Radio Electronic Token Block

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A stop sign indicates the start of a section of RETB at Rannoch Station on the West Highland Line. The blue light below is a TPWS status indicator.

Radio Electronic Token Block (abbreviation: RETB) is a train control system that is used on some single-track lines in the UK . There are three routes in Scotland , one in Wales and (until 2012) one in England .

functionality

RETB works according to the same logical rules as the older token systems . The main difference is that the tokens are no longer objects, but are exchanged via radio between RETB devices in the operations control center and on the trains.

The system offers the following core functions:

  • Issue of the travel permit for a route section (block section) from the operations control center to the train
  • Display of the driving license for the driver
  • Return of the travel permit token after the train has completed the permitted journey

Technically, it is ensured that no more than one token can be issued at the same time for each route section. Like all token systems, however, RETB cannot prevent unauthorized journeys. This is why the Train Protection and Warning System (TPWS) is also used at the beginning of the block sections today .

With regard to ETCS , RETB is managed as a Class B system (Class B system).

literature

  • Stanley Hall: BR Signaling Handbook . 1st edition. Ian Allan, Shepperton 1992, ISBN 0-7110-2052-3 , pp. 69-73 .