General Information on Track Circuits - RGS Online

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<strong>General</strong> <strong>Information</strong> on Track Circuits
Railway Group Approved Code of Practice
GK/RC0752
Issue Two
Date December 1998
Page D13 of 20
throughout except for permissible spurs (see 13.4). In electrified areas, there
are no other electrification related bonds from either rail other than via the centre
connection of impedance bonds.
Non–electrified Lines - Standard jumper bonds to both running rails.
Electrified Lines - Traction jumper bonds to both running rails.
13.3.2 DRSS (Double Rail/Single Series)
This is where each track circuit is fully isolated from its neighbours by IRJs in
both rails, and one rail of the track circuit is series bonded throughout except for
permissible spurs (see 13.4). The other rail of the track circuit contains elements
of parallel bonding.
Non–electrified Lines - Standard jumper bonds to the series bonded
rail and to the true series bonded elements of
the other rail.
Electrified Lines - Not applicable
Yellow standard bonds to interconnect the
parallel elements.
13.3.3 CR Class (Common Rail)
This is where each track circuit is isolated from its neighbours by IRJs in one rail
only (the signal rail), and that rail is series bonded except for permissible spurs
(see 13.4). The other rail is electrically common with adjacent track circuits and
may have parallel bonded elements, but does not carry traction current.
Non-electrified Lines
bonded
- Standard jumper bonds to the series
Signal Rail.
Yellow standard bonds to the common rail.
Electrified Lines
13.3.4 SR (Single Rail)
- Not Applicable
This is where each track circuit is isolated from its neighbours by IRJs in one rail
only (the signal rail), and that rail is series bonded except for permissible spurs
(see 13.4). The other rail is electrically common with adjacent track circuits and
forms part of a mesh carrying traction current.
Non–electrified Lines - Not applicable
Electrified Lines
13.4 Permissible Spurs
- Standard jumper bonds to the signal rail.
Yellow traction bonds to the traction rail.
This clause covers the permissible arrangements for parallel bonded spur
sections of an otherwise series bonded track circuit section. Parallel bonded
spurs on common/traction rail sections are not separately identified, since they
are covered by the general requirements for bonding of such rails.
Spurs up to 13m, measured from the first joint or weld of a crossing, shall be
permitted as shown in Figure D9. provided that there is a maximum of one
fishplated joint between the series bonded rail and the end of the spur, and that
this joint is properly bonded.
Spurs up to a maximum of 60m, measured from the first joint or weld of a
crossing, shall be permitted, provided they are yellow bonded to the parent
series rail.
RAILTRACK D13