50399 ‘Variable’ coverage of train protection warning system

February 2012 in Network Rail and Suppliers

Equipment Infrastructure Scotland

A reporter raises concerns about the possibility of a collision in areas of Scotland that have not yet had a Train Protection Warning System (TPWS) installed.

In some parts of Scotland, Drivers use a token system to enter sections of track.  The reporter states that Drivers have become accustomed to using TPWS on their routes, so when TPWS isn't available the reporter believes there is the possibility that a Driver could forget to halt at a stop board whilst in possession of a section token.  This could result in a signal being passed at danger and create the possibility of a head-on collision between trains and engineering vehicles.

One area where there is no TPWS is a stop at Gorton between Bridge of Orchy and Rannoch, Corrour.  Also, at Loch Eil (outward bound) TPWS has been installed on the Up line but not on the Down line.

Could Network Rail:

• Explain why some locations do not have TPWS installed?
• Consider installing TPWS in those areas?

Response from Network Rail

Network Rail would like to thank the reporter for bringing their concerns to our attention.

Could Network Rail explain why some locations do not have TPWS installed?

The design standards applied under TPWS state that TPWS shall not be fitted to stop boards where the only assessable conflict is prevented in the radio electronic token block interlocking. This will be the case where it is not possible to issue a token to one train to allow it to be at the conflict point should another train pass the stop board in question. It is for this reason that the westbound (Down) stop board at Loch Eil is not fitted with TPWS, whereas the eastbound (Up) is. The Up stop board protects moves to and from the Pulp Mill at Annat. The interlocking permits a token to be issued from Glenfinnan to Loch Eil at the same time as a token giving entry from the east into the Pulp Mill. That is why only one stop board is fitted at Loch Eil outward bound.

Roy Bridge token exchange point is similar to Loch Eil in that it consists of a single platform and a stop board in each direction. There is no TPWS at Roy Bridge since all credible conflicts are prevented by the interlocking.

Could Network Rail consider installing TPWS in those areas?

There are presently no plans to install TPWS in these locations