components and systems, shall be traceable and documented in writing.Further, quality control shall be carried out by qualified personnel at facilities and with equipment suitable forthat control.

1.2.3 The following is mandatory and a prerequisite for issuance of certificates:

— document handling system to ensure the product is free from asbestos. This shall also include control withsub-suppliers and contractors

— an Asbestos Free Declaration confirming that the product is free from asbestos and meets therequirements set forth in SOLAS Reg. II-1/3-5.2.

2 The Society's involvement

2.1 General

2.1.1 Compliance with rules for materials, components and systems will be confirmed by the types ofdocuments as defined in DNV-CG-0550 Sec.3.The applicable chapters and sections of the rules and referred offshore standards specify which types ofdocuments are required.

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2.1.2 Where the rules require product or material declaration (works certificate) or product or material testreport issued by the manufacturer, see DNV-CG-0550 Sec.3, the surveyor may at any time require the teststo be carried out in his presence and/or that the surveyor check elements of the production control.

2.1.3 For identification and traceability, certified products shall be marked in accordance with the descriptiongiven in the product or material certificate and as specified by the applicable chapters of the rules.

2.1.4 For certain components and systems the certification will be based on defined internationallyacceptable standards and certification schemes as defined in applicable chapters of the rules. Compliancewith the requirements of the standard shall be documented as required by that standard.

2.2 Plan approval

2.2.1 The plan approval of materials, components and systems shall be on a case by case basis or follow theprocedure for type approval, see [2.3].

2.2.2 When the case by case procedure is used, documentation of the design shall be submitted for planapproval for each application as required in the applicable chapters of the rules.

2.2.3 A letter of approval or design verification report will be issued by the Society when compliance with therequirements for the design has been confirmed.

2.3 Type approval

2.3.1 Type approval is a procedure for approval of standard designs and/or routinely manufactured, identicalcomponents to be used in DNV classed objects. Type approval can be applied to:

— products— groups of products— systems.

2.3.2 The type approval procedure may consist of the following elements:

— design assessment— initial survey— type testing— issue of a type approval certificate.

The type approval procedure used by the Society is described in DNV-CP-0338.

2.3.3 When the type approval procedure is used, the following shall be submitted for approval as required intype approval programmes and the applicable chapters of the rules:

— documentation of the design— results of type testing normally witnessed by a surveyor.

A type approval certificate will be issued by the Society when compliance with the design requirements isconfirmed.

2.3.4 For certain products and systems as defined in applicable chapters of the rules, only type approval isrequired. For these products and systems no survey is required, i.e. no product certificate is required.

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2.3.5 For certain products and systems as defined in the applicable chapters of the rules, type approval is amandatory procedure for plan approval.

2.3.6 Products and systems manufactured for stock shall normally be type approved.

2.3.7 For type approved products, where the basis for approval is the rules, plans and technical descriptionsof the product need not be submitted for approval for each Unit unless otherwise stated as a condition onthe type approval certificate. In such cases only the arrangement or system plans, interface plans and thoseplans mentioned on the type approval certificate shall be submitted for approval.

2.4 Survey

2.4.1 The survey of materials, components and systems shall either be on a case by case basis or on thebasis of an established manufacturing survey arrangement (MSA), see [2.5].

2.4.2 When the case by case procedure is used, the survey shall be performed on the basis of approveddesign documentation for the actual application and as required in the applicable chapters of the rulesand referred offshore standards. Compliance with the approved design documentation and applicablerequirements will be documented by certificates as required in the applicable chapters of the rules.

2.4.3 When the survey is based on an MSA, the survey shall be performed on the basis of approved designdocumentation, applicable rule requirements and in accordance with requirements and procedures laiddown in the MSA. Compliance with the approved design documentation and applicable requirements shall bedocumented by certificates as specified in the MSA and/or as required in the applicable chapters of the rulesand referred offshore standards.

2.5 Manufacturing survey arrangement

2.5.1 When the procedures and processes of a manufacturer's quality system are in compliance withthe rules, a manufacturing survey arrangement (MSA) may be established with the manufacturer as analternative to the survey described in the applicable rules.

2.5.2 The MSA shall be described in a document stating the requirements, scope, acceptance criteria,documentation and the roles of the Society and the manufacturer in connection with the survey.

2.5.3 When it is agreed through an MSA that the majority of the required surveys and tests are completedwithout the presence of a surveyor, it required that the manufacturer has in operation a quality systemcertified by an accredited certification body to ISO 9001, or equivalent.

2.5.4 When establishing an MSA, an initial assessment of the manufacturer's ability to control product qualityand to comply with the scope, requirements and criteria laid down in the MSA will be performed.The extent and frequency of periodical assessments of the manufacturer will be included in the MSA. TheSociety reserves the right to conduct further inspections without notice at its sole discretion.

2.5.5 When the MSA is based on a certified quality system, the MSA automatically becomes invalid if thequality system certificate no longer is valid.

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3 Suspension and withdrawal of certificates

3.1 General

3.1.1 A product certificate, material certificate, type approval certificate or approval of manufacturercertificate may be suspended or withdrawn at any time if the Society finds it justified.

3.1.2 The decision to suspend or withdraw a certificate is made by the Society.Suspension or withdrawal of a certificate may take effect immediately or after a specified period of time. Inspecial cases, the withdrawal of a certificate may be made with retroactive effect.

3.1.3 When a certificate is suspended or withdrawn the Society will:

— inform the customer— make the information publicly available.

In the cases of suspension, a time limit will be given for when the certificate will be withdrawn.

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CHAPTER 2 DESIGN AND CONSTRUCTION PROVISIONS

SECTION 1 DESIGN AND CONSTRUCTION REQUIREMENTS FORMAIN CLASS

1 General

1.1 Introduction

1.1.1 This section identifies design and construction requirements common to all types of mobile offshoreunits. Units complying with these requirements will be assigned a main character of class 1A followed by adescription of the basic design concept of the unit, e.g. column-stabilised unit.

1.1.2 The following discipline areas are covered within main class:

— safety principles and arrangement— materials— hull design and fabrication— temporary mooring and towing— stability, watertight and weathertight integrity— marine and machinery systems and equipment— electrical systems and equipment— instrumentation and telecommunication systems— fire protection.

1.1.3 Systems and structures will be certified or classified based on the following main activities:

— design approval— certification of materials and components (CMC)— survey during construction and installation— survey during commissioning.

Further description of activity procedures are given in Ch.1 Sec.4.

1.1.4 The requirements of this section are given as:

— references to standards, codes and rules containing technical requirements which shall be complied withfor assignment of main class

— supplementary requirements which shall be applied in conjunction with the technical reference documentsfor assignment of class

— requirements for CMC.

1.2 Technical reference documents

1.2.1 Technical requirements are given by reference to selected:

— DNV offshore standards (OS)— DNV class guidelines (CG)— DNV recommended practices (RP)— other DNV rules and standards— internationally recognised codes and standards.

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1.2.2 The technical reference documents which shall be applied are given in the following subsections andare summarised in Table 3.

1.3 General assumptions

1.3.1 Any deviations, exceptions and modifications to the design codes and standards given as referencedocuments shall be documented and approved by DNV.

1.3.2 Where referred codes and standards call for the extent of inspections and tests to be agreed betweencontractor, manufacturer and customer, the resulting extent shall be agreed with DNV.DNV may accept alternative solutions found to represent an overall safety level equivalent to that stated inthe requirements of this document or the referred standards.

2 Safety principles and arrangement

2.1 GeneralSafety principles and arrangement include the following discipline areas:

— design principles, including generic accidental loads— arrangement; including segregation of areas and location of plants and equipment— escape and communication.

2.2 Design principlesThe requirements given in DNV-OS-A101 Ch.2 Sec.1 shall be complied with.

2.3 ArrangementArrangement of the unit shall be in accordance with the requirements of DNV-OS-A101 Ch.2 Sec.2.

2.4 Escape and communicationEscape and communication shall be in accordance with DNV-OS-A101 Ch.2 Sec.5.

3 Materials

3.1 Technical requirementsMaterials for:

— rolled steel for structural applications, boilers and pressure vessels— steel tubes, pipes and fittings— steel forgings— steel castings— aluminium alloys

shall general comply with the requirements given in DNV-OS-B101 Ch.2. Offshore ship-shaped units shallcomply with the material requirements given in DNV-OS-C102 Ch.2 Sec.1 [5].

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3.2 Supplementary classification and certification requirements

3.2.1 Certification requirements for materials are in general given in DNV-OS-B101 Ch.3. For offshore ship-shaped units, the certification requirements to materials are given in DNV-RU-SHIP Pt.2 Ch.2 Sec.1 [3.1].

3.2.2 Rolled, forged or cast elements of steel and aluminium for structural application shall be supplied withDNV's material certificates.

4 Structural design

4.1 Scope

4.1.1 Class scope shall be defined by the unit type and class notations. It will typically cover the following:

— hull including superstructure and deckhouses— crane pedestals (hull foundation below connection of components delivered by crane supplier)— foundations for:

— towing and mooring equipment— launching and recovery appliances for life-saving appliances— lifting appliances (cranes, A-frames, derricks and davits) with safe working load > 30 kN or resultingstatic overturning moment at deck greater than 100 kNm

— winches with safe working load > 50 kN— equipment with operational weight > 10 tonnes.Guidance note:

Statutory scope may cover structures not covered by class scope, e.g. access platforms, handrails, stairs, ladders and otheroutfitting structures.


4.1.2 The following elements are excluded from the class scope unless covered by additional class notationsor otherwise agreed:

— environmental loads with annual probability lower than 10-2

— temporary conditions. See definition in Ch.1 Sec.1 [1.5.2]— loads due to sea ice or icebergs— loads caused by earthquake or tsunami— capacity of sea bed for bottom supported units.

4.1.3 Transit conditions are included in the scope of work.

4.2 Technical requirementsStructural design standards for different unit type is given in Table 1.

Table 1 Overview of structural design standard for different unit type and design methods

Unit type WSD LRFD

Ship-shaped DNV-OS-C102 -

Column-stabilized DNV-OS-C201 DNV-OS-C103

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Unit type WSD LRFD

Cylindrical DNV-OS-C101 DNV-OS-C101

Guidance note:

Self-elevating units are covered by DNV-RU-OU-0104 Rules for self-elevating units.


5 Fabrication and testing of offshore structures

5.1 Technical requirements

5.1.1 Requirements for:

— welding procedures and qualification of welders— fabrication and tolerances— testing— corrosion protection systems

shall in general be in accordance with DNV-OS-C401 Ch.2.For ship-shaped units the requirements are given in DNV-OS-C102 Ch.2 Sec.1 [5].For ship-shaped units intended to operate at harsh locations, the additional class notation FAB is mandatory.

Guidance note:

See Sec.7 [18] for details on FAB.


5.1.2 For ship-shaped units designed for benign waters, the requirements may be in accordance with DNV-RU-SHIP Pt.2 Ch.4, except for specific structural elements (e.g. topside structures, topside support etc). Theapplication is subject to a case by case approval.

5.2 Supplementary classification and certification requirementsClassification procedures specifically related to fabrication and testing of offshore structures are in generalgiven in DNV-OS-C401 Ch.3. For ship-shaped units, see DNV-RU-SHIP Pt.2.

6 Stability and watertight/weathertight integrity


6.1.1 Requirements for:

— intact and damaged stability— watertight integrity— freeboard— weathertight closing appliances

shall be in accordance with DNV-OS-C301.

6.1.2 If onboard computers for stability calculations are installed, these systems shall be approved inaccordance with requirements in DNV-RU-SHIP Pt.6 Ch.4 Sec.6.

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7 Mooring and towing

7.1 General

7.1.1 Depending on type of unit, main class stipulates requirements for:

— temporary mooring— towing.

Guidance note:

The above includes both normal and emergency towing. For the definitions of these and temporary mooring versus positionmooring see Ch.1 Sec.1 [1.5.2].

Certification of the position mooring equipment on request by the owner or if required by flag administration is covered by theclass notation ME as described in Sec.7 [3].

The notation POSMOOR can be assigned to units where in addition to the equipment covered under ME, the units positionmooring system capability is in accordance with DNV-OS-E301 Ch.2 Sec.2.


7.2 Temporary mooring

7.2.1 Self propelled units shall have an arrangement for temporary mooring.For ship-shaped units, the arrangement shall be in accordance with the DNV-OS-C102 Ch.2 Sec.5. For otherstructural units, the arrangement shall be in accordance with DNV-OS-E301 Ch.2 Sec.4.Equipment for barges shall be considered case by case.

7.2.2 For units with the additional class notation POSMOOR or ME, the requirements for temporary mooringare normally covered within this notation.

Guidance note:

Additional requirements or relaxations apply for specific service notations as given in Sec.2 to Sec.6.


7.3 Towing

7.3.1 Ship shaped units shall have towing arrangement according to DNV-OS-C102 Ch.2 Sec.5 [2]. Otherunits shall follow DNV-OS-E301 Ch.2.

7.3.2 The towing fittings for normal towing may also be used for emergency towing.

7.3.3 For units with the additional class notations DYNPOS(AUTR) and DYNPOS(AUTRO), towingarrangements may take into account the specific thrust capabilities of the units as described in DNV-OS-E301Ch.2 Sec.4 [16].


7.4.1 Classification procedures specifically related to mooring and towing are given in DNV-OS-E301 Ch.3.

7.4.2 Certification requirements for equipment are given in DNV-OS-E301 Ch.3.

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8 Marine and machinery systems and equipment


8.1.1 Requirements for marine and machinery systems and equipment include:

— general piping design, fabrication and testing— pumps, valves and pipe connections— ballast, bilge and drainage systems— air, overflow and sounding pipes— cooling, feed water and condensation systems— lubricating oil, fuel oil and thermal oil systems— hydraulic, steam and pneumatic systems— heating, ventilation and air conditioning systems— propulsion and auxiliary machinery including thrusters— boilers, pressure vessels and incinerators— steering gear and turret machinery

and shall be designed, manufactured, tested and installed in accordance with DNV-OS-D101.

8.1.2 Units not equipped with propulsion and steering arrangements for independent transit will be giventhe special feature notation Non-self-propelled, and shall comply with DNV-OS-D101 as applicable for suchtype of units.


8.2.1 Classification procedures specifically related to marine and machinery systems and equipment aregiven in DNV-OS-D101 Ch.3.

8.2.2 Certification requirements for equipment are given in DNV-OS-D101 Ch.3.

8.2.3 For battery and fuel cell installations, the class notations Battery and FC, respectively, are mandatoryas described in Table 2.

Table 2 Additional class notations related to propulsion, power generation and auxiliary systems

Class notation Qualifier Purpose Application Design requirements

Power Battery installationfor propulsion

Mandatory for units wherethe battery power is usedas propulsion power duringnormal operation, both purebattery or battery hybridpropulsion power.

Battery

SafetyBattery installationsused as an additionalsource of power

Mandatory for units wherethe battery installation hasan aggregate rated capacityexceeding 20 kWh (excludinglead acid and NiCd batteries)and not having the Powerqualifier.

DNV-RU-SHIP Pt.6Ch.2 Sec.1

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Class notation Qualifier Purpose Application Design requirements

Power Fuel cell installations

Mandatory where the fuel cellpower is used for essential,important or emergencyservices.

FC

Safety

Fuel cell installationswhere the fuel cellpower is not used foressential, importantor emergency users

Mandatory where the fuel usedis a gas or a liquid fuel withflash point below 60°C.

DNV-RU-SHIP Pt.6Ch.2 Sec.3

9 Electrical systems and equipmentElectrical systems and equipment include:

— system design— switchgear and control gear assemblies— rotating machinery— static converters— cables— miscellaneous equipment— installation and testing— A.C. supply systems— electric propulsion



9.1.1 Classification procedures specifically related to electrical systems and equipment are given in DNV-OS-D201 Ch.3.


10 Instrumentation and telecommunication systems

10.1 Technical requirementsInstrumentation and telecommunication systems and equipment include:

— design principles and system design— computer based systems— component design and installation— environmental conditions— user interface


10.2 Supplementary classification requirementsClassification procedures specifically related to instrumentation and telecommunication systems are given inDNV-OS-D202 Ch.3.

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DNV AS

Certification requirements for equipment are given in DNV-OS-D202 Ch.3.

11 Fire protection

11.1 Technical requirementsFire protection include:

— passive fire protection— active fire protection— fire fighting systems— fire and gas detection systems

and shall be designed, manufactured, tested and installed in accordance with DNV-OS-D301 Ch.2 Sec.1 toDNV-OS-D301 Ch.2 Sec.5.


11.2.1 Classification procedures specifically related to fire protection are given in DNV-OS-D301 Ch.3.


12 Preparation for surveys and inspections on location

12.1 General

12.1.1 It is advised that operational survey and inspection aspects are taken into consideration at the designand construction stages.

12.1.2 The following matters will be taken into consideration for acceptance of surveys to be carried out onlocation:

— arrangement for underwater inspection of hull, propellers, thrusters, rudders and openings affectingseaworthiness

— marking of the hull— means for blanking off all openings including side thrusters— use of corrosion resistant materials for shafts— use of glands for propeller and rudder— accessibility of all tanks and spaces for inspection— corrosion protection of hull or structure— maintenance and inspection of thrusters— measurement of wear in the propulsion shaft and rudder bearings— testing facilities of all important machinery.

Guidance note:

The underwater body should be marked in such a way that the surveyor can identify the location of any damages found. Oneacceptable way of preparing ship-shaped hulls for underwater inspection is described in the following.

Transverse and longitudinal reference lines of minimum length 300 mm and minimum width 25 mm should be applied as marking.The marks should be made permanent by welding or otherwise and painted in contrast colour.

Markings should normally be placed as follows:

— at flat bottom in way of intersections of tank bulkheads or watertight floors and girders

— at unit's sides in way of the positions of transverse bulkheads (the marking need not be extended more than 1 m above thebilge plating)

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DNV AS

— the intersection between tank top and watertight floors in way of the unit's sides

— all openings for sea suctions and discharges

— letter/number codes may conveniently be applied on the shell for identification of tanks, sea suctions and discharges.

Markings should be adequately documented.


12.1.3 In addition to the above ship-shaped units can apply for the class notation BIS for in water survey ofthe bottom, see Sec.7 [31].

13 Summary of technical reference standardsTechnical standards which shall be applied for assignment of main class notation for mobile offshore units aresummarised in Table 3.

Table 3 Technical reference standards for main character of class (1A)

Technical item Reference standard Applicable parts or comments

Safety principles and arrangement:

Design principles Ch.2 Sec.1 Design principles andaccidental loads

Arrangement Ch.2 Sec.2 Arrangement

Escape and communication

DNV-OS-A101

Ch.2 Sec.5 Escape and communication

Materials:

Metallic materials DNV-OS-B101For ship shape units, see DNV-OS-C102 Ch.2 Sec.1 [5]

Structural design: (select type as appropriate)

Ship-shape structure DNV-OS-C102

DNV-OS-C103 LRFD methodologyColumn-stabilised type structure

DNV-OS-C201 WSD methodology

DNV-OS-C101 LRFD methodologyCylindrical units

DNV-OS-C101 WSD methodology

Hull fabrication:

DNV-OS-C102 Ch.2 Sec.1[5.5]

For ship-shaped unitsFabrication, including welding and NDT(non-destructive testing)

DNV-OS-C401 All other types of units

Stability and watertight integrity:

Stability, watertight integrity, freeboard andweathertight closing appliances

DNV-OS-C301 Covers all types of structures

Mooring and towing:

DNV-OS-C102 Ch.2 Sec.5 Ship-shaped unitsTemporary mooring, towing

DNV-OS-E301 All other types of units

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Marine and machinery systems:

Piping design, manufacturing and testing;platform piping systems; machinery pipingsystems; machinery and mechanical equipment

DNV-OS-D101 All sections

Electrical system equipment:

Electrical systems including switchgear andcontrolgear assemblies, rotating machinery,static convertors, cables, installation, testing,and electric propulsion

DNV-OS-D201 All sections

Instrumentation and telecommunication systems:

Instrumentation systems including designprinciples, system design, computer basedsystems, component design and installation,and user interface

DNV-OS-D202 Ch.2:Sec.1 Design principles

Sec.2 System design

Sec.3 Additional requirements forcomputer based systems

Sec.4 Component design and installation

Sec.5 User interface

Fire protection:

Fire protection including passive fire protection,active fire protection, fire fighting systems, fireand gas detection systems

DNV-OS-D301 Ch.2:Sec.1 Passive Fire Protection

Sec.2 Active fire protection of specificareas

Sec.3 Fire fighting systems

Sec.4 Fire and/or gas detection andalarm systems

Sec.5 Miscellaneous items

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SECTION 2 SUPPLEMENTARY REQUIREMENTS FOR DRILLING UNITS

1 General

1.1 Introduction

1.1.1 This section identifies design and construction requirements for assignment of service notation Drillingunit.

1.1.2 The requirements in this section are supplementary to those for main class ( 1A) as stated in Sec.1.

1.2 Scope

1.2.1 Equipment installed in enclosed compartments below the damage water line that represent a risk tothe integrity to the hull, shall be included in the scope of classification.The equipments shall comply with relevant design and construction requirements given in DNV-OS-E101.

Guidance note:

Relevant equipment and systems should be evaluated on a case by case basis. Equipment included in the scope is typicallyequipment handling hydrocarbons and/or where an incident may lead to a major accident. Examples of equipment to be evaluatedare large independent pressurized bulk tanks and air pressure vessels for heave compensation.



2.1 GeneralService notation Drilling unit specifies additional requirements for:

— arrangement— area classification— shutdown— escape and communication.

2.2 ArrangementDrilling units shall comply with DNV-OS-A101 Ch.2 Sec.6.

2.3 Area classificationDrilling units shall comply with DNV-OS-A101 Ch.2 Sec.3 and DNV-OS-A101 Ch.2 Sec.6.

2.4 Emergency shutdownDrilling units shall comply with DNV-OS-A101 Ch.2 Sec.4 and DNV-OS-A101 Ch.2 Sec.6.

2.5 Escape and communicationDrilling units shall comply with DNV-OS-A101 Ch.2 Sec.6.

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3 Structural design

3.1 General

3.1.1 The structural strength shall be as required for the main class taking into account necessarystrengthening of supporting structures for equipment applied in and forces introduced by the drillingoperation. In addition to the elements as listed in Sec.1 [4.1], this includes:

— drill floor and sub-structure— topside module stools— foundation and support for heavy drill equipment (e.g. pipe rack, riser rack exceeding the limits as givenin Sec.1 [4.1]).

3.1.2 When calculating the structural strength of the drill floor and substructure, relevant loading conditionsshall be specified by the builder. Loadings from drill pipe on setback, tensioning equipment hook load, rotarytable etc. shall be considered.Local effects of horizontal components of tensioner forces, drilling torque etc. shall also be considered.

3.1.3 For ship-shaped units the structural design shall be in accordance with DNV-OS-C102 Ch.2 Sec.7 [2].

4 Fire protection

4.1 GeneralService notation Drilling unit specifies additional requirements for:

— active fire fighting systems— passive fire protection— gas detection.

4.2 Supplementary technical requirementsDrilling units shall comply with DNV-OS-D301 Ch.2 Sec.6.

5 Temporary mooringFor units with the additional class notation DYNPOS(AUTR), DYNPOS(AUTRO), DPS(2), or DPS(3),temporary mooring arrangement is not required as a condition for classification.

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6 Summary of requirementsTechnical standards which shall be applied for assignment of service notation Drilling unit are summarisedin Table 1.

Table 1 Summary of technical reference standards for service notation Drilling unit


Ch.2 Sec.1 to Sec.5. (1A requirements)Safety principles andarrangement

DNV-OS-A101

Ch.2 Sec.6, Special requirements for drilling units

Materials DNV-OS-B101For ship shape units, seeDNV-OS-C102 Ch.2 Sec.1 [5]

(No supplementary requirements to 1A)

Structural design of ship-shaped units

DNV-OS-C102 (No supplementary requirements to 1A)

DNV-OS-C103 LRFD methodology (No supplementary requirements to1A)

Structural design of column-stabilised units

DNV-OS-C201 WSD methodology (No supplementary requirements to1A)

DNV-OS-C102 Ch.2 Sec.1[5.5]

Ship-shaped units (No supplementary requirements to1A)

Structural fabrication

DNV-OS-C401 Other units (No supplementary requirements to 1A)

Stability and watertightintegrity

DNV-OS-C301 (No supplementary requirements to 1A)

DNV-OS-C102 Ch.2 Sec.5 Ship-shaped units (No supplementary requirements to1A)

Temporary mooring and towing

DNV-OS-E301 Ship-shaped units (No supplementary requirements to1A)

Marine and machinery systemsand equipment

DNV-OS-D101 Other units (No supplementary requirements to 1A)

Electrical systems andequipment

DNV-OS-D201 (No supplementary requirements to 1A)

Ch.2 Sec.1 to Sec.5 (1A requirements)Instrumentation andtelecommunication systems

DNV-OS-D202

Ch.2 Sec.6, Special requirements for drilling units

Sec.1 to Sec.5 (1A requirements)Fire protection DNV-OS-D301

Sec.6, Supplementary requirements for drilling units

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SECTION 3 SUPPLEMENTARY REQUIREMENTS FOR WELLINTERVENTION UNITS

1 General

1.1 Introduction

1.1.1 This section identifies design and construction requirements for assignment of service notation Wellintervention unit(1) and Well intervention unit(2).

Table 1 Class notation Well intervention unit

Class notation Description Qualifier Description

1 Excluding risers, i.e. no circulation of hydrocarbonsWell interventionunit

Units purpose wellintervention 2 Including risers, i.e. circulation of hydrocarbons

1.1.2 Well intervention unit(1) is applicable for units equipped for performing well intervention withoutintroducing well fluids/hydrocarbons on board. The design may be based on DNV rules for ships.

Guidance note:

By introducing well fluids it is meant an open pipe or umbilical that is connected to a live well. E.g. flushing of a lubricator that isconnected to a closed production well is not considered as introducing well fluids.


1.1.3 Units intended and equipped for direct contact with well fluids e.g. through riser, coiled tubing or drillwill be assigned class notation Well intervention unit(2).

1.1.4 For Well intervention unit(2) the requirements in this section are supplementary to those for mainclass (1A) as stated in Sec.1. Where no specific requirements for well intervention units are specified, therequirements for drilling units shall apply.

1.1.5 The service notation Well intervention unit(1) is a voluntary notation. Well intervention unit(2) ismandatory for DNV classed units.

1.1.6 Based on risk analysis or similar documentation related to the well intervention unit, DNV may acceptalternative solutions found to represent an overall safety level equivalent to that stated in the requirementsof this document or referred standards.

2 General requirements

2.1 Structural design

2.1.1 For ship-shaped units with Well intervention unit(1) or Well intervention unit(2) notation thestructural design shall be in accordance with DNV-OS-C102 Ch.2 Sec.7 [3].

Guidance note:

Note that additional requirements apply to comply with MODU Code.


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DNV AS

2.1.2 Well intervention units that are not ship-shaped shall comply with the relevant sections of DNV-OS-C101 and:

— DNV-OS-C103 for column-stabilised units or installations— DNV-OS-C106 for deep draught units or installations.

2.1.3 The structural strength shall be as required for the main class taking into account necessarystrengthening of supporting structures for equipment applied and forces introduced by the well interventionfacilities and operation.

2.2 Position keepingUnits with the notation Well intervention unit(1) or Well intervention unit(2) shall as a minimumcomply with the class notation DYNPOS(AUTR) (IMO equipment class 2) as given in DNV-RU-SHIP Pt.6Ch.3 Sec.1.

3 Requirements for Well intervention unit(1)

3.1 General

3.1.1 Service notation Well intervention unit(1) may be assigned to ships with hull, machinery, systemsand equipment found to be in compliance with applicable rule requirements as given in DNV-RU-SHIP Pt.2 toDNV-RU-SHIP Pt.4.

3.1.2 In addition to the supplementary requirements as given in [3.2], the structural design requirements of[2.1] and the position keeping of [2.2] apply.

3.1.3 Systems and equipment installed in enclosed compartments below the damage water line thatrepresent a risk to the integrity to the hull, shall be included in the scope of classification. Relevantequipment and systems shall be evaluated on a case by case basis.

Guidance note:

Equipment included in the scope is typically equipment handling hydrocarbons and/or where an incident may lead to a majoraccident. Examples of equipment to be evaluated are large independent pressurized bulk tanks and air pressure vessels for heavecompensation.


3.2 Supplementary requirements

3.2.1 The unit shall have, if applicable, a foam extinguishing system of adequate capacity to extinguishpossible pool fires in the work areas.

3.2.2 Potential reception tanks for handling of hydrocarbons shall be located taking into account the risk offire and hydrocarbon leakages.

3.2.3 If the unit is equipped with tanks for carriage of liquid cargo in bulk with flash point below 60oC, suchas crude oil, the requirements in the DNV-RU-SHIP Pt.5 Ch.6, shall be complied with.

3.2.4 Means shall be provided for rescue of personnel falling into the moon pool. The moon pool shall befitted with a rescue ladder.

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DNV AS

3.2.5 Machinery and other equipment necessary for the well intervention which shall be installed inhazardous areas shall be ex-certified corresponding to relevant zoned designation.

3.2.6 Hazardous area classification shall comply with DNV-OS-A101 Ch.2 Sec.3 [1] to DNV-OS-A101 Ch.2Sec.3 [3] and DNV-OS-A101 Ch.2 Sec.6 [3.2], as applicable. The effects of lubricator flushing shall be takeninto account for the definition of hazardous area classification.

3.2.7 The unit shall have a system for quick disconnect from the lubricator/well head.

3.2.8 The unit shall have a gas detection system and corresponding routines for shut down/isolation of non-ex equipment in case of gas detection.

Guidance note:

These supplementary classification requirements are typically written for operational modes that will introduce small volumes ofhydrocarbons on board.


4 Requirements for Well intervention unit(2)

4.1 General

4.1.1 This section identifies design and construction requirements for assignment of service notation Wellintervention unit(2).The requirements for Well intervention unit(1) apply and in addition there are specific requirements for:

— arrangement— area classification— shutdown/disconnection— escape and communication— fire protection.

4.1.2 There are similarities between a well intervention unit and a drilling unit. Therefore, reference is givento the requirements for drilling units, where no other requirements are given for such units.

4.2 ArrangementUnits shall comply with DNV-OS-A101 Ch.2 Sec.6 as applicable for well intervention units.

4.3 Area classificationUnits shall comply with DNV-OS-A101 Ch.2 Sec.3 and DNV-OS-A101 Ch.2 Sec.6 as applicable for wellintervention units.

4.4 Emergency shutdownUnits shall comply with DNV-OS-A101 Ch.2 Sec.4 and DNV-OS-A101 Ch.2 Sec.6 [4.1] and DNV-OS-A101Ch.2 Sec.6 [4.2] as applicable for well intervention units.

4.5 Escape and communicationUnits shall comply with DNV-OS-A101 Ch.2 Sec.6 as applicable for well intervention units.

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DNV AS

4.6 Fire protection

4.6.1 Service notation Well intervention unit(2) specifies additional requirements for:

— active fire fighting systems— passive fire protection— gas detection.

4.6.2 Units shall comply with DNV-OS-D301 Ch.2 Sec.6, as applicable for well intervention units.

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DNV AS

SECTION 4 SUPPLEMENTARY REQUIREMENTS FORACCOMMODATION UNITS

1 General

1.1 Introduction

1.1.1 This section identifies design and construction requirements for assignment of service notationAccommodation unit.

1.1.2 Accommodation units are units primarily intended for accommodation of offshore personnel.

1.1.3 The service notation Accommodation unit is mandatory for classification of units primarily intendedfor accommodation of offshore personnel.

1.1.4 The requirements in this section are supplementary to those for main class as stated in Sec.1.


2.1 Emergency shutdownAccommodation units that are located adjacent to operational units which have potential for hydrocarbonrelease shall comply with DNV-OS-A101 Ch.2 Sec.4.

3 Structural strength

3.1 GeneralService notation Accommodation unit includes requirements for the following:

— structural strength of the accommodation— connection of the accommodation modules to main structure— gangways.

3.2 Design loadsStructural strength shall be as required for main class assuming design loads for accommodation deck as forcrew spaces or weather deck whichever is applicable.

3.3 Containerised modules

3.3.1 If containerised modules are used for accommodation, the structural strength of the connectionsbetween the modules and between the modules and the supporting structure shall be in accordance with thegeneral requirements given for the main class, assuming forces as given for heavy components in DNV-OS-C103 Ch.2 Sec.2 [4.4].

3.3.2 For column-stabilised units the horizontal force shall not be taken less than:

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DNV AS

where:M = mass of unit, in tα = angle of heel corresponding to loss of buoyancy of one column.Permissible usage factors are given in DNV-OS-C201 Ch.2 Sec.2 Table 2.

3.4 GangwaysThe offshore gangway shall be delivered with the Society's certificates in compliance with DNV-ST-0358,Offshore gangways. In agreement with the society the gangway may be certified based on otherinternationally recognised standards. Gangways certified by other societies may be accepted based on specialconsideration.

4 Electrical systems and equipment

4.1 Emergency source of power and emergency installation

4.1.1 The emergency power supply and emergency lighting shall be operable and capable of being used inthe damaged conditions described in DNV-OS-C301.

4.1.2 Where the emergency source of power is a generator, a transitional source of emergency power shallbe installed. This shall be an accumulator battery of sufficient capacity:

— to supply emergency lighting continuously for 30 minutes— to close the watertight doors (if electrically operated), but not necessarily to close them simultaneously— to operate the indicators (if electrically operated) which show whether power operated, watertight doorsare open or closed

— to operate the sound signals (if electrically operated) which give warning that power operated, watertightdoors are about to close

— to operate the fire detection and alarm systems, unless these systems are supplied by separate batteries.

4.1.3 Arrangements shall be such that the transitional source of emergency power will come into operationautomatically in the event of failure of the main electrical supply.

4.1.4 Where the emergency source of power is an accumulator battery, arrangements shall be such thatemergency lighting will automatically come into operation on failure of the main lighting supply.

4.1.5 An indicator shall be fitted in the control room, preferably in the main switchboard, to indicate whenany accumulator battery fitted in accordance with this rule is being discharged.

4.1.6 The emergency switchboard may be supplied from the main switchboard during normal operation.

5 Position keepingShip shaped and column stabilized accommodation units shall have the class notation POSMOOR(V) orDYNPOS(AUTR).Temporary mooring is not required as a condition for classification.

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DNV AS

SECTION 5 SUPPLEMENTARY REQUIREMENTS FOR CRANE UNITS

1 Introduction

1.1 Objective

1.1.1 This section identifies design and construction requirements for assignment of service notation Craneunit.

1.1.2 Crane units are units specially intended for lifting purposes.

1.1.3 The requirements for main class 1A, as stated in Sec.1 shall be complied with in addition to thesupplementary requirements for Crane unit listed in this section.

1.2 Safety principles – emergency shutdownCrane units that are located adjacent to operational units which have potential for hydrocarbon release shallcomply with DNV-OS-A101 Ch.2 Sec.4.

2 Structural design

2.1 GeneralThe following is covered by the service notation:

— structural details relating to the lifting operations. Dynamic forces due to lifting operations and motionscharacteristics of the unit shall be taken into account

— supporting structures for the crane and strengthening of the deck structure— devices for locking the crane in parked position (unit at sea).

2.2 Technical requirementsThe hull structural strength shall in general be as required for main class taking into account necessarystrengthening for supporting the crane(s). Crane units shall comply with the requirements of DNV-RU-SHIPPt.5 Ch.10 Sec.2.

3 Stability and watertight integrityThe requirements of DNV-OS-C301 Ch.2 Sec.1 [6] shall be complied with.

4 Crane with substructure

4.1 CertificationThe crane shall be delivered with the Society's certificates in compliance with DNV-ST-0378 Offshoreand platform lifting appliances. In agreement with the society the crane may be certified based on otherinternationally recognised standards. Cranes certified by other societies may be accepted based on specialconsideration.

4.2 SubstructureDevices for locking the crane in parked position at sea will be specially considered taking into accountenvironmental load conditions as indicated for the main class of the unit.

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DNV AS

SECTION 6 SUPPLEMENTARY REQUIREMENTS FOR WIND TURBINEINSTALLATION UNITS

1 General

1.1 Introduction

1.1.1 This section identifies design and construction requirements for assignment of service notation Windturbine installation unit (WTIU).

1.1.2 WTIUs are specially intended for installation and/or maintenance of fixed and floating wind powerequipment such as:

— foundations— columns— generator house— blades.

1.1.3 Units covered by this service notation are not intended for operations related to development orproduction of hydrocarbons.

2 General requirements

2.1 Structural strengthThe hull structural strength shall be as required for the main class taking into account necessarystrengthening of supporting structures for equipment applied in the installation operations.All load effects caused by deck cargo and heavy equipment shall be accounted for in the design calculationsfor all operational phases.

2.2 Stability and watertightStability and watertight integrity shall comply with the additional requirements in DNV-OS-C301 Ch.2 Sec.1[6.2].

2.3 Position keepingIf a dynamic positioning system is installed, class notation DYNPOS or DPS is mandatory.

3 Crane installationsWind turbine installation units which are equipped with a crane, and is specially intended for lifting purposes,shall in addition to service notation Wind turbine installation unit be assigned the service notation Craneas specified in Sec.5.

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DNV AS

SECTION 7 ADDITIONAL CLASS NOTATIONS

1 Introduction

1.1 General

1.1.1 This section identifies design and construction requirements for assignment of additional classnotations relating to system, equipment and special facility installations.

1.1.2 Units fitted with systems and/or special features complying with relevant requirements of this sectionmay be assigned class notations as described.

1.2 Technical reference documents

1.2.1 Technical requirements are given by reference to selected:

— DNV offshore standards— DNV classification guidelines— DNV recommended practices— other DNV rules and standards— internationally recognised codes and standards.

1.2.2 The technical reference documents which shall be applied are given in the following subsections andsummarised in Table 30.

1.3 General assumptions

1.3.1 DNV may accept alternative solutions found to represent an overall safety level equivalent to thatstated in the requirements of this document or referred standards.

1.3.2 The requirements stated in this section for additional class notations shall be regarded assupplementary to those given for assignment of main class and relevant service notations.

2 Enhanced systems

2.1 General

2.1.1 This chapter summarizes the specific requirements for the enhanced control and safety systems, (ES)notation, as identified in the previous chapters.

2.1.2 ObjectiveThe objective of the ES notation is to increase safety and reliability over the level as is represented by IMO’sMODU Code and main class.

2.1.3 ScopeES covers requirements for machinery and systems, in special regarding control systems and fire safety.

2.1.4 ApplicationThe notation is applicable for drilling and well intervention units.

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DNV AS

2.2 Technical requirementsAll of the technical requirements as listed in Table 1 come in addition to MODU Code 2009 and main class andadditional service notation requirements as described in Sec.1 to Sec.6.

Table 1 Requirements applicable for ES only

Description Reference

Enhanced ESD DNV-OS-A101 Ch.3 Sec.1

Alarm philosophy DNV-OS-D202 Ch.3 Sec.1

Active fire protection for moon poolEnhanced fire protection

DNV-OS-D301 Ch.3 Sec.1

2.3 Certification of materials and componentsThere are no additional requirements for CMC.

3 Position mooring equipment

3.1 General

3.1.1 The notation ME may be assigned to units fitted with single or spread point mooring systems inaccordance with the requirements of this section, not having applied for the POSMOOR notation.

3.1.2 ObjectiveThe objective of the notation is to demonstrate that the mooring equipment is certified in accordance withDNV-OS-E301.

3.1.3 ScopeThe notation covers the certification of mooring equipment and safety devices used for position mooring.

Guidance note:

The notation does not cover temporary mooring equipment. This equipment is part of by main class scope described in Sec.1.

The notation does not cover the complete position mooring design and system approval to ensure mooring integrity within a setenvironmental window. For such a follow-up, the POSMOOR notation should be selected as described in [4] below and DNV-OS-E301 Ch.3 Sec.1.


3.2 Technical requirementsDesign requirements to position mooring equipment shall be in accordance with DNV-OS-E301 Ch.2 Sec.4.

3.3 Certification requirementsCertification requirements to position mooring equipment shall be in accordance with DNV-OS-E301 Ch.3.

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DNV AS

4 Position mooring system

4.1 General

4.1.1 The POSMOOR notation may be assigned to units fitted with single or spread point mooring systemsin accordance with the requirements of this section.The notation POSMOOR includes specific technical capability requirements to position mooring capabilitybeyond the class notation ME.

4.1.2 ObjectiveThe notations aim to cover the reliability of the mooring system and equipment, for the purpose of ensuringsafe position mooring.

4.1.3 ScopeThe notation covers the following aspects:

— environmental conditions and loads— mooring system analysis— thruster assisted mooring— mooring equipment— tests.

4.2 Application

4.2.1 The notation is complemented with the qualifiers as described in Table 2.

Table 2 POSMOOR class notations


<none> Passive position mooring system according the technical requirementsof DNV-OS-E301 Ch.2

A Mooring system designed according to API 2SK

V Mooring system designed for positioning in vicinity of other structures

TA Thruster assisted mooring system dependent on manual remotethrust control system

ATA Thruster assisted mooring system dependent on automatic remotethrust control system

R Remaining thruster capacity after loss of most significant redundancygroup

POSMOOR Position mooringsystem

HC Thruster configuration sufficient to perform heading control

4.2.2 The qualifiers A, V and R can be combined with TA and ATA.Guidance note:

Example of notation: POSMOOR(ATA, R, A).


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DNV AS


4.3.1 The technical requirements of DNV-OS-E301 shall be complied with for assignment of the POSMOORnotation.

4.3.2 The technical requirements of API 2SK shall be complied for the qualifier A.

4.4 Certification of materials and componentsCertification of equipment shall be in accordance with DNV-OS-E301 Ch.3.

5 Dynamic positioning systems

5.1 General

5.1.1 The notations given in Table 3 may be assigned to units with dynamic positioning systems:

Table 3 Dynamic position class notations

Classnotation Description Qualifier Description

A Annual survey required to be completed in accordance with requirementsfor complete survey

1 With an independent joystick back-up and a position reference back-up

2 With redundancy in technical design and with an independent joystickback-up

3 With redundancy in technical design and with an independent joystickback-up, plus a back-up DP-control system in an emergency DP-controlcentre, designed with physical separation for components that provideredundancy

3-CB As for DPS(3) with additional closed bus-tie operational integritydocumented through FMEA, computer simulations, testing, andinspections

3-CBS As for DPS(3) with additional closed bus-tie operational integritydocumented through FMEA, computer simulations, testing, inspections,survey and built-in test functionality

DPS Dynamicpositioning system

3-CBT As for DPS(3) with additional closed bus-tie operational integritydocumented through FMEA, computer simulations, inspections, surveyand testing including live short circuit and earth failures

A Annual survey required to be completed in accordance with requirementsfor complete survey

AUT With an independent joystick back-up and a position reference back-up

DYNPOS Dynamicpositioning system

AUTR With redundancy in technical design and with an independent joystickback-up

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DNV AS

Classnotation Description Qualifier Description

AUTRO With redundancy in technical design and with an independent joystickback-up, plus a back-up DP-control system in an emergency DP-controlcentre, designed with physical separation for components that provideredundancy

AUTRO-CB

As for DYNPOS(AUTRO) with additional closed bus-tie operationalintegrity documented through FMEA, computer simulations, testing andinspections

AUTRO-CBS

As for DYNPOS(AUTRO) with additional closed bus-tie operationalintegrity documented through FMEA, computer simulations, testing,inspections, survey and built-in test functionality

AUTRO-CBT

As for DYNPOS(AUTRO) with additional closed bus-tie operationalintegrity documented through FMEA, computer simulations, inspections,survey and testing including live short circuit and earth failures

AUTS Without redundancy

E Dynamic positioning system with enhanced reliability. Position andheading keeping ability meets intentions comparable to or exceedingDPS(2) Includes redundant DP control system and single independentalternative DP control system and manual levers control back-up Providesflexibility and increased availability of power and thrust by use ofconnected power systems, standby start and changeover of generator

ER Redundancy in technical design

Guidance note:

Example of notations: DYNPOS(AUTR, A) or DPS(2, A).


5.1.2 ObjectiveThe objective of the notations is to ensure the availability of dynamic positioning with various grades ofredundancy in line with the IMO MSC/Circ.1580 Guidelines for vessels and units with dynamic positioning(DP) systems.

5.1.3 The two notation series differ in their specific requirements and in general the DYNPOS seriesnotations are requiring a higher degree of availability and robustness as compared to the DPS seriesnotations. The detailed differences are outlined in the specific requirements given in DNV-RU-SHIP Pt.6 Ch.3.

5.1.4 ScopeThe dynamic positioning system includes requirements for the following subsystems, control panels andback-up systems which are necessary to dynamically position the unit:

— power system— controller— measuring system— thruster system— remote thrust control— control panels.

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5.1.5 These rules do not include requirements or recommendations in regard to the units operation or othercharacteristics.


5.2.1 Technical requirements for the dynamic positioning notations shall be in accordance with the DNV-RU-SHIP Pt.6 Ch.3 Sec.1.

5.2.2 Technical requirements for DYNPOS(E) and DYNPOS(ER) are given in DNV-RU-SHIP Pt.6 Ch.3 Sec.2.

5.2.3 For DPS notations granted through class entries, see DNV-RU-SHIP Pt.6 Ch.3 Sec.1.

5.2.4 For DPS(3-CB) and DYNPOS(AUTRO-CB) the system shall also comply with DNV-RU-SHIP Pt.6 Ch.3Sec.1 [11], except for the requirements for live earth fault and short circuit testing.

5.2.5 For DPS(3-CBT) and DYNPOS(AUTRO-CBT) the system shall also comply with DNV-RU-SHIP Pt.6Ch.3 Sec.1 [11].

5.2.6 For DPS(3-CBS) and DYNPOS(AUTRO-CBS) the system shall comply with DPS(3-CB) andDYNPOS(AUTRO-CB) respectively, and in addition comply with the requirements for built-in testfunctionality and testing specified in [5.2.7] through [5.2.13] below.

5.2.7 DP systems assigned the CBS qualifier shall include built-in test functionality which enablesverification by stimulating the power plant's protective functions (see [5.2.11]) by injection of current andvoltage waveforms into the power plant and appurtenant protective systems sensors.

5.2.8 The waveforms used for stimulating the power plant shall originate from:

— actual testing on the vessel power plant (i.e. recordings of relevant tests, e.g. the initial required shortcircuit testing)

— sufficient realistic system specific dynamic (time domain) computer models— other accepted means of generating waveforms suitable for verification.

Evaluation of which type of waveforms to use for verification of different protective functions shall be part ofthe approval process.

5.2.9 Dynamic (time domain) computer models of the power plant's protective system shall be establishedand used for validation of the waveforms. The wave forms shall be validated in order to ensure sufficientaccuracy and resolution, and that they can be used to demonstrate predictable system behaviour withsufficient margins.

5.2.10 Approval of the built-in test functionality shall be based on a system qualification (SQ) processas described in DNV-RU-SHIP Pt.6 Ch.5 Sec.24. The dynamic computer models shall also be subject forverification in this process.

5.2.11 The verification shall as a minimum include verification of primary and secondary protectionfunctions implemented in order to comply with the CB requirements.

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Guidance note 1:

Guidance on required protective functions can be found in DNV OTG-10 DP-classed vessels with closed bus-tie(s).


Guidance note 2:

In case some parts of the required scope cannot be verified by use of the built-in test equipment, complementary test activitiesmay be considered to be included in the test programme to prove these parts.


5.2.12 A vessel specific CBS test program shall be established. The program shall outline the testingrequired in conjunction with first time acceptance verification, annual survey, and renewal surveys of theDP system. The program is subject for approval, it shall be considered as a part of the vessel DP FMEA testprogramme. The test activities shall be witnessed by the Society. The test results record format and contentshall be agreed as part of the approval process, and the test report shall be delivered to the society aftertesting.

Guidance note:

The initial test programme should cover a comprehensive set of tests in order to cover both primary and secondary protectionfunctions, as well as a wide range of combinations of failure and operational modes. It is expected that a similar test coverage isperformed as part of the 5-yearly renewal in one test session or incrementally over the 5-yearly period.


5.2.13 For first time verification of the CBS qualifier, live short circuit and earth fault testing as requiredfor the CBT qualifier shall be performed. Time series of the system current, voltage and frequency dynamicsduring the tests shall be recorded. These time series shall be used for later comparison/validation of dynamiccomputer models and for actual testing by use of the built-in test equipment.

Guidance note:

For vessel with existing CBT qualifier the requirement for recoding of time series data may be waived in case of converting thequalifier to CBS. Such a change of qualifier are relevant for vessels which implements a built-in test functionality, according tothese requirement, to be used for verification in lieu of the 5-yearly live short circuit and earth fault testing required for renewal ofthe CBT qualifier.


5.3 Certification of materials and componentsThe certification of equipment shall be in accordance with DNV-RU-SHIP Pt.6 Ch.3 Sec.1.

6 Drilling facilities

6.1 General

6.1.1 IntroductionThe DRILL notation covers design fabrication, installation and operational aspects of offshore drilling facilitieswhich have potential to affect safety of personnel or pollution of the environment.

Table 4 Notations related to drilling facilities


Default notationDRILL Drilling facilities

MPD For units with a managed pressure drilling (MPD) system installed

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MPD-ready

For units with provisions pre-fitted for installation of a MPD system

N Evaluated with respect to requirements for operation on theNorwegian Continental Shelf (NCS)

US Covering specific requirements for Gulf of Mexico Outer ContinentalShelf

For qualifier N see DNV-SI-0166 Ch.2 Sec.7, for qualifier US see [6.4].

6.1.2 ObjectiveThe objective of the notation is to ensure the safety and reliability for drilling facilities.

6.1.3 ScopeThe DRILL notation requires certification of drilling equipment and systems, and approval of the completedrilling plant, which includes the following:

— Hoisting, rotating and handling systems

— drilling related structures— drilling hoisting and rotating systems— heave compensation and tensioning systems— handling systems— man-riding systems— other systems (e.g winches).

— Well pressure and flow control systems

— bulk and mixing systems— well influx prevention - drilling fluid circulation and cementing systems— well influx management & well shut-in and disconnect (BOP systems)— well influx relief - diverter systems— well normalising - choke and kill systems— drilling riser systems— well test systems.

6.1.4 ApplicationThe notation is applicable for units with the service notation Drilling unit.The qualifier MPD may be assigned to units with the notation DRILL where an MPD system is permanentlyinstalled.The qualifier MPD-ready may be assigned to units with the notation DRILL where there are provisions fortemporary installation of an MPD system .

6.2 Technical requirementsThe requirements for DRILL are stated in DNV-OS-E101.

6.3 Certification of materials and components

6.3.1 Procedures and requirements for classification including certification of equipment shall be inaccordance with DNV-OS-E101 Ch.3.

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6.3.2 Manufacturers of materials, components and equipment for DRILL class shall, prior to constructionis started, provide the Society with evidence of their capability to successfully carry out fabrication withadequate quality.

Guidance note:

Evidence may incorporate successful outcome of construction projects of similar nature.


6.4 DRILL(US)

6.4.1 Drilling systems and equipment for use on the Gulf of Mexico outer continental shelf shall comply withthe regulations of the Bureau of safety and environmental enforcement (BSEE).

6.4.2 ObjectiveThe objective of DRILL(US) is to ensure that the drilling plant is in compliance with relevant BSEEregulations.

6.4.3 ScopeThe scope of DRILL(US) is identical with the scope as defined in DNV-OS-E101.

6.4.4 ApplicationUnits equipped with drilling plants in compliance with DNV-OS-E101 and the requirements in this sub-sectionwill be entitled to the class notation DRILL(US).

6.4.5 Technical requirementsAutoshear and Deadman systems shall be provided on DP rigs.See BSEE CFR Title 30, Chapter II, Part 250, par 250.442(f), 250.515(e) and 250.615(e).

6.4.6 Subsea BOP stack shall be equipped with remotely operated vehicle (ROV) intervention capability. At aminimum, the ROV shall be capable of closing one set of pipe rams, closing one set of blind-shear rams, andunlatching the lower marine riser package.See BSEE CFR Title 30, Chapter II, Part. 250, par 250.442(d), 250.515(e) and 250.615(e).

6.5 Modular drilling systemsModular systems performing drilling operations may be classified according to DNV-RU-OU-0294.Modular drilling systems complying with these rules will be entitled to the class notation Modular drillingsystem.

7 Helicopter decks

7.1 General

7.1.1 Units fitted with erected landing platforms for helicopters or landing areas arranged directly on decksor top of deckhouses may be given the class notation HELDK together with qualifiers as defined in Table 5.

7.1.2 ObjectiveThe objective of the HELDK notation is to ensure the safety and reliability of helicopter deck structure andship safety in relation with helicopter operations and hangar facilities.

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7.1.3 ScopeThe scope of the notation is dependent on the qualifiers as listed in Table 5.

Table 5 HELDK class notation


<none> Structure

S Additional requirements to unit safety

H Additional requirements to helicopter safety

F Additional requirements to helicopter facilities

HELDK Helicopter deck

N Evaluated with respect to requirements for operation on theNorwegian Continental Shelf (NCS)

7.1.4 ApplicationThe application of the different qualifiers is restricted as follows:

— The qualifier N can only be applied together with qualifiers S, H or S, H, F.

7.2 Technical requirementsTechnical requirements for HELDK shall comply with DNV-OS-E401 Ch.2 and DNV-RU-SHIP Pt.6 Ch.5 aslisted below:

— DNV-OS-E401 Ch.2 Sec.1 to DNV-OS-E401 Ch.2 Sec.4 for notation HELDK— DNV-RU-SHIP Pt.6 Ch.5 Sec.5 [5] Additional requirements for qualifier S— DNV-RU-SHIP Pt.6 Ch.5 Sec.5 [6] Additional requirements for qualifier H— DNV-RU-SHIP Pt.6 Ch.5 Sec.5 [7] Additional requirements for qualifier F.

For additional requirements for qualifier N see DNV-SI-0166 Ch.2 Sec.10.

7.3 Certification of materials and componentsThere are no additional requirements regarding certification.

8 Well testing facilities

8.1 General

8.1.1 IntroductionUnits equipped with facilities for well testing may be assigned class notation WELLTEST.

8.1.2 ObjectiveWELLTEST is intended for limited testing of wells in relation to drilling activities.

8.1.3 ScopeThe scope of WELLTEST covers:

— structural requirements— area arrangement— processing facilities

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— safety systems— components.

8.1.4 ApplicationWELLTEST is applicable for units having service notation Drilling unit.

8.2 Technical requirementsThe requirements as listed in Table 6 shall be complied with.

Table 6 Overview of applicable reference standards

Technical item Reference standards Applicable parts of comments

Overall DNV-OS-E101 Ch.2 Sec.5 [8]

DNV-OS-E101 Ch.2 Sec.1 [8] and [9]Structure

DNV-OS-C101 General structural requirements

Area arrangement DNV-OS-A101 Ch.2 Sec.1 (accidental loads)

Ch.2 Sec.2 (arrangement/layout)

Ch.2 Sec.4 (hazardous areas)

Ch.2 Sec.5 (escape routes)

Ch.2 Sec 6 (supplementary requirements)

Processing facilities DNV-OS-E201 Ch.2 Sec.1 [1], [2] and [3]

Ch.2 Sec.2 [1], [2], [3], [6] and [8]

Ch.2 Sec.3 [1], [2] and [3]

Ch.2 Sec.5 (electrical, instrumentation)

DNV-OS-A101 Sec.5 (ESD)Safety systems

DNV-OS-D301 Ch.2 Sec.3 (Fire fighting systems)

Ch.2 Sec.4 (Fire and gas detection)

DNV-OS-E101 Ch.3 Sec.3Components

DNV-OS-E201 Ch.3 Sec.3

8.3 Certification of materials and componentsComponents subject to certification are given in DNV-OS-E101 Ch.3.

9 Temporary oil storage facilities

9.1 General

9.1.1 ObjectiveUnits arranged and equipped with facilities for temporary storage of oil in relation to drilling or well testingactivities may be assigned class notation TEMPSTORE.

9.1.2 ScopeThe notation covers the following:

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— arrangement— hazardous area classification— piping and equipment associated with storage— passive and active fire protection.

9.1.3 ApplicationThe following conditions apply for assignment of TEMPSTORE:

1) The notation applies to units with drilling as main activity; i.e. the unit shall have service notationDrilling Unit.

2) Well testing and crude storage shall be undertaken onboard the drilling unit; transfer and storage of welltest crude from another unit are not allowed.

3) Transportation of crude oil is not allowed (defined as carriage of oil from port to port or from field toshore with associated discharging in port).

4) Inter-field voyages between wells can be undertaken.


9.2.1 The requirements given for storage units in the following offshore standards shall be complied with asapplicable for TEMPSTORE:

— DNV-OS-A101— DNV-OS-D101— DNV-OS-D301.

9.2.2 Crude oil tanks may be arranged in pontoons and columns of column-stabilised units upon specialconsideration.

9.3 Certification of materials and componentsThere are no additional certification requirements.

10 Crane installations

10.1 General

10.1.1 ObjectiveThe additional optional class notation Crane-offshore sets requirements for a design standard for on-boardpermanently installed cranes.

10.1.2 ScopeThe scope for additional class notation Crane-offshore provides requirements for cranes with respect to:safety and functionality, devices for locking the crane in a parked position and for supporting the cranestructure.Two terms are used in this section to describe the intended use of the crane, these are: Offshore crane – forcargo handling outside the unit while at sea: Platform crane – for cargo handling on the unit.

10.1.3 ApplicationThe additional class notation Crane-offshore applies to the selected cranes installed on units.Reference is given to the applicable structural standard (i.e. from DNV-OS-C101 to DNV-OS-C201)concerning supporting structure (e.g. pedestal), DNV-OS-C301 concerning stability and DNV-OS-A101concerning ESD if applicable.

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An unit found to be in compliance with the requirements in this section may be assigned the additional classnotation Crane-offshore.

10.1.4 For units intended for lifting as main service see also the service notation Crane described in Sec.5.

10.1.5 Definitions

Table 7 Definitions and abbreviation

Term Definition or abbreviation

offshore crane a lifting appliance on board a unit intended for handling of loads outside the unit while at open sea

platform crane a lifting appliance on board an offshore unit intended for handling loads within and outside the unitwhile in harbour and within the unit while at sea

10.1.6 DocumentationThe builder shall submit the documentation required by Table 8.

Table 8 Documentation requirements – builder

Object Documentation type Additional description Info

Cranes Z030 – Arrangement plan Including:

— main dimensions— limiting positions of movable parts— location onboard during operation and in parked position.

FI

AP = for approval, FI = for information

Guidance note:

Documentation requirements to hull support of the cranes are covered in DNV-OS-C101 to DNV-OS-C104.



10.2.1 Design loadsIn addition to the specific design loads given in DNV-ST-0378 , loads due to unit motions shall be considered.Design values of linear and angular accelerations are given in DNV-OS-C101.

10.2.2 Parking and overturningDevices shall be provided for all cranes in parked position (at sea) to be anchored to the hull structure. Theanchoring devices shall be designed to withstand inertia forces due to ship motions and loads due to «outof service» winds. The strength calculations shall be based on accepted principles of statics and strength ofmaterials, applying the safety factors as stipulated for load case III in DNV-ST-0378.

10.2.3 SlidingIn parked position (for a unit at sea) sliding is preferably to be prevented by means of anchoring devices.See [3.1]. If sliding is intended to be prevented by friction between rail and wheels only, the coefficient offriction shall not be taken greater than 0.15.

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10.2.4 For a crane in operation, sliding shall not to take place unless the forces parallel to rails exceed 1.3times the values for load case II in DNV-ST-0378. When this is not satisfied, sliding shall be prevented by adevice locking the crane in position. The strength of this device shall be based on the safety factors for loadcase II/load combination II, as referred above.

10.3 CertificationFor cranes that class notation Crane-offshore shall be applied to, the builder shall request themanufacturers to order certification as described in Table 9.

Table 9 Certification requirements

Object Certificatetype Issued by

Certificationstandard *

Additional description

Offshorecrane

PC Society DNV-ST-0378 Product certificate OLA 201, see DNV-ST-0378

Platformcrane

PC Society DNV-ST-0378 Product certificate OLA 201, see DNV-ST-0378

* Unless otherwise specified the certification standard is the rules.

10.3.1 Use of crane as yard crane during new-build periodDNV certificate for crane is issued upon successful testing after installation onboard, and the operation periodstarts from date of crane certificate issuance. However, the DNV certificate is limited to use of the crane onthe unit within defined operation limitations and required safety systems activated. If the yard intends to useto use any of the unit's cranes for (typically the offshore cranes) as yard cranes during construction of theunit the yard and owner shall agree to such use prior to taking the crane(s) into use.Any planned use of the cranes outside the scope of Crane-offshore (including use as a construction craneat yard) will need to be additionally certified at site according to local legislation for such use. DNV does notengage in this type of certification as part of the Crane-offshore notation, and any additional certificationshall be obtained by the yard and at the sole yard's responsibility in accordance with local regulations andauthorizations.

10.4 TestingAfter completed installation onboard, functional testing and load testing of the crane shall be carried out asspecified in DNV-ST-0378.

10.4.1 Specific additional testing requirements for cranes used as yard cranes during constructionprior to delivery of unit to ownerWhen a crane has been in use as yard crane before entry into service as an offshore crane (corresponding todelivery date of the unit, unless otherwise formally agreed between yard and owner), the following additionaltesting shall be performed before entry into service as offshore crane:

— A complete record of the load history shall always be available for the period of crane utilization as a yardcrane. If the record of the load history is incomplete or missing, additional survey with minimum scope ofcrane renewal (5-year) shall be required before entry into service as offshore crane, regardless the periodelapsed from initial certification.

— If initial certification was completed within three (3) months before entry into service as offshore crane,no additional survey to be carried out.

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— If initial certification was completed between three (3) and twelve (12) months before entry into serviceas offshore crane, additional survey with minimum scope of annual survey to be carried out, see DNV-ST-0378 [14.3.1].

— If initial certification was completed more than twelve (12) months before entry into service as offshorecrane, additional survey with minimum scope of crane renewal (5-year) has to be performed, see DNV-ST-0378 [14.3.2].

— Reduction/waiver of the class survey scope may be considered on a case by case basis if the crane isequipped with life condition monitoring instrumentation/tools as specified in DNV-OTG-21.

Survey and testing as described above is not part of Crane-offshore, and will be considered as additionalwork by DNV.

11 Offshore gangways

11.1 General

11.1.1 Units equipped with offshore gangways may be assigned class notation Walk2work.

11.1.2 ObjectiveThe Walk2work clarifies that the gangway has been certified against DNV-ST-0358 and that the unit is fitfor Walk-to-work operations using the gangway.

11.1.3 ScopeThe scope of the notation covers the gangway's safety and functionality, devices for locking the gangwayin a parked position (unit at sea) and for supporting the gangway structure and testing of the gangway. Inaddition the notation covers the units stability and station keeping capability.

11.2 Technical requirementsThe technical requirements of DNV-RU-SHIP Pt.6 Ch.5 Sec.16 apply, taking into account main class stabilityrequirements as defined in DNV-OS-C301.

11.3 Certification of materials and componentsThe offshore gangway shall have a product certificate issues by the Society against DNV-ST-0358.

12 Additional fire protection

12.1 General

12.1.1 Units with additional fire safety measures in accommodation spaces and machinery spaces may beassigned class notation F. The various qualifiers are related to areas subjected to additional fire protection asgiven in Table 10.

Table 10 Class notations for additional fire protection


A Accommodation spaces

M Machinery spaces

F Additional fire protection

M-P Enhanced fire prevention measures for machineryspaces

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C Deck and cargo areas

12.1.2 ObjectiveThe F notation aims at increased fire protection through preventive measures as well as measures forreducing the consequences of fire.

12.1.3 ScopeThe scope of the notation covers arrangement, structural and active fire protection, fire fighting systems andfirefighter’s outfit.

12.1.4 ApplicationThe qualifiers can be applied individual or in combination.

12.2 Technical requirementsThe requirements as stated in DNV-RU-SHIP Pt.6 Ch.5 Sec.4, shall be complied with for assignment of theclass notations. For F(C) notation the requirements in DNV-RU-SHIP Pt.6 Ch.5 Sec.4 [5.1], DNV-RU-SHIPPt.6 Ch.5 Sec.4 [5.2] and DNV-RU-SHIP Pt.6 Ch.5 Sec.4 [5.4] shall be complied with as applicable.

12.3 Certification of materials and componentsThere are no additional certification requirements.

13 Loading computer

13.1 IntroductionThe additional class notation LCS sets requirements for units equipped with a loading computer system.

13.2 ScopeThe scope for additional class notation LCS concerns an onboard computer system running a combinationof software modules for stability and strength verification. The term loading computer systems applied inthese rules also covers the terms loading instruments and onboard stability computers. These rules do notcover basic (system) software such as device drivers necessary for the hardware to support the applicationsoftware. The qualifier DC added to the notation (i.e. LCS(DC)) concerns damage control software developedto assist the master as a decision aid, receiving input from flooding and filling detectors installed in thevessel's compartments.

13.3 ApplicationThe additional class notation LCS applies to units that employ a loading computer system to verifycompliance with stability and strength requirements for planned and applied loading conditions. The classnotation LCS(DC) applies to units that additionally employ the loading computer and installed sensors fordamage control assessment in real case scenarios. For assignment of the notation, the system shall beapproved, surveyed and certified in accordance with the rules.

13.4 Class notations

13.4.1 Units equipped with loading computer systems in compliance with the requirements in this section,may be assigned the additional class notation LCS as follows:

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Table 11 Additional class notation - LCS

Class notation Qualifier Purpose Description

<None> Loading computer system Loading computer calculating stability and/or hullstrength is installed

LCS

DCLoading computer system toassist the master as a decision aidunder damage conditions

Optional

13.5 Technical requirementsThe requirements of DNV-RU-SHIP Pt.6 Ch.4 Sec.6 shall be complied with as applicable.

13.6 Certification of materials and componentsThe certification covers the loading computer system and the software installed.

14 Periodically unattended machinery space

14.1 General

14.1.1 Units where all machinery in the engine room necessary for performance of main functions have beenfitted with instrumentation and automation systems in compliance with this sub-section, may be assignedclass notation E0 or ECO.

14.1.2 ObjectiveThe class notation E0 denotes that the safety of the ship in all sailing conditions, including whenmanoeuvring and alongside, is equivalent to that of a ship whose machinery spaces are attended.The class notation ECO denotes that the ship is equipped with instrumentation and automation equipmentand systems enabling the continuous supervision of its machinery from a centralised control station.

14.1.3 ScopeThe scope of the notation covers:

— engine control system— alarm system— safety system— fire detection and alarm system.


14.2.1 Assignment of class notations E0 and ECO is based on compliance with DNV-RU-SHIP Pt.6 Ch.2Sec.2, with qualifications given in [14.2.2].

14.2.2 References to DNV-RU-SHIP Pt.4 Ch.11 (fire protection) shall be replaced with DNV-OS-D301 for unitapplication.

14.3 Certification of materials and componentsCertification requirements are given in DNV-RU-SHIP.

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15 Well intervention system

15.1 General

15.1.1 The WELL notation covers design and operational aspects of offshore well intervention facilities whichhave potential to affect safety of personnel or pollution of the environment. Table 12 gives an overview of theapplicable qualifiers.

Table 12 Overview of qualifiers


1 Unit mounted system excluding subsea equipmentWELL Well intervention system

2 Unit mounted system including subsea equipment

15.1.2 ObjectiveThe objective of the notation is to ensure the safety and reliability of well intervention facilities.

15.1.3 ScopeWELL(1) notation covers the unit mounted systems used for well intervention, included but not limited to:

— structural items applicable for the well intervention installation and not covered by main class— heave compensation and tensioning systems— hoisting systems— handling system for well control equipment (e.g. EDP/LRP) and pipe handling systems— HC handling systems— bulk storage, fluid circulation and mixing, cementing and well stimulation fluids systems— other systems (e.g. winches, man riding equipment, skids, carriers)— well intervention systems (e.g. wire line, coil tubing)— well testing systems.

15.1.4 WELL(2) notation covers the unit mounted systems as for WELL(1) and the subsea equipment usedfor well intervention, included but not limited to:

— riser, well control equipment— well control system (e.g. riser, EDP/LRP).

15.1.5 WELL(1) and WELL(2) include specific requirements relating to:

— design principles— well intervention systems and equipment— materials and welding— piping— electrical and control systems— instrumentation component design and installation— user interface (optional)— manufacture, workmanship, testing and maintenance.

15.1.6 ApplicationThe notation is applicable for units with the service notation Well intervention unit(2).

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15.2.1 The requirements for well intervention systems are stated in DNV-OS-E101 App.A.

15.2.2 For well test system see Table 6 for applicable requirements.

15.3 Certification of materials and componentsProcedures and requirements for classification including certification of equipment and systems shall be inaccordance with DNV-OS-E101 App.A.

15.4 Modular well systemsModular systems performing well intervention operations (incl. completion and workover) may be classifiedaccording to DNV-RU-OU-0294 .Modular well systems complying with these rules will be entitled to the class notation Modular well system.

16 Hull monitoring system

16.1 General

16.1.1 Units equipped with instrumentation system for monitoring hull behaviour in accordance with therequirements of this section may be assigned class notation HMON as given in DNV-RU-SHIP Pt.6 Ch.9Sec.3.

16.1.2 ObjectiveThe system will give warning when stress levels and the frequency and magnitude of accelerations approachlevels which require corrective action.

16.1.3 ScopeThe owner shall decide how the hull monitoring system should be configured, i.e. which features to beincluded and how the measured and processed data shall be used.

16.1.4 ApplicationSee DNV-RU-SHIP Pt.6 Ch.9 Sec.3 for qualifier definitions.

16.2 Technical requirementsAssignment of HMON class notations is based on compliance with the DNV-RU-SHIP Pt.6 Ch.9 Sec.3.

17 Fatigue methodology specification

17.1 General

17.1.1 Units may be assigned an optional fatigue class notation FMS. The qualifiers are listed in Table 13.

17.1.2 ObjectiveThe objective of the FMS notation is to reduce the probability for fatigue cracks in the hull structure in-service by enhancing fatigue scope in the design and construction phase.

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17.1.3 ScopeThe FMS notation provides enhanced fatigue design scope by requiring:

— spectral fatigue calculations— additional details to be controlled— stricter design fatigue factors (DFF).This ensures that details are adequately designed to meet the required design fatigue life for the specifiedoperation location(s). The result from the fatigue calculations shall be used to develop the requirednewbuilding inspection plan as detailed in [17.2] and may upon the request from the owner form the basisfor an in-service inspection programme, that may be risk based (RBI), specifically made for the unit.

Table 13 Class notations related to fatigue methodology specification


Y Calculated design life inyears (only relevant for shipshaped units)

NUM Scope of notation coversfatigue assessment bynumerical twin, see DNV-RU-OU-0300 Ch.3 Sec.4 [35]

FMS Fatigue methodologyspecification

SENS Scope of notation coversfatigue assessment bynumerical twin and hybridtwin, see DNV-RU-OU-0300Ch.3 Sec.4 [35]

17.2 Technical requirementsDetail requirements for FMS(Y) are given in DNV-OS-C102 Ch.3 Sec.1 [2.1]. For construction monitoring,the methods, extent of inspection and acceptance criteria shall be described in a design specific inspectionplan with requirements specified in DNV-RU-SHIP Pt.6 Ch.9 Sec.6 for CMON notation.The technical requirements for FMS(NUM) and FMS(SENS) are given in DNV-RU-OU-0300 Ch.3 Sec.4 [35].

18 Hull fabrication

18.1 General

18.1.1 Ship-shaped units may be assigned the class notation FAB.

18.1.2 ObjectiveThe objective of FAB is to reduce the risk of disruption in the unit's operation due to repair of possiblewelding defects from fabrication by increasing the NDT scope during fabrication of hull structure.

18.1.3 ScopeThe FAB notations cover increased NDT requirements and fabrication tolerances as detailed in Table 14.

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Table 14 Class notations related to hull fabrication


<none> Increased scope of NDTFAB Additional NDT scope

+ Further increased scope of NDT and tolerance levelsaligned with DNV-OS-C401

18.2 Technical requirementsTechnical requirements are given in DNV-OS-C102 Ch.3 Sec.1 [2.3].

19 Noise, vibration and comfort rating notations

19.1 General

19.1.1 Units arranged and equipped with the aim to reduce the impact of noise or vibration may be assignedfor the following additional class notations as given below.

Table 15 Class notations related to noise and vibration


N As below, demonstrates compliance with NORSOK-S002

1 Highest level of comfort

2 Intermediate level of comfort

COMF-MOU Requirements for noise,vibration, illumination andindoor climate on boardoffshore facilities

3 Acceptable level of comfort

VIBR Vibration level criteria formachinery, components,equipment and structure

<none>

19.1.2 ObjectiveThe objective of COMF-MOU is to reduce the impact of noise and vibration related to comfort on board maybe assigned for the following additional class notations.

19.1.3 The objective of VIBR is to reduce the risk of failure in machinery, components and structuresonboard units, caused by excessive vibration.

19.1.4 ScopeThe scope of COMF-MOU covers noise, vibration, illumination and indoor climate as reflected by thequalifiers listed in Table 15.

19.1.5 The scope of VIBR covers:

— machinery components and -equipment— structure in compartments where machinery, components and equipment are situated close to thepropeller(s).

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19.1.6 ApplicationUnits arranged and equipped with the aim to reduce the impact of noise and vibration, illumination andindoor climate related to comfort on board may be assigned for the additional class notations as listed inTable 15.


19.2.1 The requirements of DNV-OS-A301 shall be complied with as applicable for the notation COMF-MOU.

19.2.2 The requirements of DNV-RU-SHIP Pt.6 Ch.4 Sec.12 shall be complied with as applicable for thenotation VIBR.

19.3 Certification requirementsThe measurement equipment used for demonstrating the compliance with the limits of COMF-MOU shall becertified or type approved as detailed in DNV-OS-A301 Ch.3.

20 Cold climate notations

20.1 General

20.1.1 Units designed or strengthened for operation within particular geographical or environmental areasfound to be in accordance with relevant class rule requirements may be assigned corresponding optionalclass notation as specified in detail in the remaining of this subsection.

20.1.2 ObjectiveThe objective of the notations Ice and PC is to ensure enough strength for navigation and operation in iceinfested waters.The objective of the notation DAT is to set requirements to materials in ship-shaped and cylindrical unitsintended to operate for longer periods in areas with low air temperatures, i.e. regular service during winter inpolar waters.The objective of the notation Winterized is to ensure operational availability of marine systems in coldclimate conditions.

20.1.3 ScopeThe notations Ice and PC cover requirements related to structural strength and are further detailed in[20.2].The notation DAT includes requirements to steel grades and material class, for a given design ambient airtemperature.The notation Winterized include additional requirements for systems as further detailed in [20.3].

20.1.4 ApplicationThe different notations and their related qualifiers are further detailed in Table 16, Table 17 and Table 18.

20.2 Structural strength

20.2.1 Column-stabilised unitsColumn-stabilised units strengthened for navigation and/or operation in defined ice conditions in accordancewith this sub-section may be assigned class notations as described in Table 16.

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Table 16 Ice class notations for column-stabilised units


1A Intended for navigating in difficult ice conditions

1B Intended for navigating in moderate ice conditions

Ice-T Navigation in ice with theassistance of icebreakerswhen necessary

1C Intended for navigating in light ice conditions

Ice-L Operation in ice <none> Intended for operation in ice determined based on definedice-conditions, ice detection and ice management systems,operational and emergency procedures

20.2.2 Technical requirements for Ice-T are given in DNV-OS-C103 App.C.

20.2.3 Technical requirements for Ice-L shall as far as relevant and practicable be based on DNV-RU-SHIP Pt.6 Ch.6 Sec.2 ice strengthening for the Nordic Baltic and DNV-RU-SHIP Pt.6 Ch.6 Sec.7, polar classnotations PC(6) and PC(7).

20.2.4 These rules do not consider aspects related to the operation of onboard equipment in cold climate. Itis recommended that column-stabilised units intended to navigate and operate in cold climate environmentsfor longer periods comply with the requirements as given in DNV-OS-A201 on cold climate (see [20.3]).

20.2.5 Ship-shaped unitsShip-shaped units strengthened for navigation in defined ice conditions in accordance with this sub-sectionmay be assigned class notations as described in Table 17.

Table 17 Ice class notations for ship-shaped units.


1A* Normally capable of navigating in difficult ice conditions withoutthe assistance of icebreakers

1A Capable of navigating in difficult ice conditions, with theassistance of icebreakers when necessary

1B Capable of navigating in moderate ice conditions, with theassistance of icebreakers when necessary

Ice Navigation in ice –baltic ice classes

1C Capable of navigating in light ice conditions, with the assistanceof icebreakers when necessary

1 Year-round operation in all polar waters

2 Year-round operation in moderate multi-year ice conditions

3 Year-round operation in second-year ice which may include multi-year ice inclusions

4 Year-round operation in thick first-year ice which may include oldice inclusions

PC Polar class –navigation in ice-infested polarwaters

5 Year-round operation in medium first-year ice which may includeold ice inclusions

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6 Summer/autumn operation in medium first-year ice which mayinclude old ice inclusions

7 Summer/autumn operation in thin first-year ice which mayinclude old ice inclusions

DAT Design ambienttemperature - forunits operatingin winter in polarwaters

t Providing material requirements for vessels intended to operate inlow air temperatures in polar waters. t denotes the lowest meandaily average air temperature in °C.

20.2.6 Technical requirements for DAT are given in DNV-RU-SHIP Pt.6 Ch.6 Sec.6.

20.2.7 Technical requirements for Ice are given in DNV-RU-SHIP Pt.6 Ch.6 Sec.2 and DNV-RU-SHIP Pt.6Ch.6 Sec.3.

20.2.8 Technical requirements for PC are given in DNV-RU-SHIP Pt.6 Ch.6 Sec.7.

20.3 Winterized

20.3.1 The table below lists the different qualifiers for the Winterized notation.

Table 18 Class notation Winterized


Basic Operation occasionally in cold climate for short periods

Cold Operation in cold climate regularly or for an extendedperiod of time, though not necessarily in ice-infestedwaters

Polar Operation in extreme cold climate of the polar regionsyear-round, typically in ice-infested waters

Winterized Operation in cold climate

tw Extreme low ambient air temperature in °C

20.3.2 ApplicationFor qualifier Basic, a relevant Ice notation is mandatory if intended to operate in ice-infested waters.

20.3.3 For qualifier Cold, a relevant Ice notation is mandatory if intended to operate in ice-infested waters.

20.3.4 For qualifier Polar, a relevant Ice notation and the class notation Clean or Clean(design) aremandatory.

20.3.5 Additional details are given in DNV-OS-A201 Ch.3.

20.3.6 Technical requirementsThe technical requirements are given in DNV-OS-A201 Ch.2.

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20.3.7 Certification requirementsThe certification requirements are given in DNV-OS-A201 Ch.3 Sec.2.

21 Environmental notations

21.1 GeneralTable 19 provides an overview of the environmental related notations.

Table 19 Class notations related to environment


E Ballast water management system based onexchange

BWM Ballast water management

T Ballast water management system ontreatment

<none> Basic operational requirementsClean Arrangements for controlling andlimiting operational emissions anddischarges Design Additional operational requirements. Design

requirements for protection against accidentsand for limiting their consequences

Recyclable Safe and environmentally soundrecycling of ships

Covering the development of inventory ofhazardous materials part 1

1 Basic installation (meeting IMO MSC/Circ.585)

2 VCS(1) overfill alarm (meeting USCG CFR 46part 39)

VCS Vapour control systems

3 VCS(2) installation for onboard vapourprocessing

21.2 Objective

21.2.1 The class notation BWM describes a ballast water management system in line with the InternationalConvention for the Control and Management of Ship’s Ballast Water and Sediments as adopted by IMO 13February 2004.

21.2.2 The class notation Clean identifies the basic requirements for controlling and limiting operationalemissions and discharges. The class notation Clean(Design) identifies additional requirements forcontrolling and limiting operational emissions and discharges. In addition, this notation specifies designrequirements for protection against accidents and for limiting their consequences.

21.2.3 The objective of Recyclable is to support early compliance with the requirements for the Inventoryof hazardous materials (IHM) set forth by the IMO Hong Kong convention for the safe and environmentallysound recycling of ships.

21.2.4 The objective of VCS is to define criteria which apply to shipboard systems for control of vapouremissions from liquid cargoes.

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21.3.1 BWMThe requirements given in DNV-RU-SHIP Pt.6 Ch.7 Sec.1, shall be complied with for assignment of the classnotation BWM following the different qualifiers as specified.

21.3.2 Clean(Design)The requirements given in DNV-RU-SHIP Pt.6 Ch.7 Sec.2, shall be complied with for assignment of the classnotations Clean with the deviations as given in [21.3.3].

21.3.3 For the application of Clean(Design) for offshore units, the requirement for NAUT(AW) orNAUT(OSV) can generally be waived based on an assumption of the lower navigational risk due to theoperational pattern of the unit (i.e. most of time in a fixed location).The requirement to oil tank protection as a distance to bottom shell plating may also be waived under certainconditions but shall be evaluated on a case by case basis.

21.3.4 RecyclableThe requirements given in DNV-RU-SHIP Pt.6 Ch.7 Sec.4 shall be complied with for assignment of the classnotation Recyclable.

21.3.5 VCSThe requirements given in DNV-RU-SHIP Pt.6 Ch.4 Sec.11 shall be complied with for assignment of the classnotation VCS.

22 Enhanced system verification

22.1 General

22.1.1 The notation ESV indicates that specified onboard system has been subject to enhance systemverification.

22.1.2 ObjectiveThe objective is to analyse the specified target system by use of one or more verification methods asdescribed in these rules in order to provide objective evidence of acceptable functionality and qualityaccording to stated requirements.

Guidance note:

Application of any enhanced system verification should provide an additional broader and/or deeper and/or earlier verification ofthe applicable requirements when compared to normal classification test activities required for the target system(s).


22.1.3 ScopeThe requirements apply to marine and offshore systems and cover test and verification methods that may beutilized to assist in verification of functionality and performance of such systems.

22.1.4 ApplicationThe target systems available for enhanced system verification methods in the ESV notation are specified inTable A1 of DNV-RU-SHIP Pt.6 Ch.5 Sec.13.Any combination of selected systems can be made.

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22.1.5 The ESV notation can only be applied for systems covered by classification through main class andadditional class notation assigned the unit.

22.1.6 The applied verification method is showed in the notation string as listed in Table 20.

22.1.7 The verification methods are aligned to be applied in conjunction with classification activities ofsystems at e.g. type approval, manufacturing survey, onboard testing, and on sea trial in order to provideadditional evidence of expected and required functionality.

Table 20 Class notations related to enhanced system verification


HIL-IS Hardware in the loop, test package incl simulatorprovided by independent supplier

ESV Enhanced system verification

HIL-DS As above, simulator provided by supplier targetsystem

22.2 Technical requirementsThere are not additional technical requirements to the target system.

22.3 Certification requirementsThere are not additional certification requirements to the target system.

23 Integrated software dependent systems

23.1 General

23.1.1 Units built and tested in compliance with the requirements of DNV-OS-D203 may be assigned one ofthe optional class notations for integrated software-dependent systems shown in Table 21.

Table 21 ISDS class notations

Notation Description

ISDS [system1,...,system n] Units having undergone enhanced software-dependent system integration for thesystem(s) according to DNV-OS-D203

23.1.2 ObjectiveThe objective of ISDS is to reduce the risk for delays in new-build projects and modification projects, as wellas for downtime and accidents caused by software in the operation phase.

23.1.3 ScopeThe systems covered by the notation shall be specified and are as shown by the given qualifiers. Theselection of systems is listed in DNV-OS-D203 Ch.3 Sec.1 Table 1.The scope of DNV’s involvement depends on the confidence level specified.

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23.1.4 ApplicationAny combination of selected systems can be made.

23.1.5 ISDS can only be applied for systems as covered by classification through main class and otheradditional class notations.

23.1.6 Unless otherwise agreed the confidence levels of DNV-OS-D203 Ch.3 Sec.1 Table 1 apply.

23.2 Technical requirementsThere are no additional technical product requirements.

23.3 Certification requirementsThere are no additional certification requirements.

24 Cyber security

24.1 General

24.1.1 Units constructed and tested in accordance with the requirements in DNV-RU-SHIP Pt.6 Ch.5 Sec.21may be assigned the class notation Cyber secure, with qualifiers, as outlined in Table 22.

Table 22 Class notation for cyber security

Class notation Qualifier Purpose Application

<None> Initial level of cyber security is based on IMOresolution MSC.428(98) and MSC-FAL.1/Circ.3

Essential Essential level of cyber security for thevessel's essential systems, see DNV-RU-SHIPPt.6 Ch.5 Sec.21 [1.4.3]

Advanced Advanced level of cyber security for thevessel's essential systems, see DNV-RU-SHIPPt.6 Ch.5 Sec.21 [1.4.4]

Cyber secure

+

Establish barriers to prevent,mitigate and respond to cyber-attacks

Selected level of cyber security for specifiedsystem(s), see DNV-RU-SHIP Pt.6 Ch.5Sec.21 [1.4.5]

24.1.2 ObjectiveThe objective of Cyber secure is to ensure that sufficient and correctly performed cyber security barriers areestablished to prevent, mitigate and respond to cyber-attacks.

24.1.3 ScopeThe notation covers critical systems, which individually or collectively make up unit functions subject forcyber security assessment, see DNV-RU-SHIP Pt.6 Ch.5 Sec.21 [2].

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Guidance note:

For Cyber secure(+), DNV-RP-0496 and DNV-RP-G108 may be used as guidance for conducting a risk assessment.


24.1.4 ApplicationThese rules may be applied to any unit where one or more functions are controlled by cyber physicalsystems. The implementation process for class notation Cyber secure constitutes activities by several rolesin the relevant phases, see DNV-CG-0325 for guidance.

24.2 Technical requirementsSystem design shall follow the requirements in DNV-RU-SHIP Pt.6 Ch.5 Sec.21 [3] and DNV-RU-SHIP Pt.6Ch.5 Sec.21 [4].

24.3 Documentation requirementsFor documentation requirements, see DNV-RU-SHIP Pt.6 Ch.5 Sec.21 [1.8].

25 Smart unit

25.1 IntroductionThe digital technology development with widespread use of digital solutions and increased connectivityavailable for the maritime industry, is enabling use of data and information to further optimize operations andreduce the environmental footprint. Efficient scale-up requires reliable data collection and exchange of datathat also will require a certain level of standardisation and data quality management. The digitalisation alsointroduces new risks towards cyber- and data-security which shall be managed.DNV has a range of notations and services contributing to more effective operations, lower environmentalfootprint and to ensure that data-driven solutions are safe and suitable for the given application.

25.2 ObjectiveThe objective for the Smart notation is to promote and visualise a shift towards more efficient and greenoperations that are based on digital or environmental friendly solutions, enhancing the performance andoperation of a unit.

25.3 ScopeThe additional class notation Smart provides a framework for profiling a variety of class services that utilisedigital and technical solutions to improve the operational efficiency or environmental footprint of the unit. Thescope of the notation is split in three (3) different qualifiers, each referring to a range of available servicesor by assessment of novel technology and solutions, denoted as enhancements, see DNV-RU-SHIP Pt.6 Ch.5Sec.24 [2.2].These rules do not give guidance on the suitability of the different enhancements or combinations, withrespect to the unit's various industrial mission(s). See DNV-CG-0508 for more details and guidance.

25.4 ApplicationThe additional class notation Smart may be applied to any unit in operation and to newbuildings.The additional class notation does not apply to remotely operated or autonomous assets, for which there areadditional requirements, see DNV-CG-0264.

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25.5 Class notationsUnits built in compliance with the requirements of this document and relevant referenced rules andstandards, and as specified in Table 23, may be assigned the additional notation Smart with qualifiers shownin Table 23.

Table 23 Class notations

Class notation Qualifier Enhancement category Additional description

OPM operations and maintenance- machinery, equipment andsystems

operations and maintenance enhancements relatedto maintenance management of machinery andequipment, condition monitoring, systems and unitperformance

OPH operations and maintenance -hull and structure

operations and maintenance enhancements related tostructural integrity management, condition monitoringof hull and structure and performance of the unit

Smart

EEN energy efficiency andenvironment

energy efficiency and environmental enhancementsrelated to fuel consumption, emission and noise

25.6 Technical requirementsSystem design and technical requirements shall follow DNV-RU-SHIP Pt.6 Ch.5 Sec.24.Units with the class notation DPS(3-CB), DPS(3-CBT), DYNPOS(AUTRO-CB) or DYNPOS(AUTRO-CBT)may use the notation as one enhancement for obtaining Smart(EEN) notation.

26 Data collection infrastructure

26.1 IntroductionOptimisation of the operations through digitalisation requires access to relevant and reliable data collectedfrom sources like sensors, control systems and other types of data acquisition or interfaces where data ismade available.The use of data extends from single parameters to larger data sets providing important information aboutperformance or condition of machinery, equipment or systems, supervisory control and quality assurance tocomplex models and applications offering predictive analytics like machine learning that can learn from vastquantities of historical data.With an increasing amount of collected data, the need for systems that offer systematic data collectionand storage becomes essential and the use of data collection infrastructures to ensure this function will benecessary.

26.2 ObjectiveThe additional class notation D-INF addresses standardisation of data and metadata to support a costeffective, scalable, reliable and secure data collection, storage and exchange of data.

26.3 ScopeThe rules for D-INF provide requirements for a data collection infrastructure established to facilitate unit-to-shore data exchange with the following main elements:

— data collection infrastructure, network and connectivity— data quality and security management.

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D-INF does not introduce requirements for applicable source systems and solutions.

26.4 ApplicationD-INF may be applied to any unit in operation and to a newbuilding.The data collection infrastructure includes those components necessary to collect, manage and relay datafrom a unit to the data consumer.A data collection infrastructure includes:

— unit server— data relay component— remote data server.The rules describing unit server, data relay component, network and connectively, may be applied by the yardas part of the unit newbuild as applicable. Rules describing requirements for remote data server, data qualityand security management, may be applied by the unit owner.The rules describing requirements for data quality and security management, see DNV-RU-SHIP Pt.6 Ch.11Sec.1 [4], may be applied to describe applicable requirements for other additional notations and/or surveyarrangements covered by the rules.

26.5 Class notationsUnits built in compliance with the requirements in this document may be assigned the additional notation D-INF with qualifiers shown in Table 24.

Table 24 Class notations


P A proprietary data collectioninfrastructure to facilitate thecollection and exchange ofdata.

Based on customisedrequirements defined by aspecific data collection usecase.

D-INF

S A standardised datacollection infrastructure tofacilitate the collection andexchange of data.

Based on standardisedrequirements defined by aspecific standard.

26.6 Technical requirementsSystem design and technical requirements shall follow DNV-RU-SHIP Pt.6 Ch.11 Sec.1.

27 Data-driven verification

27.1 IntroductionDigital technology and increased possibilities for connectivity open for the use of data-driven verification(DDV) systems and methods. Utilising the opportunities of DDV may increase effectiveness of verification andtest functionality and open for more efficient and accurate assurance processes.

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Guidance note:

As per this rule release a major part of existing maritime and offshore target systems may not be prepared for implementation ofDDV methods, nor may such methods be developed.

It is recommended to include the Society in the development of DDV methods intended to be used for retention of classcertificates.

For more information on the objectives and philosophies behind the DNV data-driven and D-class initiative , see DNV-CG-0557Sec.1 and DNV-CG-0557 App.A.


27.2 ObjectiveThese rules are developed in order to support industry development of data-driven verification systems andmethods, and to help in implementing such to provide genuine and trustworthy verification evidence whenreplacing more traditional methods.The rules build upon the principles of:

— ensuring that systems are designed to be verified— incorporating verify on-demand capabilities.The objective also aims at reducing exposure to non-productive time associated with taking units out ofservice for trials, reducing costs associated with surveyors from various organisations attending the unit,reducing redundant verification activities, and reducing the cognitive burden imposed upon unit crewscarrying out testing.

27.3 ScopeThis document sets requirements to DDV systems and arrangements onboard units, and to verificationmethods.

27.4 ApplicationThe additional class notation DDV applies to any units provided with arrangements enabling verification ofspecified on board target systems by use of data-driven verification methods.


27.5.1 Units built and tested in compliance with the requirements in this section may be assigned theadditional class notation DDV with a minimum of one qualifier describing the actual target system (TS) andverification method (VM) accordingly. Relevant qualifiers are given in Table 25 and Table 26.The resulting syntax will then be: DDV(TS1[VM1], … TSn[VMn]).

Table 25 Verification methods (VM) signifying the method of verification

Qualifier for verificationmethod VMn Description

AVA Algorithm-based verification agent and advanced data analytics: this qualifier designatesdata-driven verification functions based on an automatic algorithm with a dedicated role,purpose, function, and responsibility (i.e. agent) in conducting verification (i.e. generatingevidence) by interacting with the target system through an API or other digital interfaceusing documented methods and data structures. The AVA shall also support delivery of atamper-free data-based body of evidence which can be used for classification purposes,to the Society. The AVA acts as a 'tester' and generates evidence and possibly also makesdecisions and conclusions (e.g. go/no-go).

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Qualifier for verificationmethod VMn Description

BITE Verification based on built in test functionality: this qualifier designates data-drivenverification functions (hardware and software) which are built into, or connected to, thetarget system with the purpose of generating verification data, automatically or uponoperator request, and to deliver a tamper-free data-based body of evidence which can beused for classification purposes, to the Society. It is accepted that the target system mayneed to be taken out of operation and put into test mode for the verification activity to beperformed. The target system/BITE shall have the capability to transfer the generated BITEverification data over an API or other digital interface using documented methods and datastructures.

DSA Verification based on digital survey applications: this qualifier designates data-drivenverification functions utilising digital test tools where the complete, or specified parts ofthe verification scope is incorporated and managed by the crew or other dedicated testpersonnel. The tool incorporates test procedures to be performed for generation andgathering of onboard system(s) generated data and supports delivery of a tamper-freedata-based body of evidence which can be used for classification purposes, to the Society.The target system may need to be taken out of operation and put in to test mode for theverification activity to be performed. The interaction between DSA and the target system,and the generated target system/DSA verification data shall be carried over an API or otherdigital interface using documented methods and data structures.

DT Verification based on digital twins: verification of a target system is based on testing orsimulations performed by application of a digital twin.

SVS Verification based on self-verifying systems: this qualifier designates data-drivenverification functions where the verification function is an integral part of the target systemfunctionality (hardware and software). I.e. the system shall continuously or at specifiedintervals, during normal operation, automatically provide tamper-free data which can beused as body of evidence for classification purposes, to the Society. The delivered datashall in general provide/indicate conclusions on the acceptance criteria. The target system/SVS shall have the capability to transfer the generated SVS verification data over an API orother digital interface using documented methods and data structures.

27.5.2 The target systems (TS) defined in Table 26 apply for the DDV class notation. In case of specificagreement between a customer and the Society it may be accepted to apply a DDV method also on systemsnot listed in Table 26.

Table 26 Target systems (TS) for DDV

Qualifier for targetsystem (TS) Description Rule references

DP Dynamic positioning system DNV-RU-SHIP Pt.6 Ch.3 Sec.1, DNV-RU-SHIPPt.6 Ch.3 Sec.2

TAM Thruster assisted mooring control system DNV-OS-E301

PMS Main electric power control and monitoringsystem

DNV-RU-SHIP Pt.4 Ch.8

SPT Steering, propulsion and thruster controland monitoring system

DNV-RU-SHIP Pt.4 Ch.5, DNV-RU-SHIP Pt.4Ch.10

ICS Integrated control and monitoring system DNV-RU-SHIP Pt.4 Ch.9

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Qualifier for targetsystem (TS) Description Rule references

DRILL Drilling and well control and monitoringsystem

DNV-OS-E101

BOP Blowout prevention control arrangement DNV-OS-E101

Crane Crane control and monitoring system DNV-RU-SHIP Pt.6 Ch.5 Sec.3, DNV-ST-0377,DNV-ST-0378

NAUT Nautical system DNV-RU-SHIP Pt.6 Ch.3 Sec.3, DNV-RU-SHIPPt.6 Ch.3 Sec.4, DNV-RU-SHIP Pt.6 Ch.3 Sec.5

Guidance note 1:

The referenced rules or standards provide more specific requirements for the systems. DNV-RU-SHIP Pt.4 Ch.9 or DNV-OS-D202provides generic common requirements to, and is applicable for, all systems listed above.


Guidance note 2:

Example notation, when applying DDV method DSA for dynamic positioning and nautical safety: 1A Column-stabilised drillingunit DYNPOS(AUTR) DDV(DP[DSA], NAUT[DSA]).



28 Remote witnessing

28.1 IntroductionRemote audio and video live streaming capabilities may facilitate efficient communication between unit andshore, and can be used for multiple purposes typically related to maintenance and inspections activities. TheREW solution may be used by different stakeholders, e.g. owner, authorities, equipment manufacturers,warranty surveyors and the Society when found acceptable.

Guidance note:

Acceptance should be based on specific agreement with the involved parties. The possibility for using the installed solution dependson factors such as installation capabilities, unit to shore connectivity, inspection scope, time needed, and target system criticalityand complexity. It should be noted that remote inspection based on live streaming may also be accepted on units which do nothave a REW additional class notation, provided acceptable live streaming capabilities.


28.2 ObjectiveThe objective with the REW notation is to provide efficient solutions for remote audio and video livestreaming and/or sharing of operational system human machine interface (HMI) from unit to shore.

28.3 ScopeREW sets requirements to equipment, operation and technical installation of remote witnessing solutionson board, such as unit to shore live streaming of remote audio, video and operational HMI that enablesinteraction between unit and shore personnel.

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28.4 ApplicationThe additional notation REW is applicable for units in operation and to newbuildings.

28.5 Class notationsUnits built in compliance with the requirements of this section may be assigned the additional class notationREW with relevant qualifiers, see Table 27.

Table 27 Class notation and qualifiers


<None> Onboard arrangementfor live streaming ofactivities at bridge, deck,accommodation, enginespaces, and control rooms.The coverage may alsoinclude specified confinedspaces, like tanks andboilers.

HMI1 Including arrangementfor online sharing ofonboard target systemsscreens/views, to a remotewitnessing centre.

REW

HMI2

Connectivity, tools andinfrastructure enablingdirect online witnessingfrom a remote location.

Including arrangement foronline sharing and access toonboard target systems HMIfrom a remote witnessingcentre to enable remotecontrol of the target systemHMI interface.


29 Non-self-propelled

29.1 ObjectiveThe objective of the class notationNon-self-propelled is to indicate that the unit is not equipped withpropulsion and steering arrangements for independent transits.

29.2 ScopeFor non-self-propelled units the design scope for steering gear, tailshaft and thrusters for propulsion maybe adjusted in accordance with the intended use (e.g. for DYNPOS(AUTS), POSMOOR, as auxiliaryinstallation, or not used at all).

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29.3 ApplicationThe Non-self-propelled notation may be applied for any unit type and for any service objective.

30 Tailshaft monitoring

30.1 ObjectiveThe objective of TMON is to provide a standard for condition monitoring of the unit's propeller shaft andpropeller shaft bearing, including its lubrication.

30.2 ScopeThe notation describes the monitoring of the sterntube in order to give sufficient information to evaluate theoperation conditions for bearings, seals and shaft.

30.3 ApplicationTMON is applicable for conventional propulsion shafts with oil lubricated sterntube bearing.


31 Built for in-water survey

31.1 ObjectiveThe additional class notation BIS applies to units which has been prepared for in-water survey of the unitsoutside, which includes the openings in sides and bottom below the deepest load water line, bottom plugs,echo sounders and other underwater equipment.

31.2 ScopeThe BIS notation covers:

— onboard documentation— marking of ship’s side and bottom— rudder, tailshaft and thrusters.

31.3 ApplicationThe additional class notation BIS may be applied to units that are prepared for in-water survey duringbuilding.

31.4 Technical requirementsThe technical requirements in DNV-RU-SHIP Pt.6 Ch.9 Sec.1 shall be complied with.

32 Barrier management notation

32.1 IntroductionClassification requirements may be used in a barrier management system, but are not structured to bedirectly applicable in such a system. The Barrier notation provides a direct link between class requirements

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and safety and environmental critical elements (SECE) of a barrier management system that address majoraccident hazards for a unit or installation.

32.2 ObjectiveThe objective of Barrier is to highlight that the unit or installation has a structured safety barriermanagement system in place and to document that classification is used to follow up safety critical barriers.

32.3 ScopeThe Barrier notation may be given to a unit or installation that have a verified safety barrier managementsystem in place. For classification the notation is limited to the technical safety barriers, and with qualifiersas shown in Table 28. The Barrier notation is using SECEs that shall be pre-defined for each project, andverification will be done toward those SECEs. Depending on the qualifier selected the SECEs will cover classscope or be extended and customised to cover customer defined major accident hazards.

32.4 ApplicationThe notation may be applied to units or installations where a structured safety barrier management system isimplemented. The basic notation (without qualifier) will use the requirements specified in the relevant classrules, and the SECEs covered by Barrier will be limited to the chosen class notations as shown in Table 29.In addition statutory scope, limited to technical safety barriers, may be included where DNV is appointed asrecognised organisation. For qualifier Custom the scope may be extended and adjusted to cover unit specificloads and hazards (e.g. explosion loads, damage inclination) in cooperation with owner.

Table 28 Class notation for barrier

Class notation Qualifier Description

<none> Scope based on selected notations for unit and parametersspecified in relevant offshore standards. In addition statutoryscope may be included where DNV is appointed as recognisedorganisation (limited to technical safety barriers).

Barrier

Custom Unit specific details and evaluations performed to customize theperformance standards and verification activities, see [32.6].

32.5 Technical requirementsIn order to obtain the basic Barrier notation the following steps shall be followed:

1) The generic list in Table 29 is used to define the relevant SECEs for the unit.2) DNV will develop a verification scope based on the selected class notations and will limit the verification

requirements to class and statutory scope.3) The verification activities are followed up and documented during design, construction, and

commissioning.

Guidance note:

Shelf states may have specific requirements to content of barrier reporting. Barrier(Custom) may then be applied and scope willbe agreed on a case by case basis.

Where the shelf state does not require positive reporting the class approval letters may be used as documentation.

Statutory scope will vary based on the selected flag and statutory regime (i.e MODU Code, SOLAS etc.).


The generic SECE breakdown in Table 29 is defining typical systems found on offshore units and will form abasis for the Barrier notation. If the generic list is insufficient with respect to the major accident hazards for

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the unit the notation Barrier(Custom) may be selected, where additional SECEs may be included and thescope adjusted accordingly as described in [32.6].The SECE list in Table 29 is taking into consideration the list of major accidents and corresponding majoraccident hazards in DNV-OS-A101 Ch.2 Sec.1 [3] and DNV-OS-A101 App.B [1.5.1].

Guidance note:

Not all SECEs listed in Table 29 are relevant for all types of units.


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Rules for classification: O

ffshore units — DNV-RU-OU-0101. Edition July 2021


DNV AS

Table 29 List of safety and environmental critical elements

SECE no. Name Description Reference to DNVoffshore standards *

Class notation(s)covering scope

SECE-01 Flare, relief andblowdown system

The system shall prevent escalation of hazard andaccident situations by quickly reducing the pressurein hydrocarbon containing equipment, and it shall bedesigned so that the release of gas does not harmpersonnel or equipment.

DNV-OS-A101

DNV-OS-E201

1A

PROD

SECE-02 Fire and gasdetection system

The fire and gas detection system shall ensure quickand reliable detection of fires and gas leaks. It shallalert personnel and allow safety and control actions tobe initiated manually or automatically to minimize theprobability of personnel exposure, explosion and fire.

DNV-OS-D301

DNV-OS-D202

1A

SECE-03 Process safety The process safety system shall be designed to enter ormaintain a safe state when a fault occurs and shall beable to operate independently of other systems onboard.

DNV-OS-E201 PROD

SECE-04 Active fireprotection

Active firefighting system shall combat fires andsuppress gas explosions if this can result in lowerexplosion pressure. Active fire protection systems shallbe provided throughout the facility appropriate to the firehazard identified for each protected area and be capableof manual, automatic and/or remote actuation.

DNV-OS-D301 1A

SECE-05 Passive fireprotection

Passive fire protection (PFP) shall ensure that relevantstructures, piping and equipment have adequate fireresistance with regard to load bearing properties,integrity and insulation properties during a fire such thatunacceptable escalation or spreading of fire is prevented.

Fire divisions shall be provided to prevent a dimensioningfire from escalating into surrounding areas.

DNV-OS-D301 1A

SECE-06 ESD system The emergency shutdown (ESD) system shall havedefined and selectable levels of activation to preventescalation of abnormal conditions into a major hazardousevent, and to limit the extent and duration of any suchevents that do occur. (Note: ESD system is closely linkedto SECE-14 Ignition control).

DNV-OS-A101

DNV-OS-D201

DNV-OS-D202

1A

SECE-07 Escape,evacuation,safety and rescueequipment

Effective escape, shelter and evacuation facilities shall beprovided to safeguard all personnel, as far as practicable,at all times when the unit or installation is manned.

DNV-OS-A101 1A

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SECE-08 PA, alarm andemergencycommunication

Alarm and communication system for use in emergencysituations shall:

— alert, inform and guide personnel as quickly aspossible in the event of a hazardous or emergencysituation

— provide two-way communication of informationregarding emergency events to the central controlroom (CCR) or emergency control centre (ECC)

— provide communication of requirements foremergency action to all personnel and providetwo-way communication between the emergencycontroller and the emergency response team

— allow the coordination of rescue, recovery andemergency assistance.

DNV-OS-A101

DNV-OS-D201

DNV-OS-D202

1A

SECE-09 Emergency powergeneration, UPSand emergencylighting

The purpose of the emergency power generation, UPSand emergency lighting is to provide the following:

— electrical power when main power generation isunavailable.

— emergency electrical power supply for a specificperiod of time for systems required to be in operationduring or after a major hazardous event.

— sufficient lighting for evacuation and escape in anemergency situation.

DNV-OS-A101

DNV-OS-D201

DNV-OS-D202

1A

SECE-10 Hydrocarboncontainment

The containment function shall prevent release ofhydrocarbons, other flammable fluids, and/or harmfulfluids (chemicals, toxic gases, etc.).

DNV-OS-E201 1A

SECE-11 Natural ventilationand HVAC system

The purpose of natural ventilation and HVAC system isto maintain acceptable working and living environmentfor the personnel and non-detrimental conditions forequipment and machinery. Furthermore it shall preventescalation of abnormal conditions into a major hazardousevent, and to limit the extent and duration of any suchevent that do occur.

DNV-OS-A101

DNV-OS-D101

1A

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SECE-12 Inert gas, gasfreeing and cargotank vent system

The inert gas, gas freeing and cargo tank vent systemshall:

— ensure inerting of tanks and void spaces within thecargo area to reduce the probability of a flammablemixture and potential for ignition.

— provide an environment for inspections and tankentry of cargo tanks.

— provide over- and under-pressure relief for the cargotanks during loading, offloading and production.

DNV-OS-A101

DNV-OS-D201

1A

INERT

SECE-13 Structure (topside) Load bearing structure shall withstand all loadingsituations under normal operation and ensure structuralintegrity after a design accidental event.

DNV-OS-E201 PROD

SECE-14 Ignition control The ignition probability of flammable liquids andexplosive gas atmospheres shall be minimized byrendering the sources of ignition harmless or reducingthe likelihood of occurrence of effective ignition sources.

DNV-OS-A101

DNV-OS-D201

DNV-OS-D202

1A

SECE-15 Hull structuralintegrity

The hull structural integrity goals include:

— to provide a buoyant watertight envelope withsufficient structural strength to support, as relevant,the turret/ mooring system, topside structure, drillingfacilities, equipment, and living quarters

— to resist loads arising from all conditions includingnormal, extreme environmental occurrences, andaccidental events for the stipulated design life

— to contain the hydrocarbons, ballast and other fluidswithin the confines of the hull

— to resist loads during transportation to offshorelocation and during offshore installation.

DNV-OS-B101

DNV-OS-C101

DNV-OS-C102

DNV-OS-C103

DNV-OS-C104

DNV-OS-C105

DNV-OS-C106

DNV-OS-C201

DNV-OS-C401

1A

SECE-16 Navigation aids andcollision avoidance

Navigation aids and collision avoidance systems shall:provide visual and audible warning of the presenceof the unit to marine traffic and a visual warning tohelicopters approaching the installation, and provideearly warning of approaching vessels in order to allowtime for emergency actions to minimise the risk ofcollision.

DNV-OS-D202 1A

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SECE-17 Ballast and bilgesystem

The ballast and bilge system shall enable the unit toeffectively control water level in ballast tanks and emptycompartments using the bilge system. Ballast and bilgeare also be used to right the unit in case of inclinationand empty water from the hull in case of ingress.

DNV-OS-D101 1A

SECE-18 Lifting appliances Cranes, lifting facilities and devices shall safely lift andmanoeuvre all loads that cannot safely be manhandledby personnel.

DNV-ST-0378 Crane

SECE-19 Helideck The helicopter deck shall provide:

— safe landing area for helicopters including structure,marking and lighting

— safe means of entering/exiting helicopter irrespectiveof helicopter position on deck

— fire-fighting capacities— safe means for refuelling helicopter (if present).

DNV-OS-E401

DNV-RU-SHIP Pt.6 Ch.5Sec.5

HELDK

SECE-20 Position keeping/control

The position keeping/control system shall (as relevant):

— resist and transfer mooring loads to the turret/hullarising from all conditions including normal, extremeenvironmental occurrences, and accidental eventsfor the stipulated design life while ensuring positionkeeping is continuously maintained

— enable dynamic position keeping/control in alldesign conditions. The relevant parts of the powergeneration system to ensure the availability of the DPsystems are included.

DNV-OS-E301

DNV-RU-SHIP Pt.6 Ch.3

POSMOOR, or

DYNPOS, or

DPS

SECE-21 Turret The turret structure and system shall:

— support and transfer mooring and riser loads to hullstructure

— allow for weather vaning/heading control of unit— transfer products to and from wells.

DNV-OS-A101

DNV-OS-C101

DNV-OS-D201

DNV-OS-E301

1A

POSMOOR

SECE-22 Drain system The purpose of the drain system is to provide measuresfor containment and proper disposal of flammable liquidspills as well as handling rainwater and firewater.

DNV-OS-D101 1A

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SECE-23 Layout andexplosion barriers

The unit shall be divided into different areas accordingto the type of activities that will be carried out and theassociated hazard potential. Areas of high risk potentialshall be segregated from areas of low risk potential,and from areas containing important safety functions.Incident escalation between areas shall be avoided.

DNV-OS-A101 1A

SECE-24 Stability andwatertight integrity

The system providing the unit with control of watertightintegrity and stability shall provide the unit with a robustway of ensuring that the unit stays within the acceptedoperational parameters.

DNV-OS-C301 1A

SECE-25 Well control anddrilling hoistingsystems

The well control system shall be able to isolate thehydrocarbon fluids between the well and the unit andbe able to control the well by primary and secondarywell control means during drilling operations, wellcompletions and interventions during the well life cycle.The drilling hoisting systems shall safely lift andmanoeuvre all drilling related loads including emergencymanoeuvring (where relevant).

DNV-OS-E101 DRILL, or

WELL

SECE-26 Jacking system The jacking system shall be able to withstand theforces acting upon it from all operational phases and forexceptional loads within the design criteria specified forthe system.

DNV-OS-C101

DNV-OS-C104

DNV-OS-C201

DNV-OS-D101

1A

* Where requirements to have not been published in the referenced DNV offshore standards, performance standards for that SECE will be developedon a case by case basis.

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32.6 Development of unit specific performance standardsWhere there is a need to expand and tailor-make the scope to cover unit or installation specific requirementsthe Barrier(Custom) notation shall be selected. The workflow will then be as listed below:

1) Safety studies and HAZID's are performed to establish a list of the unit's major hazards.2) A list of safety and environmental critical elements/barriers for the major hazards is developed.3) Performance standards covering the barriers are established. The list in Table 29 will be used to the

extent possible, but will be modified as needed. The work includes developing each performancestandard into specific requirements that can be verified during design, construction, commissioning andsubsequent operation.

4) The activities are followed up during design, construction, and commissioning.

It is the owners responsibility to provide the necessary documentation in order to develop customisedperformance standards and verification activities. The development of the performance standards andverification activities will be done by DNV in cooperation with the owner.The workflow to modify generic performance standards and to create unit specific performance standardswith corresponding requirements is illustrated in Figure 1.

Figure 1 Workflow for development of Barrier(Custom) verification activities

33 Abate

33.1 IntroductionThe Abate notation addresses the management, identification, assessment and implementation of measuresintended to lead to reduced levels of greenhouse gas (GHG) emissions on offshore installations. It is amodularised notation comprising discrete qualifiers which may be selected individually or in combination.Award of the notation requires implementation of a management system which specifically addressesemission reduction and which identifies and assesses relevant abatement measures.

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33.2 ObjectiveThe objective of the notation is to permit documentation by a structured approach of the assessment of anoffshore installation with regard to GHG emissions and provide a record of measures implemented.

33.3 ScopeTheAbate notation with associated qualifier(s) may be assigned to an offshore installation which has carriedout an abatement assessment in accordance with a documented emission management system and whichhas implemented the GHG abatement measures as required in these rules. The qualifiers are as shown inTable 30.

Table 30 Abate notation and qualifiers


P Power plant optimised to limit emissionsAbate GHG emission

abatement CC Carbon capture plant installed

33.4 ApplicationThe notation may be assigned to offshore installations engaged in oil and gas exploration and production. Theprinciples involved may however be applied to other floating installations.

33.5 Technical Requirements

33.5.1 GeneralThe Abate notation requires that measures to abate GHG emissions shall be identified and assessed.Identification and assessment of potential abatement measures shall be based on a structured approach suchas the DNV marginal abatement cost curve (MACC) approach or equivalent. Identified measures shall beassessed for suitability of application based on a defined set of parameters. Such parameters would typicallyinclude:

— reliability— weight/space demands— level of technology maturity— suitability for location— capex/Opex.

33.5.2 Emission Management

33.5.2.1 The owner shall include emission management as part of the overall company managementsystem. The management system shall provide the technical, commercial and environmental justification forthe management of emissions.

33.5.2.2 Emission management shall follow similar principles as those documented in ISO 50001 whichaddresses energy management, i.e.

— a policy with respect to emission abatement— targets and pathways to meet the policy— how to use data to better understand and make decisions about emission abatement— means to measure the results

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— procedure to review how well the policy works— feedback to continually improve emission management.

33.5.2.3 Where applicable, the results of the emission abatement consideration shall be incorporated intospecification, design and procurement and operational activities.

33.5.2.4 A thorough review of best available technology (BAT) should be carried out at least at 5 yearintervals and will be reviewed as part of our renewal survey. maintenance of the Abate notation in theoperations phase will involve review of continued application of the emission abatement policy, with relationto for example:

— monitoring— application to modifications/equipment change-out— assessment of best available technology.

33.5.3 Abate(P) - Power system emission abatement

33.5.3.1 An emission philosophy related to releases from power/heat generation shall be specificallydocumented as part of the emission management system.

33.5.3.2 Measures identified to optimize/reduce energy demand shall be implemented. These are to giveconsideration to power management and power system design. The assessment of measures shall considerthe currently intended and future operational situations.

33.5.3.3 A system to monitor power consumption shall be put in place to confirm assumptions and identifypotential for energy performance improvement.

33.5.3.4 Measures shall be taken to optimize efficiency of power/heat generation. Combined cycle energygeneration/exhaust heat recovery shall be implemented.

33.5.3.5 Where assessment shows that use of sources of power with lower green house gas emissions aspart or all of the power supply is feasible and practical this shall be implemented.

33.5.3.6 Procurement shall consider selection of equipment based on efficiency and emission levels.Guidance note:

Some items which may be specifically addressed would include:

— optimisation and configuration of engines/turbines

— pump and compressor selection and configuration to optimize power demand

— use of variable speed drives (VSDs) to accommodate variations in process operation

— recovery of waste heat by installation of waste heat recovery units (WHRUs)

— use of energy efficient lighting and maximum use of natural lighting.


33.5.4 Abate(CC) - Carbon capture of power generation emissions

33.5.4.1 Installations which install carbon capture technology which is capable of removing a majority of theCO2 produced in power/heat generation will be awarded the qualifier CC.

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34 Performance standard for protective coatings

34.1 IntroductionAdditional class notation COAT-PSPC gives requirements for corrosion prevention (coating) of tanks, spacesand voids, in accordance with the IMO performance standard for protective coating. These requirements willalready be covered by main class rules for SOLAS compliant units. The IMO-PSPC standard also apply toMODU Code compliant units for ballast tanks, and can be voluntarily requested by the owner for cargo tanksand voids to show compliance with IMO-PSPC.

Guidance note:

The corrosion protection methods described in this section also include alternative corrosion protection methods which are in linewith requirement of SOLAS Reg. II-1/3-11. These alternative corrosion protection methods are not limited to coatings, and includethe use of corrosion-resistance steels in the cargo oil tanks.


34.2 ScopeThe scope of additional class notation COAT-PSPC is to add an increased level of safety related to corrosionprevention in tanks, areas and spaces, in accordance with specified coating system standards, alignedto statutory (SOLAS and MODU Code) requirements, and IMO/IACS interpretations. The rules in thissection are considered to satisfy the requirements for corrosion prevention (coating) of tanks, spaces andareas, applicable for SOLAS and MODU Code compliant units, and when compliance with the IMO-PSPCstandard has been requested by the owner. The design criteria includes qualifiers, that denotes additionalrequirements for: seawater ballast tanks, cargo oil tanks and void spaces, for all types of units. A coatingtechnical file (CTF) and an inspection agreement shall be prepared by the shipyard and shall be reviewed bythe Society. Qualifications for coating inspectors, type approval and inspection requirements are included inthe scope.

34.3 Application

34.3.1 The additional class notation COAT-PSPC is intended for SOLAS and MODU Code units, but may beassigned to all types of units. In cases where the difference between the requirements given in this sectionand the latest edition of the IMO/IACS documents given as reference documents in DNV-RU-SHIP Pt.6 Ch.1Sec.9 [1.5], the content of IMO/IACS documents and interpretations shall be applied.

34.3.2 The class notation COAT-PSPC is an optional class notation intended for:

— use prior to the IMO requirements enter into force, or— Units or installations that are not required to comply with IMO conventions ( e.g. vessels with GrossTonnage (GT) below the limits set in the different SOLAS regulations, floating wind farm installations,floating fish farms, floating infrastructure etc.), or

— spaces in units that are not covered by MODU Code (Code for the construction and equipment of mobileoffshore drilling units).

34.3.3 The application of the class notation COAT-PSPC is voluntary as compliance is already documentedby issuance of Safety Construction Certificate or MODU certificate, although it may be used to document orvisualize compliance with both mandatory and non-mandatory SOLAS or MODU regulations:

— the class notation COAT-PSPC is mainly intended for units where the IMO PSPC’s are not SOLAS or MODUrequirements

— the class notation COAT-PSPC may also be requested for units following SOLAS or MODU requirements,however, this will then be more for visualisation purpose as compliance is already documented by issuanceof the units’ certificate.

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34.4.1 COAT-PSPCUnits built in compliance with the requirements as specified in Table 31 may be assigned the additionalnotation related to structural strength and integrity as follows:

Table 31 Additional class notation - COAT-PSPC


B B requirements for dedicated seawaterballast tanks of all types of units

C C requirements for crude oil tanks(corrosion protection by coating)

CACA requirements for crude oil tanks(corrosion protection by alternativemeans)

COAT-PSPC

V

Additional requirements for corrosionprevention of tanks and spaces/areasfor newbuildings. The notation providescompliance with SOLAS Reg. II-1/3-2and IMO Res. MSC.215(82); andSOLAS Reg. II-1/3-11 and IMO Res.MSC.288(87) and MSC.289(87)

V requirements for void spaces of alltypes of units

Guidance note:

The qualifiers may be combined, e.g. a unit may have a class notation COAT-PSPC(B, C, V).


34.5 Technical requirementsThe technical requirements in DNV-RU-SHIP Pt.6 Ch.1 Sec.9 shall be complied with.

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APPENDIX A INTRODUCTION TO OFFSHORE CLASSIFICATION

1 IntroductionThis appendix is informative and should not be understood as rule requirements. The appendix explains thesystem of classification, how it works, conditions of validity, and its interaction with statutory control. Thisinformation is to a large extent implied by the rules, but a brief clarification of the essential points in oneplace is considered useful.

2 The classification system

2.1 The classification process and its limitations

2.1.1 Classification is a system for safeguarding life and property at sea, and the environment due tooperational consequences. It implies a process of verifying offshore objects against a set of requirements.The requirements are laid down in the rules and standards established by DNV. Classification has gainedworldwide recognition as an adequate level of safety and quality.

2.1.2 Classification implies an activity, in which a unit is surveyed during construction based on designapproval, tested before being taken into service, and surveyed regularly during its whole operational life untilit is scrapped. The aim is to verify that the required rule standard is built in, observed and maintained.

2.1.3 Classification is not performed as a substitute for the customer's own quality and safety control andrelated duties, or the customer's obligations to third parties, nor to relieve the customer of any consequencesof default. Classification implies that rule requirements are verified at regular intervals. It is the owner'sresponsibility to maintain the unit so as to comply with the rules at all times.

2.1.4 DNV keeps complete files on all classed ships and units covering the documentation required by therules. Reports will not be disclosed to any party, apart from the national authorities involved, without theowner's consent. DNV also undertakes all reporting to national authorities required in connection with thesafety certificates.

2.2 Who needs classification?Classification serves as verification system for a number of parties who have special interest in the safety andquality of units, such as:

— National authorities, who accept units for registry, or let units into their territorial waters, need assurancethat they are safe and represent a minimum hazard to their surroundings.

— Insurance underwriters require units to be classed in order to give insurance.— Owners, who need the technical standard of the rules as basis for building contracts and to document theunit's standard when seeking insurance or financing, or when hiring out or selling the unit.

— Building yards and sub-contractors use the rules as a tool for design and construction, as required by theircustomer.

— Finance institutions use classification as a documented indicator of the unit's value.— Charterers require confirmation of the unit's standard before hire.

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2.3 Recognition of DNVDNV is recognised as an international classification society by virtue of its position in the marine industry,founded on the following criteria:Independence:

— By classing a substantial share of the world fleet and through high equity and financial independence, theeconomic basis for independent decisions in classification matters is ensured.

High technical competence:

— Extensive research and development in class related fields sustain a process where the rules andstandards are continuously extended and improved in pace with new technology and experience gained.Research and development also contributes to a high level of staff competence.

— Continuous monitoring of a large classed fleet ensures valuable feedback from casualties, damageincidents and operational experience in general. Analyses of these data are one important source ofimprovements of the rules.

— DNV runs a scheme for training and qualification of its technical personnel to ensure correct, uniformquality of approval and survey work throughout the organisation.

Worldwide survey station network:

— DNV operates survey stations all over the world. Efficient reporting and information systems support theoperations, and provide service to customers and national authorities.

2.4 Responsibility for safety at sea

2.4.1 National law institutes national authorities' responsibility for the total safety control of units flying thenational flag. Classification cannot in any way relieve the national authorities of that responsibility.

2.4.2 National authorities may use the classification system and DNV's worldwide survey station networkas their executive branch for safety control. The convenience of this arrangement is proved by the fact thatDNV has been delegated extensive authorisation to work and certify on behalf of the majority of the maritimenations of the world.

2.4.3 The classification system applied to delegated, statutory work offers the national authorities regularmonitoring of survey and certificate status of units flying their flag. Verification of DNV's work process andquality systems may also be carried out. In this way, national control is retained at the discretion of theauthority involved.

2.5 Classification of newbuildings

2.5.1 The builder initiates the process by submitting a request for classification to DNV. In response to alist of documentation issued by DNV for the specific class notations requested, the builder and sub-supplierssubmit drawings, specifications, related technical descriptions and data, including specification of materials asrequired by class, for approval.

2.5.2 After examining the above documents, DNV informs the builder and sub-supplier whether thedesign and arrangement of structure, machinery and equipment is acceptable. If not, DNV may proposemodifications needed to meet the classification requirements.

2.5.3 During the building period DNV carries out surveys at the building yard and its suppliers. To assesscompliance with the rules the Society may require additional documentation and carry out an assessmentof yard's processes, systems and personnel related to classification projects. The results of the assessment

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should be used as a basis to decide on the extent of the involvement of surveyors of the Society. They shouldbe clearly reflected in the QSP.

2.5.4 The purpose of the surveys is to verify that the construction, components and equipment satisfy therule requirements and are in accordance with the approved plans, that required materials are used, and thatfunctional tests are carried out as prescribed by the rules.

2.5.5 When DNV is satisfied that the requirements specified for the unit in question have been met, theappropriate class notation will be assigned and confirmed by the issuance of a classification certificate.Provided the requirements for retention of class are complied with, the certificate will normally have a validityof five years.

2.6 Classification in the operational phase

2.6.1 Compliance with the rule requirements in the operational phase is verified by DNV through a systemof periodical surveys. The most comprehensive survey is the one carried out in connection with the renewalof the five-yearly classification certificate. During the five year period the unit undergoes annual andintermediate surveys covering various parts, equipment and systems, depending on the class assigned.

2.6.2 In order to confirm retained validity of class, DNV evaluates the extent of possible sustained damageand verifies ensuing repairs. Deferred repairs may be accepted by DNV, but always associated with amaximum time limit.

2.6.3 The rules allow periodical surveys to contain an element of sampling. This sampling shall be sufficientto enable the surveyor to obtain a proper assessment of the condition of the unit. This assessment is basedamongst other things on type, age and technical history of the unit.

2.6.4 Results of the surveys are reported to the owners and to DNV's central office for updating records.Special findings are also recorded and used as basis for updating and development of the rules.

2.6.5 The register of vessels classed with DNV is available for supplying information on ship's and unit's mainparticulars and details of their classification.

2.7 Owner's duties

2.7.1 In order to maintain valid class the classification system specifies the following to be observed by theowner:

— The unit has to be competently handled in accordance with the rules.— The unit has to be maintained to rule standard at all times. Any conditions of class have to be carried outas specified.

— The unit has to undergo prescribed periodical and renewal surveys, as well as surveys of damage, repairs,conversions and alterations.

— DNV shall be furnished with all information that may influence its decisions in connection withclassification.

2.7.2 Failure to meet any of these requirements may lead to termination of valid class and withdrawal of allclass and statutory certificates.

2.7.3 To assist the owner in this regard DNV supplies regular status reports on certificates, surveys carriedout and becoming due, and possible conditions of class.

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3 RemunerationRemuneration is normally based on a fee system, in which DNV invoices each type of survey according toa basic scale of fees. The basic scale of fees is developed by taking into consideration the amount of workneeded to execute, process and follow up the survey in question, as well as the items surveyed. The fees alsocover investment and development costs of the rules as well as maintenance of a worldwide survey network,central service support system, etc. Price level and costs vary from country to country and are thereforereflected in the fees charged.

4 Classification support

4.1 General

4.1.1 The staff of DNV represents a significant accumulation of knowledge and practical experience inoffshore-related technical fields. This is an asset often drawn on by the industry in matters related toclassification.

4.1.2 The expertise of DNV is available to the owner at any time when needed in connection with operatingproblems, damage and casualties.

4.2 Pre-contract supportCooperation with DNV early in the design stage, before classification is requested and any contract is signed,is usually very beneficial to both yard and owner. Different technical solutions may be evaluated, thuscontributing to a more efficient unit, and ensuring that all safety aspects as specified by the rules are takencare of. In this way, expensive changes late in a project may be avoided.

4.3 In-service supportSimilar services are given in connection with units in operation. Alternative ways of repairs may be indicated,acceptable distributions of crude cargo and ballast to alleviate overstressing may be computed in case ofdamage, stability may be investigated, etc. These are typical examples.

4.4 LimitationsTwo main restrictions prevail on DNV when undertaking classification support work:

— DNV does not carry out complete, conceptual design of units. In cases where DNV has been involved indesign support, the plans and calculations shall still be independently evaluated by DNV before beingaccepted for classification purposes.

— Information received from customers in connection with assignment of class is not disclosed and used inclassification support work.

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CHANGES – HISTORIC

July 2020 edition

Changes July 2020, entering into force 1 January 2021Topic Reference Description

Descriptive class notation Smart Ch.1 Sec.3 [2.12.5] New descriptive notation Smart forclass products related to technologicalfeatures considered as smarttechnologies in offshore and marineapplications.

Clarification of classification scope forstructures

Ch.2 Sec.1 [4.1] Defined class scope for structures tobe project specific, and clarified scopefor foundations.

Fire protection in cargo area Ch.2 Sec.7 Table 10 and Ch.2 Sec.7[12.2]

Added new qualifier C for additionalfire protection in cargo area.

Added new qualifiers NUM andSENS as an option of reusing andpreparing the FMS models for in-service calculation of fatigue wear.

Fatigue methodology specification Ch.2 Sec.7 [17]

Added reference to DNVGL-RU-SHIPPt.6 Ch.9 Sec.6 for constructionmonitoring for FMS notation.

Design ambient temperature - for unitsoperating in winter in polar waters

Ch.2 Sec.7 [20.1.2], Ch.2 Sec.7[20.1.3] and Ch.2 Sec.7 Table 16

Editorial change to clarify DATnotation.

Update of notation Cyber Secure Ch.2 Sec.7 [24] Updated Cyber Secure to correspondto updated DNVGL-RU-SHIP Pt.6 Ch.5Sec.21.

July 2019 edition edition


Substitute selected definitions andterms to those defined by DNVGL-CG-0550..

Ch.1 Sec.1 Selected definitions and terms havebeen substituted by references toDNVGL-CG-0550.This applies also to Ch.1 Sec.2, Ch.1Sec.4 and Ch.1 Sec.6.

Introduce heading control HC qualifierfor POSMOOR notation.

Ch.2 Sec.7 Table 2 Added POSMOOR(HC) qualifier forheading control.

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DNV AS


HELDK notation qualifier update toenable individual selection of qualifiers.

Ch.2 Sec.7 [7] The HELDK qualifiers S, H, F are nolonger interlinked, and can be chosenindependently.

New class notation Barrier for barriermanagement.

Ch.2 Sec.7 [25.5] New notation Barrier has beenincluded as an optional class notation.The content includes a list ofperformance standards that canbe used when developing a barriermanagement system for an offshoreunit.

Use of offshore cranes as yard cranesduring construction.

Ch.2 Sec.7 [10.3.1] and Ch.2 Sec.7[10.4.1]

Certification requirements whenoffshore cranes are used as yardcranes during construction is clarified.Additional survey and testingrequirements of cranes before deliveryof unit to owner is added.

New qualifier for additional fireprotection notation.

Ch.3 Sec.7 Table 10 Added qualifier M-P (enhanced fireprotection for machinery spaces) toadditional fire protection notationF(M-P).

July 2018 edition


Ch.2 Sec.1 [3] Subsection updated by referring given to DNVGL-OS-C102for ship shaped units.

Ch.2 Sec.1 [5]Subsection updated by referring to DNVGL-OS-C102for ship shaped units and replacing former specificrequirements with a notation.

Application of fabrication andmaterial standards, includingdefinition of FAB notation

Ch.2 Sec.7 [18] New subsection defining the notation FAB.

Ch.2 Sec.7 [6.5]Classification approach formodular drilling systems Ch.2 Sec.7 [15.4]

New clause stating acceptance for modulear well systems.

Cyber Security Ch.2 Sec.7 [24] New subsection covering notation on cyber security.



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January 2018 edition

Changes January 2018, entering into force 1 July 2018Topic Reference Description

Ch.1 Sec.1 [1] Updated subsection to reflect reduced scope and relation to new rulebook.

Ch.1 Sec.2 [2.5.5] Replace former clause [2.5.6] on applicable rules for retaining classwith a guidance note.

Ch.1 Sec.1Updated Ch.1 Sec.1 Table 2and Ch.1 Sec.1 Table 3 in line with reducedscope of the document removing definitions and abbreviations relevantfor the operational phase only.

Ch.1 Sec.3Updating Ch.1 Sec.3 Table 4, Ch.1 Sec.3 Table 6, Ch.1 Sec.3 Table7 and Ch.1 Sec.3 Table 8 by removing columns listing surveyrequirements reflecting reduced scope of document.

Ch.1 Sec.3 [1.2] Updated description to reflect definition of new rule book.

Ch.1 Sec.5 Entire section moved to new rule book DNVGL-RU-OU-0300 andreplaced by reference, no content changes.

previous App.C Moved entire appendix Mooring equipment acceptance standardguidance to DNVGL-RU-OU-0300.

Definition of newrule book fleet inservice

previous Ch.3 Deleted complete chapter (all content included in the new rule bookDNVGL-RU-OU-0300).

Ch.1 Sec.2 [2.5.9] Updated guidance note with reference to class guidance.

Ch.1 Sec.3 [2.6] New sub-section listing Battery and FC (fuel cell) notations.

Ch.1 Sec.3 [2.12] New clause describing descriptive notations.

Ch.2 Sec.1 [4.1.2] Updated clause describing classification scope on structural design,bringing this in line with IACS definitions of class scope.

Ch.2 Sec.1 [8.2.3] New clause covering propulsion and main power solutions includingbatteries and/or fuel cells.

Ch.1 Sec.4 [1.3.5] Updated references to shelf state to coastal state.

Minor correctionsand completions

Ch.2 Sec.7 [20.2.3] Update of Recyclable objective description.

Definition of newDRILL qualifiers Ch.2 Sec.7 [6]

Definition of new qualifiers DRILL(MPD) and DRILL(MPD-ready),supported by a new overview table of all qualifiers and updated scopedescription in line with the revised DNVGL-OS-E101.

January 2017 edition

Main changes January 2017

• GeneralThe document has been restructured as follows:



DNV AS

— The principles and procedures for classification as stated in its Ch.1 have been aligned with DNVGL-RU-SHIP Pt.1 Ch.1General regulations.

— Design references to DNV rules for classification: Ship has been replaced by references to DNV GL rulesfor classification: Ships.

— The scope of the document have been limited to floating units only, i.e. self-elevating units has beentaken out from scope with a reference to DNVGL-RU-OU-0104Rules for classification of self-elevatingunits.

• Ch.1 Sec.1 Introduction— Ch.1 Sec.1 Table 1: Included new guidance note in definition of main functions.

• Ch.2 Sec.4 Supplementary requirements for accommodation units— Ch.2 Sec.4 [3.4] Updated certification requirements for offshore gangways.

• Ch.2 Sec.6 Supplementary requirements for wind turbine installation units— Updated clause including content previously in DNV-OS-J301 and DNV Rules for classification: Ships.

• Ch.2 Sec.7 Optional class notations— Ch.2 Sec.7 [7.2]: Updated references to qualifiers of HELDK notation.— Ch.2 Sec.7 [11]: Included description of new notation Walk2work.— Removed notations DSV and OPP.

April 2016 edition

Main changes April 2016

• General— Clarification of the status of (top-side) modules and other subcontracted parts for new builts from a classservice point of view

— Further development of the unit specific In-service Inspection programme, defining three levels withpossibilities of further inspection scope depending on available documentation/performed analysis

— Correction of some minor issues improving efficiency and quality of iO-surveys— Clarification of the classification involvement for position mooring equipment with regard to CMCand in-operation surveys by introduction of a new notation ME and collecting all in operation surveyrequirements in dedicated sub-sections.

— Restructured newbuidling requirements for well intervention units to improve readability— Clarified scope for notations WELL(1) and WELL(2)— Corrected survey requirements related to Drilling and Well intervention units— Further detailed the survey requirements for well testing equipment— Introducing the new notation Crane-offshore replacing the earlier notation Crane together with specificdescriptions on new build and in operation survey requirements.

— Introducing the new notation COMF-MOU replacing the earlier COMF— Further development of alternative survey schemes for machinery, including among other a description fora reliability centred maintenance approach

— Further clarified the class requirements for bottom surveys.

• Ch.1 Sec.1 Introduction



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— [2.2] Updated definition on CMC— Tables 3, Table 6 and Table 7 further completed.

• Ch.1 Sec.3 Classification scope and notations— Table 5 and Table 8 updated with new notations— [2.9.1] New guidance note on service restrictions for self-elevating units.

• Ch.1 Sec.4 Assignment of class— [1.5.1] Updated guidance note.

• Ch.1 Sec.6 Certification of materials and components— [1.1.2] Included new guidance note.

• Ch.2 Sec.1 Design and construction requirements for 1A main class— [5.1.2] Included new clause to clarify use of rules for ships with regards to fabrication standards— [7.1] Updated sub-section in line with the introduction of the notation ME— [8.1.1] Removed anchoring and mooring equipment from listing.

• Ch.2 Sec.3 Supplementary requirements for well intervention units— [1.1] Former clause [1.1.5] on use of rules for ships included in clause [1.1.2]— [1.1.3] Text updated for clarification— [2.1.1] Clause updated and guidance note included to clarify application of rules for ships— [3.1.3] New clause to clarify the scope of class— [3.2] Former clause [3.2.5] on exhaust outlets deleted— [3.2.3] Added clause for liquid cargo in bulk with flash point below 60ºC— [4] Former sub-section [4.7] on supplementary classification requirements deleted— [4.1.1] Updated clause.

• Ch.2 Sec.5 Supplementary requirements for crane units— [4] Sub-section updated with new titles and new clause [4.2].

• Ch.2 Sec.7 Optional class notations— [3] New sub-section covering new notation ME— [4] Updated title and clause [4.1.1] in line with introduction of new ME notation— [6.1.2] Updated clause— [10] Updated section in line with new Crane-offshore notation and completing requirement descriptions— [15.1] Updated scope descriptions on WELL(1) and WELL(2)— [15.2.2] New clause— [18] Updated in line with the introduction of the new notation COMF-MOU— [24] Updated Table 19 in line with notation updates.

• Ch.3 Sec.1 General provisions— [1.1.5] Clause updated with added explanation— [1.2.1] Updated clause— [2.4.5] Bottom survey requirement and plan modified— [2.5.1] Table 1 updated in line with notation changes.



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• Ch.3 Sec.2 General requirements for structure and machinery surveys— Replaced former clause [2.2.4] by updated present clause [2.2.4]— Updated clauses [2.2.6] and [2.2.7].

• Ch.3 Sec.3 Periodical survey extent for main class— [1.2] Updated descriptions on in-service inspection programme by including new clause [1.2.2] andguidance note, and removing former clauses [1.2.3] and [1.2.4] on basis scope

— Table 3 modified with regards to scope of Leg & spudcan survey— [2.2] Removed former clause [2.2.5] on deck house examination— [2.2] Completed descriptions by adding clauses [2.2.7], [2.2.9], [2.2.10] and [2.2.11] and updatedclauses [2.2.5] and [2.2.18]

— [2.4.6] and [2.4.7] updated clauses— [2.4.12] Completed listed items— Removed former clauses [2.2.12], [3.2.1]. [4.2.11] and [4.2.12]on mooring systems as covered underSec.4 [8] and Sec.6

— Included new clauses [3.2.1] and [3.2.2]— [4.2.3] Updated clause and moved former Table 5 to guidance note— [4.2.4] Rewritten clause— [4.2.9] Updated clause and moved former Table 7 to guidance note— [4.4.4] Updated guidance note.

• Ch.3 Sec.4 Miscellaneous main class surveys— [7] Section re-written. Bottom survey split between MODU req. and Main Class survey req.— [8] Complete section re-written in line with new MS notation, moving original content related to positionmooring to Ch.3 Sec.6 [2].

• Ch.3 Sec.5 Periodical survey extent for additional service notations— [2.3.2] Updated wording— Former clause [2.2.3] and [3.2.3] deleted as replaced by requirements in Ch.3 Sec.3— Former clause [2.3.4] on piping systems deleted— [3.1.1] Clause updated, making section applicable for units with Well Intervention 1 notation— [3.1.2] Changed wording and include supporting structure— [3.1.3] Update clause in referring to the applicable WELL notation and included new guidance note— [3.2.1] Updated clause specifying specific structural items— [3.3.2] New clause on specific survey items.

• Ch.3 Sec.6 Optional class notation surveys— [2] New sub-section covering new class notation ME, including the applicable content as previous in Sec.4[8]

— [3.2.3] and [3.3.3] added requirements to documentation review— [5.4] New sub-section on (occasional) well test survey completing further requirements as previouslywere given in former [4.1] and [4.2]

— [9] Updated section including definition of survey requirements following new in line with new Crane-offshore notation

— [14] Re-written in-line with changes of sub-section [5]— [16] Updated section in line with introduction of COMF-MOU.

• Ch.3 Sec.7 Survey arrangement



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— [1] Updated clause and restructured together with [2]— [2.2] Restructured sub-section and added new guidance note on competence responsible person— [2.3] Brought in line with changes made in DNVGL-RU-SHIP Pt.7 Ch.1 Sec.7 and added new guidancenote on competence responsible person in [2.3.2]

— [2.4] Rewritten sub-section including:

— Added requirement for spare part management— More detailed requirements for continuous improvement— Replaced "Reliability Centred Maintenance" with "maintenance" analysis— More focus on maintenance supportability in the organisation— Options specified to use OEM maintenance recommendations, operational experience and/or RCM (IEC60300-3-11 only as guidance)

— More detailed requirements for implementation and functionalities in CMMS— More detailed survey requirements in general

— [2.5] Updated sub-section with more detailed requirements for the CM programme, including

— Guidance note on recommended competence level for oil laboratories added— Requirement for approved MPMS/DPMS removed, only approved CMMS will be applicable— Specified requirements for documentation related to the implementation of the arrangement— Removed case by case approval of thrusters for propulsion/positioning.

— [3.3] Updated sub-section with information about cancellation and new requirements for CMMSfunctionalities

— [4.4] Updated subsection including

— Updated qualifications requirements according to NS 415-1 to guidance note— Specified requirement for tutored inspection training with DNV GL.

July 2015 edition

Main changes July 2015

• GeneralGeneral Main changes July 2015, entering into force 1 January 2016 The revision of this document is part ofthe DNV GL merger, updating the previous DNV service specification into a DNV GL format including updatednomenclature and document reference numbering, e.g.:

— Main class identification 1A1 becomes 1A.— DNV replaced by DNV GL.— DNV-RP-A201 to DNVGL-CG-0168. A complete listing with updated reference numbers can be found onDNV GL's homepage on internet.

To complete your understanding, observe that the entire DNV GL update process will be implementedsequentially. Hence, for some of the references, still the legacy DNV documents apply and are explicitlyindicated as such, e.g.: Rules for Ships has become DNV Rules for Ships.

• Ch.1 Sec.1 Introduction— Definition of offshore installations has been updated.

• Ch.1 Sec.2 Classification principles— Cylindrical unit has been included as Structural Design notation.



DNV AS

• Ch.2 Sec.1 Design and construction requirements for 1A main class— Cylindrical unit has been included as Structural Design notation.

• Ch.3 Sec.1 General provisions— Table 1 and Table 2 have been corrected in line with Class systematics.

• Ch.3 Sec.2 General requirements for structure and machinery surveys— [4.3.9]: Description of follow up inspections for units FUI>1 has been updated.

• Ch.3 Sec.3 Periodical survey extent for main class— Table 1 and Table 3 have been aligned with Table 2.— Table 5: Second row has been updated to 'All other units' to make it more general applicable.— [2.4.4] has been updated to align with IACS UR Z15 2.8.2.— In [2.2] and [4.2] previous [2.2.5] on tank level measurements has been removed.— In [3.2] previous [3.2.3] on thickness measurements for renewal survey has been removed.— In [3.2] and [4.2] previous [3.2.5] and [4.2.17] on extension of thickness measurements have beenremoved.

— [4.2.4]: Description has been updated in line with general systematics.



DNV AS

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