During WWII Churchill was worried that after the Dambusters raid we would need protection of British Dams from German reprisal raids. To this end he set up a series of towers like pylons from which descended a number of wire streamers running across the dams. This apron was intended to deter or snag enemy bombers who tried a similar bouncing bomb attack.

I have tried to find out more but failed does anyone have any pictures or links that show this precaution?