Project Description: Clyde Tunnel was opened in 1963 (Northbound tunnel) and 1964 (Southbound tunnel) and crosses beneath the river Clyde in Glasgow, Scotland. Two parallel tunnel bores connect the districts of Whiteinch to the North and Govan to the South in the West of the city, each carrying two lanes of traffic as part of the A739 road. The tunnels are each 762 metres (2,500 feet) long with a gradient approaching 6%.Repairs were carried out on the RC deck slab in 1994 and in addition, the immediate area of the joints received cathodic protection (CP) in 1994 and 1996.