Thames Barrier

The Thames Flood Barrier was constructed following the passing of the Thames Barrier and Flood Protection Act 1971-2. Construction work began in 1974 and it was officially opened on 9 May 1984, though first used defensively in 1983. It is designed to prevent flooding in Central London due to unusually high tides, caused by storm surges at sea, and has been thus used over 170 times. The Barrier stretches right across the Thames, some 572 yards, dividing the river into four 200 ft sections and two 34 yard navigable spans. There are also four smaller non-navigable channels, with altogether 9 concrete piers and 2 abutments. The flood gates are raised by hydraulics from a horizontal sill on the riverbed and form a barrier of steel and concrete. Being hollow, and made of steel, the gates fill with water when submerged and empty as they emerge from the river. The concept of rotating gates was devised by Charles Draper, and the gates designed by Rendel, Palmer and Tritton for the Greater London Council. Nearby is a permanent exhibition run by the Environment Agency, which explains the construction and function of the Thames Flood Barrier.