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Big brake for safety

RAIL: TPWS Fitting the train protection and warning system is the first major network initiative Railtrack has carried out of its size. Steve Turner finds out what is being done.

By the end of next year all passenger train lines must be fitted with the train protection and warning system (TPWS).

This daunting task involves fitting over 11,000 signals, 700 buffer stops and about 2,700 sites where there are permanent speed restrictions. All the trains operating on the network must also be fitted out and the drivers trained.

But it is a challenge the industry is on target to meet, as Railtrack's sponsor TPWS Dermot Courtney explains. 'It is the first pan zonal major project that Railtrack has undertaken, with dedicated project teams in each of the seven zones. We have formed a team that will meet the challenge, and it is a team that people want to be a part of.'

The fitting of the TPWS system, that aims to reduce the consequences of a train passing through a red signal, is a requirement of the Railway Safety Regulations 1999.

Basically speaking, if a train passes a signal at danger (SPAD), or is approaching a red signal too fast, the TPWS system automatically applies the brakes, and stops the train.

This is done by a series of sensor loops on the track. The first loop starts a timer on the train. If the train passes the second trigger loop before one second has elapsed, the brakes are applied.

It will stop any train travelling at up to 115km/h within a 185m overlap that, it is estimated, will reduce fatalities caused by SPADs by 70%. Trains travelling faster than 115km/h will take longer to stop, but any resulting collision would be at a greatly reduced impact speed.

Courtney believes that the system is a step change and 'the single most important safety project for a generation that will without doubt save lives. Everyone involved is very proud.'

Railway contractors in each of the seven Railtrack regions are carrying out the fitting work under additional contracts.

Courtney estimates that there are 1,400 staff working on the project, involved with surveying, designing, installing and commissioning the system.

Fitting the system varies from site to site, depending on the signalling system in use. As Courtney explains 'the concept of wiring the loop into the signal is simple, but there are over 20 types of signals meaning over 20 different types of application.'

Add to this a complex junction like Euston station and the complexity becomes clear.

To ensure the programme remains on schedule, work is carried out round the clock all year long. Getting access to the tracks, especially on busy lines such as the West Coast Main Line and at busy stations such as Euston is difficult. Teams have piggybacked maintenance and renewals possessions and also taken advantage of quiet times on the network such as Christmas.

Once installed the equipment is proving to be very resilient and easy to maintain. Last year some of the track-mounted equipment was covered by flood water.

After two days of the water draining away, the system was in full working orders. It impressed a lot of people, Courtney says.

Railtrack estimates that it is over half way through its £500M programme, well on schedule.

Train operators, which have to fit compatible equipment to their vehicles are also on target, with over half of their trains fitted.

Courtney reports on progress to the Railway Inspectorate every month, and give a presentation every quarter. They are very happy with the progress being made. He believes the project is showing that, although fragmented, the industry can work together successfully.

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