Track Circuit Interrupters

Track Circuit Interrupter Railway 

Indian Railway Signalling Network Rail Presentation Thales

Track Circuit Interrupter  Railway 

* Track circuit interrupters are Emergency stop devices. These are provided at designated locations to provide a vital indication that a train has run into a portion of track in which movements are not permitted (e.g. into trap points or Catch points or past FRLs at terminal platforms).


* It comprises a main body, narrow neck & head which is designed to break off when a rail vehicle passes over it.


* It is bolted to running rail at a position not used by trains for legitimate movement, e.g. beyond the FRL or on stock rail of trap point & shall be insulated from rail.


* The TCI relay circuit will operate at 110v 50Hz.The supply will be electrically isolated from the TCI by a 1:1 isolation transformer, due to the susceptibility of TCIs to Earth faults and extraneous traction currents. The vital relays will be powered via a QXR1 transformer rectifier.


* These circuit will not be routed through the COC, but will be pre-tested and final connections made for phase commissioning.


* The TBTC system will interface with the existing Track Circuit Interrupters to provide automatic detection of an overrun at the ends of lines and sidings including buffer stops and trap points.


* In the event that the Track Circuit Interrupter is activated, the TBTC system will close the tracks associated with the device and will ensure that no controlled train movement is allowed into or out of the affected area.


* The Relay Rack shall continuously report the status of each track circuit interrupter to the SCS Electronics Rack.


* Operation of a track circuit interrupter that is not overridden by the VCC operator shall result in the tracks associated with the device being closed.


* Indication of the track circuit interrupter activation shall be provided at the SMC workstation.


* Track circuit interrupter activation will not have any affect on RM mode train operation and on route secure aspects.

Track Circuit Interrupters



Track Circuit Interrupters 1


Track Circuit Interrupters 2

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