Cab Secure Radio


Cab Secure Radio was an in-cab analogue radiotelephone system formerly used on parts of the British railway network. Its main function was to provide a secure speech link between the train driver and the signaller which could not be overheard by other train drivers. In areas where CSR was used it had to be the primary method of communication between driver and signaller, always being used in preference to the signal post telephone. CSR was replaced by the GSM-R digital system, forming the initial phase of rollout of ERTMS throughout the UK.

History

CSR was first introduced in the Glasgow area in 1986 to enable driver-only operation of trains. It was later used in the London and Liverpool areas.

Functions

The driver initialised the CSR with an area code followed by the identification number of the signal in front of the train. The radio then automatically sent the stock number of the train, to the signalling system. The signaller then allocated a train reporting number to the train. This reporting number was used by the signalling equipment to track the progress of the train as it moves through the rail network.
Each signalling area used a different radio channel corresponding with an area code. As the train passed from the jurisdiction of one signaller to another, the CSR in the driver's cab changed channel automatically. Lineside signs were provided to inform the driver of where the area code changes. Occasionally the radio failed to change channel or lost the signal completely, in which case the driver could enter the code manually. Lineside signs indicated the change of the CSR radio channel area.

Hardware

CSR cab equipment was either the Stornophone 6000 or a Siemens model.