Report 19/2018: Collision at London Waterloo

Collision at London Waterloo, 15 August 2017.



At around 05:42 hrs on Tuesday 15 August 2017, a passenger train was leaving London Waterloo station when it collided with a stationary engineering train at a speed of 13 mph (21 km/h). No injuries were reported but both trains were damaged and there was serious disruption to train services until the middle of the following day.

The passenger train was diverted away from its intended route by a set of points which were positioned incorrectly as a result of uncontrolled wiring added to the signalling system. This wiring was added to overcome a problem that was encountered while testing signalling system modifications which were being made as part of a project to increase station capacity. The problem arose because the test equipment design process had not allowed for alterations being made to the signalling system after the test equipment was designed.

The actions of a functional tester were inconsistent with the competence expected of testers. As a consequence, the uncontrolled wiring was added without the safeguards required by Network Rail signalling works testing standards, and remained in place when the line was returned to service.

A project decision to secure the points in the correct position had not been implemented.

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.

The RAIB has observed that there are certain similarities between the factors that caused the Waterloo accident and those which led to the serious accident at Clapham Junction in 1988. The RAIB has therefore expressed the concern that some of the lessons identified by the public inquiry, chaired by Anthony Hidden QC following Clapham, may be fading from the railway industry’s collective memory.


As a result of the investigation, the RAIB has made three recommendations. The first, addressed to Network Rail, seeks improvements in the depth of knowledge and the attitudes needed for signal designers, installers and testers to deliver work safely. Recommendations addressed to OSL Rail Ltd and Mott MacDonald Ltd seek development and monitoring of non-technical skills among the staff working for them.

The RAIB has also identified four learning points. One highlights the positive aspects of a plan intended to mitigate an unusually high risk of points being moved unintentionally. The others reinforce the need to follow established procedures, prompt staff to clearly allocate duties associated with unusual activities and remind staff that up-to-date signalling documentation must be available and easily identified in relay rooms and similar locations.

Published 19 November 2018