At 15:34 hrs on Sunday 3 April 2016, the 13:39 hrs passenger train service from Penzance to Exeter collided with an empty train which was already waiting in platform 6 at Plymouth station. The collision occurred at a speed of about 15 mph (24 km/h) and resulted in injuries to 48 people and damage to both trains.
The signaller intended that both trains should share the platform because the empty train was to form a service to London and some passengers from the Penzance service were expected to join it. Lift refurbishment work meant that without platform sharing, passengers would have needed to use the stairs and a subway when changing trains. Permissive signalling arrangements were in place at Plymouth to permit two trains to share the same platform.
The signaller misjudged the amount of space available behind the London train and wrongly believed there was room for the Penzance train. He was aware that the platform sharing arrangement required an unusual form of permissive working, but did not communicate this to the Penzance train driver, and the rules did not require him to do so.
The Penzance train driver incorrectly believed he would not be sharing a platform with the London train. There was insufficient distance to stop his train by the time he realised his mistake and had applied the emergency brake.
Great Western Railway, the operator of both trains, and Network Rail the owner of the infrastructure, had not identified the risk of a collision due to the combination of an unusual form of permissive working, the track alignment on the approach to Plymouth station, and an inexperienced driver.
The RAIB has made three recommendations. The first, addressed to Great Western Railway and possibly also relevant to other train operators, seeks improvements to the training and assessment of new drivers. The second, also addressed to Great Western Railway and possibly relevant to other train operators, arises from difficulties encountered during passenger evacuation and seeks improvements to emergency door release controls. The third recommendation, addressed to Network Rail and to be undertaken with the assistance of appropriate train operating companies, seeks a review of permissive working arrangements at stations.
Two learning points stress the care needed by drivers when undertaking permissive moves, and the value of preventing passengers boarding or alighting from trains when permissive movements are taking place in the same platform.