The Tower Bridge (officially known as Tower Bridge) is a hoist and drawer structure built over the Thames in central London. The uniqueness of the bridge lies in its complexity from a technical point of view, as well as its architectural style.
History of the project and construction
The Tower Bridge is often confused with the London Bridge, but in reality these are two different structures (the Tower Bridge is located downstream of the River Thames). The need for it arose in the 19th century, when the East End gained higher economic significance. Along with this, the flow of pedestrians and vehicles increased.
The city authorities began to develop a plan for the construction of a new crossing over the river. However, there was no question of a simple design - it would become an obstacle for ships arriving at the port of London.
In 1877, a special unit was created to deal with this issue. This is how the “Special Committee on Bridges and Underground Communications” appeared (chapter - Sir A.J. Altman). Architects began to submit various projects for consideration, in total there were at least 50 of them.
It took 7 years to study the projects, until in 1884 the committee chose the proposal of Sir Horace Johnson, a London architect. The original idea for the construction of the bridge belongs to engineer Sir D. Wolff-Barry.
Construction took another 8 years. The official opening took place on June 30, 1894. The Prince of Wales, who in the future became King Edward VII, and his wife attended the celebration of the launch of the Tower Bridge.
Subsequently, the bridge was reconstructed.For example, in 1977 it was repainted from brown to brighter colors - red, white and blue. These changes were timed to the birthday of Elizabeth II. Another, more comprehensive reconstruction was carried out at the beginning of the 21st century. At the same time, new lighting was installed, and the entire structure was repainted.
Interesting fact: Tower Bridge played a very important role during the 2012 London Olympics. At the opening ceremony, under the bridge, David Beckham drove the Olympic flame. Then, fireworks were launched from the bridge itself.
Design features
How is the Tower Bridge structured? It consists of 2 towers, which are interconnected by a pedestrian gallery and a central span. The towers are on supports. Construction sections between towers and river banks are suspension bridges. They are supported by chains: on one side, chains are attached to coastal fortifications, and on the other to towers.
Specifications:
- total length - 244 meters;
- the height of the twin towers is 65 meters;
- the length of the central span is 61 meters;
- width - 24 meters;
- the weight of each adjustable wing is 1000 tons;
- wing lift angle - 86 °;
- rise time - 1 minute;
- the length of the hanging sections is 82 meters each;
- permissible transport speed - no more than 32 km / h;
- maximum transport weight - 18 tons.
Interesting fact: The wings of the bridge rise about a thousand times a year. The passage for ships is free, but they must at least one day warn the administration of the bridge about their passage and the estimated time.
The engineers set an important goal - to ensure the movement of pedestrians on the bridge, even when the wings are spread. To do this, pedestrian walkways are provided on the sides. But most importantly - the presence of two pedestrian galleries, which were erected at a height of 44 meters.
To get to the gallery, you must climb up the stairs (entrance fee). Galleries are used as viewing platforms (since 1982), as it offers magnificent views of the city. There is also a museum. Everyone can look at the work of installations that raise the spans of the bridge.
They are located in the towers. Initially, the installation worked on hydraulic accumulators, where water was supplied due to the operation of steam engines. Since 1974, engines have become electric, and instead of water, oil.
The Tower Bridge has a combined design in which suspension and drawbridges are combined. It consists of 2 twin towers connected by a drawbridge and two galleries, which are located at a 44-meter height. The towers are mounted on poles. Suspension bridges are installed between the banks and towers, which are held by chains. The purpose of the construction is to ensure the passage of ships under the bridge, the passage of vehicles and the movement of pedestrians.
