THE first derailment in Croydon since the network was opened nearly 13 years ago was caused because a track circuit failed, an investigation has found.
Around 100 passengers were on tram 2538 when it came off the tracks outside East Croydon station during the early morning rush hour on February 27 last year.
The Rail Accident Investigation Branch (RAIB) found that a circuit had failed to lock the points as the tram approached the station at 6.23am.
The fault was caused by the preceding tram which had not stopped far enough forward on the platform to trigger the command for the points to change, a report published today (Thursday) concludes.
When that tram departed, the loop activated and caused the points to change between the wheel chassis of 2538 as it approached the station.
The tram's leading bogie (the chassis which holds the wheels) was directed towards platform 3 but the points moved as the chassis passed over it, damaging a switch rail and causing the back two sets of wheels to be directed towards the other platform.
The driver sensed an unusual movement and applied the emergency brakes. The tram, which had been travelling 7.5 miles per hour, came to a stop after travelling four metres.
None of the passengers were injured by the derailment, which caused damage to the tram's wheels, the road surface and points.
Services resumed in time for the evening rush hour and Tramlink undertook a review of the signalling outside the station.
RAIB's inspectors concluded it was possible that silt contamination had caused the track circuit to fail.
The dirt had built up despite the area being swept a week before and drainage works being undertaken in 2009.
RAIB made three recommendations in its report, including a review of signalling arrangements at East Croydon and improved inspection and clearing of silt.
Although it was the first time a Tramlink tram has derailed in Croydon, there have been five other derailments on the system since it opened in May 2000, including Beddington Lane, Beckenham road, Mitcham and twice at Phipps Bridge.
