Operation Outward [History]

Most students of world War II are aware of the thousands of barrage balloons that Britain employed throughout the war to help protect cities, ports, and other important targets from low-flying Luftwaffe dive bombers and fighters. These large gas balloons measured about 64 ft (19.5 m) long by 34 ft (10.4 m) in diameter and were tethered to the ground by steel cables attached to winches and rose to heights of up to 5,000 ft (1,524 m).