AN INVESTIGATION is underway into how a tram departed from two stops with some of its doors open.
The Rail Accident Investigation Bureau (RAIB) is exploring how the tram left Lebanon Road and Sandilands with all four doors on one side open.
No one was hurt but RAIB said there was potential for passengers standing near the doors to be "very seriously injured".
The tram was travelling between West Croydon and Beckenham Junction on April 13 when the incident occurred.
RAIB said the tram had been delayed a number of times because a warning indicator had alerted the driver to a possible problem with a parking brake.
On each occasion the driver spoke to the controller and, after receiving instructions on how to deal with the fault, continued on.
A statement released by RAIB today (Friday) said: "At some point during this early part of the journey it is believed that a switch was operated in the driving cab which had the effect of bypassing some safety systems on the tram, including the door interlocking arrangements that would normally prevent the tram from moving with one or more doors open."
At Lebanon Road tram stop, there was further communication between the tram driver and controller.
The tram then departed with all four doors on the left-hand side open and reached a maximum speed of 27 kilometres per hour (17 mph) while travelling toward Sandilands.
At some point between the two stops three of four doors closed automatically, as they are designed to do after remaining open for two minutes.
At Sandilands, neither driver nor controller were aware of the problem. Instead they focused on fixing the parking brake. The tram then left with the same doors open again.
"By this stage, the controller was monitoring the tram's departure on CCTV and noticed the doors were open," said RAIB.
"He immediately contacted the driver and instructed him to stop."
The driver then closed the doors and the tram was taken out of service at the next stop.
It is not clear whether passengers attempted to alert the driver to the open doors.
RAIB's investigation will focus on the procedure for dealing with faults on trams, the design of the controls and the training and monitoring of drivers, especially when dealing with faults.
It will publish its findings, including recommendations to improve safety, on its website.
