£7m plan to test the state of Forth Road Bridge anchorages

Published on Friday 19 February 2010 10:24

A MAJOR project to assess the condition of the anchorages holding the Forth Road Bridge in place has become the latest multi-million scheme unveiled to protect the ageing structure.

Engineers will bore into the rock at the bridge's four anchorages to check for signs of damage as part of a 7 million project – the first time the job has been done in the structure's 46-year history.

News of the project came as 13.6m plans to replace bearings on the bridge's approach viaducts were outlined, with work expected to begin within months.

The Forth Estuary Transport Authority (FETA), which maintains the bridge, said the need to check the bridge's anchorages first came to light during a feasibility study for the replacement of the main cables, during which interviews were carried out with those involved with the original construction in the 1960s.

Frequent inspections are carried out of the anchorages – where the bridge is attached to the rock – but this will be the first time that experts have dug below the surface. It is thought the salty sea air of the Forth could have corroded steel rods which are holding concrete tunnels in place.

Bridge chiefs said the safety of the structure was "not in question," adding that the work was being undertaken to safeguard its future.

A FETA spokesman said: "This work is something we have been talking about for a few years as the best way of determining the condition of the anchorages.

"If you are considering replacing the cables you need to make sure the anchorages are sound. There are no safety concerns, this is about proving the long-term structural integrity of the bridge."

He said that the information obtained from those involved in the construction of the bridge was what swung the decision to carry out the work.

Meanwhile, construction firm Balfour Beatty has been appointed to carry out a 13.6m project to replace bearings on the bridge's approach viaducts.

Work is expected to start in early summer, continuing through to January 2013, with some overnight restrictions to traffic.

Barry Colford, chief engineer and bridgemaster at the Forth Road Bridge, said: "It was always expected that these bearings would need to be replaced after a few decades.

"This will be the biggest single contract awarded since the bridge opened in 1964. However I'm confident that we've got a good contractor and a good price."

Last month the Evening News revealed that more than 112m is to be spent maintaining the Forth Road Bridge, despite predictions that only 300 vehicles a day will use it when the new 2bn crossing is up and running.