Page 176 - IRSEM_Main Book

(c) Derailing Switches on main or through line: In order to maintain safety
for through running, Points for *trap sidings/derailing switch shall not be
inserted in the main or through line. However in exceptional
circumstances, they may be allowed under approved special instructions,
only in those cases where;
(i) Owing to grades in or near stations, it is necessary to prevent -

 Trains being brought to a stand at a Stop Signal on a rising
grade, or

 Vehicles running away from the station.
(ii) It is operationally required to receive trains from different directions
at the same time.

(d) At stations where Points for trap sidings/derailing switch are inserted on
Main lines or through line for reasons given at (c) above, through running
shall be permitted only under approved special instructions.
*Note: Points leading to a short dead end and used solely for the purpose of
trapping the running line or sidings shall also be treated as derailing switch.

7.4.11 Please refer to Annexure: 7-A1 on Extract from “Rules for Opening of Railway
Lines” for Isolation for more details.

7.4.12 Siding Points on Passenger running lines outside station limits

(a) Facing Points: Where Siding Points take off a running line in a facing
direction, the following minimum equipment shall be provided:-
(i) A gauge tie plate and a facing point lock which shall lock each switch
independently.

(ii) The control of the points shall be made by means of a key or other
suitable device which shall secure the bolting mechanism of the Points
in the plunged or locked positions, i.e., when the Points are set and
locked for the running line. The means for control of the Points shall
be interlocked with the block system in force.

(iii) Where Siding Points are provided only with the minimum equipment
as specified above, an appropriate speed limit over the facing points
shall be imposed for all trains passing over such Points in the facing
direction only and an 'S' marker at the Points and a speed indicator at
not less than 30 meters from the Points shall be provided, neither of
which, need be lighted. In addition a caution and termination indicator
shall also be provided as for open line speed restrictions. Where the
sanctioned speed of the section does not exceed 50 kmph, the
'Marker' at the points and the Indicators need not be provided.

(iv) The siding points on passenger lines outside the station limit shall be
detected for permitting speeds of up to 50 kmph in facing direction. In
case the detection is not provided, speed restriction of 15 kmph shall
be imposed.

Chapter 7: Essentials of Signalling Page 145 of 535