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London Bridge (1972)
River Thames, City of London
London Bridge (1972)
associated engineer
Mott Hay & Anderson
date  November 1967 - 1972
era  Modern  |  category  Bridge  |  reference  TQ326804
ICE reference number  HEW 261
photo  London Metropolitan Archives
The three slim spans of prestressed concrete we call London Bridge today are the descendants of a venerable family of bridges on this site stretching back nearly 2,000 years to the founding of London by the Romans.
The Romans chose this spot for its favourable ground conditions on the north bank and because this was the tidal limit of the Thames at that time. They built the first of a series of timber bridges that served the city until the first stone bridge came along in 1176 — Old London Bridge, one of the sights of Europe, with its tall houses and shops. It was built a little upstream of its timber predecessor.
Old London Bridge was the only bridge on the Thames for 500 years and Bridge House Estate, which controlled it, grew rich on the rents, tolls and property bequests that came its way. Old London Bridge was replaced in 1831 by a five-arched masonry bridge designed by John Rennie (senior), paid for largely by Bridge House Estate from its reserves. It was sited a little further upstream again.
However, by the late 1950s, the Rennie bridge was judged incapable of coping with modern traffic volumes. It was decided to replace it with a new bridge on the same alignment and an Act of Parliament was passed in 1967 to enable this to happen. Work started on site Novemer 1967.
One big challenge the bridge team faced was to erect a new structure while simultaneously demolishing the old one, keeping open two waterways (each 30m wide) and maintaining access for vehicles and pedestrians. It all added up to limited site area available at any one time. For the spans, the engineers made maximum use of precasting to keep the amount of on-site work to a minimum.
The bridge's two slender piers are founded in the river bed and constructed of mass concrete faced with granite blocks with recessed joints.
The spanning elements consist of four longitudinal box beams made up of precast concrete segments. The precasting was done at Russia Dock in Surrey Docks and the segments brought to site by barge. After they were positioned, the prestressing was carried out. To do this, strands of steel were threaded through the precast box units and attached to anchorages at each end, where the tensioning was done.
The new London Bridge was opened by Queen Elizabeth II in 1972. It takes six lanes of traffic and 12.5m of its width is pavement.
Architectural advisor: Willima Holford & Partners
Contractor: John Mowlem & Co
reference sources   CEH Lond
Location

London Bridge (1972)