ALMOST a year after the contract was signed for the new Forth Road Bridge, those in charge of the £1.6 billion project today said it was on time and on budget – and vowed to keep it that way.
The first 12 months have been largely devoted to detailed design work on the massive cable-stayed structure with its three 200-metre towers and the surrounding road network.
Some of the overhead information gantries on the approach roads have already been installed. And work has begun on upgrading junction 1a on the M9, near Kirkliston. But the next stage, due to get under way imminently, will focus on building the foundations for the new crossing.
David Climie, Transport Scotland’s project director for the bridge, said: “We’ve now started to switch from detailed design to the foundations and over the next six months people will see things starting to happen.”
Dredging work has already begun for the approach viaduct on the south side and is expected to continue until June or July. Preparation work has also been carried out on Beamer Rock, on which the foundations for the bridge’s central tower will sit.
And three huge caissons – likened to six-storey-high tin cans, which will be sunk to the riverbed to provide the foundations for the north and south towers and another pier on the south side – are currently being made in Poland. They will be shipped to the Forth in three separate shipments in May and June this year. As many parts as possible are being pre-fabricated and brought to the site for installation in a bid to beat possible weather problems.
Mr Climie said: “We’re nearly a year into the project, we’re still on schedule and within budget and we’re determined to keep it that way.”
Most of the foundation works should be completed by the end of this year. The following 18 months will see construction of the three towers, approach viaduct and support piers.
Nearly 400 people are currently working on the site and that is expected to increase to a peak of 1200 during 2013 and 2014. New slip roads are being built at junction 1a on the M9 so traffic coming from the west can get on to the M9 spur to the bridge without having to go to the Newbridge roundabout first.
The work also includes installation of 17 overhead information gantries. And contractors are currently ahead of schedule after managing to put up four in one overnight closure March 3. Further closures will be needed to install the other gantries over the spring and summer.
Motorists have already been warned of a contraflow scheme on the M90 between Halbeath and Admiralty for six weeks from April 9 and four weekends of disruption from April 20, due to repaving of the M90. Two lanes will be kept open northbound, but southbound traffic will be restricted to one lane from 9pm Friday until 6am Monday each weekend.
And there will be a series of 20-minute closures from early April when traffic on the north side of the bridge will be held back for 20 minutes around 10pm once a fortnight as a safety precaution while blasting is carried out at Whinnyhill, near the Ferrytoll junction.
Officials said the blasts would be relatively small in order to fracture the rock and allow excavation for the levelling of embankments.