Histoire tower bridge en anglais

The Tower Bridge is a British bascule bridge located in London, which allows motorised vehicles to cross the Thames.

It belongs to the class of suspension bridges and is made of granite for its façade, steel for its structure and concrete for its foundations. It is located between the boroughs of Southwark and Tower Hamlets, near the Tower of London from which it takes its name. It is one of four bridges managed by the Lord Mayor's Department. Tower Bridge is located in the Pool of London, marking the boundary between the Upper Pool upstream and the Lower Pool downstream.

At the time of its construction, Tower Bridge was the largest (246 metres long and 65 metres high) and most sophisticated bascule bridge ever built. The bridge is world famous for its distinctive neo-Gothic architecture. It consists of two large towers, a rigid suspension, a deck that opens to allow the passage of the tallest ships and, at the top, two parallel pedestrian walkways. The machinery of the bascule bridge has been open to the public since 1982 in the form of a museum showing the operation of the hydraulic mechanism that has been used to lift the bascule bridge since 1894 (when it was built by Sir John Wolfe-Barry and Horace Jones).

Origine et plan initiaux :

have cut off all access for tall ships to the port in the Pool of London, now located between London Bridge and the Tower of London.

So the Special Bridge or Subway Committee was formed in 1876 and over 50 designs were submitted, including one by the road engineer Joseph Bazalgette. His project was rejected due to lack of space and the design was not approved until 1884, when it was decided to build a bascule bridge. John Wolfe-Barry was appointed as engineer for the project with Horace Jones as architect, assisted by Henry Marc Brunel. An Act of Parliament was passed in 1885, authorising the construction of the bridge. The project specified that the bridge span should be 61 metres (200 feet) wide and 41 metres (135 feet) high. In addition, the construction was to be a Gothic building.

John Wolfe-Barry designed a bascule bridge consisting of two towers built on pillars. The central part is divided into two equal parts, each of which can be raised to allow sea passage.

Travaux et construction :

Construction of the bridge began in 1886 and took eight years with 432 workers and five main contractors: John Jackson (foundations), Baron Armstrong (hydraulics), William Webster, H. H. Bartlett and William Arrol & Co. E. W. Crutwell was appointed resident engineer for the project4.

The two massive piers made from over 70,000 tonnes of concrete were cast directly into the riverbed to support the construction. The structure also contains over 11,000 tonnes of steel at the towers and walkways. They are faced with Cornish granite and Portland stone, both of which serve to protect the steelworks and give the bridge a better appearance.