Operation Outward

On 20 March 1942 the first balloons of Operation Outward were released from a golf course near Felixstowe in Suffolk. It was one of the cheapest and most unusual British weapons of the war: small, unmanned, hydrogen-filled balloons that the westerly wind carried over the North Sea and on over Germany and occupied Europe. Some trailed a steel wire intended to short-circuit high-voltage power lines; others carried incendiary loads meant for forests, heathland and fields. The operation was run not by the Royal Air Force, which that same month had resumed large raids on the Ruhr using Gee, but by the navy.

An accident in 1940

The idea grew out of an accident. Even before the war the British had studied the damage that could be done by the steel cable of a barrage balloon that broke loose from its mooring and fouled electric cables. In the first months of the war the power companies complained of such damage in England itself. On the night of 17–18 September 1940, during the Battle of Britain, a gale tore many barrage balloons loose and carried them out over the North Sea. According to British studies, the balloons damaged power lines in Sweden and Denmark, disrupted rail traffic and brought down the mast of a Swedish radio station, and a few reportedly drifted as far as Finland.

A report on this damage reached the War Cabinet on 23 September 1940. Prime Minister Winston Churchill, always open to unconventional ideas, ordered an investigation into whether free balloons might be used as a weapon against Germany. The Air Ministry was sceptical, regarding the project as of little effect and a diversion of resources from the air force. The enthusiast proved to be the Admiralty, and in particular Captain Gerald Banister, who was responsible for anti-submarine barriers. Naval meteorologists established that at an altitude of a few kilometres over the British Isles westerly winds prevailed: balloons released from England would drift over the Continent, while the Germans would find it hard to retaliate with the same weapon. Trials showed that even a thin steel wire drawn across two conductors of a high-voltage line produced an electric arc several metres long that could burn through the conductors and damage circuit breakers and transformers. After a long dispute between ministries, the British Chiefs of Staff approved the operation in September 1941.

A weapon for less than two pounds

The balloons were simply naval surplus: rubber meteorological balloons about 2.4 metres in diameter, of which some hundred thousand were lying in store. Since latex was a scarce material, being able to use up the stocks mattered a great deal. Each balloon carried a simple mechanism with a slow-burning fuse. After launch it rose to an altitude of a few kilometres, where some of the gas escaped, and began slowly to descend; after a time the fuse released oil from a tin that served as ballast, and the length of the fuse was chosen so that the load would be released once the balloon was over German-controlled territory.

About half the balloons carried wire: some two hundred metres of hemp line ending in about a hundred metres of steel wire. The balloon dragged it low over the ground for tens of kilometres until the wire caught on a power line. The other half carried incendiary loads code-named “Beer”, “Jelly” and “Socks”: bottles of a self-igniting white phosphorus mixture, tins of incendiary jelly, or canvas bags with paraffin-soaked filling that were meant to lodge in the treetops and burn for a quarter of an hour. According to British figures, a balloon with its equipment cost about £1 15s.

The operation’s base was the naval shore establishment HMS Beehive near Felixstowe, and the balloons were released from the grounds of the local golf club. The unit consisted of a few naval and marine officers, about 80 Royal Marines and about 150 women of the Women’s Royal Naval Service. The RAF supplied hydrogen in cylinders. The balloons were filled in tents sheltered from the wind and doused with water so that friction against the canvas would not ignite the gas; even so, burns from exploding balloons and broken incendiary loads were frequent. For the sake of secrecy the unit was described as an anti-submarine boom detachment, which was partly true: when the weather was unsuitable for launches, its men maintained boom nets.

Effects

According to British studies, within a few days of the first launches in March 1942 reports came in of forest fires near Berlin and near Tilsit (now Sovetsk) in East Prussia, although it was hard to establish which fires had been started by balloons. Intercepted Luftwaffe conversations showed that German fighters were hunting the balloons; the British counted this a success, since shooting down a balloon cost the Germans more in fuel and wear on their aircraft than it cost the British to make one. In July 1942 a second launch site was opened near Dover, and from August up to a thousand balloons a day were released, later as many as 1,800 within a few hours in single operations.

The operation’s greatest success, according to British and later studies, was a breakdown on 12 July 1942: a balloon’s wire caught on a 110 kV line near Leipzig, and a damaged circuit breaker started a fire that destroyed the power station at Böhlen. A report of 1946, based on incomplete German records, put the damage at no less than one and a half million pounds. The balloons, however, did not choose their targets. Because of faults in the mechanism some came down prematurely in occupied Belgium, and the wind turned others back over England, where one of them cut off the electricity in Ipswich. Neutral Sweden suffered too: on the night of 19–20 January 1944 two trains collided near Laholm, according to British studies after a balloon had damaged the power supply to the railway lighting.

Place in the war

Operation Outward lasted until 4 September 1944. By then 99,142 balloons had been released, just over half of them with incendiary loads. It was often suspended on the nights of large bombing raids so that the balloons would not endanger friendly aircraft, and from May 1944, before the Normandy landings, it was limited to occasional daytime launches. It was a weapon of harassment rather than destruction: it did not affect the course of the war, but it forced the Germans to send up fighters, keep watch over their forests, rebuild the protection of their power grid and repair numerous minor breakdowns, all at negligible cost and without risk to British aircrews.

Japan used a similar idea, on an incomparably larger technical scale, at the end of the war. Between November 1944 and April 1945 it released more than nine thousand large balloons carrying bombs (fu-go), which the jet stream at an altitude of about ten kilometres carried across the Pacific to North America. Only a small fraction of them arrived; the only fatalities, six people, were killed in May 1945 in Oregon. The British balloons had to travel only a few hundred kilometres, which is why they could be primitive and cheap, and yet they probably did the enemy considerably more damage than the Japanese weapon.