The+Thames+Barrier

The Thames barrier is one of the largest, moveable flood barriers in the world. It spans 520 metres across the River Thames near Woolwich, and it protects 125 square kilometres of central London from flooding caused by tidal surges. The barrier became useful when it was made in 1982, when it was then possible for the ten stainless steel gates could be raised into position - protecting London from floods. The pillars are 61 metres wide and sit on concrete blocks that reach down all the way to the bottom of the riverbed. When raised, the main gates stand as high as a five-storey building and as wide as the opening of Tower Bridge. Each main gate weighs 3,300 tonnes. The gates between them are normally sitting on the bottom, but can be raised to stem the incoming tide.

Flooding has been a problem in London for centuries. The earliest recorded instance of the water level rising above the banks was in 1099 it is said that: 'the Thames sprung up to such a height and did so much harm as no man remembered that it ever did before.' The flood barrier is reckoned to have saved London from floods more than seventy times since its opening. The last great flood that covered London was in 1953, when 300 people unfortunately lost their lives.It is belived that the river has risen a further 50cm since then, and will probably continue to rise another metre every century. Although, flooding is now very rare, and thanks to the Thames barrier, it will be safe for London. Thames Barrier