INVESTIGATORS have blamed wear and tear on the track for a derailment on Blackpool's tramway.
The ill-fated prototype City Class 611 tram came off the tracks during trials at Starr Gate.
But experts have deemed that it is "unlikely" that the same derailment risk faces Blackpool Transport's own trams which use different running gear.
The accident happened on May 30 last year when a driver and two technicians were aboard the vehicle which was travelling at about five miles an hour on a curved part of the track.
The same tram, operated by Liverpool-based Tram Power, caught fire in January this year while it was being driven near Central Pier and is currently under repair.
A report published today by the Rail Accident Investigation Branch (RAIB) says: "The cause of the derailment was that the tip of the wheel flange came into contact with the worn profile of the rail gauge face."
It adds that a contributory factor was the new type of running gear being used on the two-carriage prototype.
The report says: "It was travelling at about five miles per hour when about two thirds of the way round the curve, a loud noise was heard by those on board.
"One of the development team members saw that the inner and outer wheels under the central articulation module had derailed toward the centre curve.
"He alerted the driver who brought the tram to a stop."
The tram remained upright following the accident and no-one was injured.
Following the investigation, Blackpool Council has made improvements to the rail gauge, and Tram Power was put in touch with specialist companies in order that it could make further studies of the type of running gear on its prototype.
The track is currently halfway through an 11.8m upgrade with the second phase due to begin this November.