[Beeyar Wunby]

Thanks for that Philip

Originally Posted by Rail Advent

The driver of the rail grinding train applied the brakes and the train protection and warning system (TPWS) also applied the brakes, but the train did not stop within the safe overrun distance and so reached the junction.

Ooh, that's naughty. TPWS is supposed to bring an errant train to a stand within the overlap, thus preventing it from reaching the conflict point.

Something's not right here, and RAIB have dropped some clues...

The design of the signalling on the Leicester to Loughborough section of line

It not unusual to have to cross oncoming traffic when switching lines, I used to experience it on the Midland Main Line - where the Fast (Up & Down) and Slow (Up & Down) lines are paired. The East Coast Main Line has the better arrangement of pairing the Ups (Slow & Fast), and the Downs (Slow & Fast). That way there's no risk of a head-on collision when swapping lines, which is the worst collision you can get. But it's not unusual, and not a danger - provided that TPWS does its job. And it almost always does - except here.

The effectiveness of TPWS in circumstances where train braking rates are lower than those used in calculations relating to the design of the system

TPWS Grids are usually set at standard positions apart, to suit the braking curves of modern trains, which nowadays have Dynamic brakes which are very sharp.

Whilst Hi Speed passenger trains can pull up very smartly, heavy freight trains, light locos and On-Track Machines can often take further to stop.

These trains are usually restricted to running at a lower speed than the running line's Permissible Speed, eg....no more than 40mph on a 60mph line. This is calculated from the braking curve figures for each train.

But the grids are only a few hundred yards from the signal. The whole purpose of TPWS is to stop a train before it reaches the Conflict point. In some cases, the overlap needs to be correspondingly longer. But sometimes this is not possible - there is just no extra room.

Any relevant underlying factors, including the rail industry’s response to RAIB’s recommendations made in previous reports involving train driver fatigue management

Ah, the golden oldie. Some poor person working long/hard hours? Nothing new there sadly.

Well as usual, we look forward to reading the report. It's good that nobody was injured and we're not reading about a train smash.

Cheers, John.