Overhead Wiring Maintenance Standards · Overhead Wiring Maintenance Standards T HR EL 08011 ST...

Overhead Wiring Maintenance Standards

T HR EL 08011 ST

Standard

Version 1.0

Issued Date: 12 March 2015

Important Warning This document is one of a set of standards developed solely and specifically for use on public transport assets which are vested in or owned, managed, controlled, commissioned or funded by the NSW Government, a NSW Government agency or a Transport Agency (as defined in the Asset Standards Authority Charter). It is not suitable for any other purpose. You must not use or adapt it or rely upon it in any way unless you are authorised in writing to do so by a relevant NSW Government agency. If this document forms part of a contract with, or is a condition of approval by a NSW Government agency, use of the document is subject to the terms of the contract or approval. This document may not be current. Current standards are available for download from the Asset Standards Authority website at www.asa.transport.nsw.gov.au.

© State of NSW through Transport for NSW

T HR EL 08011 ST Overhead Wiring Maintenance Standards

Version 1.0 Issued Date: 12 March 2015

Standard governance

Owner: Lead Electrical Engineer, Asset Standards Authority

Authoriser: Chief Engineer Rail, Asset Standards Authority

Approver: Director, Asset Standards Authority on behalf of ASA Configuration Control Board

Document history

Version Summary of change

1.0 First issue

For queries regarding this document, please email the ASA at [email protected] or visit www.asa.transport.nsw.gov.au

© State of NSW through Transport for NSW



Preface The Asset Standards Authority (ASA) is an independent unit within Transport for NSW (TfNSW)

and is the network design and standards authority for defined NSW transport assets.

The ASA is responsible for developing engineering governance frameworks to support industry

delivery in the assurance of design, safety, integrity, construction, and commissioning of

transport assets for the whole asset life cycle. In order to achieve this, the ASA effectively

discharges obligations as the authority for various technical, process, and planning matters

across the asset life cycle.

The ASA collaborates with industry using stakeholder engagement activities to assist in

achieving its mission. These activities help align the ASA to broader government expectations of

making it clearer, simpler, and more attractive to do business within the NSW transport industry,

allowing the supply chain to deliver safe, efficient, and competent transport services.

The ASA develops, maintains, controls, and publishes a suite of standards and other

documentation for transport assets of TfNSW. Further, the ASA ensures that these standards

are performance based to create opportunities for innovation and improve access to a broader

competitive supply chain.

This standard supersedes RailCorp document EP 08 00 00 02 SP Overhead wiring

maintenance Standards, Version 4.0.

The changes to previous content include:

• updates to reflect organisation changes and resulting changes in responsibilities

• minor amendments and clarification to content

• conversion of the standard to ASA numbering, format and style

© State of NSW through Transport for NSW Page 3 of 30



Table of contents 1. Introduction ............................................................................................................................................ 5

2. Purpose ................................................................................................................................................... 5 2.1. Scope ..................................................................................................................................................................... 5 2.2. Application ............................................................................................................................................................. 6 3. Reference documents ........................................................................................................................... 6

4. Terms and definitions ........................................................................................................................... 7

5. Vegetation clearances ........................................................................................................................... 8 6. Maintenance of overhead wiring to design ......................................................................................... 8

7. Maintenance of contact wire ................................................................................................................. 9 7.1. Contact wire material ............................................................................................................................................ 9 7.2. Contact wire wear ................................................................................................................................................ 10 8. Conductor splices................................................................................................................................ 15 8.1. Catenary splices .................................................................................................................................................. 15 8.2. Contact splices .................................................................................................................................................... 15 9. Dropper arrangements ........................................................................................................................ 16

10. Section insulators ................................................................................................................................ 16

11. Insulated knuckles ............................................................................................................................... 16 12. Surge arresters .................................................................................................................................... 16

13. Wood pole support structures ........................................................................................................... 16

14. Corrective maintenance triggers........................................................................................................ 17 14.1. General ................................................................................................................................................................. 17 14.2. Conductors .......................................................................................................................................................... 18 14.3. Conductor fittings ............................................................................................................................................... 20 14.4. Switching and feeding arrangements ................................................................................................................ 21 14.5. Support and registration arrangements ............................................................................................................ 22 14.6. Anchor arrangements ......................................................................................................................................... 22 14.7. Support structures .............................................................................................................................................. 23 15. Base safety or operating limits .......................................................................................................... 23 15.1. General ................................................................................................................................................................. 24 15.2. Conductors .......................................................................................................................................................... 25 15.3. Conductor fittings ............................................................................................................................................... 27 15.4. Switching and feeding arrangements ................................................................................................................ 28 15.5. Support and registration arrangements ............................................................................................................ 28 15.6. Anchor arrangements ......................................................................................................................................... 29 15.7. Support structures .............................................................................................................................................. 29 16. Data set associated with overhead wiring maintenance ................................................................. 30




1. Introduction Overhead wiring (OHW) is used to transmit power from traction substations to electric trains.

OHW generally consists of catenary and contact wires. The contact wire provides a

mechanically continuous path for train pantographs, and the catenary wire is used to support

the contact wire. The traction current to trains is carried by both the catenary and contact wires.

2. Purpose The purpose of this document is to set out the maintenance requirements for RailCorp's

1500 V dc OHW network.

2.1. Scope This document sets out the maintenance policies and parameters associated with the OHW

system including the following:

• vegetation management

• maintenance tolerances with respect to design

• contact wire

• catenary and contact splices

• section insulators

• insulated knuckles

• surge arresters

• wood pole support structures

Additionally, this document also includes information on the following:

• OHW maintenance tolerances and conditions that trigger corrective maintenance actions

that do not require urgent repair work. The maximum times to complete the corrective

actions are also specified.

• base safety or operating limits, which are the threshold conditions at or below which urgent

or emergency repair work to the OHW work shall be carried out

This document does not include maintenance triggers for OHW structures and their associated

bonding arrangements. OHW structures are maintained by the Civil discipline. Maintenance

triggers for structure bonding arrangements are covered in EP 12 20 00 01 SP Bonding of

Overhead Wiring Structures to Rail. However, this document requires the OHW maintainer to

report obvious visual defects to the maintainers of these assets.




This document does not cover the requirements for the preventative maintenance of the

RailCorp 1500 V dc OHW system. This shall be done in accordance with the technical

maintenance plan (TMP).

2.2. Application This document applies to all OHW in RailCorp's 1500 V dc network that is in service.

3. Reference documents Transport for NSW standards

EP 00 00 00 13 SP Electrical power equipment – Design ranges of ambient conditions

EP 08 00 00 01 SP Overhead wiring standards for the electrification of new routes

EP 08 00 00 15 SP Overhead wiring construction and commissioning

EP 08 00 00 24 SP Contact wire

EP 10 01 00 02 SP Aerial line maintenance standards

EP 10 01 00 03 SP Aerial line base safety and operating standards

EP 10 01 00 05 SP Requirements for electric aerials crossing RailCorp infrastructure

EP 12 20 00 01 SP Bonding of overhead wiring structures to rail

EP 19 00 00 01 SP DCCB and Delta I relay setting calculation method

ESC 210 Track geometry and stability

ESC 330 Overhead wiring structures and signal gantries

T HR EL 08003 ST Level crossings – OHW requirements

T HR EL 08009 ST Designations of overhead wiring conductor systems

T HR EL 10003 ST Wood pole serviceability

T MU MD 00009 ST AEO Authorisation Requirements

T HR RS 00100 ST RSU 100 Series - Minimum Operating Standards for Rolling Stock –

General Interface Standards

TMC 212 Survey

TMC 331 Design of overhead wiring structures and signal gantries




Transport for NSW standard drawings

CV 0131343 Standard Pantograph Profiles

EL 0002017 Contact Splice

EL 0006421 Mark 2 Cantilever Construction Pantograph Security Description Sht. 1/2

EL 0006422 Mark 2 Cantilever Construction Pantograph Security Description Sht. 2/2

EL 0011035 Catenary Feeding Loop Arrangements

EL 0026992 Contact Wire Wear Strip

EL 0034083 Catenary Terminating Clamp Details

EL 0034703 0.213 in² & 0.3 in² Contact Wire Splice & Terminal Fitting Packing Shims

EL 0040770 Contact Wire Section Area 193 mm²

EL 0189852 Contact Wire Section Area 137 mm²

EL 0251310 Contact Steady Wire Fender 6”

EL 0251311 Contact Steady Wire Fender 4”

4. Terms and definitions The following terms and definitions apply in this document:

ASA Asset Standards Authority

AEO Authorised Engineering Organisation

contact wire gradient is the ratio of the difference in height of the contact wire at two

successive supports to the length of the bay

contact wire elastic limit the elastic limit for a material is the stress beyond which permanent

deformation will occur. For the purpose of this document, the elastic limit of a contact wire is the

thickness of a contact wire at a localised wear point below which permanent deformation will

result when the wire is subjected to the maximum tension at the limits of design operating

conditions.

DCCB direct current circuit breaker

EOC electrical operating centre

heel height is the vertical distance between the contact wire at the pull off arm and the pivot

point at the heel of the pull off arm

ESR Eastern Suburbs Railway

JOS judgement of significance




OHW overhead wiring

passing clearance is the minimum clearance required between live parts of OHW equipment

and any earthed material or rail vehicle, or between the pantograph and any earthed material,

under any permissible conditions of operation and maintenance of vehicles, track and OHW

equipment

static clearance is the minimum distance required between live parts of OHW equipment

(under any permissible conditions of maintenance when not subject to uplift from a pantograph)

and a structure or earthed part of the OHW equipment

TCM Track Control Mark

TfNSW Transport for New South Wales

TMP technical maintenance plan

5. Vegetation clearances Vegetation near OHW shall be maintained and controlled so that it is not within the following

clearance envelopes:

• 3 m from live exposed 1500 V dc equipment

• 1.5 m from overhead wiring structures and guys, and dead OHW conductors

Vegetation that has been assessed to be at risk of falling into the OHW shall also be removed,

even if it is located outside of the clearance envelopes specified above.

Allowance for regrowth between inspection and maintenance cycles shall be made when

undertaking vegetation control activities.

All vegetation control activities shall be undertaken in accordance with relevant environmental

and safety management system requirements.

6. Maintenance of overhead wiring to design New or rebuilt OHW shall be constructed and commissioned to the approved and accepted

design and within the tolerances stipulated in EP 08 00 00 01 SP Overhead Wiring Standards

For The Electrification Of New Routes.

After commissioning, the OHW shall be maintained so that deviations from the approved and

accepted design are within the tolerances set out in Table 1. These tolerances are required to

ensure pantograph security with an effective pantograph half-width of 700 mm (refer to drawing

CV 0131343 Standard Pantograph Profiles for further detail), and with the allowable vehicle

movement and track tolerances specified in T HR RS 00100 ST RSU 100 Series - Minimum

Operating Standards for Rolling Stock – General Interface Standards and ESC 210 Track

Geometry And Stability (refer to drawings EL 0006421 and EL 0006422 for further detail). © State of NSW through Transport for NSW Page 8 of 30



The OHW design geometry at a structure is defined with reference to the relevant track control

mark (TCM) for the structure. Within the electrical discipline, this TCM is also referred to as the

'reference nail' when installed on a mast, or 'brass bar' when installed in rock foundation. Critical

dimensions of the design track geometry relative to the TCM at the structure location are given

in the survey plaque associated with the TCM. Refer to ESC 210 Track Geometry and Stability

and TMC 212 Survey.

If the track is positioned outside of tolerances, it may be necessary to temporarily adjust the

OHW outside of the tolerances specified in Table 1 to allow for train running. Under these

circumstances, both track and OHW shall be restored to within the specified tolerances from

design as soon as practicable.

Table 1 – OHW maintenance tolerances to design

Parameter Maintenance tolerances to design

Catenary height +/- 50 mm

Contact height +/- 50 mm, subject to minimum contact height conditions in Section 14.2

Contact stagger +/- 50 mm

Pull off arm heel height +/- 25 mm

7. Maintenance of contact wire Maintenance of contact wire shall be undertaken in accordance with the requirements set out in

this section.

7.1. Contact wire material Contact wire material is identified by grooves provided at the upper lobe of the wire. The

number of identification grooves provided for each type of material is as follows:

• cadmium copper – nil

• hard drawn copper – 1

• tin bearing copper – 2

Except as noted below, tin bearing copper contact wire in accordance with EP 08 00 00 24 SP

Contact Wire shall be used for replacement of existing contact wires.

Settings of relevant dc circuit breakers (DCCBs) shall be checked and adjusted where

necessary, in conjunction with all contact wire replacement and renewal if the existing contact

wires are not tin bearing copper. Where the DCCB settings do not allow the replacement of

existing hard drawn copper contact wires by tin bearing copper wires, hard drawn copper

contact wires in accordance with EP 08 00 00 24 SP shall be used for the replacement.




Replacement of localised worn hard drawn copper contact wire by a short piece (< 10 m) of tin

bearing copper contact wire is permissible.

7.2. Contact wire wear Contact wire wear shall be managed by the measures set out in this section.

7.2.1. Measuring contact wire wear The severity of localised contact wire wear is generally determined by measuring the contact

wire thickness at the thinnest point of the localised wear area. The thickness is measured along

an axis perpendicular to the bottom (wearing surface) of the contact wire. However, where

contact wire side wear, for example at wire junctions, is also observed, a measurement along

the axis perpendicular to the side wear surface shall also be made and recorded. The

cross-section area of the contact wire at the thinnest point, and the corresponding safety factor

at limiting operating conditions, shall be determined from these two measurements for contact

wire with side wear.

Contact wire thickness measurement shall be taken with an instrument with an accuracy of

± 0.05 mm, and recorded in units of millimetres to the first decimal place, for example 8.9 mm.

Contact wire thickness measurements shall be taken periodically in accordance with the

Electrical TMP. Measurements shall be made at the thinnest point as close as practicable at the

following locations:

• pull off arms

• contact wire full splices

• kinks in the contact wire

• contact wire knuckles

• pantograph forking in points

• section insulators

• wearing strips – measurements shall be made for both the contact wire and the wearing

strip wire

• other localised thin spots observed from sighting along the contact wire between the above

measurement locations




7.2.2. Contact wire condemning size The contact wire condemning size is the contact wire thickness at a localised wear point below

which the localised wear has to be programmed for removal. See Table 8 for corrective

maintenance triggers of conductors.

Condemning sizes of contact wires in the RailCorp OHW network are given in Table 2 and

Table 3.

The condemning sizes are determined with the following criteria:

• a minimum factor of safety of 2.0 at the limit operating conditions

• a margin of 10% is added to the maximum calculated conductor tensions, as determined

by the conductor system details and ambient conditions stipulated in EP 00 00 00 13 SP

Electrical power equipment – Design ranges of ambient conditions and T HR EL 08009 ST

Designations of overhead wiring conductor systems. This margin is made to allow for

tolerances such as those in tension regulator weights and contact wire dimensions.

• the condemning contact wire thickness shall not be less than 8.1 mm for 137 mm² contact

wire, and 9.7 mm for 193 mm² contact wire. These dimensions correspond to the thickness

of a contact wire with the semi-circular section fully worn, plus a safety margin of 1.5 mm.

See drawings EL 0040770 Contact Wire Section Area 193 mm² and EL 0189852 Contact

Wire Section Area 137 mm².

• a margin of 0.6 mm is added to the calculated condemning sizes for installations inside

tunnels to allow for difficulty in detecting thin wire spots from patrols. As a result, the

condemning sizes for fixed anchored single 193 mm2 contact wires in the City and Eastern

Suburbs Railway (ESR) Tunnels have a factor of safety greater than 2.0.

The City tunnels include:

o tunnels in the City Inner

o tunnels in the City Outer

o the North Shore Line from Goulburn St portal to Argyle portal

o the Engine Dive into Eveleigh Yard

The ESR tunnels include:

o the Eastern Suburbs Line between Erskineville and Bondi Junction

o the Up and Down Illawarra Dives

The nominated contact wire condemning sizes are not applicable to conductor systems 26 and

35 (fixed anchored with 137 mm² contact wire at a tension of 12.46 kN at 21 °C). The relevant

Authorised Engineering Organisation (AEO) shall provide a proposal to the Lead Electrical

Engineer, ASA, for such systems. © State of NSW through Transport for NSW Page 11 of 30



The values given in Table 2 and Table 3 are only valid for contact wires with no side wear. For

contact wires with side wear, the cross-section area shall be determined using the two

measurements as set out in Section 7.2.1. The wire shall be 'condemned' if the cross-section

area is less than or equal to the 'section area at condemning' listed in Table 2 and Table 3.

It is unlikely to have a contact wire run to be uniformly worn down to the '50% worn' section area

in accordance with EP 19 00 00 01 SP DCCB and Delta I relay setting calculation method

before part or all of the wire run has to be replaced to remove localised wear points. Contact

wire resistance is therefore not considered in the determination of condemning sizes.

Table 2 - Condemning sizes for 137 mm2 contact wire with no side wear

Material Configuration Location Condemning size (mm)

Section area at condemning (mm2)

Hard drawn copper Regulated All 8.1 81.1

Tin bearing copper Regulated All 8.1 81.1

Tin bearing copper

Fixed twin contact All 8.8 90.7

Tin bearing copper

Fixed single contact All 9.0 93.1

Cadmium copper Regulated All 8.1 81.1

Cadmium copper


Cadmium copper


Table 3 - Condemning sizes for 193 mm2 contact wire with no side wear





Tin bearing copper

Fixed single contact

All areas except City and ESR tunnels

11.6 141.5

Tin bearing copper


City and ESR tunnels 10.7 127.7







Cadmium copper



11.2 135.5

Cadmium copper



7.2.3. Removal of localised contact wire wear points Localised contact wire wear points at or below the condemning size shall be removed by

replacing a length of the contact wire containing the wear point. The replacement length shall be

spliced into the existing contact wire run by approved contact wire splices in accordance with

Section 8.2.

Where it is not practicable to have the localised wear point removed within the time as specified

in Section 14, a contact wire wear strip shall be installed in accordance with drawing

EL 0026992 Contact Wire Wear Strip as a temporary measure.

7.2.4. Contact wire elastic limits For the purpose of this document, the elastic limit stress of contact wire is taken to be 55% of

the ultimate tensile stress, and is the base safety or operating limit for localised contact wire

wear. Elastic limits of contact wires in the RailCorp OHW network are given in Table 4 and

Table 5.

The nominated elastic limits are not applicable to conductor systems 26 and 35 (fixed anchored

with 137 mm² contact wire at a tension of 12.46 kN at 21°C). The relevant AEO shall provide a

proposal to the Lead Electrical Engineer, ASA, for such systems.

The nominated limits are also not applicable to contact wires with side wear. For contact wires

with side wear, the cross-section area of the wire shall be determined in accordance with

Section 7.2.1. The maximum stress at the localised wear point shall be calculated to determine

if the elastic limit has been exceeded.




Table 4 - Elastic limits for 137 mm² contact wire with no side wear

Material Configuration Location Elastic limit (mm)

Section area at elastic limit (mm2)



Tin bearing copper


Tin bearing copper



Cadmium copper


Cadmium copper


Table 5 – Elastic limits for 193 mm² contact wire with no side wear

Material Configuration Location Elastic limit (mm)

Section area at elastic limit (mm²)



Tin bearing copper



10.7 127.7

Tin bearing copper




Cadmium copper



10.4 123.0

Cadmium copper






8. Conductor splices The requirements for splicing of OHW conductors are provided in this section.

8.1. Catenary splices ASA type approved helical fittings shall be used for splicing 165 mm², 270 mm² and 327 mm²

catenaries. These fittings may also be used to repair damages to these catenaries if less than

25% of the wires in the outermost layer have been severed or have other equivalent damage.

Droppers, in-span feeders, and other fittings that clamp on the catenary wire may have to be

relocated so that they are clear of the helical fitting.

Splicing of 510 mm² catenary shall be done by terminating the conductors, installing a suitable

link between the terminating clamps and connecting the 'tails' of the catenary conductors

together, in a manner similar to that shown in drawing EL 0011035 Catenary Feeding Loop

Arrangement. The termination clamp shall be fitting number 281/9 (drawing EL 0034083

Catenary Terminating Clamp Details).

8.2. Contact splices 'In running' contact wires shall be spliced by fitting number 462/8 (drawing EL 0002017 Contact

Splice) with suitable wedges and shims in accordance with drawing EL 0002017.

For worn contact wires, copper shims are installed in the mouth of the splice fitting to ensure

that the running edge of the contact wire is flush with the underside of the splice. Table 6 gives

a guide to the number of shims to be used. The contact wire splice is not suitable for contact

wires with a thickness less than 9.9 mm. Hence contact wire replacement may have to be

extended beyond the localised wear point.

As contact wire splices are 'hard spots' for pantograph running, no more than three contact

splices shall be installed between two adjacent support structures.

Table 6 – Guide to shim installation requirements for contact wire full splice

Contact wire thickness (mm) Number of long shims (fitting 462/6; drawing EL 0034703)

Number of short shims (fitting 462/16; drawing EL 0034703)

16.4 – 15.5 (new 193 mm²) 0 0

15.4 – 14.6 1 0

14.5 – 13.5 (new 137 mm²) 2 0

13.4 – 12.5 1 1

12.4 – 11.5 2 1

11.4 – 10.5 1 2

10.4 – 9.9 2 2 © State of NSW through Transport for NSW Page 15 of 30



9. Dropper arrangements Where existing droppers have to be replaced, they shall be replaced by insulated droppers in

accordance with EP 08 00 00 01 SP.

10. Section insulators Where existing section insulators have to be replaced, they shall be replaced by 'Type 6' section

insulators in accordance with EP 08 00 00 01 SP.

11. Insulated knuckles There is currently no suitable replacement for insulated knuckles with timber beams. Existing

OHW with such insulated knuckles may need to be reconfigured when the knuckles are no

longer suitable to remain in service. The maintainer shall plan the required modifications with

sufficient time allowed for design and construction.

12. Surge arresters Some previous standard arrangements for OHW required surge arresters to be installed on the

overhead wiring approximately mid-way between substations. This practice is no longer

required. Existing 'mid-way' surge arresters shall be removed at the next hands-on inspection or

when the overhead wiring in the area is modified.

Surge arresters are still required at cable to aerial feeder junction locations. See

EP 08 00 00 01 SP for further information.

13. Wood pole support structures Standard T HR EL 10003 ST Wood pole serviceability details serviceability criteria of wood

poles.

Where an existing OHW wood pole support structure has to be replaced, it shall be replaced by

one or more structure(s) satisfying the requirements of ESC 330 Overhead wiring structures and

signal gantries and TMC 331 Design of overhead wiring structures and signal gantries.




14. Corrective maintenance triggers Common conditions that trigger corrective maintenance actions are listed in the subsections

below. Care shall be exercised by the maintainer to ensure that base safety and operational

limits (see Section 15) are not breached before the completion of corrective actions.

The values listed under 'time to complete corrective action' are maximum allowable times.

Depending on the nature and extent of the defect, shorter time periods may need to be applied

for individual cases to ensure that the risks to personnel safety and train operations caused by

failure of the identified defect(s) are as low as reasonably practicable. Longer periods to

complete corrective action may be approved by the responsible AEO under a judgement of

significance (JOS) process for OHW on a case by case basis. Refer to T MU MD 00009 ST

AEO Authorisation Requirements for further information.

14.1. General The corrective maintenance triggers for general items associated with OHW along with the

maximum corrective action time to repair each defect is given in Table 7 below.

Table 7 – Corrective maintenance triggers - General

Parameter Corrective maintenance trigger Time to complete corrective action

Insulators Cracked or chipped porcelain 3 months

Insulators Excessive pollution build up 6 months

Insulators Corroded cap or tongue 3 months

Insulators Twist in polymeric insulator greater than 30° but less than 40° 3 months

Insulators

Insulator skirt clearance above in running contact wire – < 300 mm for porcelain insulators < 200 mm for composite insulators

3 months

Small parts steelwork Signs of excessive corrosion, deformation such as bending and cracks 6 months

Fasteners

Loose, missing or corroded fasteners that are not critical to the functioning of the fittings/assemblies, for example those with redundancies in the number of fasteners

6 months

Vegetation clearance Vegetation within the clearance envelopes specified in Section 5, or assessed to be potentially at risk of falling into OHW

6 months (refer note 1)

Clearances Static clearance (normal) < 150 mm 3 months





Clearances Static clearance to non-conductive material (for example non-reinforced concrete or brickwork) < 120 mm

3 months

Clearances (refer note 2) Passing clearance (normal) < 200 mm 3 months

Clearances (refer note 2) Passing clearance to non-conductive material (for example non-reinforced concrete or brickwork) < 150 mm

3 months

Clearances Vertical clearance from catenary to overline bridge less than the minimum values stipulated in EP 08 00 00 01 SP

3 months

Signs Missing, obscured or wrong information on signs due to vandalism, corrosion or degradation

3 months

Note 1 – An assessment should be made of the rate of vegetation growth. A shorter

time frame for completion of corrective action may be required as a result of the

assessment.

Note 2 – Passing clearance to pantographs may be analysed and determined by ASA

approved software tools.

14.2. Conductors The corrective maintenance triggers for OHW conductors along with the maximum corrective

action time to repair each defect is given in Table 8.

Table 8 – Corrective maintenance triggers - Conductors


General Signs of conductor stranding, annealing, burning, abnormal wear, or kinks 3 months

General

Catenary/contact alignment across track at a dropper > 20% of dropper length, except where the wires are designed to be not aligned with each other, for example Liverpool to Glenlee

6 months

General

Clearance of span wire above in running contact wire (without fender fitting 395 or 395/1 as per drawings EL 0251310 and EL 0251311) < 300 mm

3 months

General

Clearance between 2 parallel wires of different electrical sections (for example mid-bay in open overlaps on tight curves) under worst case of blowout < 150 mm

6 months





General

Clearance to HV aerial lines less than that stipulated in EP 10 01 00 05 SP Requirements for electric aerials crossing RailCorp infrastructure.

6 months

Contact wire height (refer note 1)

< 4.75 m in open route 6 months


< 4.65 m at low bridges and tunnels 6 months


Contact wire height less than minimum stipulated in T HR EL 08003 ST Level crossings – OHW requirements at a level crossings

6 months

Contact wire stagger > 460 mm (priority 2 exceedance for OHW geometry measuring vehicle) 6 months

Contact wire gradient

Contact wire gradient exceeds maximum values listed in EP 08 00 00 15 SP Overhead wiring construction and commissioning.

6 months

Contact wire thickness Contact wire thickness at or below condemning size. See Section 7.2. 6 months

Overlaps Signs of poor running performance such as arcing, burning and excessive wear; Contact wire 'scissor' in excess of 50 mm

6 months

Catenaries crossing Clearance between catenary conductors < 20 mm 3 months

Auxiliary feeder Clearance of auxiliary feeder at support < 400 mm above tie rod chain or portal boom

6 months

Note 1 – For fixed anchored OHW, minimum contact height at the maximum design

conductor temperature (generally 55 °C for open route and 45 °C in tunnels) shall be

determined by height and temperature measurements. RailCorp program MinCont

may be used to calculate the minimum contact height from these measurements.




14.3. Conductor fittings The corrective maintenance triggers for OHW conductor fittings along with the maximum

corrective action time to repair each defect is given in Table 9.

Table 9 - Corrective maintenance triggers – Conductor fittings


General

Signs of stranding, annealing, burning, abnormal wear or looseness for feeding jumpers, potential jumpers and in-span feeders.

3 months

Droppers Dropper broken or detached from contact wire with no objects below contact 3 months

Droppers Dropper rubbing against another conductor or fouling sliding knuckle 1 week

Droppers Vertical alignment of standard dropper along track > 20% of dropper length (drifted droppers)

3 months

Droppers Vertical alignment of short dropper along track > 10 mm 3 months

In-span feeders Vertical alignment of in-span feeder along track > 20% of in-span feeder length 6 months

In-span feeders In-span feeder rubbing against another conductor 3 months

Contact wire full splice Excessive wear indicated by the development of a 'V' shape at the point where the contact wire enters the body

6 months

Section insulators Signs of poor running performance such as arcing, burning and excessive wear 3 months

Section insulators

Bent or damaged arcing horns, damaged or skewed runners, guy slackness, loose attachment bolts, damaged insulator. If a risk assessment determines that pantographs may suffer damage then the base safety parameters are to apply.

1 week

Knuckles Signs of excessive degradation or corrosion, out of adjustment or loose attachment bolts (refer note 1)

3 months

Over-run protection Signs of damage or incorrect alignment 3 months

Note 1 – Consideration should be taken for possible long lead times to implement

corrective maintenance actions for insulated knuckles with timber beams. See

Section 11 for information on insulated knuckles.




14.4. Switching and feeding arrangements The corrective maintenance triggers for OHW switching and feeding arrangements along with

the maximum corrective action time to repair each defect is given in Table 10.

Table 10 - Corrective maintenance triggers – Switching and feeding arrangements


General Signs of stranding, annealing, burning, abnormal wear or looseness for feeders and jumpers.

3 months

Switches

Signs of burning or overheating. Misalignment of blade with jaws. Blade not fully engaged with jaws when switch is in closed position.

3 months

Switches Surface deterioration or contamination of insulated operating rod 6 months

Switches Operating handle mechanism damaged or not operating freely and smoothly. Parts of mechanism loose or missing.


Switches Operator platform damaged or missing 3 months (refer note 1)

Switches Bonding between switch handle and operator platform damaged or missing


Switches Rail connection cable, where applicable, missing, damaged, or disconnected from mast or rail.


Switches Labels (switch identification and switch handle position) incorrect, missing, obscured or not securely attached.


Aerial feeders Clearance of aerial feeder to adjacent track < 1.5m when they are of different electrical sections

3 months

Aerial feeders

Minimum electrical clearance of aerial feeders from other conductors at crossing under worst case (wind, wire movement and temperature) < 150 mm

3 months

Aerial feeders Feeders do not have sufficient slack to allow for full range of conductor movement 3 months

Surge arresters Damaged or missing connection to earth electrode 1 week

Structure earthing and bonding

Switch or feeding structure not earthed or bonded to rail in accordance with design


Note 1 – Arrange for switch operation to be disabled immediately by appropriate

locking mechanism in accordance with the TfNSW safety management system, and

arrange for advice of alteration to electrical operating diagrams. © State of NSW through Transport for NSW Page 21 of 30



Note 2 – Install temporary signs or warning labels immediately.

14.5. Support and registration arrangements The corrective maintenance triggers for OHW Support and registration arrangements along with

the maximum corrective action time to repair each defect is given in Table 11.

Table 11 - Corrective maintenance triggers – Support and registration arrangements


Pull off arm Heel height negative but heel is clear of pantograph running from observation of the passage of trains

3 months

Catenary support Deviation from design along track position > 100 mm, having due regard to conductor temperature and distance from fixed anchor

6 months

14.6. Anchor arrangements The corrective maintenance triggers for OHW anchor arrangements along with the maximum


Table 12 - Corrective maintenance triggers – Anchor arrangements


Guy arrangement Excessive corrosion with more than 10% loss in section or damage to guy rods, fittings or wires

6 months

Guy arrangement Lugs or fittings buried by ballast 6 months

Fixed midpoint arrangement

Signs of conductor movement through clamps 3 months

Weight tensioner arrangement

Weights unable to move freely up and down with conductor temperature changes 3 months


Movement of weight stack through the design conductor temperature range (as determined by RailCorp program 'WeightSet.xlt') is impeded due to the presence of obstructions or incorrect position of weight stack.

To be determined from extent of allowable travel and consideration of time of year


Yoke plate of combined weight tensioner arrangement jammed 3 months


Damage (for example excessive corrosion or stranding) to tension regulator wire rope 3 months




14.7. Support structures The corrective maintenance triggers for OHW support structures along with the maximum


Table 13 - Corrective maintenance triggers – Support structures


Clearance to HV aerial lines

Clearance to high voltage aerial lines less than that stipulated in EP 10 01 00 05 SP


Structure deformation Deformation of structures, for example twisting of mast or drop vertical

Report to civil discipline within 1 day

Structure and guy foundation Signs of movement in ground Report to civil

discipline within 1 day

Structure and guy foundation

Corroded steel work, for example bridge and tunnel supports, and anchor lugs

Report to civil discipline

Drop verticals Clearance of drop vertical to superelevated centreline of adjacent track < 1500 mm

3 months

Labels Incorrect, missing, or obscured structure labels


Structure bonding Missing, damaged, or incorrect installation of structure bonding arrangement 3 months

Wood poles See EP 10 01 00 02 SP HV aerial line maintenance standards

See EP 10 01 00 02 SP

Note 1 – Temporary warning signs or access barriers to be in place within one day.

Note 2 - Temporary labels to be in place for critical structures (for example structure

with switch) within one day.

15. Base safety or operating limits Common base safety or operating limits, as well as maximum allowable time to complete

repairs, are listed in the subsections below.

Except where immediate repair action is required as outlined in this section, a risk analysis shall

be performed immediately after a breach of any of the base safety and operating limits is found.

Restrictions on OHW and/or train operations may have to be imposed prior to the completion of

the repair work. Such restrictions include the following:

• track speed limits

• suspension of train services through the affected area

• removal of power from OHW




The values listed for 'time to complete corrective action' are maximum allowable times.

Immediate action shall be initiated if there is a risk of imminent failure. The maximum allowable

times may be varied as a result of a risk analysis performed by the responsible AEO under a

judgement of significance (JOS) process for OHW, with consideration given to the applicable

site specific operating environment and the implementation of temporary measures.

15.1. General The base safety or operating limits for general items associated with OHW along with the

corrective action time to complete the repair of each defect is given in Table 14.

Table 14 – Base safety or operating limits - General

Parameter Base safety or operating limit

Immediate checks and temporary measures

Time to complete corrective action

Insulators Loss of insulation (for example broken porcelain)

Stop trains Immediate

Insulators Sustained arcing across insulator Stop trains Immediate

Insulators

Insulator at risk of detachment failure due to excessive corrosion of tongue or cap

As required from risk analysis 1 day

Insulators Twist in polymeric insulator > 40°


Insulators

Insulator skirt clearance above in running contact wire – < 150 mm for porcelain insulators < 75 mm for composite insulators


Small parts steelwork

Risk of component failure due to excessive corrosion


Vegetation clearance

Vegetation touching live OHW or pantograph Stop trains Immediate

Static clearances Signs of arcing across an air gap

As required from risk analysis Immediate

Static clearances Static clearance to 'earthed' metalwork < 50 mm

Install bonding to rail via a spark gap if metalwork may be touched

1 day

Static clearances Static clearance to 'earthed' non-conductive material < 20 mm


te of NSW through Transport for NSW Page 24 of 30

© Sta






Passing clearance (refer note 1)

Signs of striking by or arcing from pantograph Stop trains Immediate


Passing clearance to 'earthed' metalwork < 50 mm

Install bonding to rail via a spark gap if metalwork may be touched

1 day


Passing clearance to 'earthed' non-conductive material < 20 mm


Note 1 – Passing clearance to the pantographs shall be determined by ASA approved

software tools.

15.2. Conductors The base safety or operating limits for OHW conductors along with the corrective action time to

complete the repair of each defect is given in Table 15.

Table 15 – Base safety or operating limits – Conductors




General

Clearance between 2 parallel wires of different electrical sections (for example midbay in open overlaps) under worst case of blowout < 100 mm

Advise Electrical Operating Centre (EOC) immediately

As per instruction from EOC

General

Clearance of span wire above in running contact wire (without fender fitting) < 75 mm at support structure < 150 mm at mid bay

Impose speed restriction under continuous observation

1 day

General Object hanging below the in running contact wire Stop trains Immediate

Contact wire height < 4.47 m

Check with the EOC to see if the relevant DCCB’s are tripping. Perform immediate repairs if so.

1 day







Contact wire height

< 4.9 m at a public road level crossing, or at a service road level crossing without a warning frame

Advise police (for public road level crossings) and use traffic controllers to exclude high vehicles from the level crossing.

1 day

Contact wire height

< 0.3 m above the maximum permissible vehicle height at a service road level crossing with a warning frame.

Use traffic controllers to exclude high vehicles from the level crossing.

1 day

Contact wire stagger

> 500 mm (priority 1 exceedance for OHW geometry measuring vehicle)

Observe passage of trains, and impose speed restrictions (refer note 1) if contact wire is within 100 mm of the pantograph horn.

1 day

Contact wire thickness

Contact wire thickness at or below elastic limit. See Section 7.2.4

Repairs may be deferred by up to one day if the temperature remains sufficiently high for fixed anchored systems, or if the contact wire tension is reduced temporarily by removing sufficient number of weights from the tension regulator.

Immediate

Damaged conductors

Signs of damage (for example stranding) with less than half the original conductor cross-sectional area remaining.


Note 1 – Do not reduce speed on curve if excessive stagger is at structure but midbay

stagger is acceptable.




15.3. Conductor fittings The base safety or operating limits for OHW conductor fittings along with the corrective action

time to complete the repair of each defect is given in Table 16.

Table 16 - Base safety or operating limits – Conductor fittings




General

Any damaged equipment (for example broken or detached droppers, in-span feeders, wear strips, jumpers and knuckles) hanging below the contact wire


Cast tension fittings

Cracked or fractured cast tension fittings Stop trains Immediate

Contact wire full splice

Excessive wear with the distance from the end of the splice to the vertex of the 'V' shape > 135 mm


Contact wire full splice

Deformation along the edge of the 'V' shape opening


Section insulators

Broken or detached runner or guy or any outcome from a risk assessment that determines an unacceptable risk in damage to pantographs.

Stop trains, except that trains may proceed under continuous observation if approved by the relevant AEO

Immediate

Electrical connections

Signs of excessive burning that may cause imminent failure of the conductors





15.4. Switching and feeding arrangements The base safety or operating limits for OHW switching and feeding arrangements along with the

corrective action time to complete the repair of each defect is given in Table 17.

Table 17 - Base safety or operating limits – Switching and feeding arrangements




Aerial feeders

Aerial feeders hang below contact wire Stop trains Immediate

Aerial feeders

Feeder displaced and bridging two electrical sections (electrical protection compromised)

Advise EOC

1 day, unless immediate repair is required by EOC

15.5. Support and registration arrangements The base safety or operating limits for OHW support and registration arrangements along with

the corrective action time to complete the repair of each defect is given in Table 18.

Table 18 - Base safety or operating limits – Support and registration arrangements




Pins/fasteners

Dislodged pin or fastener which may cause fitting (for example pull off arm) to fall below contact wire or in front of train


Pins/fasteners Partially dislodged pin/fastener

Monitor and observe passage of trains Immediate

Pull off arm heel height

Signs of striking by pantograph Stop trains Immediate

Pull off arm heel height

Clearance of pantograph to heel of pull off arm < 20mm Impose speed restriction 1 day




15.6. Anchor arrangements The base safety or operating limits for OHW anchor arrangements along with the corrective

action time to complete the repair of each defect is given in Table 19.

Table 19 – Anchor arrangements





Weights bottomed or pulley blocks in contact with each other

Patrol tension length and observe performance of OHW with passage of trains. Impose speed restriction if required.

1 day, if no other critical issue is identified by the patrol.


Weights 'top out' at pulley

Patrol tension length and observe performance of OHW with passage of trains. Impose speed restriction if required.

1 day, if no other critical issue is identified by the patrol.


Damage (for example excessive corrosion and stranding) to more than half of the strands of the wire rope


15.7. Support structures The base safety or operating limits for OHW support structures along with the corrective action

time to complete the repair of each defect is given in Table 20.

Table 20 – Base safety or operating limits – Support structures




Guy foundation

Guy foundation moving in ground

Stop trains. Report to Civil Discipline immediately. Immediate

Structure bonding

Bond wire hangs below contact wire Stop trains Immediate

Structure bonding

Bond wire hanging and touching or near live equipment

Check spark gap arrangement. Repair immediately if arcing or if spark gap has been activated.

1 day, if there is no arcing and spark gap has not been activated

Structure bonding

Damage to bond wire insulation at crossing with rail

N/A Immediate

Wood poles See EP 10 01 00 03 SP HV aerial line base safety and operating standards

See EP 10 01 00 03 SP See EP 10 01 00 03 SP




16. Data set associated with overhead wiring maintenance The maintainer shall ensure that the data set associated with OHW, as stipulated in

EP 08 00 00 01 SP is up to date and in accordance with the as-built configuration.

Any deviations from standard operating conditions, such as a maximum conductor temperature

higher than 60 °C for regulated OHW with 'short' tension lengths, shall be clearly indicated on

the relevant layout drawing(s).

Where urgent repairs are carried out, the maintainer shall ensure that the data set associated

with the OHW is updated in accordance with the as-built configuration as soon as practicable,

and not less than one month after the completion of the repairs.


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