1

Houston Tanker Event 2007

Houston, TX 26 March 2007

Common Structural Rules for Tankers

Gary Horn, P.E.Director, TechnologyABS Houston

2

IACS Common Structural Rules

AIM:To develop a set of unified Rules and Procedures for the

determination of the structural requirements for oil tankers and bulk carriers

3

Tanker Operations

Tanker incidents by cause 1978-2004

Source: Intertanko

4

Tanker Operations

Improvements made in tanker operational, safety and pollution performances

We have “come a long way…”

However, we wanted to employ continuous improvement principles and take the next step…

Common Structural Rules intended to enhance safety, robustness and durability.

5

IACS Common Structural Rules

CSR for Bulk Carriers Complete set of Structural Rules for

SSS and DSS Bulk Carriers

Length greater than or equal to 90m

CSR for Tankers Complete Set of Structural Rules for

Double Hull Oil Tankers

Length greater than or equal to 150m

6

Features of the new CSR

1. Rules are to result in common scantling requirements

2. Net scantling approach includes a clear link between newbuilding strength checks and in-service gauging review standards

3. Include coating standard criteria

4. Fatigue standard enhanced to include exposure to North Atlantic environment with minimum life of 25 years

5. Includes the results from industry input and feedback

7

IACS Common Structural Rules

Section Topic1

2

3

4

5

6

7

8

Introduction

Underlying Principles

Rules Applications

Basic Information

Structural Arrangement

Material and Welding

Loads

Scantling Requirements

Section Topic

9

10

11

12

A

B

C

D

Design Verification

Buckling and Ultimate- Strength

General Requirements

Renewal Criteria (SiO)

Hull Girder Ultimate Strength

Structural Strength Assessment

Fatigue Strength Assessment

Buckling Strength Assessment

Tankers

8

CSR/Tanker - Overview

Deck housesSection 11/1

Fore and Aft EndsSection 8/3 & 8/5

Plating and LocalSupport Members

Section 8/2

Longitudinal StrengthSection 8/1

Criteria AssessmentYield, Shear,

Buckling

Primary SupportMembers Inc Bhds

Section 8/2.6

Scantling Requirements

Sloshing and ImpactSection 8/6

Structural designdetails (welding,

brackets)Section 4/3

Machinery SpaceSection 8/4

Strength Assessment(FEM)

Section 9/2

Hull Girder UltimateStrength

Section 9/1

Criteria Assessment

Fatigue StrengthSection 9/3

Nominal StressApproach

Appendix C/1

Global Cargo TankStructural Strength

AnalsisAppendix B/2

Design Verification

Local Fine MeshStructural Strength

AnalysisAppendix B/3

Evaluation of HotSpot Stress for Fatigue

AnalysisAppendix B/4

Criteria AssessmentFatigue Damage

Hot Spot Stress (FE)Approach

Appendix C/2

Criteria AssessmentYield, Shear,

Buckling

MinimumRequirements

Minimum ThicknessSection 8/2

Other MinimumRequirements

Stiffness andProportionsSection 10/2

Hull Girder Inertiaand Section Modulus

Section 8/1

GeneralRule Requirements

Basic InformationSection 4

StructuralArrangements

Section 5

MaterialsSection 6

General DetailedRequirements

Section 11

Design Requirements

OperationalRequirements

Section 2/4

Design BasisSection 2/5

Loading ManualSection 8/1

Loads

Static LoadsSection 7/2

Dynamic LoadsSection 7/3

Impact and SloshingLoads

Section 7/4

Load CombinationsSection 7/6

Static LoadCombinations

Section 7/6

Static Plus DynamicLoad Combinations

Section 7/6

Dynamic LoadCombination FactorsDLCFs Section 7/6.5

Accidental LoadsSection 7/5

Design Require-ments

General Rule

Require-ments

Minimum

Require-ments

Loads

Scantling Requirement

s

Design Verification

9

CSR & Coating Performance Standards

Promote effective use of protective coatings

Provide a protective barrier to delay onset of corrosion, noting;

Corrosion wastage allowance is still included in rules Wastage allowances are not reduced due to presence of coatings

Target useful coating life of 15 years

Added benefit – facilitate in-service inspection Top coat to be a light color to easily distinguish from rust

RequiredRenewalThickness

WastageAllowance

Annual ThicknessMeasurements

Predicted corrosion

in 2.5 years (0.5 mm)

Protective Coating

10

Coating Performance Standards

IMO Res MSC.215(82) Performance Standard for Protective Coatings for Dedicated Seawater Ballast Tanks in All Types of Ships and Double-Side Skin Spaces of Bulk Carriers

IACS PR No. 34, IACS Procedural Requirement on Application of the IMO PSPC under IACS Common Structural Rules for Bulk Carriers and Oil Tankers

IACS Common Interpretation and answers to frequently asked questions on IACS website www.iacs.org.uk

ABS Guide for the Class Notation Coating Performance Standard (CPS), December 2006

11

CSR Rule Status CSR - effective date 1 April 2006

Tanker updates:

Corrigenda 1 – effective date 1 April 2006

Corrigenda 2 – effective date 1 April 2006

Rule Change Notice (RCN) No. 1 – effective date 1 April 07 or earlier if agreed between yard and owner

All future updates to follow IACS process:

PR32

Hull Panel

Project Teams

Rule updates and maintenance

Rule interpretations, Q/A

12

CST/Tanker RCN No.1 Effective 1 April 2007, may be applied earlier if agreed

by builder and owner.

Can not be partially applied

Contents:

Corrosion additions for heated cargo tanks

Clarification of heavy ballast condition

Buckling assessment in way of bottom portion

FE analysis of tight floor, girders and webs

Slenderness ratio of bulb profiles

Deck equipment welding

Tolerance of hopper knuckle connection

13

Oil Tanker Orders - Gross Tons

Oil Tanker N/C ContractsMonthly KGT

0

2,000

4,000

6,000

May-06 Jun-06 Jul-06 Aug-06 Sep-06 Oct-06 Nov-06 Dec-06 Jan-07 Feb-07

Worldwide

Source of feedback…

14

Oil Tanker Orders – Number of orders

Oil Tanker N/C ContractsMonthly Count

0

20

40

60

80

100

May-06 Jun-06 Jul-06 Aug-06 Sep-06 Oct-06 Nov-06 Dec-06 Jan-07 Feb-07

Worldwide

Source of feedback…

15

IACS Project Teams for CSR Maintenance

IACS implemented 2 Project Teams for CSR Maintenance Active from 1st June 2006 PT for Bulk Carriers: 3 JBP + 1 JTP members PT for Oil Tankers: 3 JTP + 1 JBP members Rotation among members every 2 years Running of the PT governed by IACS procedure IACS COUNCIL

HULL PANELChairman: T. Yoneya

CSR Bulk Carriers

K. ABEABS

G. CESARINEBV

S. HARADAProject Manager

ClassNK

A. Schulz-HeimbeckGL

CSR Oil Tankers

P. BAUMANSBV

F. CHENGLR

R. NAGAYAMAABS

P. SALTVEDTProject Manager

DNV

PERMANENTSECRETARIAT

R. Leslie

CSR SecretariatG-Y Han

SG/CSRNK, LR, BV, ABS

16

IACS CSR Knowledge Center/Database Centralized mechanism for collecting, categorizing and storing

questions and answers, feedback and responses, tasks and pending actions, interpretations and rule changes

Basis for future improvements

External access to Q&A and Interpretations from IACS Web Site

Transparency and consistent implementation of the Rules

17

GBS Overview

Basic Principles of Goal-Based Standards Broad, over-arching safety, environmental

and/or security standards that ships are required to meet during their lifecycle

The required level to be achieved by the requirements applied by Class Societies and other ROs, Administrations and IMO

Clear demonstratable, verifiable, long standing, implementable and achievable irrespective of ship design and technology; and

Specific enough in order not to be open to differing interpretations

IMO

18

Tier V

Tier I

Tier III

Tier IV

Tier II

IMO

IMO

IMO

IACS

Industry

GBS Overview

Procedures and Quality Systems

Requirements, Rules and Industry Standards

Verification and Acceptance criteria

FunctionalRequirements

Goals

IACS CSR for Oil Tankers & Bulk Carriers

IMO

19

Influence of GBS on future CSR developments

Structural residual strength: the CSR partially cover the GBS intent, but additional work necessary to define assumed extent of structural damage, environmental loads and acceptance criteria

Structural redundancy: the CSR partially cover the GBS intent, but additional work necessary to develop method to confirm structural redundancy and structural hierarchy

Reference to other standards: cross reference other regulations or standards

Human element Design transparency Survey and maintenance Structural accessibility Recycling considerations

20

Why Common Structural Rules?

An improved structural standard.

A major aspect in a complex yet integrated set of initiatives with the goal of improving performance for the safety of life, property and the marine environment.

21

Thank you

Common Structural Rules for Tankers

Gary Horn, P.E.Director, Technology

ABS Houston