Southall crash inquiry may also investigate Paddington

The Paddington train crash could be investigated by the same public inquiry which is looking into the Southall crash of two years ago. The decision will be made by the transport minister, John Prescott, if Health and Safety Executive inspectors find that Tuesday’s accident was caused by the Thames Trains service passing a danger signal […]

The Paddington train crash could be investigated by the same public inquiry which is looking into the Southall crash of two years ago.

The decision will be made by the transport minister, John Prescott, if Health and Safety Executive inspectors find that Tuesday’s accident was caused by the Thames Trains service passing a danger signal before the collision. Last year there were 643 incidents of trains passing red signals, up 8% on 1997.

Pressure for a prompt investigation into this latest crash has been increased by the two-year delay to the Southall inquiry investigating the fatal 1997 crash, in which a high-speed Great Western train passed a danger signal. The Paddington crash happened on the same line as the Southall accident and re-opens the debate on the choice of safety systems used in UK trains.

Three train safety systems are now in use. The automatic warning system (AWS) is already fitted to all trains. It applies emergency brakes if the train passes a danger signal but can be manually overridden.

Automatic train protection (ATP) uses trackside radio beacons to communicate with the train’s computer, which analyses speed, proximity to signals and their status, as well as speed limits. It can override the driver if it predicts the train will pass a red signal or is travelling too fast.

The train protection warning system (TPWS) uses two radio beacons placed before signal-protected junctions to measure train speed. Trains passing danger signals trip beacons which apply emergency brakes. The drawback of this system is that it will not stop a train before a danger signal is passed.

Trials of ATP on the Paddington line and TPWS on the Marylebone line in the early 1990s concluded that TPWS could provide 80% of ATP’s functions at a fraction of its £1bn cost. TPWS could be fitted near important signals only and it could be retrofitted, unlike ATP, to existing signalling infrastructure.

`Both trains involved in Tuesday’s crash would have had AWS fitted, but only the Great Western high-speed service had ATP installed,’ said Graham Coombs, director of communication of the Railway Industries Association.

ATP could have prevented the Thames Train from passing the danger signal, Coombs said.

* Leader comment, p10