Tower Bridge

The Tower Bridge, Tower Bridge in English, is a drawbridge located in London over the River Thames. It is situated near the Tower of London, which gives it its name.

The bridge is maintained by Bridge House Estates, a non-profit company under the tutelage of Corporation of London, one the city council of the City of London.

During the second half of the nineteenth century, economic development in East London, led to the need for a new step on the river below London Bridge. You could not build a traditional fixed bridge because it would cut off access to the port at that time were at the Pool of London (the Port of London original), between London Bridge and the Tower of London. A tunnel under the Thames, Tower Subway opened in 1870, but served only to pedestrian traffic.

In 1876 a special committee was formed to find a solution to pass over the river, which held a competition to choose the design of the future bridge. More than 50 designs were proposed, including one of Sir Joseph Bazalgette. The evaluation of the designs was surrounded by controversy, and it was not until 1884 when created by Horace Jones, the City Architect, was approved.

Jones's design was a drawbridge of 244 m in length, with two towers of 65 m height. The center distance of 61 m between the two towers, is divided into two cams that can be raised to an angle of 83 degrees to allow river traffic to pass. Although each cam weighs more than 1000 tons, are counterbalanced to minimize the energy required to elevate one minute. The original hydraulic mechanism used pressurized water stored in six accumulators. The water was pumped into the accumulator by steam engines. Currently, the original hydraulic machinery still opens the bridge, but has been modified to use oil instead of water, and electric motors have replaced the place of steam engines and accumulators. The former mechanism is open to the public. The bridge can carry more than 2000 tons.