Monday, May 17, 2010

Two Views of the Thames Barrier

The Thames Barrier (above) is an impressive and strangely beautiful structure.

It is the second largest moveable flood barrier, with rotation mechanisms contained within the stainless steel clad piers which remind me a little of the Sydney Opera House. There are ten spans in total: the four main 61 metre spans were designed to be the same width as that at Tower Bridge.

London depends upon it raising the gates when high tide and a storm surge combine to send water funnelling up the Thames estuary, threatening to flood the capital. And the risk is becoming ever greater, as the south east of England is gradually sinking while water levels rise higher.

And this is another view of the Barrier, using sound not light:

The photo was taken just after we powered through one of the gaps, and you can see the flat bit which shows the gate underwater in the horizontal lowered position.


bonnie said...


I've now heard a couple of people here in NYC saying we should have something like this, possibly at the Verrazano Narrows. Actually seems like you might need 3 (1 at the Narrows, one at Throg's Neck & one at the Raritan Bay end of the Arthur Kill), and you'd still have a fair bit of coastline left, well, high and dry, which is to say low and wet.

It would cost a lot, but we are on the hurricane track & statistically past due.

Wonder if a set of barriers would pay for itself in averted damages in one hurricane with a storm surge at high water?


Baydog said...

Bonnie: Chances are a set of barriers would offset the cost of one major hurricane. But too often politicians are not as reasonable and logical as you and me.

JP: The first thing I thought of when I saw the first image was definitely Sydney!

JP said...

With the estimate of one bad flood costing London £ 13 billion I'm pretty sure it has paid for itself already!

One worrying thought is that as sea levels are rising faster than forecast when it was built there is already talk of needing a new one!

....but not until 2060 :)