Page 182 - IRSEM_Main Book

7.6.9 Signal Passing at Danger (SPAD) mitigation

To mitigate the adverse effects of a Train Passing Signal at Danger, appropriate
devices, circuits, methods may be provided as necessary such as;

(a) Station staff shall set the relevant facing points to unoccupied line, soon
after the arrival of a previous Train, through a provision in Station
Working Rules (SWR).

(b) Train Protection Devices (Refer to Chapter 13 of SEM).

(c) Any other approved type of method/Equipment.
7.6.10 Fail safe Features: Signal and interlocking circuits (including hardware and
software as applicable), shall be so designed and equipment so installed and
maintained with it`s connections, that the relevant signal shall remain at or
return to its most restrictive aspect and Points shall remain locked in their last
operated positions in the event of failure of any part of its connections and
circuits.

Section 7: Operation of Signals & Points - Control Panel

7.7.1 The Interlocking installations are of two types, Route Setting Type i.e. on the
basis of Entry/Exit principle, Non-route Setting Type i.e. Route is set with
individual operation of points.

(a) The points and Signals shall be operated from a:-
(i) Control panel for Relay Interlocking.

or
(ii) Control panel and/or Control Terminal (Video Display Unit (VDU)) for
Electronic Interlocking.
Note: Dual VDU shall be provided in lieu of Control Panel and VDU in all future
Installations. However, in those existing Installations having one VDU and one
Control the same may continue.
(b) Based on size, complexity of the yard or operational reasons more than

one Control panel/Control terminal may be provided for operation of the
points and signals. In such cases, necessary inter-slotting controls shall
be provided.

7.7.2 Control Cum Indication Panel (CCIP)/Control Panel

(a) The display of the layout on the front of the Control Panel shall be well
proportioned, and each track circuit shall be clearly distinguished by
different colours.

(b) A Control cum operations panel with Indications (CCIP or control panel)
for route switches/buttons, point switches etc. shall be provided in
Geographical order. However a separate Indications panel and a
separate operating panel may also be provided for large installations for
convenience.

Chapter 7: Essentials of Signalling Page 151 of 535