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Overhead Wiring Conductor System Selection

T HR EL 08010 ST

Standard

Version 1.0

Issued date: 09 May 2016

Important Warning This document is one of a set of standards developed solely and specifically for use on Transport Assets (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 is uncontrolled when printed or downloaded. Users should exercise their own skill and care in the use of the document. This document may not be current. Current standards may be accessed from the Asset Standards Authority website at www.asa.transport.nsw.gov.au. © State of NSW through Transport for NSW

http://www.asa.transport.nsw.gov.au/

T HR EL 08010 ST Overhead Wiring Conductor System Selection

Version 1.0 Issued date: 09 May 2016

Standard governance

Owner: Lead Electrical Engineer, Asset Standards Authority

Authoriser: Chief Engineer, Asset Standards Authority

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

Document history

Version Summary of Changes

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 document supersedes RailCorp standard EP 08 00 00 17 SP Overhead Wiring Conductor

System Selection, Version 2.1. Changes to the previous standard include the following:

• updates to reflect ASA organisation and responsibilities

• minor amendments and clarifications

• conversion to the ASA numbering, format and style

This standard has been approved by the ASA Configuration Control Board and is a first issue.

© State of NSW through Transport for NSW of 18



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

2. Purpose .................................................................................................................................................... 5 2.1. Scope ..................................................................................................................................................... 5 2.2. Application ............................................................................................................................................. 5

3. Reference documents ............................................................................................................................. 6

4. Terms and definitions ............................................................................................................................. 6

5. Approved OHW systems ......................................................................................................................... 6

6. Operating conditions .............................................................................................................................. 7 6.1. Ambient temperature range ................................................................................................................... 7 6.2. Maximum train speed ............................................................................................................................ 7 6.3. Operation of electric locomotives .......................................................................................................... 8 6.4. Traction current demand ...................................................................................................................... 11 6.5. OHW junctions ..................................................................................................................................... 15 6.6. Life cycle costs .................................................................................................................................... 16

Appendix A OHW system continuous current carrying capacity ...................................................... 17




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 the trains is carried by both the catenary and contact wires.

2. Purpose This standard specifies the requirements for selecting an OHW conductor system to suit the

train operating conditions on the Transport for NSW (TfNSW) heavy rail network.

2.1. Scope This document sets out the technical criteria for the following:

• selecting an OHW conductor system for electrification or major upgrading works that is

most suitable for a particular section of track

• determining if an existing OHW conductor system is suitable for proposed changes to

operating conditions

The different OHW systems are referred to in this document by the system numbers defined in

T HR EL 08009 ST Designations of Overhead Wiring Conductor Systems.

2.2. Application The requirements of this document are applicable to new OHW electrification projects and major

modifications to existing OHW. This document can be used in assessing the suitability of an

existing OHW conductor system for proposed changes to operating conditions.

This standard is intended to be used by competent personnel engaged in the provision of

services relating to rail infrastructure. Compliance with the requirements in this standard will not,

by itself, be sufficient to ensure that satisfactory outcomes will be produced. Personnel providing

services based on the standard need to bring appropriate expertise to the matters under

consideration. In addition to the requirements of this standard, asset decisions should take into

account the lifecycle cost considerations specified in T MU AM 01001 ST Life Cycle Costing.

If, when using this standard, it is considered that the intent of stated requirements is not clear, a

clarification should be sought from the Lead Electrical Engineer, Assets Standards Authority

(ASA).




3. Reference documents The following documents are cited in the text. For dated references, only the cited edition

applies. For undated references, the latest edition of the referenced document applies.

Australian standards

AS/NZS 7000 Overhead line design – Detailed procedures

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

T HR EL 08009 ST Designations of Overhead Wiring Conductor Systems

T MU AM 01001 ST Life Cycle Costing

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

ASA Asset Standards Authority

droop the amount the contact wire is lowered at mid-bay in fixed anchored OHW due to the

heating of its supporting catenary wire. This amount is relative to a flat contact wire through the

bay which corresponds with the design temperature of the conductor system

hog the condition in which the contact wire between two OHW support structures is above the

straight line joining the contact wire registration points at the structures

OHW overhead wiring

TfNSW Transport for NSW

5. Approved OHW systems The OHW system selected for the electrification of new routes and major upgrading works for a

particular section of track shall meet the following:

• be one of the systems that are classified as 'current'

• be suitable for operating conditions required in the section of OHW

• have a life cycle cost that satisfies the financial objectives of the investment

Refer to T HR EL 08009 ST Designations of Overhead Wiring Conductor Systems and

EP 08 00 00 01 SP Overhead Wiring Standards for the Electrification of New Routes for the

OHW conductor systems that are classified as current and their intended application.




6. Operating conditions Satisfactory train operation requires that the contact wire provide a near flat profile with a

gradual change in height for smooth and uninterrupted pantograph current collection.

The capacity of the different OHW systems to perform under various operating conditions as

provided in Section 6.1 through to Section 6.6 is for newly installed OHW. Where it is required to

assess the suitability of existing OHW for proposed changes in operating conditions,

consideration shall be given to the condition of the existing OHW.

6.1. Ambient temperature range The conductor tension of fixed anchored OHW systems varies with temperature variations and

as a result, the contact wire droops or hogs with the temperature variations (hot and cold

respectively).

Fixed anchored systems therefore provide less satisfactory dynamic pantograph performance at

temperatures that are significantly different from the design temperature.

The operating temperature of OHW conductors is a function of the traction current, ambient

temperature and other environmental conditions. Due to variances in conductor tension of fixed

anchored OHW systems, caused by temperature changes, a fixed anchored system will reach

one of the operational limits, specified in Section 6.4, at a wire temperature lower than that for a

regulated system with similar conductors. Therefore, fixed anchored systems have lower current

carrying capacities when compared with regulated systems.

Fixed anchored OHW systems are not suitable for areas with large ambient temperature ranges

where high speed train operations or high current carrying capacities are required. Refer to

Section 6.2 and Section 6.4 for limitations of each OHW system for maximum train speed and

traction current demand.

6.2. Maximum train speed Fixed anchored OHW systems are not suitable for high train speed operations as outlined in

Section 6.1. The maximum speeds that electric trains can operate under each of the OHW

systems are given in Table 1. Lower speed restrictions are placed on the operation of coupled

electric locomotives for some OHW systems. Refer to Section 6.3 for operation of multiple

coupled electric locomotives.

Table 1 - Maximum train speeds for OHW systems

System identification number Maximum train speed (km/h)

1 130

2 160

3 130 © State of NSW through Transport for NSW of 18



System identification number Maximum train speed (km/h)

4 130

5 130

6 130

7 130

8 130

9 130

10 60

12 160

13 130

14 25

15 160

21 100

22 80

23 100

24 100

25 60

26 60

27 100

28 115

33 25

34 25

35 115

36 25

6.3. Operation of electric locomotives The operation of electric locomotives can result in increased uplift on the contact wire or wires.

This uplift is further increased if both pantographs of each coupled locomotive are raised.

Excessive uplift of the contact wire or wires results in unsatisfactory pantograph operation and,

in extreme cases, can cause damage to the pantograph and OHW equipment.

The effect of uplift forces is limited by having an OHW system with relatively high contact

tension and with more weight in the contact wire.

Table 2 lists the suitability of each OHW system for the operation of multiple coupled electric

locomotives and the number of pantographs that can be raised.




Table 2 - Operation of multiple coupled electric locomotives

System identification number

1 locomotive & 1 pantograph

1 locomotive & 2 pantographs per locomotive

2 locomotives & 1 pantograph per locomotive

2 locomotives & 2 pantographs per locomotive





1 Yes Yes Yes Yes Yes No Yes No

2 Yes Yes Yes Yes Yes Yes Yes No

3 Yes Yes Yes Yes * Yes No Yes No










14 Yes Yes Yes No Yes No Yes No












System identification number

1 locomotive & 1 pantograph

1 locomotive & 2 pantographs per locomotive












Note: * Limited to maximum speed of 80 km/h.




6.4. Traction current demand The capacity of any OHW system to carry the required traction current is limited by the

maximum conductor temperature (catenary or contact). The maximum conductor temperature of

an OHW system is the lowest of the conductor operating temperatures corresponding to the

limit conditions detailed in Section 6.4.1 to Section 6.4.5.

6.4.1. Annealing The design operating temperature of OHW conductors shall not exceed 80 °C to avoid damage

from annealing.

6.4.2. Conductor temperature range for regulated OHW The average conductor temperature for regulated OHW over a tension length shall be within the

ranges stipulated in EP 08 00 00 01 SP.

6.4.3. Electrical clearance to rolling stock

In a fixed anchored system the catenary wire supports the contact wire such that the contact is

a straight wire or 'flat' at the design temperature, which is typically 21 °C for open route

situations.

Any change in the catenary shape has a direct impact on the level of the contact wire

particularly towards mid-bay. When the catenary heats up, any additional catenary sag will

cause the contact wire to also sag or droop from its flat profile by a similar amount. Refer to

Figure 1 for an example. Under cold conditions the reverse happens, that is, the contact wire

hogs (rises from its flat profile towards mid-bay).




60m bay

(a)Design catenary

sag @ 21 °C

(b)Catenary sag

@ 55 °C

System weight = 42 N/m

Catenary virtual span = 58.5 m

Contact virtual span = 4.57 m(b)

Contact wire droop @ 55 °C catenary

temperature Catenary tension reduced from 15.9 kN @ 21 °Cto 13.0 kN @ 55 °C(18% reduction in tension)

265

mm

Height of trainnot to scale

Top of train = 4.42 m

(a)Design contactheight @ 21 °C

Minimum contact wire height

(EP 08 00 00 01 SP)


Figure 1 – Fixed anchored OHW profiles and clearances at (a) 21 °C (design) and (b) 55 °C (hot)

The droop in the contact wire shall not cause the contact wire height to fall below the limits

stipulated in EP 08 00 00 01 SP.

In the open route, the contact wire droop under hot conditions can be somewhat compensated

for by having a higher standard contact wire height at the supports. This allows for a greater

range of contact droop before the minimum contact wire height is reached. This means that

longer bay lengths can be used.

However, in a tunnel where the OHW heights are typically much reduced because of the limited

headroom, the lower design contact wire height does not allow for as great a range in droop

before reaching the minimum contact wire height. This necessarily limits the bay lengths.

6.4.4. Contact wire droop The tension in a conductor of a fixed anchored OHW is determined by the virtual span and the

conductor temperature. Refer to AS/NZS 7000 Overhead line design – Detailed procedures for

an explanation of 'ruling span' or 'virtual span'. The catenary tension at its maximum operating

temperature sets the maximum amount of contact wire droop at mid-bay.

The contact wire droop due to temperature rise shall not unduly affect the collection of current

by train pantographs at speed. The maximum contact wire droop at mid-bay from the level

(design) condition shall not exceed the limits provided in Table 3.



Table 3 - Maximum contact wire droop for various train speeds

Track speed (km/h) Maximum contact wire droop (mm)

Up to 80 Bay length in meters x 4.2

80 to 100 Bay length in meters x 3.5

Over 100 Bay length in meters x 2.8

An example of contact wire droop in a fixed anchored OHW system with a 60 m bay and train

speeds up to 100 km/h is given in Figure 2.


Figure 2 – Fixed anchored OHW contact wire droop limit

6.4.5. Contact wire stiffness There is a risk that the pantograph may be hit by OHW fittings where there is excessive

pantograph uplift. At the maximum operating temperature the contact wire tension shall be

sufficient to withstand pantograph uplift pressure.

The small virtual span of the contact wire has an enormous impact on its tension change with

temperature. Figure 3 shows the ripple effect as the contact wire sags between supporting

droppers on a contact wire with minimal tension. Figure 4 shows the distorted shape of a

contact wire with insufficient tension interfacing with a pantograph.



Figure 3 - Contact wire profile under hot conditions - contact ripple


Figure 4 - Contact wire profile under hot conditions - excessive contact uplift

To ensure that pantograph uplift is controlled, the product of the contact wire tension (at

maximum temperature) and its weight shall not be less than 50,000 N2/m for new contact wire.

That is

ω x T ≥ 50,000 N2/m

Where: ω = contact wire weight (N/m), and

T = contact wire tension @ maximum temperature (N)



For systems with multiple contact wires, the sum of the product (ω x T) for each wire shall not

be less than 50,000 N2/m.

Table 4 lists the minimum contact wire tension required to control pantograph uplift.

Table 4 - Minimum contact tensions (new wire) at hottest operating temperature

Contact size (mm²) Minimum contact tension (kN)

193 3.0

137 4.2

2x137 2.1 each

6.4.6. Current carrying capacity The adequacy of the OHW to carry the required traction current can only be ascertained after a

detailed analysis with the following inputs:

• modes of train operation including:

o type of trains, traction current load characteristics under starting, powering and

regenerative modes

o frequency of trains

o frequency of train starting

• track gradient

• type and size of conductors

• contact wire wear

• OHW design parameters including contact height, maximum bay length, virtual span, and

design temperature and wire tensions

• distance of the OHW section from the feeding substations

• ambient temperature

• wind speed

• solar radiation

Refer to Appendix A for the continuous current ratings of the various OHW systems.

6.5. OHW junctions Configurations with a regulated wire run interfacing with a fixed anchored wire run at a wire

junction are not permitted except where existing OHW systems at junctions are being upgraded

or remodelled.




Such junctions include turnouts and crossovers.

The risks associated with different wire sags shall be adequately addressed in the design when

such junctions are being upgraded or remodelled.

At such junctions, the designer shall ensure that both wires are supported and registered at

appropriate locations so that there is no risk of a pantograph getting above either of the contact

wires when trains traverse the junction in any direction.

6.6. Life cycle costs The selection of an OHW system for electrification and major upgrading works shall be made on

the basis of minimising the life cycle cost as specified in T MU AM 01001 ST.




Appendix A OHW system continuous current carrying capacity Typical continuous current carrying capacity for OHW conductor systems with typical wire run characteristics and the corresponding conductor limit temperatures are

given in Table 5. The following reference conditions are applicable:

• all regulated systems have been limited to a maximum temperature of 60 °C. See EP 08 00 00 01 SP

• twenty per cent wear on the contact wire has been assumed in the calculations

• wind speed in tunnels is considered to be 0.25 m/s

• EP 00 00 00 13 SP Electrical Power Equipment – Design Ranges of Ambient Conditions examined for the location and applicable ambient conditions of each

area

Table 5 - Continuous current carrying capacity for OHW systems

System Type Area 1 (A) ampere

Area 2 (A) ampere

Area 3 (A) ampere

Area 4 (A) ampere

Area 5 (A) ampere

Tunnel (A) ampere

Limiting temperature

1 Regulated 1230 965 930 1230 1440 1130 Catenary – 60 °C













System Type Area 1

(A) ampere

Area 2 (A) ampere

Area 3 (A) ampere

Area 4 (A) ampere

Area 5 (A) ampere

Tunnel (A) ampere

Limiting temperature



14 Regulated 530 420 410 530 620 470 Contact – 60 °C


21 Fixed Anchored 890 480 430 890 1155 N/A Contact – 49 °C

22 Fixed Anchored 1000 605 1000 1200 805 Catenary Contact –

– 59 °C (open route) 42 °C (tunnel)

23 Fixed Anchored 915 360 280 915 1210 N/A Catenary – 54 °C

24 Fixed Anchored N/A N/A N/A N/A N/A N/A N/A



27 Fixed Anchored (Compound) N/A N/A 1150 1715 2070 N/A Catenary – 62 °C

28 Fixed Anchored 1545 1160 1105 1545 1810 1180 Catenary Catenary

– –

66 °C (open route) 57 °C (Tunnel)






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