The tram that derailed in Croydon killing seven people was travelling at 43.5mph in a 12mph zone, investigators have revealed.
The Rail Accident Investigation Branch (RAIB) said in its interim report that there was no evidence of any track defects, or obstructions on the tracks.
It also said that there was no evidence of malfunction in the braking system.
The tram, which was carrying around 60 people, derailed last Wednesday morning shortly after coming out of a tunnel. Initial analysis shows that the driver, Alfred Dorris, did apply the brake after coming out of the tunnel, but only enough to reduce his speed from 50mph to 43.5mph.
Mr Dorris, from Beckenham, has been arrested on suspicion of manslaughter and released on bail until May. It is understood that establishing whether the 42-year-old had fallen asleep or blacked out are further lines of inquiry.
The RAIB has advised London Trams and Tram Operations Ltd to put speed restrictions in place before the bend out of the tunnel.
Mike Brown, London's transport commissioner, said:
"We will follow the RAIB's advice and, before service is resumed, will implement additional temporary speed restrictions and associated signage near Sandilands to supplement existing safety arrangements.
"We are continuing to carry out a thorough safety assessment and are taking the advice of an independent panel of tram experts."
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