Email highlighted need for Forth Road Bridge repair
The operator of the Forth Road Bridge was told of a need for repairs 10 months ago, a leaked email has revealed.
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.
The email 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.
"This will not be done before 31 May 2015. TS (Transport Scotland) will have to make the decision on what to do with the truss end links after 31 May 2015."
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.
"Restrictions on loads of this type have little impact as there are very few movements of this size and they are agreed in conjunction with Transport Scotland, local authorities and Police Scotland who escort such loads."
He added that since the start of 2013 only one load of 140 tonnes had crossed the bridge so the additional restriction was a further safety measure that would have minimal impact and would allow hauliers to pre-plan their routes.
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."
The spokesman added that "critical maintenance" had always been funded.
It was announced last Thursday that the bridge, which carries an estimated 70,000 vehicles a day between Edinburgh and Fife, would be closed after engineers spotted a crack in a steel truss close to the north tower.
It was later confirmed the crossing would have to remain shut until the new year for repair work to take place.
A temporary repair will involve the shear truss end having metal splints attached to either side.
Last week, Scotland's Transport Minister Derek Mackay said that five years ago Forth Road Bridge bosses had considered replacing the part of the crossing which has cracked, but decided not to.
It was later announced that a Holyrood committee is to examine options for a "focused inquiry" into the issues leading to the closure of the bridge.
Speaking on BBC Scotland's Sunday Politics programme, Kenneth Gibson, the SNP convener of the finance committee, said: "Derek Mackay has been quite clear and frank about what the difficulties are and what we are doing to resolve this.
"The first minister made it crystal clear that this problem that was found a few weeks ago was not picked up on previous maintenance because it was only a new flaw in the bridge."
Speaking on the same programme, Scottish Labour's Jackie Baillie said: "You only need to listen to people on phone-in programmes to understand just how agitated and angry they are with all of this. So that has to be the priority.
"But we do need to learn from our mistakes and we do need the Scottish government to put everything in the public domain, to be transparent and not to engage in ever-increasing amounts of spin to hide the truth from people about cut budgets and cancelled maintenance contracts."
Scottish Liberal Democrat leader Willie Rennie repeated calls for former Forth Road Bridge chief operating officers Barry Colford and Alistair Andrew to provide evidence to any inquiry into the closure of the bridge.
He added: "Reports that have emerged over the past week regarding maintenance budgets and missed opportunities for repair work underline the need for a wide-ranging inquiry."