circuits. This has been replaced
by the installation of a new,
small, green-sheathed, double
insulated, super armoured
cable (DISAC) 24-fibre cable,
designed to be laid on the
surface, running the length of
the branch. SSI track function
modules (TFM) interface the
data link via optical data link
modules.Signalling
On the ground, the signalling
modifications and additions
were extensive. In summary:
» Cutting the existing SSI data
links into the new location
areas to bring them onto the
existing data stream;
» 86 location equipment
cabinets have been affected
(59 altered, five abolished,
22 new);
» Existing signals re-allocated
with new identities relating
to the new Felixstowe
workstation rather than
Colchester prefix;
» 25 new lightweight LED
signals (21 main aspects, four
three-state banner repeaters
but with only ON/GREEN
used, two additional route
indicators either side of
Derby Road);» Recovery of SPAD indicator
signals (surplus since the
provision of TPWS);
» 24 new AWS (Automatic
Warning System);
» 35 new TPWS (Trains
Protection and Warning
System);
» Five new In-bearer Clamp
Lock (IBCL) point ends;
» Eight existing point ends re-
controlled and re-numbered;
» Four new MCB level crossings;
» Existing Felixstowe Beach
and Trimley MCB-CCTV
crossings and associated
Time Division Multiplex
(TDM) systems re-controlled
to new workstation;
» Alterations to insulated block
joint (IBJ) positions to extend
or reduce the length of
existing track circuits;» Provision of new standard-
issue AC-immune DC track
circuits to BR 867 track feed
sets.Electrical & Power (E&P)
E&P teams installed a new
650V DC signalling power
supply feeder throughout
the branch comprising a new
power supply point (PSP) at
Westerfield, upgrade and
modifications to other existing
PSPs, the installation of 42
functional supply points (FSP)
and installation of 45km of new
cabling.
The works also covers the
installation of direct power and
lineside power supplies for
a number of level crossings,
as well as new level-crossing
lighting.
In addition, three points
heating cubicles (PHCC) were
supplied and installed along
with points heating supplies,
transformers and heating strips
for point ends.Permanent way
Track panels and switches and
crossings (S&C) were brought in
by road, rather than the more
usual unloading from tilting rail
wagons, due to limitations of
the single line. There are two
new modular crossovers and
a single turnout. Switches are
type CEN56 EVS.
Redundant trap points were
removed from Trimley.
Thankfully, the line was
originally well built, with a well-
drained and stable formation
including embankments and
cuttings, well able to support
the heavy pounding from
today’s freight tonnage.Trimley track installation.52 FE ATURE