The Croydon tram service has reopened, just over a week after the derailment in which seven people died.
Investigators have said the tram was travelling at three-and-a-half times the speed limit when the crash happened near the Sandilands stop.
The Rail Accident Investigation Branch (RAIB) said the tram, which was carrying about 60 people, was doing 43.5mph in a 12mph zone.
In its interim report, it said there was no evidence of any track defects, or obstructions on the track.
The investigation also found no malfunction of the braking system.
The tram derailed on Wednesday morning last week, shortly after coming out of a tunnel with a 50mph speed limit.
A tram driver who appears to fall asleep at the wheel in a video filmed by a commuter has been suspended.
Transport for London has offered to pay for the funerals of the seven people killed in the tram crash in Croydon.
The Rail Accident boss from Network Rail says that investigators have 'downloaded data from a black box' from the derailed Croydon tram.