In the dark days of September 1940, Britain and the Commonwealth stood alone. The Nazis occupied most of Europe, the Japanese were on the offensive and had the upper hand in the Far East and even Egypt and the Middle East weren’t safe. Fear of invasion from Italian forces in North Africa had stretched the British Army to breaking point. The fiasco that was the rout at Dunkirk had had a positive spin put on it by politicians and was made to be seen as a victory. In reality, it was a defeat — most of the modern tanks, vehicles and heavy weapons that had gone to France with the BEF had been left behind. Prime Minister Winston Churchill called for action but what action could the country take when so thoroughly on the back foot? Then on the night 17/18 September 1940, Britain conducted a stealth raid into occupied Europe. A raid so stealthy, they didn’t know they had done it!
Strong winds had broken loose a number of barrage balloons from their moorings. These balloons drifted across the North Sea and (crash) landed in Denmark and Sweden. The sturdy steel cables trailing from the balloons caused damage to power lines, careered into railway traffic and collided with the antenna of the Swedish International radio station, causing it to go offline for a while. Five balloons (but maybe more) were reported to have drifted as far as Finland.
How many balloons had ‘escaped’ was never reported but upon hearing the news of the damage and confusion they caused, Churchill was jubilant. He reasoned that if such a low cost ‘weapon’ could do this, then a further, more detailed study should be taken with a view to doing something along the same lines…but deliberately.
In fact the matter had already been investigated a few years earlier. The British Air Ministry had begun producing barrage balloons as far back as 1936. Forward thinkers had seen the war clouds gathering so in 1937 the Air Ministry conducted a study to determine how much damage a balloon could cause if it broke free from its mooring and its steel cable was dragged across the countryside. The study showed that, if the steel cable were to short out power lines, electricity supplies would be out for at least six hours. This study had been undertaken as a Civil Defence measure — to determine how long people and industry would be without power in the event of an accidental balloon drift over Britain. The use of barrage balloons as an offensive weapon had not been considered — until Churchill became involved.
Initially the Air Ministry opposed it on the grounds that the balloons would interfere with flight operations. Friendly balloons floating about in the darkened skies might become entangled with RAF aircraft. It also argued the point that these balloons were unguided and uncontrollable and any success would be more by chance than design. Retaliation in kind by the Germans from the occupied coasts of Europe could not be ruled out either.
In contrast, the Admiralty Board was more open to the idea, arguing that it was a ‘cheap and cheerful’ way to strike back at the enemy. Comparing the cost of a balloon to a front line bomber was persuasive and, as there was also an ample supply of hydrogen gas for the balloons, the program started in earnest. Meteorological studies had shown that more winds blew from Britain towards the continent than blew from the continent towards Britain. In an average year the prevailing wind was west to east 55% of the time and only east to west 38% of the time. This made the idea of German retaliation highly improbable and probably less effective if implemented. More importantly an engineering study had shown Germany’s power grid was considerably more vulnerable to damage by short-circuit than the British system. Coupling this with the fact that large pine forests (which were considered more vulnerable to incendiary attacks than British hard wood forests) covered many parts of the German heartland and continental Europe, the program was begun. However, as with all things involving two branches of the British military a long, bureaucratic struggle between the Air Ministry and the Admiralty began. The programme was held up until September 1941 when the go-ahead was finally given: Operation Outward would commence.
The Balloon Goes Up
The first launch site was Landguard Fort south of Felixstowe situated in a remote southern part of Suffolk. Originally built as one of a string of Napoleonic Forts for home defence, it was situated at the mouth of the River Orwell. Designed and built over a century earlier, its purpose was to guard the entrance to the port of Harwich (and the surrounding area) from the perceived Napoleonic invasion threat. An old imposing structure with high, thick walls, it would be able to store the balloons and their associated equipment, whilst keeping prying eyes at bay.
Following detailed studies and tests of balloon designs, two types of balloon were to be used. The first type was a typical eight feet round weather balloon modified to carry three six pound incendiary ‘socks’. These socks were designed to set fire to pine forests and heathland. A second balloon tested was similar to, but not as large as, a standard barrage balloon. This smaller barrage balloon would trail a long steel cable which, it was hoped, would hit power lines and create a short circuit. Tests were conducted on the balloons regarding duration of flight and with a timed ‘burn fuse’ attached. This saw their ceiling height set at about 16,000 feet, give or take a few hundred feet for wind and other atmospheric conditions. Natural leakage of the hydrogen gas from the balloons, along with a timed deflation valve obviated the need for any ballast or pressure-control systems to control and maintain altitude. As the Spitfire fighter and Lancaster bomber could fly in excess of 20,000 feet, the balloons should not interfere with any normal RAF flight operations.
With the balloons simple and easy to operate, no expert crew had to be employed in their usage. Fighting men could be freed up and used elsewhere so the role of balloon handlers fell mainly onto the shoulders of the WRNS (Women’s Royal Navy Service) or WRENS (as they were commonly called). These personnel were supervised by a few (male) NCOs and technicians! A detailed plan for launching the balloons was introduced so as not to conflict with either incoming or outgoing RAF flight operations. Times were set for balloon launch operations but these could be changed if RAF aircraft were grounded due to bad weather. The balloons could fly even if the aircraft could not.
The first launches took place on 20 March 1942 and, within a few days, encouraging reports of forest fires near Berlin and in East Prussia were received. Radio intercepts showed that the Luftwaffe was sending up fighters to try to destroy the balloons. This was very encouraging news to both Churchill and the combined RAF and Admiralty operation. It would appear that the Germans were spending far more resources trying to destroy the balloons than the British were by launching them. Sending up fighters to try to destroy the balloons meant they were using extra fuel, putting more strain onto airframes, increasing aircrew fatigue etc. Whilst the Germans did their best to intercept as many balloons a possible, they soon realised they were fighting a losing battle.
Reports from French Resistance cells and other, neutral sources claimed that the balloons were causing a lot of disruption to rail, road and agriculture operations and services. These encouraging reports reached the ears of the French Government in exile in London, and they wanted more released to help tie down enemy forces.
The balloon operation had proven successful — for very little outlay a lot of disruption had been caused. These initial successes led to two other launch sites being set up in April and May 1942. One site chosen was on the coast at Oldstairs Bay between Dover and Deal in Kent, the other being Waxham in Norfolk. The latter site was an isolated coastal village north of Great Yarmouth. These sites brought anywhere from Northern France to Scandinavia within a balloon’s sphere of operation with a good wind blowing to the continent.
Success for the Balloons
Whilst the balloons proved to be an economical way to strike back at the enemy in the short term, they were never intended to be a realistic military weapon to cause mass damage or destruction. Their launch was seen as being of a nuisance value. Although they did tie up a lot of enemy manpower resources, in reality they caused very little military damage. People in the higher chain of command began to doubt that the effort put into this operation was worth it. However, the night 12 July 1942 began to change a some minds. A cable-trailing balloon struck a 110,000 volt power line near Leipzig. The overload switch in the nearby Bohlen power station did not trip quickly enough and this resulted in a fire which spread and destroyed the entire complex. The damage was estimated at £1,000,000 compared to the £220,000 spent on Operation Outward.
By August 1942 up to a thousand balloons per day were being released, weather permitting. The Germans were now tied up fighting in the east and the balloons seemed to have free rein over the skies of occupied Europe. Some reports even state they reached as far as Hungary. The German military were engaged in fighting in the Soviet Union leaving it to the German civilian services to try to fight the ‘balloon war’ on their own.
The balloon offensive had proven a success but this success did come at a price. On the night of 19/20 February 1944 a cable-trailing balloon shorted out a Swedish overhead rail lighting system. This short circuit of the system resulted in a collision between two trains. The number of people injured or fatally wounded was never revealed but a diplomatic protest was issued by the Swedish government. Other than to say sorry and perhaps compensate a neutral country for any material loss, there was little the British government could do. This unfortunate incident did prove without doubt the potential of the balloon campaign, raising the question of how much damage wasn’t being reported by the German authorities.
End of Operations
With the tide of the war turning in the Allies’ favour and having achieved virtual air superiority over occupied Europe, it was decided that the number of balloons being released should be cut back. From May 1944 a change of tactics was also implemented. Mass balloon launches were stopped and replaced with a trickle of balloons launched from the three sites at ten-minute intervals throughout daylight hours. Only 2% of these balloons were to be of the trailing wire type — a type which could have caused major damage to allied aircraft. The remaining 98% carried of incendiary bombs. Cutting back on balloon launches increased the availability of hydrogen gas for use elsewhere and freed up much-needed transport vehicles and compressed gas cylinders ready for the planned Normandy landings. With the success of the D-Day landings on 6 June 1944 and with the Allies making gains into Occupied Europe the last offensive balloons were launched on 4 September 1944.
Further Research and Reading
Thanks to something Alan Hamilton said on the SOTCW Forum I set off to research this unusual operation. Using Google as my first port of call most of what I have written here is gleaned from various sources online. There is still a lot of technical, detailed information about Operation Outward that I haven’t included. I haven’t set out to write a complete history of the Operation but just to give the reader a taste of something unusual that happened in the darkest days of WWII. It would be advisable to read this article in conjunction with online maps and images of the locations mentioned. That way (hopefully) you’ll be able to see how remote and secretive the chosen balloon release sites were. I hope you enjoy it.
Featured image: The National Archives UK [OGL v1.0]
Article by Grant Parkin.