Conveying the A739 road under the River Clyde in W Glasgow, the Clyde Tunnel connects Linthouse in the south with Whiteinch in the north. Sometimes known as the Linthouse Tunnel, it was built 1957-64 by Sir William Halcrow and Partners. At the time tunnels were the only option for a river-crossing at this point, permitting shipping to move upstream. The structure actually comprises two separate tunnels, each 762m (2500 feet) in length and carrying two lanes of traffic in opposing directions. It cost £10.5 million and took the lives of two construction workers as a result of inadequate decompression after working in a pressurised environment. There is a cycleway and pedestrian walkway under the roadway. The tunnel was officially opened by HM Queen Elizabeth II on the 3rd July 1963, nine months before the southbound tube was completed.
At both ends of the tunnel are buildings each with prominent ventilation towers and control rooms looking out over the tunnel entrances. Long approach ramps descend through cuttings, but the tunnel beneath the relatively narrow river is so short that the roads have no sooner reached their maximum depth than they rise once again to the exit. A southern interchange connects with the A8 and M8, while a northern interchange provides access to the A814 Clyde Expressway.
The tunnel was built with the expectation of being used by 9000 vehicles daily, but by 1965 the actual figure was 22,000 and today this has risen to 65,000. In 2006, a major refurbishment included the installation of a secondary lining incorporating the latest fire protection materials in both tunnel tubes at the cost of £9 million.
In 2013, HRH The Princess Royal attended celebrations for the 50th Anniversary of the opening.