Page 368 - IRSEM_Main Book

(g) Whenever mechanized equipment is used, the work shall be carried out by
a trained operator under the supervision of SSE/JE(Signal), incharge of the
work.

(h) Where the cable drum is in damaged condition the cable may be placed on
a horizontal revolving platform and the cable paid out in the same manner
as given in paras above.

(i) Paying out of cable should be done by rotating the cable drum and not by
pulling the cable with excessive force.

15.2.2 Trenching

(a) The width of cable trenches should commensurate with number of cables.
The minimum width shall be kept as 0.3 meters. The bottom of the cable
trench should be levelled and got rid of any sharp materials. In the soft
ground, the cable should be laid at the bottom of the trench previously
levelled. In the rocky ground, the cable should be laid on a layer of sand or
sifted earth of 0.05 meters thickness previously deposited at the bottom of
the trench. In both the above cases, the cable should be covered with a
layer of sand or sifted earth of 0.10 meters thickness and thereafter a
protective cover of trough or a layer of bricks or split DWC-HDPE pipe of
approved type or any other approved means should be placed.

(b) Bottom of Trench shall be cleared in such a way, so as to remove all the
boulders having sharp edges. In rocky soil, the bottom of the trench shall be
filled with river sand or any other soft material and cable shall be laid on
smooth surface.

(c) In block section horizontal directional drilling method may also be used based
on site conditions for the laying of Quad and OFC cables across the track at
sufficient depth to avoid damage due to future work of doubling etc.

(d) Where it is not feasible to achieve required depth due to rocky soil/other
obstructions, protective measures as shown in Drg. No.15-D2 shall be taken.
(e) Where feasible, trenching may be done with suitable machinery, with due
precautions towards safety of the running trains. For carrying out such
works, the rules governing the working of machinery along the track shall
be followed scrupulously. Suitable instructions in this regard shall be issued
by the Railways in the form of a joint circular.

15.2.3 Laying Of Cables

(a) Cables shall be laid generally as per instructions given in this chapter.
However, special precautions to be taken in the station yards etc., where a
number of other utilities may be existing, may be detailed in a joint circular
issued by the Civil Engineering, Signalling and Electrical Department(where
applicable) of the Railway.

(b) Cables may be laid underground, either in the trench, in ducts, in cement
troughs, in pipes or in any other approved manner.

Chapter 15: Cables Page 316 of 535