Failure to vet the competence of signalling workers resulted in a passenger train derailing and colliding with another train at Waterloo Station in London in August 2017, according to accident investigators.
The train was leaving the terminus when it derailed and collided with a “barrier train” at 5:42am on 15 August, at a speed of 21km/h. There were no injuries, but a report published by the Rail Accident Investigation Branch says both trains were damaged and there was serious disruption to train services until the middle of the following day.
The barrier train was being used as a buffer between ongoing works at the station and the live railway.
The report said the derailment had been as a result of incorrectly positioned points caused by “uncontrolled wiring” which was used to test the signalling system which controlled the points. This was not removed, after the signalling system had been tested
It described the actions of a “functional tester” - a person who tested the signalling system – were “inconsistent with the competence expected of testers” and as a consequence, the uncontrolled wiring was “added without the safeguards required by Network Rail signalling works testing standards”.
“An underlying factor was that competence management processes operated by Network Rail and some of its contractors had not addressed the full requirements of the roles undertaken by the staff responsible for the design, testing and commissioning of the signalling works,” it said.
The station is currently undergoing a massive £800M programme of upgrade works to increase capacity at the station by 30% at peak hours.
At the time of the incident, the programme was half way through an intensive three-week series of platform alterations with around 1,000 workers working in shifts around the clock to extend platforms one to four, and modify platforms five to eight.
The body said that the accident had “certain similarities” with those which led the fatal accident at Clapham Junction in 1988. It warned some of the lessons identified by the public inquiry following the Clapham accident which killed 35 and injured 415 were “fading from the railway industry’s collective memory”.
The RAIB said it had made three recommendations as a result of the investigation. The first is that Network Rail, should improve the “depth of knowledge and the attitudes needed for signal designers, installers and testers to deliver work safely”.
The other recommendations were addressed at sub-contractor OSL Rail and consultant Mott MacDonald. They said the two firms should improve the “development and monitoring of non-technical skills among the staff working for them”.
The report also issued four learning points, the first of which highlighted the “positive aspects of a plan intended to mitigate an unusually high risk of points being moved unintentionally”.
However, in its following learning points, it reinforced the need to follow established procedures and prompt staff to clearly allocate duties associated with unusual activities. It also said staff should be reminded that up-to-date signalling documentation must be available and easily identified in relay rooms and similar locations.
A Mott MacDonald spokesperson said: “We have established a working group to review the recommendations in the report and determine any appropriate action that may be required in the short, medium and or long term.
“We will also continue to work collaboratively with Network Rail as part of our shared commitment to upholding the highest safety standards across all facets of the rail industry.”
Network Rail has said that the lessons from the incident have already been shared across the industry and the report’s recommendations will help further. It added the derailment highlighted that it can “never afford to be complacent” when it comes to passengers and workers.
OSL Rail declined to comment.