The end of Operation Outward

On 4 September 1944, according to British figures compiled after the war, the last balloons of Operation Outward were released from the English coast. So ended one of the strangest campaigns of the Second World War: for two and a half years the Royal Navy had been sending cheap, unmanned, hydrogen-filled balloons over Germany and occupied Europe, trailing steel wire to short out high-voltage power lines or carrying incendiary loads meant for forests and heathland. The last launches were nothing spectacular – from the spring of 1944 the operation had been gradually winding down, and its end came in the days when Allied troops were entering Belgium and liberating Brussels, and the front was moving rapidly eastwards, ever closer to the borders of the Reich.

Two and a half years of balloons

The first balloons were launched on 20 March 1942 from the Felixstowe Ferry golf course near Felixstowe in Suffolk, home to the naval base HMS Beehive. In July 1942 a second site was opened above Oldstairs Bay near Dover. The weapon was surplus stock: the navy held some 100,000 latex meteorological balloons about 2.4 metres in diameter, and since latex was a scarce material, making use of these stocks was what made the venture worthwhile. A simple mechanism with a slow-burning fuse and a can of oil serving as ballast was meant to ensure that the balloon would descend and release its load only over German-controlled territory. By British reckoning a single balloon cost about £1 15s.

According to published accounts, the sites were operated by more than 230 people: naval officers, men of the Royal Marines and women of the Women’s Royal Naval Service, supported by RAF Balloon Command, which supplied hydrogen in cylinders, and by naval meteorologists. The work could be dangerous – burns occurred while filling the balloons and handling the incendiary loads – and for security reasons the unit was described as an anti-submarine barrage unit.

From August 1942 up to a thousand balloons a day were released, and in individual operations as many as 1,800 in three to four hours. The greatest success proved to be the failure of 12 July 1942: a balloon’s wire short-circuited a 110 kV line near Leipzig, and a damaged circuit-breaker started a fire that destroyed the power station at Böhlen. The balloons, however, did not choose their targets. Some came down prematurely in occupied Belgium, shifting winds carried others back over England, and in neutral Sweden, on the night of 19–20 January 1944, two trains collided near Laholm – according to British accounts, after a balloon had damaged the power supply to the railway lighting.

From mass launches to the “trickle”

From the outset the operation clashed with the air offensive against Germany. On the nights of major Bomber Command raids, launches were suspended for fear that a steel wire or an incendiary load might hit one of the RAF’s own bombers. When, in the spring of 1944, the skies over the Channel, the North Sea and Western Europe filled with Allied aircraft preparing for the invasion, that risk grew considerably. In May 1944 it was therefore decided to change tactics. Mass launches were abandoned and replaced by the so-called “trickle”: from three sites, single balloons were released every ten minutes throughout the day. Only about 2 per cent of them were to carry wire; the rest were balloons with incendiary loads.

The British judged that such a thin stream of balloons posed no serious threat to their own aircraft, so it could continue without interruption. This also simplified the supply of hydrogen to the sites and released lorries and compressed-gas cylinders that were now needed elsewhere – for the Normandy landings and for the defence against the German V-1 flying bombs, which from June 1944 were falling on London and south-east England. Barrage balloons, which required the same equipment and the same gas, were deployed in the summer of 1944 in a dense belt south of the capital as one of the barriers against the flying bombs.

Why the balloons stopped flying

The available studies do not cite a single order that ended the operation; rather, they point to a combination of causes. Launches had been dwindling for months, as they had to give way to the bombing of Germany and to invasion operations. The balloons – as authors writing about Outward stress – could not distinguish occupied from liberated territory, and their loads could endanger Allied airmen and troops. At the turn of August and September 1944, after the destruction of the Germans at Falaise and the liberation of Paris, the Allied armies were advancing through northern France and Belgium by several dozen kilometres a day; on 4 September, the day of the last launches, the British 11th Armoured Division entered Antwerp. Balloons released from Suffolk and Kent and carried by the wind over the Netherlands, Belgium and western Germany were increasingly likely to come down on territory already liberated or behind the Allies’ own lines. It seems that in these circumstances the cheap harassing weapon had simply lost its point, and the men and equipment could be put to better use.

The balance sheet

In just under two and a half years – 899 days, by some counts – a total of 99,142 Outward balloons were launched, roughly half with wire and half with incendiary loads. A breakdown found in the literature of 53,343 incendiary balloons and 45,599 wire-carrying ones gives a total slightly smaller than the overall figure; the difference probably stems from incomplete records. The effects of the fires could scarcely be assessed: it was hard to tell whether a given forest fire had been caused by a balloon, an accident, sabotage or an incendiary bomb dropped from an aircraft. Information came mainly from newspapers in occupied Denmark, France and other countries, which wrote about “British balloons” in order to show the enemy in a bad light.

The damage to the electricity grid proved better documented. A British report of 1946, based on captured German documents, put it at no less than one and a half million pounds, with the proviso that the real losses must have been much higher: the documents were incomplete, increasingly unreliable after 1943, and entirely missing for the Soviet occupation zone. According to that report, the Germans had tried to record faults on lower-voltage lines, but these occurred so often that they gave up. Luftwaffe fighters were sent up and anti-aircraft artillery used against the balloons, and when a balloon attack was expected the threatened lines were sometimes switched off. This was exactly what the British had counted on from the start: shooting down a balloon cost the Germans more in fuel and aircraft wear than it cost the British to make one.

Place in the war

Operation Outward was a weapon of harassment, not of destruction. It did not affect the course of the war, but at negligible cost and with no risk to British crews it forced the enemy to keep watch over its forests, rebuild the protection of its power grid, repair countless minor faults and divert fighters from combat duties. For the industry of the Reich, whose power supply was to suffer far more seriously from bombing in the last year of the war, it was no more than an irritating background.

Its end coincided with the moment when the tide of “unmanned air weapons” turned against the British. Four days later, on 8 September 1944, the first German V-2 rocket fell on the London district of Chiswick – a weapon against which there was no defence at all. Japan, for its part, released more than nine thousand large fu-go balloon bombs over the Pacific between November 1944 and April 1945; technically far more advanced, they were carried by the jet stream to North America, and in May 1945 they killed six people in the state of 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 more damage than the Japanese weapon of the same kind.