Rail Accident Report Electrical arcing and fire under a train near Windsor & Eton Riverside 30 January 2015 Report 18/2015 October 2015 This investigation was carried out in accordance with: l the Railway Safety Directive 2004/49/EC; l the Railways and Transport Safety Act 2003; and l the Railways (Accident Investigation and Reporting) Regulations 2005. © Crown copyright 2015 You may re-use this document/publication (not including departmental or agency logos) free of charge in any format or medium. You must re-use it accurately and not in a misleading context. The material must be acknowledged as Crown copyright and you must give the title of the source publication. Where we have identified any third party copyright material you will need to obtain permission from the copyright holders concerned. This document/publication is also available at www.raib.gov.uk. Any enquiries about this publication should be sent to: RAIB Email: [email protected] The Wharf Telephone: 01332 253300 Stores Road Fax: 01332 253301 Derby UK Website: www.gov.uk/raib DE21 4BA This report is published by the Rail Accident Investigation Branch, Department for Transport. Preface The purpose of a Rail Accident Investigation Branch (RAIB) investigation is to improve railway safety by preventing future railway accidents or by mitigating their consequences. It is not the purpose of such an investigation to establish blame or liability. Accordingly, it is inappropriate that RAIB reports should be used to assign fault or blame, or determine liability, since neither the investigation nor the reporting process has been undertaken for that purpose. The RAIB’s findings are based on its own evaluation of the evidence that was available at the time of the investigation and are intended to explain what happened, and why, in a fair and unbiased manner. Where the RAIB has described a factor as being linked to cause and the term is unqualified, this means that the RAIB has satisfied itself that the evidence supports both the presence of the factor and its direct relevance to the causation of the accident. However, where the RAIB is less confident about the existence of a factor, or its role in the causation of the accident, the RAIB will qualify its findings by use of the words ‘probable’ or ‘possible’, as appropriate. Where there is more than one potential explanation the RAIB may describe one factor as being ‘more’ or ‘less’ likely than the other. In some cases factors are described as ‘underlying’. Such factors are also relevant to the causation of the accident but are associated with the underlying management arrangements or organisational issues (such as working culture). Where necessary, the words ‘probable’ or ‘possible’ can also be used to qualify ‘underlying factor’. Use of the word ‘probable’ means that, although it is considered highly likely that the factor applied, some small element of uncertainty remains. Use of the word ‘possible’ means that, although there is some evidence that supports this factor, there remains a more significant degree of uncertainty. An ‘observation’ is a safety issue discovered as part of the investigation that is not considered to be causal or underlying to the event being investigated, but does deserve scrutiny because of a perceived potential for safety learning. The above terms are intended to assist readers’ interpretation of the report, and to provide suitable explanations where uncertainty remains. The report should therefore be interpreted as the view of the RAIB, expressed with the sole purpose of improving railway safety. The RAIB’s investigation (including its scope, methods, conclusions and recommendations) is independent of any inquest or fatal accident inquiry, and all other investigations, including those carried out by the safety authority, police or railway industry. Report 18/2015 October 2015 Windsor & Eton Riverside This page is intentionally left blank Report 18/2015 4 October 2015 Windsor & Eton Riverside Electrical arcing and fire under a train near Windsor & Eton Riverside, 30 January 2015 Contents Preface 3 Summary 7 Introduction 8 Key definitions 8 The accident 9 Summary of the accident 9 Context 10 The sequence of events 12 Key facts and analysis 17 Background information 17 Identification of the immediate cause 22 Identification of causal factors 22 Factors affecting the severity of consequences 32 Observations 35 Previous occurrences of a similar character 38 Summary of conclusions 40 Immediate cause 40 Causal factors 40 Factors affecting the severity of consequences 40 Additional observations 40 Actions reported as already taken or in progress relevant to this report 42 Actions reported that address factors which otherwise would have resulted in a RAIB recommendation 42 Learning points 43 Recommendations 44 Appendices 46 Appendix A - Glossary of abbreviations and acronyms 46 Appendix B - Glossary of terms 47 Appendix C - Investigation details 49 Appendix D - Fleet check of class 458/5 cable joints 50 Report 18/2015 5 October 2015 Windsor & Eton Riverside This page is intentionally left blank Report 18/2015 6 October 2015 Windsor & Eton Riverside Summary Summary On the evening of 30 January 2015, the 19:53 hrs South West Trains service from Windsor & Eton Riverside to London Waterloo left its origin station on time. After the train had travelled about 400 metres, there was a small explosion under the sixth carriage, followed by about 22 seconds of severe electrical arcing. The train, which was formed of two class 458/5 electric multiple units (ten carriages), was travelling at about 14 mph (23 km/h) at the time. The brakes applied because of damage to air pipes, and the train stopped very rapidly. Some smoke entered the carriages through ventilators. There were two passengers in the sixth carriage, and they moved quickly into another part of the train. The driver contacted the signaller by radio to ask for the electric power to be switched off. While he was doing this, the floor of the sixth carriage was penetrated by fire, and smoke rapidly filled the vehicle.A few minutes after this, the lights in the rear five carriages went out. There were 19 passengers on the train. Some of them operated the emergency door release in the rear carriage, got down onto the track, and walked back to Windsor station. Railway staff later evacuated the remaining passengers to the track, and helped them walk back to the station. The fire brigade were called, and confirmed by 20:50 hrs that the fire was out. None of the passengers were hurt, but the guard of the train was taken to hospital and treated for smoke inhalation. The fire occurred because a joint between three power cables, located under the floor of the sixth carriage, had not been secured correctly when the carriage was reassembled after being rebuilt and refurbished in 2014. Electrical arcing had developed at the loose joint, and this damaged the ends of the cables and eventually led to the arcing which badly damaged the structure of the train. This in turn caused a fire that penetrated the floor. The RAIB has made four recommendations. One, addressed to Wabtec Rail Ltd, covers the review and improvement of quality assurance arrangements at the factory where the refurbishment work was done. The second, addressed to Network Rail, relates to the need for changes to the rules relating to the conditions under which passengers are evacuated from trains after incidents. The third and fourth, addressed to South West Trains, concern the way in which the emergency lighting on the trains is configured to operate in the event of a loss of external power, and the need to review the risks associated with power cables and the joints between them. The investigation also identified four learning points for the railway industry, relating to the design of electrical junction boxes, the need for train crew to be fully aware of how on-train equipment works, the organisation of train conversion projects, and the importance of ensuring that records relating to train design are accurate and kept up-to-date. Report 18/2015 7 October 2015 Windsor & Eton Riverside Introduction Introduction Key definitions 1 Metric units are used in this report, except when it is normal railway practice to give speeds and locations in imperial units. Where appropriate the equivalent metric value is also given. 2 The report contains abbreviations and technical terms (shown in italics the first time they appear in the report). These are explained in appendices A and B. Sources of evidence used in the investigation are listed in Appendix C. Report 18/2015 8 October 2015 Windsor & Eton Riverside The accident Summary of the accident The accident 3 On the evening of Friday 30 January 2015, train 2U641, the 19:53 hrs South West Trains service from Windsor & Eton Riverside to London Waterloo, had travelled about 400 metres after starting its journey, when severe electrical arcing began under the sixth carriage of the ten-carriage electric multiple-unit (EMU) train. This lasted for about 22 seconds. 4 The train, which was travelling at about 14 mph (23 km/h) at the time, stopped immediately. Some smoke entered the carriages through ventilators. There were two passengers in the sixth carriage, and they moved quickly into another part of the train. The guard of the train moved from the tenth to the sixth carriage to investigate, and the driver also moved to the middle of the train. They could see that there was still smoke coming from below the sixth carriage, so the driver returned to the front of the train from where he contacted the signaller by radio to ask for the electric power supply to be switched off. While he was doing this, fire broke through the floor of the sixth carriage, and smoke rapidly filled the vehicle.