Operation Outward

Operation Outward was a British campaign of the Second World War that attacked Germany and German-occupied Europe with free-flying balloons. It made use of cheap, simple balloons filled with hydrogen and carrying either a trailing steel wire to damage high-voltage power lines by producing a short circuit, or incendiary devices to start fires in fields, forests and heathland. A total of 99,142 Outward balloons were launched; about half carried incendiaries and half carried trailing wires. Compared to Japan's better-known fire balloons, Outward balloons were crude. They had to travel a much shorter distance so they flew at a lower altitude – 16,000 ft (4,900 m), compared with 38,000 ft (12,000 m) – and had only a simple mechanism to regulate altitude by means of dropping ballast or venting lifting gas. This meant the balloons were simple to mass-produce and only cost £1 15/- each (approximately equivalent to £85 in 2025). The free flying balloon attacks were highly successful. Although difficult to assess exactly, their economic impact on Germany was far in excess of the cost to the British government. Because there was concern over what could happen if a barrage balloon accidentally got loose, in 1937 the British carried out a study on the damage that may be caused by a balloon-carried wire hitting power lines. These concerns were evidently borne out when early in 1940, the Air Vice Marshal Balloon Command, the organisation responsible for the barrage balloons, wrote that "Since the outbreak of the war, I have had constant complaints from the electricity distributors regarding the damage done in this country by [barrage] balloons that have broken away from their moorings". to which he added "...advantage might be taken of this to impede and inconvenience the enemy".