General Information on Track Circuits - RGS Online

<strong>General</strong> <strong>Information</strong> on Track Circuits
1 Introduction
2 Responsibilities for
Bonding Design
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Part D
Planning and Design
Railway Group Approved Code of Practice
GK/RC0752
Issue Two
Date December 1998
Page D1 of 20
The principles laid down here apply to the planning, layout and design of all
types of track circuits and track circuit bonding. Special requirements for
individual types of track circuit are given in subsequent Codes of Practice within
the Track Circuit Handbook. Signalling design requirements are contained in
GK/RT0201.
Many of the parameters affecting track circuit design are related to the physical
and electrical characteristics of the trains operating over the track circuits.
Dimensions of track sections which are critical for achieving safe and reliable
detection are contained in GK/RT0011 Appendix A. If the accuracy quoted
cannot be attained, dimensions should be rounded up unless otherwise stated
(ie. if a maximum is given).
For a description of terms and definitions used in track circuit design and
operation, see Part B.
For details of symbols used on scheme plans and bonding plans, see Part C.
2.1 <strong>General</strong>
Bonding requirements are contained in GK/RT0252.
2.2 Non–electrified Lines
The design of all track circuit bonding on non–electrified lines is the responsibility
of the Signal Engineer.
This requires the production of detailed scale bonding plans for all track circuiting
in switch & crossing work, usually based on the Permanent Way Engineer’s
track layout plan. On plain line a detailed bonding plan need not be produced,
as long as sufficient detail of feed and relay leads is provided in lineside
apparatus housing diagrams.
2.3 Electrified Lines
Both Signal and Electric Traction Engineers require connections to the running
rails, so compatibility between them is essential. In addition, there are a number
of connections upon which there is common reliance. It is therefore necessary
to have common plans/records that show in detail the track bonding
arrangements. There must be agreement between both parties before any new
work or alterations are carried out. Design Standards are contained in
GM/TT0126 and GM/TT0129.
The Signal Engineer is responsible for the design of:
a) All fishplate bonds in non–traction rails.
b) All fishplate bonds in traction rails of a.c. only electrified areas.
c) The position of all insulated rail joints.
d) All jumper bonds between separate sections of non–traction rails.
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