Automatic Train Protection (United Kingdom)
Automatic Train Protection (ATP) is a method of beacon based railway cab signalling developed by British Rail. The system is only installed on the Great Western Main Line between London Paddington and Bristol Temple Meads, and the Chiltern Main Line from London Marylebone to High Wycombe and Aylesbury. History Background 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. From the onset, it was recognised that considerable work would be involved both to develop and deploy the envisioned system. Accordingly, in 1988, BR launched a three-year program to develop and deploy this new system, with the aim of starting its implementation by 1992. It was assigned the name Automatic Train Protection (ATP), and was a considerably more comprehensive system than the Automatic Warning System (AWS) that was already in operation at that time. Whereas the AWS system only issued alerts to the train's driver, effectively an