Page 369 - IRSEM_Main Book

(c) The main cable laid parallel to the track shall normally be buried at a depth
of 1.0 meters from top of cables to ground level, including those laid across
the track (1.0 meter below the rail flanges). The depth shall not be less than
0.50 meters for tail cables. In theft prone areas, the cables may be laid at a
depth of 1.2 meters with anchoring at every 10 meters.

(d) Half Cut DWC-HDPE pipe/RCC or any other approved type of ducts/pipes
shall be used while laying the cable for protecting it.

(e) The ducts being used shall be of such design and length to
prevent/minimise damages to cable by any other future digging activities in
the vicinity. The ducts shall have suitable covers to prevent water collection
in the duct.

(f) When cables are to be laid in rocky area, where depth of 1.0 metre is not
feasible, it is desirable that such cables are protected as shown in
Drg. No: 15-D2.

(g) Cables belonging to other department must not be laid in the same trench
along with Signal & Telecommunication cables.
(i) A distance of approximately 10 cm must be maintained between cables
of other department and signalling cables.
(ii) The signalling cables must be separated from LT power cables by a row
of bricks or any other approved means and from HT power cables a
minimum of 3 meters separation shall be maintained.

(h) Where several cables of different categories have to be laid in the same
trench, they shall be placed as far as possible in the following order starting
from the main track side, so that in the event of failures, the maintenance
staff may easily recognise the damaged cables.
(i) Telecommunication cable

(ii) Signalling cable
(iii) Power cable

(i) Signalling cables for outdoor circuits should not normally be laid above
ground. In exceptional cases where it becomes unavoidable, the following
precautions should be taken.

(i) The cable should be suspended in wooden cleats, from cable hangers or
in any other approved manner so that no mechanical damage occurs to
the cable even under exposed condition.

(ii) The cable supports shall be so spaced as to avoid sag.
(iii) In station yards, cable shall be laid in ducts suitably protected.
(iv) Indoor signalling cable should normally be laid on ladders, channels or
in any other approved manner. The cables should be neatly tied/laced.

Note: For laying cables in RE area, please refer to Section 3 of this Chapter.
(j) Where it is necessary to take the cable between the tracks, it shall be
carried in trunking/Duct/pipe kept sufficiently below the ballast level.

Chapter 15: Cables Page 317 of 535