London Bridge
It is thought that the first bridge on the site was built in 994 AD by the Pious Brothers of St. Marys Monastry on the Bankside. This initial structure was built of wood, but was badly damaged by the Danes in 1008. However it was completely destroyed by a flood in 1091. Now a necessity, William II comissioned another bridge to be built. Also in wood, this burnt down in 1136. Forty years later, in 1176, a more substantial bridge was started by Peter of Colechurch. It was completed in 1209 and had houses on each side. Despite multiple fires, the structure remained and became The place to be for booksellers! Famous names such as Holbein, Bunyan, Hogarth and Peter Monamy ( a marine painter) all took residence on the bridge at various times. Some of the best known book sellers that could be found on the bridge were Herbert (printer), Crispin Tucker, Swift and Pope. In 1212 another disaster struck and 3000 people died in the flames.
The residential bridge endured and developed until 1756, when the houses were all pulled down. The Southwark gate remained until 1766.
1749 London Bridge was the only fixed link across the Thames until Westminster Bridge was opened in 1749. Otherwise passengers relied on ferry links, of which there were probably many.
1817 The first Waterloo Bridge was opened
1822 Plans for a new London Bridge were detailed by John Rennie (Snr), but he didn't live to see the work. The construction of the bridge was Superintended by his son Sir John Rennie (Jnr). The first pile was laid in 1824. The finished bridge was opened in 1831 by William VI and Queen Adelaide. It is described in 1894 as a granite bridge with 5 elliptical arches. It was reputed to have cost over £2.5 million.
1902 The bridge was widened to 65 ft.[1]
1967 Parliamentary consent was obtained to rebuild in the London Bridge Act 1967.[2]
The Present Bridge
The present bridge, opened on 16 March 1973, was designed by Mott, Hay and Anderson, and built by John Mowlem and Co. The facework masonry of the old bridge was bought by an American businessman and rebuilt in Arizona. It was required that during construction of the proposed new bridge shipping movement should be maintained, and access for pedestrian and road traffic had to be fully maintained during construction except for limited periods at night or during weekends.
The specified width was such that four parallel concrete box beam bridges could be built and brought into use one at a time. The beams were assembled from prefabricated sections. Two outer box beams were constructed either side of the old bridge and opened for use before major demolition of the old bridge.
The beams are not continuous, having cantilevered sections supporting suspended spans. This principle had been adopted for the Waterloo Bridge, constructed about 30 years earlier. London Bridge is assembled from pre-cast segments, post-tensioned.
Construction of the deep foundations was particularly challenging.
The box section segments were cast at Mowlem's yard in the Surrey Commercial Docks. Due to access restrictions, the prefabricated box beam segments were taken to site by barge. The river piers and abutments are faced in Cornish granite. The exposed concrete on the elevations of the bridge was lightly grit blasted.
The above information is largely condensed from here. [3]
See here for a report and video of a walk through the inside of the bridge beams.[4]
A massive temporary steel gantry structure weighing 1900 tonnes was used to support the weight of the existing structure during demolition, and the weight of the new precast units during construction. The bridge consists of two large cantilevers which support a short central suspended span.
The appearance of the present bridge is restrained and elegant, but not particularly memorable. It has aged well and, technically, it is an impressive structure, particularly in view of the constraints imposed by the need to built at the location of the previous bridge while still allowing traffic to pass.[5]
In 2009 (2007?), the part played by CCL in the construction of the bridge was acknowledged and the company was awarded the Concrete Society Award for Mature Structures, which recognises excellence in the use of concrete and specifically in structures over 25 years of age.[6]
See Also
Sources of Information
- ↑ Samuel Jones Quarterly Magazine 1969 (Vol XLVII No.1)
- ↑ Samuel Jones Quarterly Magazine 1969 (Vol XLVII No.1)
- ↑ [1] Building: Our history: 180 years of Building: From the archives: The new London Bridge, 1973, by Tom Lowe 30 July 2024
- ↑ [2] 'Into the Secret Chambers of London Bridge: Reader, it is hollow. I walked through it' by Matt Brown, Sep 18, 2024
- ↑ [3] The Happy Pontist: 23 September 2013: London Bridges: 31. London Bridge
- ↑ [4] CCL (GB) Ltd: London Bridge