During the Second World War, the aerial defence of Yeovil was provided in a number of ways. Clearly the primary target was the Westland Aircraft Works which, as an aircraft factory, enjoyed a high priority in defence terms. The Royal Air Force provided the primary air defence, from various airfields, all of which were located at some distance from Yeovil. RNAS Yeovilton was a training airfield and not involved in air defence.

In the pre-war period, Yeovil and indeed the entire south western peninsula had not been considered to be at risk from enemy bombers, as at that time bombers operating from German soil or even the low countries did not have the range to reach the south west. The German blitzkrieg and the subsequent fall of France changed the situation drastically and defences then considered necessary to meet the threat were built up as quickly as possible.

Local defences were made up of three elements, anti-aircraft guns, searchlights and a balloon barrage. The anti-aircraft defences were manned by men of territorial units of the Royal Artillery, who operated four heavy guns with a number of light guns and, additionally, the searchlight units. The balloon barrage, however, was operated by the Royal Air Force, which formed a number of squadrons to operate them. Number 957 Squadron, operating the Yeovil balloons, was responsible for the defence of Yeovil. It assumed this task on 24th July 1940 and operated twenty-four balloons from sites in and around Yeovil¹. The squadron HQ was at Braggchurch House, Hendford Hill, Yeovil and there was a repair facility in St Michaels Church Hall, this being the only suitable building in Yeovil where the balloons could be repaired and inflated indoors. Number 11 Balloon Base at Pucklechurch, near Bristol, administered the squadron¹. The Yeovil unit would have consisted of slightly less than four hundred personnel. It is not known where they were accommodated, although the majority would have lived at the individual sites, initially in tents and later in huts, probably of the Nissen type. Indeed one of these Nissen huts survived within the Westland site until the late 1950’s². The site at Yew Tree Close certainly had a hut by May 1941, when an enemy bomber struck the cable of their balloon. It dropped its bombs, one of which destroyed the site hut. The remaining bombs falling in open country. There were no casulties³.

Balloon squadrons were manned almost entirely by Royal Auxiliary Air Force personnel or in some cases women of the Womens’ Auxiliary Air Force. It is not known whether any WAAF served at Yeovil but the four fatal casualties suffered by the squadron were all male and this suggests that at least the majority of the unit was male manned. Each balloon site was manned by two corporals and ten men, or by two corporals and fourteen women⁴ . 957 Squadron also assumed control of the local “Starfish” decoy site at Chinnock from 1st June 19415. Although not specifically mentioned, it can be assumed that the QF/QL decoy site at Closworth would also have been included. In June 1944 part of the squadron was re-deployed to the south east of England to assist in the defence of London which was then under attack by V-1 flying bombs⁴.

The balloons used were the Low Zone version, being approximately 19m long and 7.7m in diameter. They were inflated by approximately twenty thousand cubic feet of hydrogen gas. They were fitted with relief valves, which released gas from time to time to prevent them from reaching too high an altitude, or to prevent pressure rising to excessive levels in sunny conditions. This meant that the balloons required topping up with hydrogen at regular intervals. When operating for defence purposes, the balloons were flown at an altitude of about 1500m. They could be close hauled to 150m when not operating. Being in close proximity to the Westland airfield they would have spent most of the time being close hauled. They were normally controlled by means of a winch mounted on a three axle Fordson lorry. This was able to winch the balloon in at a rate of about 125m per minute⁵. The hydrogen was supplied from an Imperial Chemical Industries plant specially built to supply the hydrogen to units in the south-west⁶. It was located beside the town gasworks in Weston-super-Mare. The balloons were very vulnerable to weather damage, particularly lightning strikes and gales, not to mention enemy action. On at least two occasions it was recorded that enemy aircraft had machine gunned balloons in the Yeovil barrage. On the 12th December 1941 during an air raid two balloons were shot down⁷. The balloons were also machine gunned during the evening of 8^th August 1942 but no damage was reported on that occasion⁷.

The aim of the balloon barrage was not (as is often thought) to enmesh enemy aircraft in their tethering cables but to force the aircraft to greater altitude. This not only made the bombing less accurate but also forced the bombers to an altitude where they were vulnerable to the anti-aircraft gun defences.

Nationally, the use of balloon barrages was very extensive, there being some 2,368 in use by the end of August 1940 and over 3,000 when Balloon Command was stood down in 1944⁴. They were operated not only from static sites but also had mobile units, especially during the flying bomb attacks of the late war. A slightly smaller version was also flown from ships, being conspicuous on photographs of the D-Day landings⁴.

The balloons normally operated from fixed bases, typically a circular concrete pad of about 11m in diameter, surrounded by a circular fence at some distance from the pad. Where the site was not adjacent to a road an access track, often a loop was built near to the circular pad. Road access would be required not only for the balloon winch truck but also for transport of the heavy cylinders of pressurised hydrogen gas required to top up the balloon. Some method of communication would probably have been provided, as the requirements of test flying at Yeovil, would have necessitated the frequent winching down of the barrage, or alternately to quickly erect the barrage on the approach of enemy aircraft, if the barrage was not normally flown.

Balloon Command, which was in overall control of all the balloons, was formed on 1st November 1938. The country was broken down into areas known as Balloon Centres. There was also a balloon school at Cardington in Bedfordshire⁴.

The locations of the Yeovil Balloon sites have been established by means of both aerial photographs and research in the National Archives, for which I am indebted to the work of David Hunt. Two documents in the National Archives list the sites, dated June 1941⁸ and May 1943⁹. There are some inconsistencies between these two documents as regards the precise positions and named locations, and indeed with the aerial photographic evidence^2,10. The grid system in use during wartime was the Cassini grid, which bears no relationship with the Ordnance Survey grid system in use today. There is no standard method of conversion possible even with modern software and therefore the wartime grid locations are necessarily inaccurate when converted. Wherever possible the details listed below represent the aerial photographic evidence. The location is that recorded in the modern Historic Environment Record for Somerset, with supplementary location information were necessary.

1. ST520146   South of Leaze Plantation, West Coker (Camp Road, West Coker)
2. ST536155  South of Yeovil Airfield, Westland, West Coker (nr Watercombe Lane former Railway Bridge)
3. ST535149   Ashmead, West Coker (Ash Copse)
4. ST531138   South-east of Culliver’s Grave, East Coker
5. ST538145   South of Plackett Lane, East Coker
6. ST540137   Gunville Lane, East Coker
7. ST543149   Yew Tree Close, Yeovil
8. ST546142   Yeovil Road/Plackett lane Junction, East Coker (Ackmans Farm, Yeovil)
9. ST547162   West end of Linden Road, Yeovil (School playing field)
10. ST550156   Rear of 129-143 West Hendford, Yeovil (former cricket ground)
11. ST551149   East of Lovers’ Lane, Yeovil (Aldon Farm, Dorchester Road, Yeovil)
12. ST552138   West of Keyford Roundabout, East Coker (Dunnock’s Lane, Yeovil)
13. ST563148   Two Tower Lane, Barwick
14. ST563160   South-east of Ivel Court, Yeovil (Windmill Hill, Yeovil)
15. ST557167   Kingston View Recreation Ground, Yeovil
16. ST545156   Westland Aircraft Factory, Yeovil (east end of Westland works buildings)
17. ST547173   142-148 Thatcham Park, Yeovil (Coronation Avenue, Yeovil)
18. ST541156   190m north-east of Kingfisher Close, Yeovil (W end of Westland works buildings)
19. ST539169   Larkhill Lane, Yeovil (west side of Larkhill Road, north-west of Royal Standard)
20. ST538165   Stratford Road, Yeovil ( former Yeovil Bacon Company site)
21. ST532173   Stourton Way, Brympton
22. ST530164   Houndstone Retail Park, Yeovil (east of Focus DIY store)
23. ST525161   Bluebell Road, Brympton (Alviston Road, Brympton)
24. ST520156   North-east of Brympton House, Brympton d’Evercy (Rex Road, Brympton)

APPENDIX 1

Casualties of No 957 Squadron whilst at Yeovil¹¹

The following four servicemen are recorded as having died whilst serving with the squadron. No details of the circumstances of their deaths are known. The case of Herbert Shinn is particularly intriguing, as its difficult to understand him having no known grave whilst serving at Yeovil.

Chivers, Frank 985665 Aircraftsman 1 RAFVR died 6th December 1940 aged 26.

Shinn, Herbert Stanley 965992 Aircraftsman 2 RAFVR died 21st March 1941.

Austin, Victor Marcel Spencer, 535414 Leading Aircraftsman RAF died 11th November 1941 aged 23.

Reed, Albert , 859611 Ldg. Aircraftsman RAuxAF died 1st November 1943 aged 44.

APPENDIX 2

Notes on the development of balloons for military Purposes

The first flight by hydrogen filled balloons took place in Paris on 27th August 1793¹². This was a spherical design. All the early balloons were in fact spherical, being used for observation purposes in the American Civil War and the Franco-Prussian War. The first British use was in South Africa in the Boer Wars. The spherical design suffered from the disadvantage of instability, making observation extremely difficult.

This problem was addressed to some degree by the Drachen balloon, which was developed in Germany in 1896¹³. The Drachen was a long sausage like shape, with a large stabilising fin inflated by the wind. This design was quickly adopted by the German Army, but ignored by the British and the French. In 1914 the allies soon discovered that the Drachen was far superior to their spherical types and they quickly copied the German design. Although this design was still somewhat unstable, it was a great improvement upon the earlier spherical design.

In 1915 a Capitaine Albert Caquot of the French Army designed a new balloon, somewhat similar to the barrage balloons of World War 2, but with a single wind filled fin at the extreme rear. The Allies quickly adopted this design. A further development of this basic design took place in 1916, when the single fin at the rear was replaced by three fins each at an angle of 120 degrees to each other, positioned slightly forward of the rear of the balloon. This was the design which was first used for air defence purposes in 1916, protecting Venice. The Germans also used balloons for defence purposes around strategic targets in southern Germany in late 191614 . In 1917 the Central Powers introduced a new design, the AE balloon, which was, in fact, a direct copy of the Caquot design. It was modelled on a British Caquot balloon, which had broken loose and drifted over the lines into enemy territory¹³.

The use of balloon defences in Italy led to a further improved version, the Avorco-Prassone design, which was similar to the improved Caquot 1916 design but somewhat more portly. Additional sprung pleats were introduced into the envelope to accommodate the greater expansion of the hydrogen experienced in the Mediterranean climate. It was in fact this design, which was used in the balloon barrage flown to protect London in 1918. This barrage, some 82km long was made up by balloons arranged in groups of three⁴. Cables connected these groups, with further vertical cables, some 300m long, suspended from them, to form a formidable barrier. This barrier was flown at sufficient height to prevent it being over flown by enemy bombers.

During the inter war period, balloons were seen as being obsolete and all work on them was abandoned.

However the looming clouds of war brought about further examination of the potential of balloons for air defence. On the 17^th March 1937 a Special Balloon Unit was formed. This unit was incorporated into Balloon Command on its formation on 1^st November 1938⁴.

At the outbreak of war, the Caquot design, now described as the LZ or Low Zone type, was the chosen type for air defence. Initially they were established around London. The British Expeditionary Force also took a number of balloons to France to protect certain priority targets. The first enemy bomber brought down, by a balloon was in fact brought down by part of the barrage protecting Le Havre in the early part of 1940⁴. As more balloons became available, priority targets in England, notably ports and aircraft factories, were given barrages.

Elsewhere, barrages were flown during the landings in Sicily, at Salerno and on D-day. The United States developed their own version of the LZ balloon, designating it the ZK balloon, which was manufactured in large numbers by Goodyear. Six balloon squadrons were formed for the protection of naval bases and depots⁴.

It may be considered that the story of balloon defences is a matter of history. However, there have been suggestions in the United States, that balloon barrages would make a good form of defence for nuclear power stations from 9/11 type of terrorist attack. Perhaps the story is not yet complete.
 

Notes and References

 
Further Reading