Traffic Engineering

The Boyne Bridge is a 350m long, cable-stayed, high level bridge carrying the M1Northern Motorway (Dublin-Belfast) across the River Boyne to the west of Drogheda. It is amongst the largest bridge projects undertaken in Ireland and it is one of the best known landmarks in the County. It consists of an asymmetrical cable-stayed bridge with an overall length of 350 metres and spans of 42.5m, 170.0m, 40.0m, 45.0m, 30.0m and 25.0m. The 35m wide deck comprises two longitudinal steel plate girders with transverse girders at 3.333 metres centres supporting an insitu reinforced concrete slab. The deck is supported from a 95m high reinforced insitu concrete pylon by 14 pairs of stay cables. Each stay cable consists of between 32 and 68 No. 15.7mm diameter 7-wire strands.