St. Nazaire - WWII submarine pens

In the New Forest there is a building called the submarine pens. It is here during 1942 a concrete structure was built so that the Tallboy Bomb, 10,000lbs, could be tested to see what effect it had on a strong structure. After the test a couple of corners had been knocked off and the structure still stands today as do the pens in St. Nazaire.

A photo of the pens with 2 U-boats

The pens today

These pens took 2 years to build. The walls are 3.5 metres thick, the roof slabs are 4 metres thick. The whole structure is 301 metres long, 130 metres wide and 18 metres high. 480,000 cubic metres of concrete was used. That's got to be quite a few tons.

The roof - this was built in such a way that if a bomb hit the destructive power would be dispersed.

Fortified lock seen from the top of the submarine pens.

There are 14 pens in all.