In the aftermath of the Croydon Tram incident many questions were being raised, however the RAIB (Rail Accident Investigation Branch) have just issued their report states “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. The investigation has found that a possible explanation for this loss of awareness was that the driver had a microsleep, and that this was linked to fatigue”
Metrolink used to have a set of ‘parameters’ which set out the duty lengths, rest periods between duty’s, rest periods during duty’s and so on, for drivers, these gave strict limits on driving and were better, and safer, than the legal limits.
However Unite signed away these strict ‘parameters’ to allow the Metrolink operator to:
Increase the length of duty’s from average 7.5 hours to some now being 9.5 hours long
Instead of a rest break between the 3rd and 5th hour of their duty a driver can now work 5.5 hours without a break.
Some drivers are having to drive an up to an hour to get to work, do a 9.5 hour shift, and then drive up to another hour after work to get home, which was not taken into account when working out the duties.
The above naturally increases the fatigue levels of drivers, the risk of ‘microsleep’, and the risk of incidents occurring with trams when a driver is suffering from fatigue.
Why did Unite sign an agreement that increased the working day for the drivers, increased the time before having a break, which increases fatigue, when other unions are looking to reduce Fatigue and increase safety on our public transport?
Stephen Morris
General Secretary
Workers of England Union
Rail Accident Report
On the morning of 9 November 2016, tram 2551 reached the maximum permitted speed of 80 km/h as it entered the first of three closely spaced tunnels, which together extended for about 500 metres. When leaving the tunnels, the tram should have been reducing speed significantly as it was approaching the sharp curve round to Sandilands junction, where there is a 20 km/h limit. This was marked by a speed limit sign at the start of the curve. On the day of the accident, the tram was travelling at 73 kilometres per hour when it reached this sign.
The excessive speed caused the tram to overturn as it passed through the curve. Passengers were thrown around inside the tram and the tram slid along the ground on its side. Of the 69 passengers involved in this tragic accident, seven died and 61 were injured, 19 seriously.
Investigation methods included:
obtaining data from the tram’s onboard recorder and the tramway’s signalling system
conducting tests on the tram’s safety systems
using computer modelling to understand the minimum speed that would overturn a tram on the curve at Sandilands
reviewing the design of the infrastructure
reviewing the tramway’s safety and risk management systems
interviews with people and organisations involved
surveying tram drivers to understand how trams were being driven on that route
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. The investigation has found that a possible explanation for this loss of awareness was that the driver had a microsleep, and that this was 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.
It is also possible that, as he regained awareness, the driver became confused about his location and direction of travel through the tunnels. The infrastructure did not contain sufficiently distinctive features to alert tram drivers that they were approaching the tight curve.
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 has made 15 recommendations intended to improve safety. Recommendation areas include:
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 so as to encourage staff to report their own mistakes and other safety issues
reviewing how tramways are regulated
a dedicated safety body for UK tramways
Video summary and animation
Overturning of a tram at Sandilands junction, Croydon
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[Microsleep – Unintentional periods of sleep lasting anywhere from a fraction of a second to a few minutes. They are often, but not always, characterised by the closing of eyes or head nodding actions.]
