Monday, May 3 was the Spring Bank Holiday, so we decided to take the day and go exploring a bit. While we originally intended to go down to the white cliffs of Dover, the weather looked a bit dodgy so we changed plans at the last minute. Instead we went out to explore the Thames Barrier, and it was lovely!
London has a long history of being inundated by flood waters: the first recorded mention of a flood is in the 13th century; it mentions that you could take a rowboat up the center aisle at Westminster Cathedral. There have long been plans to create some sort of flood control device, but in 1974 construction finally began on the Thames Barrier.
The Barrier is the world’s second largest movable flood barrier, and sits across the River Thames just below Greenwich in eastern London. This site was chosen because the banks are relatively straight, and the chalk bed at the bottom of the river was strong enough to bear the weight. Large pylons were driven into the river bed, and rotating gates were installed. Then very large and very heavy barriers were placed in the gates, to stop the movement of the water.
I was pretty confused at first, until I realized that it functions a lot like a garage door. The two smaller barriers sit above the water and rotate down into the river to block the flow. The eight larger barriers actually sit under water, and rotate up out of the river. The can even over-rotate them, so that some water can escape beneath the barrier if necessary.
The barrier is only closed at high tide when there is a surge of water from the North Sea. This happens about 5 times per year, although the gates are closed once a month for maintenance purposes. There is an excellent education center with a very helpful staff to answer questions. While there is a small park on the site, I’d only recommend the barrier for a quick visit, unless you’re very engineering oriented.
Here are some pictures from the Thames Barrier!
After our tour we followed the very helpful signs to the free ferry across the Thames. It was pretty fast, even for such a big river! Then we hopped on the DLR (Docklands Light Rail) and continued our day. Hope you all had a nice weekend!