The Forth Road Bridge spans the Firth of Forth, connecting Edinburgh at South Queensferry to Fife at North Queensferry.
The bridge has provided a major improvement to the Scottish transport network since it was opened in 1964 by Her Majesty Queen Elizabeth II.
Unfortunately, despite significant investment and maintenance over its lifetime, the bridge is showing signs of deterioration and is not suitable in the long-term as the main crossing over the Firth of Forth.
Following research in 2006 and 2007 as to the best solution, it was decided that the Forth Replacement Crossing would be a cable-stayed bridge to the west of the existing Forth Road Bridge.
Construction began on all phases of the project in autumn 2011, following the completion of a two-year procurement process. All three main contracts that make up the FRC project have now been awarded, with all the successful bids coming in under budget.
There are three main phases to the project, each involving different contractors.
Phase One is the principle contract to build the new bridge and connecting roads. The contract was awarded to the Forth Crossing Bridge Constructors (FCBC) consortium, comprising Hochtief, Dragados, American Bridge International and Morrisons. The construction of this part of the project is scheduled for completion in 2016 at a cost of £790 million.
Phase Two is the installation of elements of the project’s Intelligent Transport System (ITS) on the M90 in Fife at a cost of £12.9 million. This contract was awarded to John Graham (Dromore) Ltd and is scheduled for completion in summer 2012.
Finally, Phase Three is scheduled for completion in 2013. This phase involves the upgrade M9 Junction 1a at Kirkliston and the contract has been awarded to a consortium between John Sisk and Roadbridge at a cost of £25.6 million.
The bulk of construction activity will take place from barges in the Firth of Forth however the Forth Crossing Bill Transport Scotland is also seeking provision for three construction compounds which are required to build the scheme.
The proposed new cable-stayed bridge will be 2.7km long and will have three slender single column towers, including approach viaducts.
The road carried by the bridge will be designated as a motorway, with two lanes of traffic in each direction and hard shoulders to ensure that breakdowns, incidents and any maintenance works do not cause the severe congestion which is currently experienced on the Forth Road Bridge.
The hard shoulders also provide the flexibility to carry buses unable to travel on the Forth Road Bridge during periods of high wind. Windshielding on the new bridge will provide a more reliable corridor, particularly for lorries and other HGV’s.
In the second Phase, the ITS measures will extend along a 22km corridor from the M90, over the Forth Replacement Crossing to the M9. Overhead signal gantries along the route will provide lane control, incident detection and variable mandatory speed control.
These gantries will provide traffic information to drivers and ITS allows variable speed limits to be applied so that vehicle speeds can be managed during congested periods and in response to incidents. The system can automatically detect incidents and provide information on the road network.
In Phase Three, there will be improvements to M9 Junction 1a at Kirkliston, including new slip roads to the motorway. This will also incorporate new slip roads between the M9 and M9 Spur, which will require a new bridge across the motorway and the extension of an existing bridge.
Due to the lower than expected cost for the winning contracts, the total estimated cost range of delivering the FRC project is now £1.45 billion to £1.60 billion, a substantial reduction on the previous estimate of £1.7 billion to £2.3 billion. The Forth Replacement Crossing is scheduled for completion in 2016.