The Erskine Bridge:
Celebrating Fifty Years
A898 | M898
The Erskine Bridge is a major crossing of the Clyde Estuary to the west of Glasgow. Designed by Freeman Fox and Partners, the cable-stayed steel box girder bridge opened to traffic on 2nd July 1971.
Discussions on the need for a bridge began in the 1930s, though it was the early 1960s before significant progress was made. As proposals for the network of motorways and dual carriageways in Central and West Scotland matured, it became clear that a bridge at this location would be an important piece of the jigsaw. The ambitious and technically challenging project created the first fixed link between Dunbartonshire and Renfrewshire. Its completion led to significant reductions in journey times, particularly during the busy tourist season when traffic reaches its peak.
Today, the bridge carries over 35,000 vehicles every day. A notably slender design adds to the unique and recognisable appearance of what was not just the first large-scale cable stayed bridge in Scotland but, for a time, the bridge with the longest cable-stayed span in the world. The project cost £10.5 million, the equivalent of almost £150 million today.
to July 1971
(£150 million today)
Planning and Design
Traffic growth in the 1930s placed the ferry service between Erskine and Old Kilpatrick under increasing strain. In 1934, with public dissatisfaction growing, the need for a bridge was accepted. The Counties of Dunbartonshire and Renfrewshire began planning to replace the ferry, which had been running for two hundred years, but this was interrupted by the Second World War and it was 1955 before further progress was made.
The Scottish Office, which took on responsibility for trunk roads in Scotland in April 1956, agreed to the formation of a Joint Committee. Its first meeting was held in March 1963 and a technical panel was set up to proceed with detailed design, traffic studies and site investigations. In December 1963, Freeman Fox and Partners were appointed as Consulting Engineers. Their commission included the preparation of a design for the bridge and its main approach roads.
In September 1965, as the scale of the project became clear, the Scottish Office assumed responsibility for the funding of the project. Maintaining shipping in the River Clyde dictated that a high level bridge would be the only acceptable solution and various proposals including a tied arch, a steel truss and box girder were considered. The selected design was a multi span mono cable stayed steel box girder bridge with a main span of 300m and side spans of 110m.
A ferry service operated between Erskine and Old Kilpatrick for almost 200 years before the bridge was completed. It carried vehicles and pedestrians across the river on a ferry painted in the familiar blue seen on other Clyde services. © Scottish Life Archive.
With a total length of 1.3km, the Erskine Bridge would be carried on fourteen slender reinforced concrete supports,the tallest of which is over 50m long. These are supported on piles, which in some cases, were driven to depths 190 ft (58m). When piling works were completed over 43,000 ft (13.1km) had been driven. The piers are diamond shaped and vary in height from 22 to 175 feet (6.7 to 53m). These were designed specifically for the bridge by Dr W.A. Fairhurst.
The bridge deck, over 30m wide in the main span and on a gentle curving alignment, is carried on a steel trapezoidal box girder supported by a single 715m cable over two 40m tall towers. The box girder is comprised of 80 steel sections welded together. The bridge has two traffic lanes as well as pedestrian footways and cycleways in each direction.
The designer of the Erskine Bridge was William Brown, a renowned structural engineer and bridge designer. From 1956 to 1985, he was a key member of Freeman Fox & Partners. He was particularly talented in the field of suspension bridges, and is credited with inventing the aero-foil shaped cross section for bridge decks, an invention created to combat an array of wind conditions.
A network of approach roads was to provide free-flowing links to local roads and the new motorway and trunk road network planned for Strathclyde Region. The bridge would also carry services including new water and gas mains to supply the Renfrewshire area.
Freeman Fox and Partners revealed their design for the Erskine Bridge in 1966. The necessary parliamentary approvals were granted quickly and construction on the project, valued at over £10 million, began in April 1967. A formal ceremony, attended by the Secretary of State for Scotland, Willie Ross, was held on 6th June.
The project was split into four distinct contracts: foundations and piers, designed separately by W.A. Fairhurst and Partners; the bridge steel superstructure; the northern approach roads (A82 interchange); the southern approach roads (first stage of the M8 Bishopton Bypass and M898) including the toll plaza and administration building.
The main construction contract comprising the bridge superstructure was awarded to Fairfield Mabey Ltd in February 1968, valued at £4.5 million. Construction of the foundations and piers was undertaken by Christiani-Shand Ltd from March 1967 at a cost of £720,000. The contract for the north approach roads and link with the A82 at Dalnottar was awarded to Peter Lind & Co. in December 1967, valued at £1.4 million. The south approach roads were awarded to Whatlings (Civil Engineering) Ltd in July 1968 and cost £2.6 million. Other construction costs totalled £1.3 million.
By 1969 the fourteen soaring reinforced concrete piers were completed. Throughout 1970 the steel box girders were lifted in place, gradually crossing the River Clyde. © West Dunbartonshire Council Arts and Heritage
The main steelwork was erected from both ends simultaneously, with completion being near the centre of the main span. Being longer, construction on the north section began six months before the south. A cantilevering process was utilised which is illustrated below. Each section, weighing up to 170 tonnes, was loaded onto a trolley and winched out to the edge before being lowered into position and cantilevered from previously erected steelwork. Temporary props and cables were used during this process to ensure stability. For the main span, each girder extended by 150m before being jacked and welded together.
The bridge towers were completed in advance to allow the connection of cables for additional support. Each cable is over 210m long and comprises 24 strands, each 75mm in diameter. The 24 strands are clamped together to form a rectangular cable six strands wide by four strands deep. Prior to erection each strand was pre-tensioned and marked to the required length under a dead load of 170 tonnes.
The bridge consists of a continuous steel box girder with a cable-stayed main span of 330m. It varies in width from 30m to 31m. Clearance above the high water mark of the Clyde is 55m (higher than the Forth Road Bridge). There are two anchor spans of 110m and twelve approach spans each of 68m. The total weight of all steelwork is around 11,000 tonnes. The erection of all steelwork was largely completed by end of 1970.
1. Bridge Foundations & Piers*
2. Bridge Steelwork & Erection
Fairfield Mabey Ltd.
3. North Approach Roads
Peter Lind & Co Ltd.
4. South Approach Roads, Toll Plaza & Administration Building**
Whatlings (Civil Engineering) Ltd.
* Design by W.A Fairhurst & Partners
** Included M8 Bishopton Bypass (Stage 1) and M898
At Erskine Bridge the deck is comprised of 80 sections welded together to create a continuous hollow steel box girder. Internally it resembles the hull of a ship and is a particularly efficient design.
The bridge was surfaced with a type of mastic asphalt which is laid directly onto the steel deck. The bridge is provided with footways and cycle paths on each side, and it was part of the original design that they could be removed to provide and additional traffic lane should it have been required.
Construction of the north and south approach roads began in 1968. On the north side, traffic from the bridge is led on to the A82 by the Dalnottar Interchange which also provides local connections to Old Kilpatrick. To obtain free-flowing traffic routes, six new concrete bridges and two service culverts were built, and the Dalnottar Burn was put into a culvert that passes under the interchange.
The southern approaches comprised the first stage of the M8 Bishopton Bypass, a three-level motorway interchange at Craigton, and about 1 mile of motorway leading through the former toll area to the bridge itself. Local road connections to Erskine were built via the A726 where the bridge administration building is also located. These works included a two-level structure and three other bridges in reinforced concrete.
The approach roads as well as the administration building were largely operational by early 1971. This was followed by the completion of the toll plaza, high mast lighting, CCTV and remote controlled warning signage.
Construction proceeded from both banks of the river. Sections weighing up to 170 tonnes were launched by cantilevering them from previously built steelwork in a carefully controlled sequence using specially designed, temporary launching girders.
The Erskine Bridge was completed on schedule and opened by HRH Princess Anne on Friday 2nd July 1971. The ceremony was attended by several hundred people with commemorative plaques unveiled on the west footpath. During its first weekend of operation thousands of vehicles made journeys across the new bridge. They were joined by intrigued locals enticed by the stunning views available from the bridge's footways.
The bridge was opened by Princess Anne in a ceremony attended by several hundred people. The crowds included workers, politicians and local people from both sides of the River Clyde. © Scotsman Publications Ltd
Until March 2006, users of the Erskine Bridge were required to pay a toll charge. Tolls were introduced on many new major bridges at this time as a way of recovering the enormous costs of their construction.
At Erskine, a toll plaza was constructed at the southern end of the bridge, opposite the administration building. Four toll booths were in place on each carriageway. Day to day running of the bridge was to be entirely self sufficient. To enable this, the administration building would be one of the most advanced in the UK with staff facilities, CCTV control, toll computer systems, maintenance workshops, a fire engine, road sweeper, snow plough and patrol vehicles. The designers even included a narrow tunnel that would allow personnel to cross the dual carriageway safely.
Though a variable toll had been planned, when the bridge opened in 1971 the charge was a flat rate of 15p for all vehicles. This had increased to 60p by 1992 and remained at this level till 2006, with exemptions for motorcycles. The removal of tolls encouraged more people to use the bridge. The first year after abolition saw a 25% increase in traffic though this was offset by lower flows through the Clyde Tunnel, the nearest crossing upstream.
The Bridge Today
The Erskine Bridge is now managed by Transport Scotland on behalf of the Scottish Ministers. It is estimated that more than 400 million vehicles have used the bridge since it was completed.
On the 4th August 1996, the Erskine Bridge was seriously damaged when a 6,500 tonne oil rig being towed downstream struck its underside. Damage measuring 10 metres long and 30 centimetres wide was left in the steel box girder forcing the bridge to close to traffic and pedestrians. Repairs costing over £3.5 million were required and the bridge was not fully reopened until December 1996. What was then the Scottish Office was later reimbursed for the cost of the damage.
Historic Environment Scotland listed the bridge as a Category A structure in November 2018, recognising its unique architectural and technical features. The bridge is a key link in the Scottish trunk road system and a series of multi-million pound projects are planned to ensure it remains operational for decades to come.
The bridge deck was refurbished in the 1990s and new inspection gantries and access points were installed between 2009 and 2011. Since 2010, works have been undertaken to replace the parapet and barrier systems as well as upgrade the lighting and electrical systems. A programme of steelwork painting is currently underway. This will be completed in 2025 along with works to resurface the bridge deck. To date, more than £50 million has been spent.
Celebrating 50 Years
2nd July 2021 marked Erskine's 50th anniversary. The anniversary was covered widely on TV and in the national press. To mark the occasion the Glasgow Motorway Archive produced a special podcast and, with Transport Scotland's help and support, a booklet featuring new and unseen images from the archive.
Printed copies of the booklet are available at our Online Shop.
From the Archive
The Scottish Development Department (now Scottish Government), commissioned Films of Scotland to produce a film charting construction of the bridge. The film was released in 1971.
A copy of the film was donated to the Glasgow Motorway Archive in 2021 and we are delighted to present it here. With special thanks to Transport Scotland.
This article was first published in June 2021.
A special podcasting celebrating the 50th anniversary of the bridge was released in July 2021. It can be heard below.