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Latest rail investigation summary - February 2017

This is a collation of some of the world’s railway formal inquiry reports. It includes a brief incident synopsis, along with the main causes and recommendations from each investigation.

Readers may find some of the actions and recommendations useful to their own operations.

Co-ordinated by Greg Morse,Operational Feedback Specialist, RSSB.


  • US: Freight train collision in Hoxie, Arkansas, 17 August 2014
  • UK: Collision at Plymouth station, 3 April 2016
  • UK: Trains passed over washed out track at Baildon, West Yorkshire, 7 June 2016

Some of the key issues raised and/or suggested by the stories in this edition:

  • Fatigue (risk management)
  • Sleeping disorders and fitness criteria
  • Train protection systems
  • Permissive working
  • Safety critical communications
  • Driver training and assessment
  • Earthworks
  • Reactions to information received
  • Action against recommendations

1 February 2017

​US: Freight train collision in Hoxie, Arkansas, 17 August 2014

Full report External link

Australian freight train

At 02:28 (local time) on 17 August 2014, a southbound Union Pacific freight collided with a northbound one while traversing a turnout in Hoxie, Arkansas. As a result of the collision, the driver and guard of the southbound train were killed; the driver and guard of the northbound train were seriously injured.

​The National Transportation Safety Board (NTSB) determined the probable cause of the accident to be the failure of the southbound crew to respond to the signal indications requiring them to slow and stop their train ahead of the turnout, because they were fatigued and had fallen asleep due to:

  • The driver’s inadequately treated obstructive sleep apnoea;
  • The guard’s irregular work schedule;
  • The crew operating in the early hours, when they were predisposed to sleep.

Contributing to the accident were:

  • The lack of a functioning positive train control system; 
  • The use of an automatic horn sequencer that, when activated, negated the operation of an electronic alertness device;
  • The failure of the Federal Railroad Administration (FRA) to promulgate rules regarding sleep disorders; and 
  • The absence of federal regulations requiring freight railroads to use fatigue modelling tools for train crew work schedules.


  • The FRA should require freight operators to use validated biomathematical fatigue models, similar to those used by passenger operators, to develop work schedules that do not pose an excessive risk of fatigue. 
  • The FRA should develop and enforce medical standards that safety critical staff diagnosed with sleep disorders must meet to be considered fit for duty. 
  • BNSF Railway, Canadian National Railway, Canadian Pacific Railway, CSX Transportation, Kansas City Southern Railway, Norfolk Southern Railway, Intercity Railroads and Commuter Railroads should review and revise as necessary their medical rules, standards, or protocols to ensure they are informed of any diagnosed sleep disorders that employees in safety critical roles must report and, when an employee makes such a report, perform periodic evaluations to ensure the condition is appropriately treated and the employee is fit for duty.
  • Class I operators should revise their scheduling practices for train crews and implement science-based tools, such as validated biomathematical models, to reduce start time variability that results in irregular work-rest cycles and fatigue.
  • Union Pacific should revise its medical rules to add any diagnosed sleep disorder to the list of medical conditions that employees in safety critical roles must report and, when an employee makes such a report, perform periodic evaluations to ensure the condition is appropriately treated and the employee is fit for duty.

13 February

UK: Collision at Plymouth station, 3 April 2016

Full report External link

Plaform at Twyford station

At 15:34 on Sunday 3 April 2016, the 13:39 from Penzance to Exeter (formed if a Class 150 DMU) collided with an empty HST that was already waiting in Platform 6 at Plymouth.

The collision occurred at around 15 mph and resulted in injuries to 48 people and damage to both trains.

The signaller intended that both trains should share the platform because the empty train was to form a service to London and some passengers from the Penzance service were expected to join it. Lift refurbishment work meant that, without platform sharing, passengers would have needed to use the stairs and a subway when changing trains. Permissive signalling arrangements were in place at Plymouth to permit two trains to share the same platform.

The signaller misjudged the amount of space available behind the London train and wrongly believed there was room for the Penzance train. He was aware that the platform sharing arrangement required an unusual form of permissive working, but did not communicate this to the Penzance driver, and the rules did not require him to do so.

The Penzance driver incorrectly believed he would not be sharing a platform with the London train. There was insufficient distance to stop his train by the time he realised his mistake and had applied the emergency brake.

The training and assessments undertaken by the driver had not ensured a correct understanding of permissive working. Furthermore, he had not previously experienced the type of permissive move arranged as he approached Plymouth on the day of the accident.

Great Western Railway (GWR), the operator of both trains, and Network Rail had not identified the risk of a collision due to the combination of an unusual form of permissive working, the track alignment on the approach to Plymouth station, and an inexperienced driver.

The following factors affected the consequences of the accident:

  • The trains’ performance was as expected for trains designed before the introduction of modern crashworthiness standards;
  • Keeping the doors locked on the London train during the permissive movement meant that there were no passengers on it when the collision occurred; and 
  • One passenger and a member of GWR staff were injured when they broke the protective covers in order to operate the emergency door release handles.

RAIB has identified the following key learning points:

  • Train drivers undertaking permissive moves should not presume the extent of the movement permitted by the signalling system, for example, assuming a train will proceed as far as the relevant platform car stop sign. Train drivers must always check carefully the route ahead and be prepared to stop short of any obstruction, taking account of any sighting limitations.
  • Train operators should consider reducing risk to passengers by preventing them from boarding or alighting while a second train is entering the same platform under permissive working arrangements.

Action taken

Following the accident at Plymouth, ORR served improvement notices on Network Rail and GWR saying both organisations had not carried out suitable and sufficient assessments of the risks of permissive working at Plymouth station, in breach of the Management of Health and Safety at Work Regulations 1999 External link, and the Railways and Other Guided Transport Systems (Safety) Regulations 2006 External link.

The accompanying letter sent to Network Rail in May 2016 required it to review, along with relevant train operating companies, all risk assessments at stations where permissive working is undertaken, and to ensure that ‘any control measures identified are implemented’. ORR also wrote to GWR saying it ‘should cooperate and collaborate with Network Rail to ensure the risks are suitably and sufficiently assessed’ at the stations it operates.

Network Rail and GWR have completed a risk assessment for permissive working at Plymouth station and implemented additional control measures including:

  • Briefing drivers about local risks such as track curvature that can restrict sighting, gradients, and the difficulty of identifying what platforms trains are standing in;
  • Instructing drivers to restrict the train’s power setting, and thus limiting the train’s acceleration, when proceeding under permissive working arrangements, and not to exceed 10 mph at the start of the platform (GWR has also required its drivers to apply this instruction at all stations); and 
  • Prohibiting permissive working in Platform 6 when the stationary train is formed of HST stock.

Network Rail has begun a programme to assess the risks from permissive working nationally. This was a requirement of the ORR’s improvement notice and letter. Network Rail reported to RAIB that it commenced this work following the accident at Plymouth, but before it was required to do so by the ORR improvement notice.


  • GWR should review its driver training and assessment processes that relate to permissive working with the overall objective of ensuring that new drivers have the knowledge and skills that are needed to address the hazards they may encounter when entering an occupied platform. The review should include consideration of how best to:
  • Discourage drivers from making any assumptions about the length of platform that is clear, and to avoid presuming that the line is clear to a car stop sign; and
  • Provide practical experience in a variety of permissive platform working situations, for example, at through platforms, into bay platforms, in track circuit block areas and under absolute block arrangements. 
    • GWR should implement any enhancements to its existing training and assessment processes that have been identified.
    • Network Rail, with the assistance of the relevant train operating companies, should review and, where necessary, enhance the following aspects of operating arrangements at stations where permissive working for passenger and ECS trains is authorised:
  • The means by which signallers should establish the combinations of trains which can be safely accommodated at platforms (to include considering provision of simple look-up tables, whether particular processes should be mandated, and the safe useable length of platforms);
  • Defining any particular circumstances in which the signaller should speak to the driver in order to provide details of an intended movement into an occupied platform; and
  • Speed restrictions applicable to trains entering platforms during permissive working.
    • GWR should modify the emergency door release arrangements on Class 150s so that passengers are not put at risk of injury when using them. It should also review emergency door release arrangements on other trains it operates to determine whether, and when, a similar modification is required.

    16 February

    UK: Trains passed over washed out track at Baildon, West Yorkshire, 7 June 2016

    Full report External link

    Trains passed over washed out track at Baildon, West Yorkshire

    Between 16:29 and 17:58 on 7 June 2016, three passenger trains passed over a section of the single line at Baildon, where part of the supporting embankment had been washed away by flood water. This left one of the rails unsupported over a length of between 3 and 4 metres. None of the trains derailed and no one was injured.   

    The washout occurred following a period of intense rainfall between around 15:30 and 16:00 that afternoon. A member of the public had noticed the washed out track and had reported it to the local Fire and Rescue Service who had then informed Network Rail shortly before 16:30.   

    Around the same time, the driver of a train on that line reported there was flooding in the area, with the water being above the level of the rails. Network Rail stopped train movements and sent staff to inspect the track at the location reported by the train driver. The inspection found that the flood water had receded significantly, but did not identify the washout because it was at a different location. At 17:30, the line was reopened for use at its normal maximum speed of 50 mph.   

    At 17:45, a second train passed over the damaged section of track. The driver did not report any fault, but a call from a member of the public was received by the local police stating they had witnessed this train passing over the unsupported section. The message was passed to Network Rail, but before the line was again blocked to traffic, a third train passed over it. This train also had not been stopped from running over the washout. The driver of this train saw the washout, but was unable to stop his train, passing over it at a speed of 38 mph. He subsequently stopped the train and made an emergency call to the signaller.   

    These near miss incidents occurred because the reports of the damaged track from members of the public, via the emergency services, were not dealt with appropriately by railway controllers, who did not listen with sufficient care to the emergency telephone calls, and did not direct its incident responders to the correct location. For their part, the responders were not aware of the vulnerability of the embankment to flooding. The track damage was similar to a previous washout at the same location that occurred in August 2012. Since that incident, no action had been taken on the recommendations considered by Network Rail to prevent a recurrence.

    RAIB has identified the following key learning points:

    • Controllers and signallers are reminded to manage operational communications with great care. In particular it is important to: 
  • Identify and capture key descriptions and safety critical information;
  • Not interrupt the caller even if they think they know what the message is about (it is possible that a new message about an incident that is already known about may provide further important information about the nature of the incident which may require a modification to the railway’s response);
  • Avoid passing on messages to others in an informal manner while also listening to an emergency call.
    • Control room managers are reminded of the need to continuously monitor and maintain a good standard of safety critical communications within their control offices as required by the Network Rail operations manual.
    • Duty holders should not assume others have reported incidents to RAIB. The Railways (Accident Investigation and Reporting) regulations requires all duty holders to report in accordance with the schedules.

    Action taken

    In July 2016, Bradford Metropolitan District Council undertook a CCTV survey of the drainage system downstream of the culvert and has reported that no debris or blockage was found. Network Rail has reported that a full survey of the culvert and extensive lengths of the upstream and downstream pipes was completed in November 2016.

    The Baildon site is on the Network Rail Weather Service list and a procedure on the necessary actions to take in the event of an extreme weather alert is being prepared. Additionally, the company notes that it has assessed the capability of the 2016 repair as being adequate to withstand the water flows seen in 2012 and 2016.

    The quality of incident controller communications is now being monitored and assessed in accordance with the requirements of the operations manual.


    • Network Rail should put measures in place to reduce the risk of a track washout at Baildon. Measures to be considered should include, but not be limited to, the following:
  • Following the inspection of the drain system that leads from the culvert in question, an assessment of whether there is any blockage that needs clearing, or a permanent restriction in the drain system;
  • Installation of a line-side flood water capture system to carry flood water away safely from the site to prevent further washouts; and
  • Completion of the work already begun on providing alerts to trigger actions of incident responders following heavy rainfall events detected in the Baildon area by the Network Rail Weather Service system.
    • Network Rail should develop and implement a system to enable its controllers to be able to rapidly translate geographic or post code information provided by others on locations adjacent to the railway, into track location information so enabling the effective direction of responders.
    • Network Rail should review how its controllers respond to emergency phone calls about the safety of the line, to make sure that important information is captured and accurately transmitted to relevant railway responders, and implement any identified improvements. The scope of the review should include consideration of the following:
  • Controllers making direct contact with the initiator of the emergency call to clarify the nature of the emergency situation and its location; and
  • The most appropriate way for GSM-R emergency calls to be made to train drivers, whether from the control room directly, via the shift signalling manager, or via the signaller.
  • Previous rail investigation summaries

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