dst 34-511- 273a - pongola/impact phase... · 2013. 8. 15. · bob branfield distribution...

DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE

SUB-TRANSMISSION LINES SECTION 7: 273A GUYED LATTICE STRUCTURES

Unique Identifier: 34-511

Type: DST

Revision: 1

Page: 3 of 20

ESKOM COPYRIGHT PROTECTEDWhen downloaded from the IARC WEB, this document is uncontrolled and the responsibility rests with the user

to ensure it is in line with the authorised version on the WEB.

Foreword

The Distribution Standard is a multi-part document whose total structure is defined in Part 0. This part of the Distribution Standard is indexed fully in Section 0.

Revision history

This revision cancels and replaces revision no 0 of document no. DST_34-511.

Date Rev. Clause Remarks

March 2012 1 -

Compiled By: B Branfield

Reformatted in the new format and no content changes

March 2007 0 Original document

Acceptance

This document has been seen and accepted by:

Name Designation

P Moyo Power Delivery Engineering GM (Acting)

V Singh Power Plant Technologies Manager

R Branfield Overhead Lines Study Committee Chairman

This standard shall apply throughout Eskom Holdings Limited, its divisions, subsidiaries and entities wherein Eskom has a controlling interest.

Development Team

The original standard was prepared by a working group comprising the following members:

Rob Stephen TAP/ Distribution Technology

Riaz Vajeth TAP

Jose Diez Serrano TAP

Aroon Sukhnandan TAP

Shelley Le Roux TAP

Dan Dukhan Eskom - Eastern

Neal Bodger Eskom - Eastern

Pete van Heeswijk Eskom - Eastern

Bob Branfield Distribution Technology

The drawings were prepared by:

Johan Scholtz Eskom Distribution Technology

ESKOM COPYRIGHT PROTECTED

B Morrison / March 2012 / Rev 1

Standard Group Technology

Title: SUB-TRANSMISSION LINES SECTION 7: 273A GUYED LATTICE STRUCTURES

Unique Identifier: 34-511

Part 6 - HV

Area of Applicability: Distribution Engineering

Documentation Type: Standard

Revision: 1

Total Pages: 20

Next Review Date: March 2017

Disclosure Classification: Controlled Disclosure

Compiled by Approved by (SCOWT SC Chairperson)

Bob Branfield

Senior Consultant

Riaz Vajeth

Line Engineering Service Manager

Date: 10/03/2012 Date: 10/03/2012

Functional Responsibility (Dx) Authorized by

Vinod Singh

Power Plant Technologies Manager

Prince Moyo

Power Delivery Engineering GM (Acting)

Date: 23/03/2012 Date: 27/03/2012



Unique Identifier: 34-511 Type: DST Revision: 1 Page: 2 of 20

ESKOM COPYRIGHT PROTECTED When downloaded from the IARC WEB, this document is uncontrolled and the responsibility rests with the user


Content

Page

Foreword ................................................................................................................................................ 3

Introduction ............................................................................................................................................ 4

1. Scope ............................................................................................................................................ 4

2. Normative references .................................................................................................................... 4

3. Definition and abbreviations.......................................................................................................... 4

3.1 Definitions ................................................................................................................................. 4

3.2 Abbreviations ............................................................................................................................ 6

4. General requirements and practices ............................................................................................. 6

4.1 Requirement for guyed lattice design in Distribution business ................................................. 6

4.2 Design requirements and philosophy ....................................................................................... 7

4.3 Optimisation requirements ........................................................................................................ 9

4.4 Construction and maintenance ................................................................................................. 9

4.5 Manufacturing ......................................................................................................................... 10

4.6 Advantages and disadvantages of guyed lattice structure ..................................................... 10

5. Testing ........................................................................................................................................ 10

6. Marking, Labeling and Packaging ............................................................................................... 11

7. Spares ......................................................................................................................................... 11

Annex A - General Arrangement of Type 273A Structure ................................................................... 12

Annex B - Summary of design criteria for type 273A tower (extract from TAP report) ....................... 13

Annex C1 - Design parameters and information for SINGLE CIRCUIT guyed 273A lattice structure for Chickadee conductor ........................................................................................................................... 14

Annex C2 - Design parameters and information for SINGLE CIRCUIT guyed 273A lattice structure for Kingbird conductor ............................................................................................................................... 15

Annex D - Test load cases for type 273A Guyed Lattice Tower ......................................................... 16

Annex E – Impact Assessment ............................................................................................................ 17






Foreword

The Distribution Standard is a multi-part document whose total structure is defined in Part 0. This part of the Distribution Standard is indexed fully in Section 0.

Revision history

This revision cancels and replaces revision no 0 of document no. DST_34-511.

Date Rev. Clause Remarks March 2012 1

- Compiled By: B Branfield Reformatted in the new format and no content changes

March 2007 0 Original document

Acceptance

This document has been seen and accepted by:

Name Designation

P Moyo Power Delivery Engineering GM (Acting)

V Singh Power Plant Technologies Manager

R Branfield Overhead Lines Study Committee Chairman

This standard shall apply throughout Eskom Holdings Limited, its divisions, subsidiaries and entities wherein Eskom has a controlling interest.

Development Team

The original standard was prepared by a working group comprising the following members:

Rob Stephen TAP/ Distribution Technology

Riaz Vajeth TAP

Jose Diez Serrano TAP

Aroon Sukhnandan TAP

Shelley Le Roux TAP

Dan Dukhan Eskom - Eastern

Neal Bodger Eskom - Eastern

Pete van Heeswijk Eskom - Eastern

Bob Branfield Distribution Technology

The drawings were prepared by:

Johan Scholtz Eskom Distribution Technology






Introduction

This part of the Distribution Standard has been prepared to establish specifications for, and promote the use of, standard designs, structures and materials for sub-transmission overhead lines.

Keywords

Sub-Transmission lines, lattice structures

Bibliography

Design report for 132kV guyed lattice tower (TYPE 273A) – S le Roux

1. Scope

This section of Part 6 of the Distribution Standard addresses a guyed lattice 132kV suspension structure for use in conjunction with other 132kV delta configuration structures already in the standard.

2. Normative references

The following documents contain provisions that, through reference in the text, constitute requirements of this standard. At the time of publication, the editions indicated were valid. All standards and specifications are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the documents listed below. Information on currently valid national and international standards and specifications can be obtained from the Information Centre and Technology Standardization Department at Megawatt Park.

IEC 60050-466:1990, International electrotechnical vocabulary — Chapter 466: Overhead lines.

TRMSCAAC1:Rev.3, Transmission line towers and line construction.

Transmission Line Loading Part I: Recommendations and Commentary (Nov 1990)

Transmission Line Loading Part II: Appendices (Nov 1990)

DST_34-1209: Distribution Standard, Part 6: Sub Transmission lines, Earthing.

DSP-34-1657: Specification for conventional stay planting, percussion stay and rock anchor installation and testing

3. Definition and abbreviations

3.1 Definitions

angle strain structure: A structure at the beginning or end of a section, which carries the resultant conductor tensile forces where the line changes direction

cantilever load: A load applied to a supporting member which induces a bending moment at the support.

conductor uplift (minimum weight span): The upward vertical load imposed by the conductor at a support resulting from the gradient to the adjacent supports and conductor tensions.






dead man anchor: A stay anchor consisting of a single block of concrete into which the stay rod or anchor bolts are embedded.

earth conductor: A conductor of low impedance that provides an electrical connection between a given point in equipment (an installation or system) and an earth electrode.

earth electrode : One or more horizontal conductors and/or earth rods bonded together and embedded in the earth for the purpose of making effective electrical contact with the general mass of the earth and to act as a path for the discharge of either lightning or fault currents

earth rod: An earth electrode consisting of a metal rod driven onto the ground

electrical/clashing span: The maximum span considering the conductor configuration and spacing adopted to ensure midspan electrical clearance.

factor of safety (of any component): The ratio of a component’s failing load to the maximum safe working load for which it is designed.

foundation: A structure set in or on the ground to which the base of a support is attached to provide the necessary anchorage to withstand all applied loads

guyed structure: A structure whose stability is ensured by stays.

horizontal line post insulator: A rigid insulator with metal base and end fittings, which is mounted horizontally onto a structure and is capable of withstanding cantilever loads.

intermediate structure: A structure that supports the overhead line in a section by means of either post or suspension insulators.

long-rod insulator : A single insulator designed for tensile loading to support an overhead line conductor under tension or suspension.

planting centres: The distance between the centres of the support members at ground level.

pole: A vertical single member support made from wood, concrete, steel or other material.

section: The portion of line between two structures onto which the conductors are made off

shield wire: A conductor connected to earth at some or all structures, which is normally (but not necessarily) suspended above the line conductors to provide a degree of protection against lightning strikes.

soil nomination: The process by which a professional civil engineer categorises soils according to their bearing capacities

soil type: The classification of soils according to their pressure bearing capabilities.

span: The part of the line between two consecutive points of support of a conductor.

span length: The horizontal distance between two adjacent supports.

stay: A steel wire, rope or rod, working under tension, that connects a point of support to a separate anchor, or connects two points of a support.

stay anchor: A device, usually buried in the ground, so installed as to provide a firm point of attachment for resisting uplift.

stay rod assembly: A rod and plates that are buried to a specific depth and compacted so that they can carry the required stay loadings of the structure.

strain structure: A structure at the beginning or end of a section, which carries balanced conductor tensile forces.

structure, support (of an overhead line): A device designed to carry, through the insulators, a set of conductors of the line.






suspension structure: A structure that supports the overhead line in a section by means of suspension insulators.

temporary stay: A stay, of equivalent strength to a permanent stay, that is used to temporarily support a structure during construction or stringing activities.

tension imbalance: The condition that exists when the loads on each side of the tower differ due to conductors tensions.

terminal structure: A structure that carries the total conductor tensile forces on one side of the tower.

test hole : A hole excavated near a proposed tower to determine the soil type for foundation purposes.

ultimate design load/ultimate tensile strength: The load that all elements should just sustain without failure during any specified operation.

weight span: The horizontal distance between the lowest points of the conductor on either side of the support.

wind loading: The horizontal load imposed by wind pressure applied to any element of the overhead line, with or without ice loading.

wind span: Half the sum of the adjacent spans on each side of a support.

working load of the foundation: The load transferred from the tower to the foundation for given load conditions excluding factors of safety or overload factors.

3.2 Abbreviations

TAP: Trans Africa Projects

UTS: Ultimate tensile strength

4. General requirements and practices

4.1 Requirement for guyed lattice design in Distrib ution business

It is widely recognised that guyed structures are the most economical types of structure design due to the large strength contribution by relatively cheap guys. At present the only guyed structure at Distribution level is the guyed tubular structure. (D-DT-7621) This structure is however more suited to Chickadee conductor and spans not exceeding 330m.

KZN survey and design staff considered the topography where future 132kV projects are situated and identified a need for a guyed structure with a capacity larger than the present widely used type 255A intermediate tower. Through a research project TAP was appointed to develop a structure in conjunction with the inputs from a development team. The initial scope was for the development of a guyed lattice structure with a windspans and weightspans as set in the table below. At present the suspension structure will be used in conjunction with the type 255 strain structures which have a similar configuration. The remainder of the tower family will be developed in late 2007.

Table1. Structure parameters for Kingbird and Chick adee conductors

Conductor Wind Span Weight Span Conductor Wind Span Weight Span

Kingbird 400m 600m Chickadee 500m 750m






4.2 Design requirements and philosophy

4.2.1 Mechanical design requirements and philosophy

The structure was designed using the design philosophy set out below.

The CSIR loading criteria was adopted. This criteria allows varying loads with varying heights above ground level and is aligned with IEC 60826 recommendations. There is a benefit utilizing this instead of SABS 0280 which assumes a constant wind pressure for all heights.

Loading criteria assumed were:

• Wind speed = 40m/s (3 second gust speed).

• Terrain category = 2 (large open fields).

• Site altitude = sea level.

• No allowance was made for topographical locations.

• Reliability level = 1,5.

• Return period = 100 years.

Modeling and Analysis:

• The tower was designed for Chickadee and Kingbird conductors with 7/3.35 shield wire. Wind and weight spans parameters are given in Table 1. Appropriate reduction in parameters shall be applied if larger than specified conductors and shield wire are used.

• Modelling was carried out with two cross arms on the right side of the tower and one cross arm on the left side of the tower. The tower was also rotated at 180 degrees to simulate reverse loads and the worst cases used from these comparisons.

• The following load cases were applied;

1. Wind perpendicular to line (positive and negative)

2. Wind at 75 degrees to line (in 4 quadrants)

3. Wind at 45 degrees to line

4. Stringing loads for all conductors and shield wires

• Analysis was done for the tallest tower with stays at 60 degrees to ground level. A stay angle of 45 degrees may be used.

Properties of materials used in analysis

• All bolts are grade 6.8 bolts with bolt shear capacities based on shear over the shank of the bolt and not over the threaded portion of the bolt.

• All steel is grade 300W steel.

• All conductor related hardware is rated for 120kN.

• All guys are 16mm (19/3.15) 1400MPa wire (UTS= 189kN).

• All guy hardware is rated for 210kN.

No broken conductor cases were designed for. The imbalance capacity was, however, determined by test.






4.2.2 Electrical design requirements and philosophy

4.2.2.1 Lightning performance and Insulation co-ord ination

The inherent properties of the guyed structure are such that the surge impedance of the tower body is reduced during a lightning strike. This reduces the voltage rise and probability of back-flash to the conductors. The lightning performance of the structure if properly earthed will exceed that of the conventional free-standing structures. The 2,55m x-arm with suspension insulators ensures that if back-flash occurs it will only occur across the insulator.

The 2,55m x-arm has several other advantages and disadvantages with regard to insulation co-ordination;

Advantages:

• the insulator string may be either polymer or glass (swing characteristics will be different)

• the angle of shield from the shield wire is at least 300

• Under insulator swing conditions the clearances exceed the minimum requirements.

Disadvantages:

• the structure geometry is less compact than the post insulator structure and for the same attachment height has to be 2,7m taller than a compact structure

• the taller structures will be subjected to more lightning strikes

• The longer x-arms will open up the delta of the structure and the electrical parameters will not be as good as a compact structure.

4.2.2.2 Earthing

The structure shall be earthed in accordance with DST-34-1209: Distribution Standard, Part 6: Sub transmission lines, Earthing and TRMSCAAC1:Rev.3, Transmission line towers and line construction.

The earthing of the structure determines the surge impedance of the structure which will in turn directly impact on the electrical performance of the structure and the whole line. The default earthing layout of the structure shall be the connection of all fours guys to the centre point with trench earths. The connection at the foundation points shall be done in such a manner that lightning surges are contained to the earth conductor and do not blow out concrete from the foundations, exposing rebar.

4.2.3 Civil design requirements and philosophy

The type of soil and bearing capacity thereof shall be determined under the supervision of a professional civil engineer or suitably qualified person, as described in DSP-34-1657, Specification for conventional stay planting, percussion stay and rock anchor installation and testing

This information shall in turn be used to select a suitable foundation.

4.2.3.1 Structure Foundations

The structure foundation is a simple pad and chimney design. The predominant load will be a vertical load and a small shear force will be present. The foundations will be designed according to the in-situ bearing capabilities of the soil. The foundation shall make provision for a steel locating pin onto which the tower will connect.






4.2.3.2 Guy Foundations

The guy foundations are far more significant as they are vital for the integrity of the structure. As the guy angle is at 600 to the ground and structures are relatively tall, the guys are different to what most Distribution staff are accustomed to. The hardware assembly of the guy is rated at 210kN while the wire is rated at 189kN. Guy foundations shall be designed for uplift forces suitable for the in-situ capabilities of the soil.

4.3 Optimisation requirements

4.3.1 Tower clearance under wind conditions

The clearances (with and insulator string of 2100mm) allowed are as follows:

Table 2. Clearance and swing criteria under differe nt wind conditions

Condition Wind Clearance Angle of swing

Condition 1 still air 1450mm 000

Condition 3 500Pa 500mm 700

The clearance window is too small to accommodate conductor weights.

4.4 Construction and maintenance

4.4.1 Construction

The body of the structure is a slim lattice design. All standard equipment required for this type of design will be required for the construction of the body. As it is a guyed structure temporary guys will be required if the body is not erected as one complete assembly but as sectional assemblies.

Step bolts are provided on one vertical leg of the tower, from ground level to the top of the tower.

Structure specific anti-climbing devices shall be fitted to all structures.

Anti vandalism bolts shall be applied below the anti-climb devices in areas where there is either a history of vandalism or vandalism is deemed as probable.

In areas where large birds may be expected to perch on the tip of the x-arm, bird guards shall be fitted to prevent such perching.

4.4.2 Maintenance

Visual inspection from ground level for corrosion is possible as all faces of the members are visible. The structure is accessible on all four faces and easily climbable. The anti-climb device may either be by-passed by placing a ladder against the structure above the device or by removing a panel of the device. The cross-arms allow easy access to the insulators.

Clearances are sufficient to allow live-line work. This has been ratified by the live work study committee.

No portion of the tower is buried beneath ground level, eliminating ground level corrosion.






Regular inspection of the guys is essential. Any signs of tampering with the guy assembly or movement of the guy foundation shall be treated as important and receive immediate attention. (Any slackening of the guy itself may be considered as a sign of possible movement of guy foundation)

Guys in arable soil or any other position where they may be exposed to vehicular traffic shall be clearly marked.

4.5 Manufacturing

All members are standard angle iron sections as listed below.

40 x 40 x 3, 50 x 50 x 4, 60 x 60 x 5, 70 x 70 x 6

They shall be manufactured in accordance with the applicable SANS codes.

4.6 Advantages and disadvantages of guyed lattice s tructure

Advantages:

• Easily transported in inaccessible areas

• Economical in undulating terrain.

• High loading capacity for structure mass.

• “Vulture friendly”.

• Live line friendly.

• Good lightning performance if earthed well.

• Good clashing span values due to distance between conductors

Disadvantages:

• Large footprint

• Lattice members vulnerable to theft.

• Structure vulnerable if guys are tampered with.

• Easily climbable up to anti-climbing device.

• Guys can become hooked by machinery when cultivating fields.

5. Testing

The tower was tested at TIC (Testing and Inspection Centre) which is situated in Rosherville. TAP and Eskom witnessed the tests.

The tower was subjected to the following load cases (full details in Annexure C);

a) Wind at 90 degrees to line

b) Wind at 75 degrees to line

c) Wind at 45 degrees to line

d) Broken shield wire (not designed for but tested for)

e) Broken top phase (not designed for but tested for)

f) Stringing wires top






Loads simulating Kingbird conductor were applied to the structure.

The broken shield wire case deformed the top of the earth peak at 75% of the full load. The peak was revised to obtain 100% of the full longitudinal load and re-tested. The revised earth peak successfully passed 100% broken shield wire loads. The tower successfully passed all other load cases.

Before being revised, the original earth peak was further tested for loads simulating wolf conductor at 525m wind span and 735m weight span. The earth peak successfully passed this test.

A full report is available from Tower Test Station upon request.

6. Marking, Labeling and Packaging

The structure members shall be hard stamped to clearly identify manufacturer, tower type and part number.

7. Spares

Spares shall be held at the discretion of the region.






Annex A - General Arrangement of Type 273A Structur e (normative)






Annex B - Summary of design criteria for type 273A tower (extract from TAP report)

(normative)

Voltage 132kV

Phase configuration Delta - Single circuit

Maximum attachment height 23m

Servitude width 36m

Slope of stays 60 degrees to ground

Shield wire 7/3.35 (possibly 19/2.65 or OPGW)

Shield wire covering angle 30 degrees

Weight to wind span ratio 1.4

Wind span Chickadee 500m

Weight span Chickadee 700m

Wind span Kingbird 400m

Weight span Kingbird 560m

Templating temperature 75 degrees

C value conductor 1800m

C value shield wire 2100m

Swing clearance still air 1450mm

Normal swing clearance (40 degrees) 1450mm

Maximum swing clearance (60 degrees) 500mm (70 degree capacity)

Insulator assembly length 1765mm (31mm/kV)

Insulator assembly mass 50kg

Live line locating pin As per 255A

Cross arm Conventional – No “blade” cross arms

Splices Angle instead of outside plates (preferably both)

Bolts M12 & M16 Grade 6.8 bolts

Anti-vandalism bolts Optional and dependant on sites traversed

Grade of steel 300WA

Galvanising thickness 600 gr/m2

Stay strength 1400 MPa

Cross arm length 2550 mm

Detailing requirements:

Live line locating pin to cross arms Done

Earth peak detail Similar to 126A






Annex C1 - Design parameters and information for SI NGLE CIRCUIT guyed 273A lattice structure for Chickadee conducto r

(informative)

Structure Height

Conductor attachment heights Nominal design span

Design wind span

Design weight span

Clashing

span Lower Centre Top Shield

Wire

Nom 11.235 13.235 15.235 19.905 200m 500m 750m 1000m*

+1,5m 12.735 14.735 16.735 21.405 240m 500m 750m 1000m*

+3.0m 14.235 16.235 18.235 22.905 280m 500m 750m 1000m*

+4,5m 15.735 17.735 19.735 24.405 310m 500m 750m 1000m*

+6.0m 17.235 19.235 21.235 25.905 340m 500m 750m 1000m*

+7,5m 18.735 20.735 22.735 27.405 370m 500m 750m 1000m*

+9.0m 20.235 22.235 24.235 28.905 400m 500m 750m 1000m*

+10,5m 21.735 23.735 25.735 30.405 425m 500m 750m 1000m*

+12.0m 23.235 25.235 27.235 31.905 450m 500m 750m 1000m*

* indicates a clipped number

FOR USE WITH ALTERNATIVE CONDUCTORS, THE ABOVE WIND SPANS MAY BE ADAPTED USING THE METHOD AND FORMULA AS STATED IN SCSASAAV1: GENERAL

Swing angles

Conductor Swing angle at 100Pa wind Swing angle at 500Pa wind Weight/Wind ratio Chicadee 40o 70o 52%

Wolf 40o 70o 44% Kingbird 40o 70o 41%






Annex C2 - Design parameters and information for SI NGLE CIRCUIT guyed 273A lattice structure for Kingbird conductor

(informative)

Structure Height

Conductor attachment heights Nominal design span

Design wind span

Design weight span

Clashing

span Lower Centre Top Shield

Wire

Nom 11.235 13.235 15.235 19.905 200m 400m 600m 1000m*

+1,5m 12.735 14.735 16.735 21.405 240m 400m 600m 1000m*

+3.0m 14.235 16.235 18.235 22.905 280m 400m 600m 1000m*

+4,5m 15.735 17.735 19.735 24.405 310m 400m 600m 1000m*

+6.0m 17.235 19.235 21.235 25.905 340m 400m 600m 1000m*

+7,5m 18.735 20.735 22.735 27.405 370m 400m 600m 1000m*

+9.0m 20.235 22.235 24.235 28.905 400m 400m 600m 1000m*

+10,5m 21.735 23.735 25.735 30.405 425m 400m 600m 1000m*

+12.0m 23.235 25.235 27.235 31.905 450m 400m 600m 1000m*

* indicates a clipped number

FOR USE WITH ALTERNATIVE CONDUCTORS, THE ABOVE WIND SPANS MAY BE ADAPTED USING THE METHOD AND FORMULA AS STATED IN SCSASAAV1: GENERAL

Swing angles

Conductor Swing angle at 100Pa wind Swing angle at 500Pa wind Weight/Wind ratio Chicadee 40o 70o 52%

Wolf 40o 70o 44% Kingbird 40o 70o 41%






Annex D - Test load cases for type 273A Guyed Latti ce Tower (informative)

LOADS ARE IN NEWTONS

Case 1 Wind at 90 degrees

Node Vertical Transverse Longitudinal

5P 4373 4732 0

TI 6138 10963 0

MI 6138 10663 0

BI 6138 10413 0



5P 4373 4415 0

TI 6138 10254 201

MI 6138 9974 201

BI 6138 9741 201



5P 4373 2366 0

TI 6138 5642 550

MI 6138 5493 550

BI 6138 5368 550

Case 4 Broken top phase


5P 3610 940 0

TI 4050 1670 -15740

MI 6750 2070 0

BI 6750 2070 0

Case 5 Stringing Wires

Top


5P 6560 0 0

TI 12280 0 0

MI 9210 0 0

BI 9210 0 0

LAST CASE TO CHECK FOR (ALTERNATIVE USERS)

Case 6 Broken S/W


5P 2166 700 -25290

TI 6750 2180 0

MI 6750 2070 0

BI 6750 2070 0






Annex E – Impact Assessment (Normative)

Impact assessment form to be completed for all docu ments.

1 Guidelines

o All comments must be completed.

o Motivate why items are N/A (not applicable)

o Indicate actions to be taken, persons or organisations responsible for actions and deadline for action.

o Change control committees to discuss the impact assessment, and if necessary give feedback to the compiler of any omissions or errors.

2 Critical points

2.1 Importance of this document. E.g. is implementation required due to safety deficiencies, statutory requirements, technology ch anges, document revisions, improved service quality, improved service performa nce, optimised costs.

Comment: Revision only

2.2 If the document to be released impacts on statutory or legal compliance - this need to be very clearly stated and so highlighted.


2.3 Impact on stock holding and depletion of existing s tock prior to switch over.


2.4 When will new stock be available?


2.5 Has the interchangeability of the product or item b een verified - i.e. when it fails is a straight swop possible with a competitor's product?


2.6 Identify and provide details of other critical (ite ms required for the successful implementation of this document) points to be consi dered in the implementation of this document.


2.7 Provide details of any comments made by the Regions regarding the implementation of this document.

Comment: (N/A during commenting phase)






Annex E (continued)

3 Implementation timeframe

3.1 Time period for implementation of requirements.


3.2 Deadline for changeover to new item and personnel t o be informed of DX wide change-over.


4 Buyers Guide and Power Office

4.1 Does the Buyers Guide or Buyers List need updating?


4.2 What Buyer’s Guides or items have been created?


4.3 List all assembly drawing changes that have been re vised in conjunction with this document.


4.4 If the implementation of this document requires ass essment by CAP, provide details under 5

4.5 Which Power Office packages have been created, modi fied or removed?


5 CAP / LAP Pre-Qualification Process related impac ts

5.1 Is an ad-hoc re-evaluation of all currently accepte d suppliers required as a result of implementation of this document?


5.2 If NO, provide motivation for issuing this specific ation before Acceptance Cycle Expiry date.


5.3 Are ALL suppliers (currently accepted per LAP), awa re of the nature of changes contained in this document?







Annex E (continued)

5.4 Is implementation of the provisions of this documen t required during the current supplier qualification period?


5.5 If Yes to 5.4, what date has been set for all curre ntly accepted suppliers to comply fully?


5.6 If Yes to 5.4, have all currently accepted supplier s been sent a prior formal notification informing them of Eskom’s expectations , including the implementation date deadline?


5.7 Can the changes made, potentially impact upon the p urchase price of the material/equipment?


5.8 Material group(s) affected by specification: (Refer to Pre-Qualification invitation schedule for list of material groups)


6 Training or communication

6.1 Is training required?

Comment: (If NO then 6.2 – 6.6 will be N/A)

6.2 State the level of training required to implement t his document. (E.g. awareness training, practical / on job, module, etc.)

Comment: N/A

6.3 State designations of personnel that will require t raining.

Comment: N/A

6.4 Is the training material available? Identify person responsible for the development of training material.

Comment: N/A






Annex E (continued)

6.5 If applicable, provide details of training that wil l take place. (E.G. sponsor, costs, trainer, schedule of training, course material avai lability, training in erection / use of new equipment, maintenance training, etc).

Comment: N/A

6.6 Was Technical Training Section consulted w.r.t modu le development process?

Comment: N/A

6.7 State communications channels to be used to inform target audience.


7 Special tools, equipment, software

7.1 What special tools, equipment, software, etc will n eed to be purchased by the Region to effectively implement?


7.2 Are there stock numbers available for the new equip ment?


7.3 What will be the costs of these special tools, equi pment, software?

Revision only

8 Finances

8.1 What total costs would the Regions be required to i ncur in implementing this document? Identify all cost activities associated w ith implementation, e.g. labour, training, tooling, stock, obsolescence

Comment:

Standard revision only ………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………….

Impact assessment completed by:

Name: ______R Branfield__________________________________________________________

Designation: __Senior Consultant_____________________________________________________

A4L

1 2 3 4

1 2 3 4

A

B

C

D

E

F

A

B

C

D

E

F

REVISIONSET SHEET

DATE:

REV REVISION DESCRIPTION BY CHKD AUTH DATE

AUTH:

DATE:

CHKD:

DATE:

DRAWN:

PROJECT NO.PROJECT NO.

DISTRIBUTION TECHNOLOGYRETICULATION/SUB-TRANSMISSION LINE

03 1

132KV LATTICE STEEL - GENERAL ARRANGEMENT

THIS IS AN EXTRACT OF DRAWING

NO. 0.69/255d/1 Rev1 FOR

ILLUSTRATION PURPOSES ONLY

NOTE:

255D 0^-90^ ANGLE STRAIN / 0^-60^ TERMINAL

RAB

20/09/04

COPY ONLY

D-DT 7713

A4L

1 2 3 4

1 2 3 4

A

B

C

D

E

F

A

B

C

D

E

F

REVISIONSET SHEET

DATE:

REV REVISION DESCRIPTION BY CHKD AUTH DATE

AUTH:

DATE:

CHKD:

DATE:

DRAWN:

PROJECT NO.PROJECT NO.

DISTRIBUTION TECHNOLOGYRETICULATION/SUB-TRANSMISSION LINE

01 1

THIS IS AN EXTRACT OF DRAWING

NO. 0.69/255C/1 Rev1 FOR

ILLUSTRATION PURPOSES ONLY

NOTE:

132KV LATTICE STEEL - GENERAL ARRANGEMENT

RAB

20/09/04

COPY ONLY

255C 0-45^ ANGLE STRAIN / 0^ TERMINAL

D-DT 7712

dst 34-511- 273a - pongola/impact phase... · 2013. 8. 15. · bob branfield distribution...

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