16.11.16
Croydon tram was travelling over three times speed limit, RAIB finds
The RAIB has released its interim report into the Croydon Tramlink accident last week, which killed seven and hospitalised 51 others, concluding that the vehicle was travelling over three times the permitted speed limit at the time.
Just after 6am on Wednesday 9 November 2016 a tram running between New Addington and Wimbledon derailed and overturned on a curve as it approached Sandilands Junction, Croydon.
The RAIB’s initial investigation found that the tram was travelling at approximately 70km/h when it derailed, almost three and a half times the maximum permitted speed on the curve. The driver was the only member of staff on board the tram which was carrying around 60 passengers.
“The RAIB’s initial review of the on-tram data recorder (OTDR) shows that the tram was travelling at a speed of approximately 70km/h (43.5 mph) as it entered the curve, which had a maximum permitted speed of 20km/h (12.5 mph),” the interim report said.
The maximum permitted speed for trams approaching the area from Lloyd Park tram stop, where the tram had just left, is 80km/h (50mph) until the curve near Sandilands Junction where it drops to 20km/h.
The drop in speed restriction is marked by a reflective board 30 metres before the curve. However, the RAIB found that a tram approaching the speed restriction board at 80km/h would need to begin braking at full service approximately 180 metres before the board in order to slow down in time.
“Initial analysis of the tram’s OTDR indicates that some braking was applied in the 180 metres before the 20km/h (12.5 mph) speed restriction board, but this was only sufficient to reduce the tram’s speed from 80km/h (50 mph) to approximately 70km/h (43.5 mph) by the time the tram passed the board and entered the curve on which the accident occurred,” the report said.
It is still unknown why the tram was over-speeding. At the time of the accident it was dark outside and raining heavily. The RAIB said there appears to have been no malfunction with the tram’s braking system and so far no evidence has been found of obstructions or defects on the track.
“The factors that led to the over-speeding are still under investigation,” the RAIB added in the urgent safety advice issued to London Trams after the accident. “Until these factors are better understood, and before the junction re-opens to passenger operation, the RAIB advises London Trams and Tram Operations Ltd to jointly take measures to reduce the risk of trams approaching Sandilands Junction from the direction of New Addington at an excessive speed.”
The RAIB also suggested the imposition of a further speed restriction before the start of the existing 20km/h speed restriction or additional operational signs.
Mike Brown MVO, London’s transport commissioner, thanked the RAIB for their “thorough and swift” interim investigation and offered assurances that TfL will follow the RAIB’s advice before service on the track is resumed.
“Our thoughts are with everyone affected by what happened last Wednesday, and we are working with the local community to ensure that they continue to receive all the support they need at this incredibly difficult time,” Brown said.
“We are continuing to carry out a thorough safety assessment and are taking the advice of an independent panel of tram experts. We will only resume services for the local community once that rigorous assurance process has been completed.”
Finn Brennan, district organiser for the train drivers’ union ASLEF, called the incident a “terrible tragedy” and suggested that Tramlink’s lack of adequate safety systems were to blame for the incident.
“While individuals will be held accountable for their actions, it is clear that the lack of adequate safety systems were at the root of this dreadful accident,” Brennan commented.
“On the mainline railway, or London Underground, long established, tried and tested technology such as Train Protection Warning System (TPWS) or Automatic Train Protection (ATP) is in place to ensure that a train traveling too quickly in a potentially dangerous area will be slowed and stopped. This technology is not in place on Tramlink. If it had been then this awful event could have been avoided.”
Brennan added that there are also “serious” questions about Tramlink’s failure to investigate previous incidents following reports of passengers experiencing several near-misses on the curve.
“The operation of Tramlink should now be taken under the direct control of TfL so that immediate steps can be taken to implement the recommendations of the RAIB, and to put in place modern safety systems and a management structure that puts the welfare of its passengers, not value for shareholders, at the centre of everything it does,” he concluded.
(Image c. Steve Parsons from PA Wire and PA Images)
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