At 12:30 hrs on 10 April 2016 a passenger train travelling from Norwich to Cambridge collided with an agricultural tractor and trailer on a level crossing at Hockham Road, near Thetford in Norfolk. The train was travelling at 87 mph (140 km/h) when, on the approach to the crossing, the train driver saw a tractor moving closer to the railway tracks. The train driver sounded the train’s horn and applied the emergency brake, but could not stop before colliding with the tractor. The train did not derail, but its driving cab was damaged, and the driver and four passengers suffered minor injuries. The tractor was destroyed, and its driver was seriously injured.
The level crossing at Hockham Road is on a restricted byway, and has gates which are operated by crossing users. About one minute before the collision, the tractor driver had obtained permission to cross from a signaller at the Network Rail signal box at Cambridge. The signaller had given him permission to cross when there was insufficient time before the train would arrive at the crossing. This was because the signaller had lost his awareness of the position of the train because his levels of concentration may have lapsed, and his competence to operate the workstation safely and effectively had not been adequately monitored.
A system that had been installed at the level crossing in 2012, intended to display green or red lights to crossing users to warn them whether or not it was safe to cross, was not working at the time of the accident. It had been decommissioned by Network Rail following concerns which the company had about the safety integrity of the system. This had meant that users had to telephone the signaller for permission to cross. The RAIB found that Network Rail had not come to a clear understanding with the manufacturer of the system about how the equipment met the required safety integrity level, and having assessed the risks, had decided to turn off the system while improvements were made.
An underlying factor was that the arrangements in Cambridge signal box for managing fatigue among signalling staff were inadequate.
The RAIB has made three recommendations to Network Rail. The first concerns Network Rail’s approach to managing user worked level crossings, with the intention of either eliminating the need for a signaller to have to decide whether it is safe for a user to cross the railway or providing better information for signallers when making these decisions. The second relates to the processes that Network Rail uses when introducing new signalling equipment whose operating interface differs significantly from existing equipment, and the third covers the management of the competence of signalling shift managers when they also operate signalling equipment.