News: Incident investigation explained


The Rail Accident Investigation Branch (RAIB) has been operational at Farnborough since 2005 following a recommendation by Lord Cullen, after the 1999 Ladbroke Grove rail accident, to provide an independent investigation body to identify causal factors into rail accidents and incidents and improve rail safety.

The RAIB generously hosted a CIEHF Southern Regional Group event in mid-October when Simon French, their Chief Inspector welcomed 26 human factors practitioners and academics to the Farnborough site. He emphasised that human factors was integral to the investigations carried out. Mark Young, RAIB Inspector and Chartered Member of the CIEHF, gave an overview of the RAIB and provided a summary of the investigations into the fatal tram accident at Sandilands Junction, Croydon in November 2016. The factors leading to an overspeed situation were complex and Mark emphasised that, in many cases, human factors causal factors could only be considered as possible or probable, as human performance evidence is difficult to prove conclusively. The full report is now available.

We were shown the kit that is taken to the accident sites in a specially modified van to obtain the required data and measurements to assist the investigation. In this instance the derailed tram was moved from Sandilands Junction to the RAIB site to enable the detailed investigations to take place. RAIB Inspector Richard Brown explained why and how it was necessary to identify the forces that resulted in seven passengers being fatally injured when they were ejected through the windows and doors.

The Air Accidents Investigation Branch (AAIB) is also located on the same site as the RAIB. AAIB Inspectors Lisa Fitzsimons and Toni Flint took us on a tour of the AAIB hangar, identifying some of the high profile aircraft accidents that have been investigated recently. These included the EC 135 helicopter which crashed on the Clutha Vaults pub in Glasgow in November 2013 and the Hawker Hunter which crashed at Shoreham Airshow in August 2015. They summarised the causal factors of those incidents. We also saw the wreckage from a variety of general aviation accidents, for which the investigations are still ongoing. 

Professor Paul Salmon of the University of the Sunshine Coast in Australia, is currently visiting the UK and gave us four case studies that the University's Centre for Human Factors and Sociotechnical Systems has worked on. Paul emphasised the importance of a systemic approach in his accident investigations. He covered a broad area including level crossing accidents, rail safety, sport and outdoor recreation accidents, and autonomous vehicle accidents. He illustrated the power of Jens Rasmussen’s AcciMap technique as a tool to capture the various causal factors from a total systems perspective.

An open forum session allowed us to share concerns about the quality of fault reporting data and the use of methods like AcciMap to assist in accident investigation.

A most educational day which, although focused on rail investigation, was completely transferable to other domains. Our thanks to the RAIB for hosting this event.