Works to repair the pier defences on the Forth Road Bridge could cost up to £1.53 million.
A series of steel cofferdams which surround the base of the bridge’s main towers, they aim to reduce the risk of marine vessels damaging the towers below deck level.
But the system has failed to provide the level of protection set out in the original specification.
The system involves the application of an electrical current to the cofferdams which helps control corrosion to the steel surface below mid-tide level.
Forth Estuary Transport Authority (FETA) revealed this week that, while no significant damage to the integrity of the cofferdams was found during the last dive in 2008, action is required in the short to medium term.
Legal advice was sought to find out who was liable for the system failure. And a settlement between the engineer, contractor and FETA found the Authority’s contribution towards the remedial works to be £118,000.
Works will get underway in April to apply a new coat of bituminous paint.
A FETA spokesman said: “To estimate the cost of such a project depends on access and level of containment required.
“A sum of £1.53 million is estimated.”