A tram that crashed in south London killing seven people was travelling at more than three times the speed limit when it derailed, accident investigators have said.
The on-board data recorder showed the vehicle was doing about 44mph in Croydon as it entered a sharp bend with a 12mph limit, according to an interim report by the Rail Accident Investigation Branch (RAIB).
Investigators found no evidence of track defects or a malfunction of the tram’s braking system.
The RAIB gave no indication why the vehicle was speeding.
Around 60 passengers where on the two-carriage tram approaching Sandilands Junction when it came off the tracks, overturned and slid for 25 metres.
The investigation could be hampered as the RAIB revealed that the Bombardier-built vehicle’s CCTV system does not appear to have been working.
Six men and one woman were killed in the accident, which occurred in darkness and heavy rain at 6.07am on November 9.
A further 51 people were taken to hospital, eight with injuries described as serious or life-threatening.
The tram’s driver, Alfred Dorris, 42, from Beckenham, south-east London, was arrested at the scene and questioned on suspicion of manslaughter before being bailed until May.
It is understood that establishing if Mr Dorris was asleep or had blacked out are lines of inquiry.
Analysis of the tram’s data recorder revealed that the vehicle was travelling at 50mph - the maximum limit allowed on the network - as it approached the scene of the derailment.
The tram’s brakes were applied in the 180 metres before a 12mph speed limit sign ahead of the bend, but this was only enough to slow it to 44mph by the time it entered the curve.
The RAIB issued “urgent safety advice” to First Group, which carries out the day-to-day operation of the trams, and Transport for London, which manages the overall performance of the network.
Both organisations were urged to reduce the risk of more trams approaching the location of the crash “at an excessive speed” once the line is reopened.
This could be done with a further speed restriction before the start of the 12mph limit and additional warning signs, the report suggested.
London mayor Sadiq Khan said he had received “guarantees” from TfL that “all the advice” will be acted on before services resume.
The seven people killed in the crash were Dane Chinnery, 19, Philip Logan, 52, Philip Seary, 57, Dorota Rynkiewicz, 35, and Robert Huxley, 63, all from New Addington, and Mark Smith, 35, and Donald Collett, 62, both from Croydon.
Chief inspector of rail accidents Simon French said he would be in contact with the casualties and the families of those who died to keep them updated throughout the investigation “which will take some months to complete”.
He went on: “Our ongoing, detailed investigation will now look at the wider context of the accident, including the sequence of events, the way the tram was driven, the infrastructure and how people received their injuries.
“We will also be looking into previous occurrences of over-speeding in this area and underlying management issues.
“Our final report will include recommendations to reduce the likelihood and consequences of similar events occurring in the future.”
A passenger posted a message on social media on October 31 saying that a tram had “lifted on to one side” at 40mph in the same area as the crash.
Mike Brown, London’s transport commissioner, described the RAIB’s interim investigation as “thorough and swift” and confirmed that additional temporary speed restrictions and signage would be implemented “to supplement existing safety arrangements”.
He said TfL is carrying out a “thorough safety assessment and taking advice from an independent panel of tram experts”.
Engineers have repaired the track and associated equipment, and trams have run over that section of the line, but Mr Brown said services will only resume once a “rigorous assurance process” has been completed.
First Group chief executive Tim O’Toole said the company is working with TfL to follow the RAIB’s advice and provide “clear instruction on this to our drivers”.
The Aslef union said a lack of adequate safety systems was “at the root of this dreadful accident”.
It claimed that technology to automatically slow and stop a tram travelling too quickly in a potentially dangerous area - as used on the mainline railway and London Underground - would have prevented the incident in Croydon.