We visited the Thames Barrier on Sept 28, 2006  The Barrier was completed in 1984 to protect London from flooding.           How it works              Detailed Maths background There are 10 gates across the river.  Aerial photo  All the gates are made of steel. The four large central gates are 61 metres long, 10.5 metres high (above local ground level) and weigh 1,500 tonnes; the outer two gates are 31.5 metres. Stainless steel sails straight from the Sydney Opera House! It is just downstream from the Millennium Dome and Canary Wharf This shows one flood gate closed........The flood gates across the openings are radial, i.e., half-cylindrical, and they operate by rotating, raised by hydraulics out of a horizontal sill below the water to form the barrier.  [see Operations] Note the different positions of the gantry arms. Four radial gates by the riverbanks can be lowered. These gate openings, unlike the main six, are non-navigable. Detail showing the rotating mechanism. Some local inhabitants This is a personal website run by John & Judy Saville.  All web pages are Copyright John & Judy Saville as are all photographs unless otherwise indicated. Other information (e.g. maps etc) may be copyright to others as indicated. No information may be copied or reproduced without prior permission (from: john-saville@ntlworld.com) but this will almost certainly be willingly granted.