Page 177 - IRSEM_Main Book

(b) Trailing Points (Double Line): Where Points take off a running line in a
trailing direction, the following minimum equipment shall be provided for
unrestricted speed:

(i) A gauge tie plate.
(ii) A suitable type of key lock or equivalent mechanism, the key of which
can only be extracted when the Points are set and locked for the
running line. The points shall be controlled through the block system
in force.

(iii) A 'S' Marker at the Points, which need not be lighted.

Note: Some provisions given in this section may be applicable for Mechanical/Electro
mechanical Signalling (where existing) only.

Section 5: Interlocking of Catch Siding and Slip Sidings

7.5.1 At stations where *Catch and Slip Sidings are provided in accordance with
the Rules for opening of a Railway, interlocking arrangements and other
safeguards shall be provided as given in this section.
*Note: Catch Siding is provided to protect the Station Section, if the gradient is
steeper than 1 in 80 falling towards the station section. Slip Siding is provided to
protect Block Section, if the gradient is steeper than 1 in 100 falling towards the
Block Section

7.5.2 Reception of Trains

(a) Either a minimum of two Stop Signals shall be provided in rear of the
Catch Siding points or the First Stop Signal shall be at an adequate
distance equal to Block overlap from the catch siding points.

(b) A train shall first be brought to a stop at the First Stop Signal, before the
Catch Siding points are set for the main line and the reception signals
shall not be taken 'OFF' unless the following conditions are satisfied:

(i) The line on which the train is to be received is clear and the train is to
be received on the main line.

(ii) The points leading to the Catch Siding as well as all the Points
required for a run through train are set for the main line immediately
after granting Line Clear to the Block station in rear.

(iii) Line clear has been obtained from the Block section in advance.
(iv) The gradients in the block section ahead are such that the train can be
brought under control easily.

7.5.3 Setting of Catch Siding/Slip Siding: The take off points of a Catch/Slip
siding shall normally be set and locked for the siding and interlocking
between the points and block instruments shall be provided as in Para 7.5.4
and other safeguards as in paras 7.5.5 to 7.5.7.

Chapter 7: Essentials of Signalling Page 146 of 535