Engineering Specification
Signals
SPG 1012
CABLES FOR RAILWAY
SIGNALLING APPLICATIONS SINGLE AND TWIN CONDUCTOR
CABLES
Version 1.1
Issued May 2010
Owner:
Warwick Allison, Chief Engineer Signals and Control Systems
Approved
by:
Warwick Allison
Chief Engineer
Signals and Control Systems
Authorised
by:
Paul Szacsvay
Principal Engineer
Signalling Technology
Disclaimer
This document was prepared for use on the RailCorp Network only.
RailCorp makes no warranties, express or implied, that compliance with the contents of this document shall be
sufficient to ensure safe systems or work or operation. It is the document user’s sole responsibility to ensure that the
copy of the document it is viewing is the current version of the document as in use by RailCorp.
RailCorp accepts no liability whatsoever in relation to the use of this document by any party, and RailCorp excludes
any liability which arises in any manner by the use of this document.
Copyright
The information in this document is protected by Copyright and no part of this document may be reproduced,
altered, stored or transmitted by any person without the prior consent of RailCorp.
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Page 1 of 5
Engineering Specification
Equipment Specification
RailCorp Engineering Specification — Signals — Equipment Specification
Cables for Railway Signalling Applications - Single and Twin Conductor Cables
SPG 1012
Document control
Version
Date
Summary of change
1.0
September 2005
Replaced SC 11 11 09 00 Cables for Signalling Applications Single and Twin Conductor Cables
1.1
May 2010
Application of TMA 400 format
Contents
1
Scope and Application ...........................................................................................................3
2
Applicable Standards .............................................................................................................3
Australian Standards .................................................................................................3
RailCorp Specifications..............................................................................................3
3
Types Of Cables ......................................................................................................................3
3.1
Twin Twist Cable .......................................................................................................3
3.2
Twin Cable for "Staff Line".........................................................................................3
3.3
Twin Cables ...............................................................................................................4
4
Construction............................................................................................................................4
4.1
Conductor ..................................................................................................................4
4.2
Insulation ...................................................................................................................4
4.3
Twisting......................................................................................................................4
4.4
Nylon Covering ..........................................................................................................5
4.5
Length ........................................................................................................................5
5
Identification (Marking)...........................................................................................................5
5.1
Marking on Cables.....................................................................................................5
5.2
Resistance of Cores (Specified Values) ....................................................................5
© RailCorp
Issued May 2010
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Page 2 of 5
Version 1.1
RailCorp Engineering Specification — Signals — Equipment Specification
Cables for Railway Signalling Applications - Single and Twin Conductor Cables
1
SPG 1012
Scope and Application
This Specification describes the specific requirements for Single and Twin Conductor
Cables for use on RailCorp Network for signalling applications.
This Specification shall be read in conjunction with Specification SPG 1010 Cables for
Railway Signalling Applications - General Requirements.
2
Applicable Standards
Australian Standards
This Specification refers to the following Australian Standards:
AS 5000-1999 - Electric Cables – Polymeric insulated for working voltages up to and
including 0.6/1KV
RailCorp Specifications
This Specification refers to the following RailCorp Specifications and Standards:
Specification SPG 1010 Cables for Railway Signalling Applications - General
Requirements
3
Types Of Cables
This Specification covers the following types of cables:
3.1
a)
Single conductor P.V.C. insulated and P.V.C. sheathed cable.
b)
Single conductor P.V.C. insulated, P.V.C. sheathed and nylon covered cable.
c)
Two single conductor P.V.C. insulated and sheathed cables combined to form a
twin twist cable.
d)
Two single P.V.C. insulated conductors combined to form a twin cable with a
P.V.C. sheath and a nylon covering.
e)
Twin conductor cable having individually P.V.C. insulated conductors laid up in
a P.V.C. sheath wound with copper tapes and the whole sheathed in P.V.C. and
covered in nylon.
Twin Twist Cable
2x (7/0.5 Red, Blk PVC/Blk PVC) -RailCorp Item No 8 termed as "TWIN TWIST cable"
Two cables of this type are to be used to form a twin twist cable. One inner core
insulation to be red, the other inner core insulation to be black (Two individual cables
twisted).
3.2
Twin Cable for "Staff Line"
2x (7/0.85 Blue, Yel PVC)/Blk PVC/Nylon - RailCorp Item No 12 (Core colours Blue &
Yellow)
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Issued May 2010
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Version 1.1
RailCorp Engineering Specification — Signals — Equipment Specification
Cables for Railway Signalling Applications - Single and Twin Conductor Cables
SPG 1012
Two cables of this type are to be used to form a twin cable. One inner core insulation to
be blue, the other inner core insulation to be yellow.
3.3
Twin Cables
Twin cables mentioned below shall have individually P.V.C. insulated conductors laid up
in a P.V.C. sheath wound with copper tapes and the whole sheathed with P.V.C. and
covered with nylon.
Between the inner and the outer sheath two layers of copper tape each 0.08mm thick
with a 10% gap shall be provided. The centre of the second layer shall be located
accurately over the centre of the gap of the first layer.
The width shall not exceed 2 x the diameter of the inner sheath and shall be within the
range of 1 to 2 times the OD.
2x (7/0.85 Red, Blk PVC)/Blk PVC/DCT/Blk PVC/Nylon - RailCorp Item No 11 (Core
colours Red & Black)
2x (7/1.7 Red, Blk PVC)/Blk PVC/DCT/Blk PVC/Nylon - RailCorp Item No 17 (Core
colours Red & Black)
2x (19/1.78 Red, Blk PVC)/Blk PVC/DCT/Blk PVC/Nylon - RailCorp Item No 20 (Core
colours Red & Black)
(Refer to Specification SPG 1010 Cables For Railway Signalling Applications - General
Requirements.)
4
Construction
4.1
Conductor
Conductors used in the manufacture of cables for this Specification shall be un-tinned
plain-annealed copper.
For power cables finer wire strands even in the order of 0.3mm can also be considered,
as evaluations proved the suitability for certain applications. This applies to cables with
conductor cross sectional area ranging up to 120mm2.
4.2
Insulation
In addition in cables requiring a nylon covering the sheath shall have incorporated in it a
compound that will tend to extinguish the nylon covering in case of fire. In the case of
Cable (1/1.7 Blk PVC/Blk PVC), the sheath shall be extruded over the primary insulation
without the use of chalk so as to form a bond between the insulation and sheath.
4.3
Twisting
In twin core cables the cores shall be uniformly twisted together to form a pair with a lay
length of not greater than 150mm for cables up to 16 mm2. The lay of the Twin Twist
Cable shall be approximately 50mm.
Each conductor shall be double insulated and then twisted.
© RailCorp
Issued May 2010
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Page 4 of 5
Version 1.1
RailCorp Engineering Specification — Signals — Equipment Specification
Cables for Railway Signalling Applications - Single and Twin Conductor Cables
4.4
SPG 1012
Nylon Covering
A nylon covering shall be provided where specified, having a radial thickness as specified
in Specification SPG 1010 Cables For Railway Signalling Applications - General
Requirements. The nylon shall be a black ultraviolet stabilised type 11 or 12 covering.
4.5
Length
Length shall be as specified in Specification SPG 1010 Cables for Railway Signalling
Applications - General Requirements.
5
Identification (Marking)
Marking on cables shall be in accordance with Specification SPG 1010 Cables for
Railway Signalling Applications - General Requirements. The additional information shall
be as follows:
5.1
Marking on Cables
The following additional requirements shall apply:-
5.2
a)
RailCorp Item No8:- the sheath of one core shall be embossed or indented "For
Telephone Circuits Only"
b)
RailCorp Item No14:- the information shall be embossed on the sheath length
markings are not required
c)
RailCorp Item No13:- length markings are not required
d)
RailCorp Item No12:- Nylon covering and drums to be marked with legend"RailCorp 2x 7/0.85mm B/Y"
Resistance of Cores (Specified Values)
© RailCorp
Issued May 2010
Conductor Size
Max. Resistance
Nominal Resistance
(as per AS 1125)
7/0.50mm
14 Ohm/km
13.6 Ohm/km
7/0.85mm
6 Ohm/km
4.61 Ohm/km
7/1.70mm
1.5 Ohm/km
1.15 Ohm/km
19/1.78mm
0.495 Ohm/km
0.387 Ohm/km
37/1.78mm
0.27 Ohm/km
0.199 Ohm/km
37/2.03mm
0.20 Ohm/km
0.152 Ohm/km
1/1.78mm
11 Ohm/km
7.28 Ohm/km
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