General Information on Track Circuits - RGS Online

<strong>General</strong> <strong>Information</strong> on Track Circuits
Railway Group Approved Code of Practice
GK/RC0752
Issue Two
Date December 1998
Page E3 of 52
4 Identification of
Track Circuit
Boundaries Where required, a plate may be fixed to the sleepers or to the lineside track
circuit equipment to assist identification of track circuit limits.
5 Protection of
Cross Track
Cables
Withdrawn Document
Uncontrolled When Printed
Wherever a track circuit boundary occurs in a tunnel, a plate bearing the track
circuit name or number must be fixed to the tunnel wall on each side of the IRJ
(or equivalent in the case of a jointless track circuit).
5.1 <strong>General</strong>
Cross track tail cables and jumpers should be protected from damage, eg. by
means of orange plastic pipe. This protection need not be continuous across the
cess or six–foot, but should be used where tail cables pass under walkways.
5.2 Orange Pipe Installation
Cut the pipes to length so that the ends are clear of the ballast shoulder. This
helps to prevent ballast from entering. Restrict each pipe length to 3 metres
maximum as long lengths of pipe will not move out of the way if struck by a
tamper tine. However, in S & C areas it may be necessary to use longer lengths
to give full protection across the sleeper bay. It is particularly important that the
pipe is laid straight and centrally in the sleeper bay, and that holes for rail leads
are as close to the rail as possible, in order to give maximum protection from
tamping machines.
Do not use the ballast to restrain sideways movement. Dig the pipe into a
shallow depression in the ballast keep it visible but allow sideways movement if
struck.
Do not fill a pipe more than half full with cables. This reduces the chance of cable
damage if the pipe is crushed by a tamper. If more cables have to be run,
provide another pipe.
Wherever possible, do not install a pipe in a sleeper bay adjacent to conductor
rail ramped end to prevent the pipe being ignited by sparks from the collector
shoe.
To allow the Permanent Way Engineer maximum opportunity for tamping, do not
position a pipe:
• in a bay where there is a rail joint or weld, or in a bay adjacent to them;
• in a bay which is less than 0.37 metres (1 foot 3 inches) wide, unless there
is no other choice;
• in a bay which already has an orange pipe or other obstruction, or in one
adjacent to it. Always leave at least one clear bay between obstructed bays.
If a pipe needs side holes for the exit of track connection cables:
a) Cut the holes with a good quality 40 to 50 mm fixed diameter hole saw. Do
not use other methods of making holes. Round off the sharp edges of the
hole with a file or deburring tool.
R A I L T R A C K E 3