PUBLIC transport campaigners are backing moves to keep extra trains and rolling stock in Scotland to help deal with the Forth Road Bridge closure, even after it is up and running again.

It is understood talks are being held to procure the extra seats at the public expense as a contingency after the bridge is reopened in case there is a recurrence of any problems.

The development came as a leaked email revealed that Transport Scotland was told of an urgent need to repair the bridge 10 months ago.

Chief engineer Barry Colford imposed a restriction on "abnormal" loads and said it needed to remain until all the truss end links were strengthened.

One of the links has since cracked, leading to the closure of the bridge.

Transport Scotland said the restriction imposed was not related to the current structural defect.

Details have also emerged of how safety works on the the bridge were put off for at least seven years, amid mounting concerns behind the scenes over funding and transport disruption.

The bridge is due to reopen in the new year after repairs to its structure are completed. It comes after Transport Scotland confirmed the discovery of a crack on one of the bridge’s truss end links. Engineers say progress is "vulnerable to weather conditions".

ScotRail has hired two extra high speed trains from England and Stagecoach had found 33 extra buses to run more services from Fife to Edinburgh to help deal with the emergency closure of the bridge on December 4.

Used by about 100,000 people and 70,000 vehicles a day, the bridge normally sees 6,300 cars crossing it southbound in peak morning rush hours.

ScotRail, which is run by Dutch company Abellio, has leased one locomotive with six carriages and more than 300 seats from DB Schenker, a transportation logistics company.

Its depot is based in Eastleigh, near Southampton, and it was expected the train would remain on hire for as long as the bridge is closed.

A second locomotive and six carriages has been hired from another company and is based at depots in Glasgow and Motherwell.

Now there are moves to try to keep rolling stock after the bridge re-opens as long as Transport Scotland agrees to carry the cost.

John McCormick, chairman of the Scottish Association for Public Transport said: "There is a quite a shortage of rolling stock in Scotland. When Abellio took over the franchise in April, there were some trains sent off down to one of the franchises in England and they have been short of rolling stock ever since then. So they are running with a very tight fleet at the moment.

"If they can get their hands on extra trains they should hang onto them. They should not just be held as a reserve in case there is any problem with the bridge; that would be waste. They should be used."

The leaked email from Mr Colford was sent to Lesley Hinds, convener of the Forth Estuary Transport Authority - which formerly ran the bridge - in February.

Mr Colford said he was banning all vehicles weighing more than 150 tonnes from using the bridge because of analysis carried out about the pressure on key beams.

He said he would discuss the matter directly with Transport Scotland, and added: "The restriction needs to be in place until all the truss end links are either strengthened or replaced."

It is understood the replacement of the problem truss end links on the Forth Road Bridge was recommended by consultants WA Fairhurst five years ago.

But that work, along with other repairs, were not approved because of concerns of lengthy closures while the £1 billion second Forth crossing was due to open in 2016.

A Transport Scotland spokesman said: "The restriction on exceptionally large abnormal loads was not related to the present defect on the bridge.

"It was related to potential unacceptable overstress to the truss end brackets and associated welds within the towers. This is being addressed by the ongoing strengthening works."

He said: "The defect which has resulted in the closure of the Forth Road Bridge was identified in the last few weeks. It was unexpected and not predicted by previous analysis that was carried out by Forth Estuary Transport Authority."