West Coast Rail Modernization, Train Protection and Warning System

Client: WS Atkins Rail Ltd.
Location: United Kingdom
Construction Cost: $8.7 billion

Gannett Fleming implemented the Train Protection and Warning System (TPWS) as part of the West Coast Main Line modernization project. The West Coast Main Line extends 500 miles from London to Glasgow.

Since high-speed passenger trains require approximately two kilometers to come to a stop, the railway’s signal system provides two warnings in advance of a red signal: a double yellow signal approximately two kilometers from the red signal and a single yellow signal one kilometer from the red signal. Drivers heed these advance warnings and consider the train’s performance and the physical characteristics of the railway line (curves, grades, etc.) to safely stop the train. To decrease the occurrence of signals being passed at dangerous speeds, the TPWS will set the train’s brakes if the train passes or approaches a stop signal at an excessive speed. This system was chosen over other proposals as a way to receive the maximum benefit in the shortest amount of time.

Our firm checked all signal drawings, as they were converted from hand drafting to CADD format, and provided detailed circuit design and wiring plans for all TPWS locations. The TPWS was designed as an overlay to the existing signal system, which dates back to the 1960s and includes 78 major interlockings. In addition to the TPWS, plans also are underway to increase line speed.