A LOST pin in a train wagon caused it to derail while passing through York station.

The wagon was part of an English Welsh and Scottish Railway train on its way from Tees Yard to Newport on January 18 this year.

It came off the tracks while travelling past platform three of York station at about 11.20pm.

The train was moving at 27mph at the time and the wagon was derailed for 250 metres. But no one was hurt, said the Rail Accident Investigation Branch report, published yesterday.

The report said: "Station staff heard a loud bang as the train travelled through platform three and observed damage to the infrastructure after the train passed.

"The signaller at York IECC (Integrated Electronic Control Centre) was contacted and a request made that the train be stopped for examination."

After the accident the driver checked the train, but could find no fault with it.

But a second examination, together with the Network Rail mobile operations manager, revealed collapsed suspension in one wheel, and a missing brake block in another.

The impact of the derailed wagon also damaged a coping stone on platform three, and 400 railway sleepers.

After the accident, the train was moved at walking pace up to the Normanton line next to the junction at Colton, near Tadcaster, to allow service to resume on the main line.

An investigation revealed the wheel suspension collapse which led to the accident had been caused by the loss of a link pin. It found that the track was in satisfactory condition and was not a factor.

Investigators concluded it was likely the underlying cause was that the pin had been lost because of "degradation, fatigue cracking and rapid overload", which had not been picked up early enough by maintenance staff. "However, the underlying causes could not be proved conclusively as the missing pin could not be found," said the report. Its recommendations included:

* That wagon owner GE Rail Services should revise maintenance procedures to ensure run down pins were detected and replaced before they failed.

* English Welsh and Scottish Railway should ensure wagons were checked and documented as fit to run before being put to use.

* All freight operators with similar wagons should make sure worn down link pins were checked and replaced.