Published 8th March 2012
CROYDON - The RAIB summed up the accident as happening at about 06:25 hrs, tram number 2538 was approaching East Croydon tram stop travelling west from the direction of Sandilands at a speed of about 12 km/h (7.5 mph).
The driver observed that a “points set” indication was showing for the left-hand route, towards platform three. As the tram passed over motorised facing points, they changed between the first and second bogies, so that the leading bogie took the left-hand route and the centre and trailing bogies (wheelsets) took the right-hand route (towards platform two).
The centre bogie was dragged into derailment, the pantograph came off the contact wire, and the tram came to a stop. There were about 100 passengers on board the tram, and none of them were hurt.
Initial investigations indicate that tram 2538 was not detected by the track circuit which locks the facing points, and that the points were commanded to change because platform three was already occupied by a preceding tram.
The RAIB’s investigation will seek to understand the reasons why the tram was not detected and this will examine the design and condition of the tram, and the rail head conditions at the time of the derailment.
Sometimes the railhead can be covered in materials that prevent the electrical detection signal to fail which in turn fails to ‘alert’ the signalling system which is linked to points and how they work.
The RAIB’s investigation is independent of any investigations by the safety authority (the Office of Rail Regulation).