An accident investigation into an earlier runaway tram incident found there were defects with mechanisms on both parking brakes.

Vintage Snaefell tram no.3 was completely destroyed in March last year when it left the Summit station unmanned and uncontrolled, and travelled about 1.75km before crashing off the track .

It was lucky no one was on board and that it derailed before it reached the Bungalow road crossing.

Results of the accident investigation by the Health and Safety at Work Inspectorate were released following a Freedom of Information request - but only after Isle of Man Newspapers requested a review of an earlier refusal.

A letter giving an update on the investigation revealed the motorman had left the tram unattended, having applied the parking brake and secured the tram to stop passengers boarding.

The line on which the tram was parked was on a slight downhill slope and it started rolling downhill at about the same time as the next tram approached on the up line.

Transport division engineers found that a toothed ratchet wheel in the parking brake mechanism at one end of the tram showed signs of wear or damage.

And subsequent investigations by the health and safety inspector identified that the metal shaft from the identical parking brake mechanism at the other end of the tram had fractured.

Further testing could not establish whether the crack had formed before or during the crash.

No written inspection or maintenance procedure for the parking brakes was in place, the investigation also found.

Mr Longworth insisted that the issue with the parking brakes was ’irrelevant’ to the cause of the crash, while Bernard Warden, environment, safety and health director, said it was ’peripheral’.