Automatic Train Protection (United Kingdom)

Automatic Train Protection (ATP) is a method of beacon based railway cab signalling developed by British Rail.

A noticeable uptick in signal passed at danger (SPAD) instances in the 1980s led to calls for a new safety system to be adopted that would entirely prevent their occurrence; specifically, the report into the Clapham Junction rail crash (itself not a SPAD accident) specifically stipulated that British Rail (BR) was to fully implement such a system on nationwide basis within five years.

[2] As a means of risk mitigation, BR opted to perform two ATP pilot systems, the results from these separate schemes was intended to inform planners on what would be involved in a wider rollout as well as to identify which implementation was superior and thus should be installed nationally.

[5] Railtrack, the agency that took over the management of Britain's railway infrastructure from BR in 1994, subsequently only committed to completion of the two pilot schemes, adaptation for new high-speed lines, and to search for a cheaper alternative for the rest of the network.

During 2011, roughly 21 years after ATP's instigation, Thales issued a formal advisory that the SELCAB system was to be declared obsolete within the near future.

[1] The announcement motivated railway managers to perform large final purchases of spare equipment and components so that there was sufficient stock to sustain ATP's infrastructure and fleet fitment alike for the medium term.

In spite of a life extension programme performed during the 2010s, the decommissioning of ATP has been viewed as inevitable as a long term outcome.

[1] The European Train Control System (ETCS) has been viewed as a natural replacement to ATP, which is gradually being rolled out across the British rail network as its principal signalling solution.

This substitution required an exemption from RSR1999 stipulations by regulatory authorities along with a review of all existing TPWS installations along the Chiltern route, which upgrades being performed where relevant.