The M74 Completion was the biggest infrastructure project ever to take place in Scotland. Four steel bridges were erected along a five mile stretch of new motorway extension to provide a strategic link between the M74 and the M8 motorways in Glasgow. The project aimed to reduce congestion and improve both journey times and road safety whilst helping regenerate the area and provide economic growth. The new route across the South of Glasgow involved complicated bridges curved in plan and elevation crossing heavily developed parts of the city, multiple existing road and railway infrastructures as well as the River Clyde.
Cleveland Bridge were responsible for the fabrication, supply, erection and protective treatment of 21,180 tonnes of steel bridge girders as well as the design, supply, erection and final removal of 1,700 tonnes of temporary steelwork.
The largest of the bridges was the Port Eglinton Viaduct at 16,039 tonnes totalling 750m in length. The longest span of this bridge was 130m which crossed the West Coast Main Line Railway and a very busy road network. This steel span was launched into position in two sections, 200m in length, weighing 4,500 tonnes each. The launch was a 180m distance following a plan curve with both sections accurately moved into position within millimetres.
Rutherglen Station Bridge’s steelwork weighed 1,956 tonnes with four spans totalling 186m in length. The bridge spanned over multiple electrified railway lines which meant the erection could only take place during 2 hour night rail possessions.
As the M74 moved East, the Auchenshuggle Bridge was required to cross a 90m span over the River Clyde. Constructed from 7 lines of curved box girders, this structure had a total steel weight of 1,840 tonnes. Europe’s largest mobile strut jib crane was required to overcome access restrictions and lift individual box girders weighing over 300 tonnes. The largest mobile strut jib crane in the UK was used throughout the rest of the project, even necessary for the lightest structure, the M8-Link Bridge, weighing 1,346 tonnes over its 232m span.
Overall the M74 project was opened to the public on the 28th June 2010 and brought major economic and social benefits to businesses, communities and industries in the West of Scotland and the country as a whole, with Cleveland Bridge playing a significant part in the projects overwhelming success.