Scotland’s Forth Road Bridge is to remain closed until early in the New Year following the discovery last week of a fracture in a key load-bearing steel element.

Repair work has already begun and the aim is that the bridge will be reopened in time for people’s return to work after the New Year. The bridge over the Firth of Forth near Edinburgh is a key route on Scotland’s transport network and its closure means lengthy detours.

The decision to close the bridge was taken after detailed inspections and assessments following the initial discovery of the problem.

The inspections identified a failure of the truss end link - the vertical structural load-carrying component located immediately adjacent to the north-east tower face. One side of the component has failed completely, leaving the load to be carried by the adjacent element.

Testing on the non-broken element identified propagation of a potential crack at a very similar location to its neighbour.

Transport minister Derek Mackay said: “The decision to close the Forth Road Bridge is not taken lightly. It is based on the expert opinion of the engineers who operate the bridge day to day and that of independent experts in the field.” He added that bridge operator Amey has a robust inspection team in place.

“This is a complex engineering challenge,” said chartered engineer Mark Arndt, Amey's account director responsible for the bridge. “The component failure is in a difficult to access location and our response is also highly dependent on weather conditions.

“We continue to work around the clock on inspections, assessments and calculations along with the development of designs to effect the necessary repairs, while at the same time mobilising all the resources required to reopen the bridge as soon as is possible.”

Construction of a replacement for the 51-year-old bridge is already well under way - the Queensferry Crossing is due to open in about a year.

Earlier this year extra inspections of the main cables were ordered after an increase in wire breaks was recorded.