Tower Bridge at dusk.
Tower Bridge is a combined bascule (drawbridge) and suspension bridge in London, over the River Thames. It is close to the Tower of London, which gives it its name. It has become an iconic symbol of London.
The bridge consists of two towers which are tied together at the upper level by means of two horizontal walkways which are designed to withstand the horizontal forces exerted by the suspended sections of the bridge on the landward sides of the towers. The vertical component of the forces in the suspended sections and the vertical reactions of the two walkways are carried by the two robust towers. The bascule pivots and operating machinery are housed in the base of each tower. The bridge's present colour dates from 1977 when it was painted red, white and blue for the Queen's Silver Jubilee. Originally it was painted a chocolate brown colour.
In the second half of the 19th century, increased commercial development in the East End of London led to a requirement for a new river crossing downstream of London Bridge. A traditional fixed bridge could not be built because it would cut off access by tall-masted ships to the port facilities in the Pool of London, between London Bridge and the Tower of London.
The bridge was officially opened on 30 June 1894 by The Prince of Wales (the future King Edward VII), and his wife, The Princess of Wales (Alexandra of Denmark).
Tower Bridge is still a busy and vital crossing of the Thames: it is crossed by over 40,000 people (motorists, cyclists and pedestrians) every day. The bridge is on the London Inner Ring Road, and is on the eastern boundary of the London congestion charge zone.
The bascules are raised around 1000 times a year. River traffic is now much reduced, but it still takes priority over road traffic. Today, 24 hours' notice is required before opening the bridge. There is no charge for vessels.