Barrage Balloons

// Information about the barrage balloons used by the British and Americans throughout the world war.

Length 18.9 m
Diameter 7.6 m
Volume 538 m3
Maximum Altitude 1.524 m

The barrage balloon was simply a bag of lighter-than-air gas attached to a steel cable anchored to the ground. The balloon could be raised or lowered to the desired altitude by a winch. Its purpose was ingenuous: to deny low-level airspace to enemy aircraft. This simple mission provided three major benefits:

  • forced aircraft to higher altitudes, thereby decreasing surprise and bombing accuracy;
  • enhanced ground-based air defenses and the ability of fighters to acquire targets, since intruding aircrafts were limited in altitude and direction; and
  • the cable presented a definite mental and material hazard to pilots.

Mindful of these capabilities, the British saw the barrage balloon as a viable mean to counter low-level attackers during the world wars.

During the last years of World War I, the British employed the barrage balloon in response to attacks by German Gotha bombers on London. The success of the barrage balloon in the First World War paved the way for its use in the Second. This time, however, instead of a mere handful, thousands of balloons dotted the British skies. Again, the balloons provided a partial solution in countering fast, low-flying German bombers and fighters and in protecting key installations. The British believed that an integrated air defense system should use every viable air defense weapon for self-protection - a combination that included the principal means of fighters, antiaircraft artillery and balloons. The only modification in balloon usage from World War I concerned the apron concept (more than one stuck on balloon). Instead, single balloons were used because they could be sent aloft more quickly and were easier to operate. Thus, in 1936 with war clouds darkening the horizons, the Committee of Imperial Defense authorized an initial barrage of 450 balloons for the protection of London.

With the capital securely covered, barrage balloons also flew at fleet anchorages and harbors from threatened areas. Although airfields also requested them during the early months of the war, the balloons were not available because of slow production and losses due to combat and bad weather. However, thanks to a new balloon plant, the barrage system had 2,368 balloons by the end of August 1940 and would maintain approximately 2,000 operational balloons until the end of the war.

These figures demonstrate the great value given by the British to the balloons. They had even formed Balloon Command in 1938, an independent command under the leadership of Air Marshal Sir E. Leslie Gossage, to control the 52 operational barrage balloon squadrons stationed across Great Britain. The Balloon Command was charged with the job of creating a barrage of huge balloons aimed at protecting British towns and cities, as well as key targets such as industrial areas, ports and harbors. They were made to protect everything at ground level from the threat of low-flying German dive-bombers. The barrage balloons, which were set at heights of up to 1,524 meters, would force these aircraft to fly high, making them less accurate, and bring them within range of the antiaircraft guns. Eventually, this command consisted of 33,000 men. The amount of equipment and the number of personnel, however, tell only part of the story. Performance in combat is the main indicator of a weapon system's success, and the balloons received a thorough test during World War II.

By the middle of 1940, there were 1,400 balloons, a third of them over the London area. By 1944 the number had risen to nearly 3,000. Later in the war, the barrage balloons were moved to combat the V-1 flying bomb.

The balloons were huge (on average, about 18.9 meters long and 7.6 meters in diameter), fixed to the things that being protected or from the back of lorries with a winch. By 1944 the balloons were moved to make up a ring around south London to combat the V-1 menace with a fair degree of success - as many as 100 V-1s snagged themselves on the balloons' cables. It was not all plain sailing, however. Some of the balloons were struck by lightning while others were shot down - 50 were shot down in one day when they were set up round Dover. (The Scottish physicist Arthur Vestry [1869-1959] later devised a method for protecting barrage balloons from lightning.)


During the Battle of Britain and throughout the war, the balloons proved their value. Besides protecting strategic cities and ports, barrage balloons mounted in boats defended estuaries against mine-laying aircraft. A declassified wartime report assessed their performance: Following the aerial sowing of mechanical mines, the reallocation of various units of the balloon barrage system to places like the Thames Estuary, and certain other channels, has resulted in effectively reducing the aerial mine sowing operations of the German Air Force. Barrage balloon cables also successfully frustrated German attempts to achieve surprise, low-level penetration at Dover.

The Dover incident deserves elaboration because it provided, in the words of Air Marshal Gossage, a clear indication of their [the Germans'] respect for the British barrage balloon. In an attempt to clear the balloons from Dover, the Germans launched a major effort in late August 1940. They destroyed 40 balloons but lost six aircraft in the process. Much to the Germans' misfortune, 34 new balloons appeared the very next day. Air Marshal Gossage commented on the action: The protective balloons still fly over Dover. The attack on the barrage has proved too costly... In general, major attacks on balloon barrages have ceased, the enemy realized that the game was not worth it. The fact, however, that he hoped to destroy our balloons is in itself proof of the utility of the barrage. During the Blitz, 102 aircraft crashed in the cables, resulting in 66 crashed or forced landings.

After the Battle of Britain, balloons continued to prove their effectiveness in combat. Because of heavy losses during the day, the Germans switched to night attacks. Defensive night fighters were still in their rudimentary stages of development, so guns and balloons had to do most of the work against German bombers. Even after advances in night-fighter technology, it was the opinion of London that balloons and guns were still essential. Two examples illustrate London's sentiments. First, an installed aerial barrage at Norwich that surprised the Germans and diffused their bombardment by forcing them to attack above 2,400 metres. Second, the barrage balloons at Harwich saved that city from an attack by 17 bombers because the Germans went after their secondary target at Ipswich-Felixstowe, a place not protected by balloons. Overall, balloons decreased the severity of night raids on England by deterring point-blank bombing. Incidentally, they also had some tangible results in February and March of 1941, in that seven enemy aircraft crashed after striking cables in various parts of Great Britain.

In spite of the decrease of German aerial activity over England, British balloon activity did not. Balloon Command units accompanied troops in North Africa and Italy, where they protected beachheads against low-level attack. Four thousand balloon personnel even took part in the invasion of Normandy, crossing the channel on D-day to protect artificial harbors, captured ports, and ammunition dumps of the Allies. But perhaps the best example of balloons in combat occurred during the V-1 offensive against London in 1944. Once again, balloons were an integral part of the air defense system and, in this case, formed the third and last line of defense against this low-flying weapon. Approximately 1,750 balloons from all over Great Britain were amassed around London, forming what one British officer called the largest balloon curtain in history. Although guns and fighters destroyed most of the V-1 bombs (1,878 and 1,846, respectively), balloons were credited with 231 kills. Basically, that was the last hurrah for British barrage balloons, and as the war gradually wound down in 1945, so too were the balloons of Balloon Command.

Great Britain was not the only country interested in aerial barriers. Many Americans would be surprised to know that the United States had its own extensive barrage balloon defense during the early part of World War II. In fact, many areas of the West Coast had balloon curtains protecting cities, factories, and harbors. By August 1942 approximately 430 balloons defended important areas in California, Oregon, and Washington against low-level attack. Several balloon units were also sent overseas into combat. In late 1943, for example, Army balloon batteries deployed to the fighting in the Mediterranean.

The North Africa campaign covered a fairly large front, and, as expected, many areas lacked sufficient air defenses. Balloons provided protection to several important ports, effectively enhancing the existing antiaircraft defenses. For example, in August 1943 the air defense region protecting Oran, Algeria, requested 60 balloons for its sector in order to discourage torpedo, dive bombing, and low level bombing attacks. By October 1943 three American barrage balloon batteries (each with 45 balloons) operated in various ports in North Africa and Italy. When the port of Naples was captured, a battery of balloons operated there as part of the overall protection of that harbor from air attack. Naples was crucial to Allied operations in Italy: Among [Mediterranean] ports Naples was the most important in the Allied line of communications; during January 1944 the port handled more tonnage than any other port in the world with the exception of New York. Although it was close to the German lines and received many air attacks, Naples had a solid air defense system and suffered only slight damage. A Fifth Army antiaircraft officer stated that a good port defense consisted of several elements, including an ample number of barrage balloons. The AAF Air Defense Activities in the Mediterranean summarized balloon operations in that theater: Although American barrage balloons were not of primary importance in the Allied air defense system, they were undoubtedly valuable as a supplementary device to fighter aircraft and AA.