Recent incident reports
29 June 2018
The following is a summary of four recently released investigation reports into light rail and heritage rail incidents that occurred in UK, Belgium, and the Republic of Ireland. These investigation reports have been released since the last review of incidents in the Rail Safety News. A common theme in these reports is the adequacy of risk assessments.
Fatal collision between a tram and pedestrian
Woodbourn Rd, Sheffield, UK - 22 December 2016
Rail Accident Investigation Branch
The fatal collision between a tram and pedestrian occurred when a pedestrian was struck and fatally injured by an outbound tram travelling on a parallel track. The pedestrian, who had just got off an inbound tram at Woodbourn Road, was using a crossing at the tram stop. No one was waiting at the outbound platform and no one on board the outbound tram had requested that it stop, so it was travelling non-stop through the platform at around 21 km/h.
The investigation reported that the pedestrian was seemingly unaware that the tram was approaching the crossing. The data recorder on the tram showed that no warning was sounded and the tram’s brakes were not applied prior to the collision. The driver had been looking in the left-hand external mirror to check that no one suddenly hailed the tram as it passed through the platform. The driver had also looked in the internal rear-view mirror as she did not want to miss any passengers who might suddenly request to get off at Woodbourn Road. The CCTV camera that recorded the forward-facing view from the tram showed the driver’s hands on the controls reflected in the windscreen as it passed through the stop.
An underlying cause was that the operator had not assessed the risk of trams in service running non-stop through stops when it first introduced the system of request stops around 1999. The investigation also found inconsistencies between the training and assessments for new tram drivers when making non-stop movements through stops and the operational standards that drivers are required to follow for such movements.
Other possible contributing factors were that the driver was wearing sunglasses, which might have reduced the visibility of the pedestrian who was in a shaded area, and the driver’s concentration level might have been reduced by that stage of the journey.
Since the accident, the operator has mandated audible warnings for all non-stop movements through tram stops and acted to reduce driver distraction due to looking in mirrors. It has also updated its risk assessment to include trams in service running non-stop through tram stops and implemented measures to reduce the risk of collisions with pedestrians. The measures include such things as reducing tram speed, introducing ‘look both ways’ signage and revising crossing audits.
Findings from the investigation included:
- the need for an industry working group to monitor the development and application of new pedestrian detection technology to alert drivers to potential collisions with pedestrians
- the importance of tram operators actively assessing and managing the additional risk to users of foot crossings associated with trams making non-stop movements through stops
- reminding tram drivers to only use driving mirrors for essential tasks related to the safe operation of the tram during non-stop movements through tram stops
- understanding how sunglasses can affect the wearer’s r vision when passing from sunlit to shaded areas, particularly during the winter months when the sun is low.
The investigating body (RAIB) has completed six previous investigations involving trams colliding with pedestrians, four of which were collisions on a crossing over the tramway.
Overturning of a tram
Sandilands Junction, Croydon, UK - 9 November 2016
Rail Accident Investigation Branch
A tram derailed and overturned on a curve as it approached Sandilands Junction, Croydon (U.K.). Seven people were killed and a further 19 people were seriously injured. The Rail Accident Investigation Branch’s (RAIB) review of the on-tram data recorder (OTDR) showed that the tram was travelling at a speed of approximately 70 km/h as it entered the curve. It had passed a speed limit sign showing a maximum permitted speed of 20 km/h. RAIB found that the risk of trams overturning on curves was not properly understood by the tramway and so there were insufficient safety measures. All the passengers who were killed, and many of those who were seriously injured, fell through the windows or doors as the tram tipped over. This catastrophic accident was the worst to occur on a British tramway for more than 90 years.
The RAIB’s investigation concluded that it is probable that the driver temporarily lost awareness on a section of route on which his workload was low. A possible explanation for this loss of awareness being that the driver had a microsleep linked to fatigue. Although it is possible that the driver was fatigued due to insufficient sleep there is no evidence that this was the result of the shift pattern that he was required to work.
The investigation found that:
- there was no mechanism to monitor driver alertness or to automatically apply the brakes when the tram was travelling too fast
- there was inadequate signage to remind drivers when to start braking or to warn that they were approaching the sharp curve
- the windows broke when people fell against them, so many passengers were thrown from the tram causing fatal or serious injuries.
The RAIB made 15 recommendations intended to improve safety which included:
- technology, such as automatic braking and systems to monitor driver alertness
- better understanding the risks associated with tramway operations, particularly when the tramway is not on a road, and the production of guidance on how these risks should be managed
- improving the strength of doors and windows
- improvements to safety management systems, particularly encouraging a culture in which everyone feels able to report their own mistakes
- improvements to the tram operator’s safety management arrangements to encourage staff to report their own mistakes and other safety issues
- reviewing how tramways are regulated
- a dedicated safety body for UK tramways.
Less than two weeks before the accident, there had been an incident in which a tram went too fast round the curve at Sandilands. On that occasion a different tram driver mistook his position in the tunnel and braked late. The tram entered the curve at more than 45 km/h, a speed at which it is likely that it was close to tipping over. For various reasons, this incident was not fully investigated by the operator. Some tram drivers reported to the RAIB that there had been occasions on which they had used heavy braking or used the emergency brake to control their speed at this location. None of them reported these events to the operator because of the perceived attitude of some managers and f feared consequences. This meant that the operator’s management did not understand the extent of late braking and so took no action to mitigate the risk. Although there was evidence of some tram drivers sometimes exceeding the speed limit, generally by small amounts, no evidence of a culture of speeding contributing to the accident was found.
While the operator had carried out an assessment of the hazards on the route, it had not identified the risk of overturning on this curve, or on any other curves, because of excessive speed. There had been no accident in the UK involving a tram overturning since 1953.
The investigation found that the risk of trams overturning due to excessive speed around curves had not been addressed by UK tramway designers, owners, operators or the safety regulator. Additional signs were added after the RAIB issued urgent safety advice to the tramway industry during the investigation.
Although they met regulatory requirements and were made of toughened glass the tram windows provided little resistance to the ejection of passengers. Similarly, although complying with relevant design standards, it is also likely that the way the doors were attached meant that some of them were not able to contain passengers when they fell against them during the accident. The emergency lighting was also disabled when the tram overturned.
The regulator’s compliance strategy provided a lower level of intervention for tramways than for other sectors, consistent with its evaluation of the risk and the regulatory framework in place. However, the RAIB’s analysis of the evidence suggested that the overall level of risk on tramways, and the potential for multiple fatality accidents, was higher than assumed. The RAIB therefore found a need for a review of the regulatory strategy.
Difflin Light Rail Passenger Fall
Co. Donegal, Republic of Ireland - 17 December 2016
Railway Accident Investigation Unit
In 2016 a Santa Express train service was operating at Difflin Light Railway (DRL), Co. Donegal, Republic of Ireland. Just before starting to travel around a right-hand curve, a six-year girl fell from the train, became entangled with the side of the train and was dragged a short distance along the gravel before the train came to a stop. The child sustained injuries to her legs that required hospital treatment and a skin graft as an outpatient. The investigation estimated that the girl of 23kg experienced a relatively minor force in the region of 27.6N which, owing to her position and movement, would have caused her to slip over a safety chain.
The investigation found that there were insufficient physical or procedural safeguards to prevent small children falling from an open carriage, and that the risk assessment within the Safety Management System (SMS) did not identify the risk posed to small children. The DLR ‘Operating instructions for passenger trains’ included the requirement that passengers are to be ’instructed to remain seated and to keep their arms, legs and heads within the width of the carriage at all times’. The DLR risk assessment identified ‘passengers falling out of trains’ as a hazard. Using the normal definitions of hazard and risk, passengers falling out of trains would be a risk, the hazard could be identified as open carriages. The risk assessment did not identify the open carriages as a hazard.
Findings made by the investigation included:
- DLR failed to carry out the emergency plan as required by its SMS following an accident
- DLR did not report the accident to the RAIU or Commission for Railway Regulation (CRR) as required
- staff were not seasonally re-briefed
- risk assessments were not reviewed periodically as called for by DLR SMS
- there was no dedicated first aid location at DLR to treat injuries to staff or passengers.
The RAIU recommended DLR should:
- review the physical and procedural safeguards for the operation of their trains to prevent small children whose feet do not touch the ground in a seated position from falling from open carriages,
- review their risk assessment process to ensure that all reasonably foreseeable risks associated with the operation of trains are identified and suitable control measures identified,
- review its SMS, in its totality, and ensure that there were internal monitoring procedures that mandate the periodic checking of application of SMS processes and practises
- review its responsibilities under the Safety and Welfare at Work Regulations in relation to dedicated first aid areas.
Failure of a flue on the smoke box side of a steam locomotive on a tourist train line
Maldegem, Belgium - 30 April 2016
Investigation Body for Railway Accidents and Incidents
During a 2016 steam train festival at Maldegem, Belgium, a failure occurred on a steam locomotive and two engineers on the footplate received serious burns. The investigation found that an implosion of a flue tube allowed pressurised steam to enter the firebox of the boiler and, via the door of the firebox, also the driver’s cab. The implosion of the tube was probably due to the weakening of the seam in the tube sheet by caulking as well as corrosion of the tube. The organisation that owned and maintained the rolling stock (CFV3V) had received a permit to operate at the festival, providing a rolling stock expert had checked that the rolling stock was compatible with the museum line infrastructure. The operator of the museum railway line had prepared, in accordance with its operating authorisation (accreditation), a file with a technical description of the rolling stock.
The investigating body found that visual inspection of the tubes at a distance did not allow the weakening of the seam to be detected. With implosion having not been identified as a risk by the company, the inspection intended to detect this potential type of damage did not allow a sign of weakness to be seen. The organisation was unaware of the phenomenon seen in the context of the accident. According to the statements from CFV3V, this phenomenon had never happened before.
In addition to the inspections carried out by the operator (internal inspection), an inspection by an approved body takes places regularly, comprising:
- an annual internal cold inspection
- an annual external hot inspection
- a complete hydraulic test every five years.
The steam locomotive was subject to internal and external inspections. The internal inspection before the incident was done by an approved inspection body in March 2016 with the next visit due in March 2017. The conclusion of the report indicated that the equipment could be put back into service at the pressure of 14 bar. It was noted however that the cleaning of the tubes and the tube plate was not satisfactory. The external inspection carried out by an approved inspection body took place in September 2015. It looked at the visible and/or accessible parts of the water and steam chambers and no leakage was noted. The most recent hydraulic test, was carried out in September 2014, recorded a satisfactory hydraulic test at 20 bar after repair of a cross-bar tie rod. Hydraulic tests were carried out at five yearly intervals.
A feasibility study was conducted following the incident. The aim was to determine the dosage of the water treatment product used in the boiler to reduce the harmful effects of oxidation and increase the longevity of the tube bundles. The investigating body recommended that operators of museum railway lines evaluate and take measures, if necessary, to limit the impact of the water used.