Page 502 - IRSEM_Main Book
P. 502
Para no: 21.1.21 Timers in Various circuits – Table-1
S.No Description Delay in Conditions/Remarks
seconds
1 Main Stop Signal (Route 120 1) Before movement, if back lock track circuits are clear. Sub routes (if any) should also get released
cancellation)-Home, Starter etc with main route.
2) After movement, either back lock track circuits are clear or after physical verification by SM, if
any back lock track circuit has failed.
2 Sub Route (Emergency 120 1) Where a route is divided into sub routes and such facility is operationally required.
Cancellation) 2) On physical verification of the route by SM if any back Lock track circuits is showing occupation.
3 Crank handle (CH) emergency 120 Points are locked due to failure in any route/sub route. Cancellation timer to start after cancellation
key release time buttons are operated duly putting back to ON position those signals which were taken OFF.
4 Shunt Signal (Route 120 1) Before movement, if back lock track circuits clear. Sub routes (if any) should also get released
cancellation) with main route.
2) After movement, either back lock track circuits are clear or after physical verification by SM, if
any back lock circuit has failed.
5 Calling On Signal (Route 120 1) Proving all back lock track circuits are clear (if they are functional).
cancellation/Release) 2) Emergency cancellation of calling route (without proving any back lock track) can be provided,
on physical verification of the full route by SM.
6 Signal Overlap (release) 120 Timer to start automatically , on clearance of last back track circuit of Home Signal route and on
occupation of berthing track circuit (or as soon as Train has passed beyond signal overlap track
circuits in which case timer gets bypassed).
7 -do- 60 For big yards with the approval of PCSTE. On clearance of last back lock track circuit of Home Signal
route and on occupation of berthing track circuit.
8 Calling On Signal below Home 60 Calling on track circuit is occupied.
(Initiation)
9 Calling On Signal below the 0 SM to ensure that train has come to a stop, before taking Off Calling-on.
starter (Initiation)
Chapter 21: Relay & Electronic Interlocking Page 447 of 535
