What is a barrage balloon?
Barrage balloons or “Bulging Berthas” were inflatable shiny silver-painted balloons, made of rubber-coated fabric, and filled with hydrogen gas, which were attached on deck and floated above ships to prevent low level attacks by enemy aircraft. The balloons flew at 500 feet when the ship traveled in dangerous waters, but were raised to 2000 feet when under attack. At that height the 15 gauge flying wire could clip the wings off a plane. In winds greater than 25 miles per hour kites were used.
