Project completed by staff prior to FINLEY
The crossing is 3.186 miles (5.127 km) long, consisting of a single central navigation span over the “Shoots” channel and approach viaducts on either side. The 37 bridge pier foundations on the approach viaducts are 98.11m (321.9-ft) apart and consist of concrete pneumatic caissons weighing 37 tons, which were sunk into the mud of the estuary. The decking consists of 3.5m (11.5 ft) post-stressed match cast sections, weighing 200 tons each. The cable-stayed section of the crossing is over 900m (2,953 ft) long, consisting of a 35m (115 ft) wide deck made from steel plate girders with a composite reinforced concrete slab. These were prefabricated on shore and put in place using balanced cantilever methods. There are two 149m (489 ft) high twin leg, reinforced and pre-stressed concrete pylons carrying 240 cables which support the bridge deck.