Permissive working - Swindon and Westbury

[whole diary]

[grahame]

RAIB^▸ (Rail Accident Investigation Branch) has today released its report into a collision at Plymouth station, 3 April 2016.

Simon French, Chief Inspector of Rail Accidents said:
This collision caused great distress to the large numbers of passengers and staff involved, particularly those who suffered injuries. It occurred when a train was routed into a platform that was already occupied by a stationary high speed train. This form of train working, known as permissive platform working is not unusual on the UK^▸ (United Kingdom)’s busy network and is usually performed safely. Platform sharing allows trains to be joined together or, as was intended in this case, can facilitate the easy movement of passengers between connecting train services.

This accident reinforces the need for drivers to take great care when signalled into an occupied platform - assumptions should never be made about the length of platform that is unoccupied. This learning applies to all drivers but is particularly applicable to those who are inexperienced or new to a route. For this reason we have today issued a recommendation to Great Western Railway concerning the training and assessment of new drivers to better prepare them for permissive platform working. I am also urging other train operators to think about how well they prepare their drivers for similar circumstances.

Although the RAIB recognises the need for permissive working in station platforms, we have recommended that Network Rail, in conjunction with train operators, carries out a review of the way it is implemented at all stations where permissive platform working is currently authorised. This should include an assessment of a range of risk factors, including the information provided to the signallers when deciding whether or not to route a train into an occupied platform.

Posting in the none-public area.

The bay platform at Swindon is worked permissively and if something were to go wrong there it would be more damaging that pushing the front train a bit down the track.  Fortunately, everyone's aware and all trains come in very slowly indeed, even if the bay is empty. 

((Posting here to note a risk, which is lessened because it's identified and steps taken to avoid a problem))

[IndustryInsider]

The bay platform at Swindon is worked permissively and if something were to go wrong there it would be more damaging that pushing the front train a bit down the track.  Fortunately, everyone's aware and all trains come in very slowly indeed, even if the bay is empty. 

Dead end platforms are fitted with OSS (Over Speed Sensors) part way along the platform as part of the TPWS^▸ (Train Protection and Warning System) system - trains have to be doing less than 10mph at that point otherwise the brakes apply.  There is also an old ruling that platform ends should be reached at no more than 15mph, which has now been tightened so that, if working permissively, a maximum of 15mph from the signal and a maximum of 10mph from the end of the platform.  This applies regardless as to whether it's a through or dead end platform.

Should prevent (or greatly lessen the impact speed) in the situation that caused the Plymouth collision.  However, it does cause delays at places like Oxford where anything coming out of the sidings into the up platform used to be able to reach 25mph and brake for the applicable stopping point on the platform, but now has to go 15mph then down to 10mph at the platform end and along the long platform even when the driver can see the platform is clear.