Authors: Bickers Richard Townshend
Radio had also become a valuable source of intelligence before the war. The Organisation that provided it was the Y Service, which listened to German broadcasts and provided clues to the Luftwaffe's strength, movement and intentions, helping the Intelligence Branch to compile the Luftwaffe's Order of Battle. Coded messages were broken down at the Government Code and Cypher School, Bletchley Park.
At first the Y Service was confined to Morse transmitted by wireless telegraphy (W/T). In December 1939 steps were taken to begin listening to R/T on the 40 megacycle band. No suitable sets were made in England, so some Hallicrafter 510s, manufactured in the USA and popular among radio âhams', were bought and set up in a hut at Hawkinge by March 1940. Two months later the first message was picked up. Only then did anyone realise that none of the operators knew German. A German-speaking soldier on an anti-aircraft site at the airfield was found and rushed to the R/T receiver, and willy-nilly transferred to the RAF within days.
What was really needed were not people who had studied German academically but those who had lived in Germany and acquired a command of idiom. Recruiting from within the WAAF began immediately and by June 15 six airwomen had been posted to a new listening site at Fairlight near Hastings, equipped with two Hallicrafters.
Experienced RAF wireless operators searched the air for traffic and as soon as a transmission was picked up a WAAF interpreter would take over and log it. Anything of immediate tactical significance was passed at once to No. 11 Group.
Much of the traffic was from E-boats (Schnellboote, or fast boats, known logically to the Germans as S-boats and bizarrely to the British as above), and this was forwarded to the Admiralty via Air Ministry. Less urgent material was sent to Air Ministry for analysis. The girls quickly
learned the Luftwaffe R/T code and became familiar with individual enemy fighter pilots by their callsigns, accents and personalities. They recorded exchanges between fighters and bombers attacking airfields and convoys, and reports from reconnaissance aircraft when convoys were sighted. These last were passed to the naval authorities at Dover as well as to No. 11 Group.
Increasing knowledge of the callsigns and frequencies used by the Luftwaffe enabled the listeners to warn No. 11 Group of the Geschwader and the type of aircraft involved in an imminent attack. Some of the intercepted messages even gave the time, height and place for a rendezvous between fighters and bombers, and their target. Y intelligence was also a useful means of cross-checking reports of enemy casualties, when, in the speed and confusion of a fight, more than one pilot claimed the same victory.
Among the less salubrious events recorded were the occasions when British pilots commented on comrades being shot at by the enemy's gallant fighter pilots while parachuting out of aircraft they had been forced to abandon. Added to the use for reconnaissance of supposedly ambulance aircraft, allegedly on air-sea rescue missions, and the strafing of civilian refugees on French roads, which was also frequently reported, the RAF was inclined to be cynical about the Luftwaffe's boast that it was fighting a clean and chivalrous war.
To provide accommodation for more sets, six more WAAF and additional RAF wireless operators, the unit was moved to Hawkinge in July. Towards the end of that month it was they who intercepted messages indicating that the enemy was using aircraft marked with the red cross on reconnaissance over the Channel. Air Ministry duly warned the German High Command that such aircraft would no longer have immunity; as related elsewhere, Ginger Lacey was among the pilots who shot one down,
By August, the unit moved again, to a small house and adjacent toy factory at West Kingsdown on the Kentish Downs, the highest point in the county, which increased the range of the R/T receivers. The other Fighter Groups soon asked for the same information as No. 11 Group was getting. The listening posts were given the name âHome Defence Units' (HDU) and by the time the Battle of Britain was coming to an end new ones had been set up at Street, Devon, for No. 10 Group; Gorleston, Norfolk, for No. 12; and Scarborough, Yorkshire, for No. 13. An HDU was also placed on Beachy Head as a back-up to Kingsdown â which had
become the HQ of the Y Service â to concentrate on raids against convoys and southern airfields and ports.
The examination of enemy aircraft that crashed in Britain, the interrogation of captured aircrew, and agents in Germany were other sources of intelligence, but the most prolific and versatile was photographic reconnaissance. This was one of the earliest uses to which aeroplanes had been put in World War I, yet Britain allowed it to languish in the inter-war years. It was indispensable in the planning of both strategy and tactics. In 1938 General Werner von Fritsch, Commander-in-Chief of the German Army, said, âThe military organisation that has the best photographic intelligence will win the next war.' The RAF School of Photography at Farnborough was formed in 1912, but in the 1920s and 1930s its skills were turned mainly to the photographing of British colonial territories for map-making. The system was cumbersome. All three of the armed Services required aerial intelligence: the RAF took the photographs, but only the Army had photographic interpreters. It took a week for the results of a sortie to be delivered.
When, in 1936, information about German industry was sought, a squadron leader was sent to Germany to collect photographs and maps. It was only when Wing Commander F. W. Winterbotham, Chief of Air Intelligence in the Special Intelligence Service, wanted specific information about the Luftwaffe's air defence of the German frontier that aerial âphoto recce' or âPR', as it was called, began to be used. In cooperation with the French intelligence organisation, the DeuxiÃ¨me Bureau, the right man was found to take on the work.
F. Sidney Cotton was an Australian pilot who had done pioneering work in Canada and Greenland and over the Atlantic. In 1938 the colour film business he owned failed. He accepted the task of spying on Germany and a company named Aeronautical Research and Sales Corporation was formed as a cover. The aircraft had to be one that could fly on ostensibly legitimate civil business. Cotton chose a Lockheed 12A, which could carry six passengers, and one was delivered in January 1939. He asked for a first-class engineer who was also a pilot, and a Canadian in the RAF, Flying Officer R. H. Niven, was selected. The DeuxiÃ¨me Bureau provided a photographer and on March 25th the operation was based at a pretty little airfield 15 miles (24km) south-west of Paris, Toussus-le-Noble.
Cotton and his crew made their first flight on March 30, over Krefeld, Hamm, MÃ¼nster and the Dutch frontier to photograph the road and rail
systems. More flights were made on April 1, 7 and 9, covering the Black Forest, armament factories and new aerodromes in the Mannheim area and the Siegfried Line. There was no intercommunication between cockpit and passenger cabin. Monsieur Blois, the photographer, tied a long string to each of Cotton's elbows and tugged the appropriate one to indicate the direction in which to turn! They also made flights over Italy and the North African coast.
One man who knew that special equipment and training were needed for first class PR was Air Chief Marshal Sir Edgar Ludlow-Hewitt, who had joined the RFC in August 1914 and served at the Western Front throughout World War I. When appointed C-in-C Bomber Command in September 1937 he had stated the need for a special long-range reconnaissance aircraft. But the Service showed little interest and, anyway, the Defence Budget could not afford it. He had to compromise by fitting cameras to the Blenheim bombers of Nos. 21, 82, 107, 114 and 139 Squadrons. In 1938 the Air Ministry did, under pressure from him, set up the Air Intelligence Department to co-ordinate PR. In 1939 an Air Intelligence Section was introduced at HQ Bomber Command and Station Intelligence Officers were made responsible for a preliminary interpretation of photographs.
In the summer of 1939 Cotton and Niven flew to Germany allegedly to sell colour film. His camera was installed under the cabin floor in a dummy fuel tank. This ruse enabled him to fly all over the country, sometimes with German passengers, taking photographs of enormous value. Two weeks after the outbreak of war, when Blenheims on photographic sorties had suffered casualties without achieving adequate results, Sir Cyril Newall, Chief of Air Staff, authorised Cotton â who was in due course commissioned in the RAF and rose to be a wing commander â to form and command a specialised unit, for which he would select his own personnel, aircraft and equipment. Based at Heston, it was named Photographic Development Unit (PDU).
Dowding had been greatly impressed by Cotton's achievements and, in October, agreed to lend him two Spitfires so that undetected reconnaissances could be made at a height above the limit of heavy flak (25,000ft/7,575m), at a speed greater than the Bf 109. These Spitfires had to be stripped of guns and ammunition to reduce weight and allow adequate range and height. From take-off the aircraft could attain 30,000ft (9,090m), and as they consumed fuel their ceiling rose to
35,000ft (10,600m). They were camouflaged duck egg blue to merge with the sky and relied on speed and stealth for survival.
The first Spitfire PR sortie was flown on November 18, 1939, and revolutionised the whole concept of this means of intelligence. The Spitfires flew only 15 flights but achieved twice as much, in half the time, as seven Blenheim squadrons. Between September 3 and December 31, 1939, the Blenheims had flown 89 sorties over 2,500 square miles (6,475km
), obtained photographs on only 45 sorties and lost 16 aircraft. In just 15 sorties, the Spitfires came back with photographs on 10 and covered 5,000 square miles (12,950km
) without loss. By the end of February 1939 Cotton had three Spitfires, one of which was for training.
In bad weather, the recce Spitfire's solitary pilot was handicapped by lack of navigation instruments: of 19 sorties flown in the first quarter of 1940, weather made 13 ineffective. The PDU acquired three Hudsons in February, to reconnoitre above cloud the weather along a Spitfire's intended route and report by radio. If conditions were unsuitable for a Spitfire, the Hudson would descend below cloud and take the photographs.
On July 8, 1940, as the Battle of Britain was about to be fought, the PDU became the Photographic Unit of the RAF and command was given to Wing Commander Geoffrey Tuttle.
Among the most valuable items of intelligence garnered by the RAF was one that was delivered from the enemy side. In the early hours of November 5, 1939, a parcel was left outside the British Consulate in Oslo with a letter signed, âA German scientist who wishes you well.' In it were a proximity fuse for anti-aircraft shells, details of the new Junkers 88 and its intended use as a high-speed dive bomber, an account of German rocket development and a description of the device known as Y-GerÃ¤t that enabled German bombers to find their targets by following a beam.
A final gift to Britain's benefit was possession of a machine that could decypher German codes. It was invented in Holland and the patent was bought by a German manufacturer in 1923. It was discovered by Polish Intelligence when Customs examined one that had been sent to the German Legation in Warsaw. In 1934 the RAF began development of this machine, known as the Typex, which the Government Code and Cypher School had bought in 1928 and neglected. In August 1939 the Poles gave the British the result of their work in breaking the latest German codes.
The Germans had called their first encyphering machine âEnigma' and the British gave this name to all German cyphers. âUltra' was the British codename for intelligence derived from Enigma and other machine cyphers. The only two commanders in the RAF who knew of Enigma and Ultra were Dowding and No. 11 Group's Air Vice Marshal Keith Park. A specific instance of its importance in the Battle of Britain was that the heavy air raids on August 15, 1940 did not take these two senior officers by surprise. The information given to them was precise: Luftflotten 2, 3 and 5 would make the attacks, which were timed to keep the defenders at full stretch throughout the day. F. W. Winterbotham, who, as a group captain, was responsible for Ultra, recorded that Dowding told him that it was of the greatest help to him to know what Goering's policy was and enabled him to use his fighter squadrons with the greatest possible economy.
Fighter Command entered the Battle of Britain with an infrastructure that provided increasingly skilled and detailed intelligence and a Ministry of Aircraft Production that achieved an output of fighters much in excess of the scheduled number. It was closely integrated with Anti-Aircraft Command, which comprised seven divisions with an establishment of 2,232 heavy and 1,860 light guns, and 4,128 searchlights, under Lieutenant General Sir Frederick Pile.
The third weapon of defence was the barrage balloon. On November 1, 1938, Balloon Command had been formed and expanded with Auxiliary Air Force balloon squadrons. It operated in three Groups. No. 31 Group consisted of Nos. 901 to 910 Squadrons, numbering 450 balloons. No. 31 Gp squadrons were Nos. 911 to 926, with 456 balloons. No. 32 Gp squadrons were Nos. 927 to 935, totalling 224 balloons. No. 33 Gp squadrons were 936 to 947 squadrons, with 320 balloons. As would be expected, the RAF's Order of Battle changed many times during the Battle of Britain, as shown in a later chapter. A secret document, âState of Aircraft in Operational Commands', was issued every week.
ighter Command's Order of Battle for August 8, 1940 shows 30 squadrons equipped with the Hawker Hurricane I,19 squadrons of Supermarine Spitfire Is, two flying the two-seat Boulton Paul Defiant turret fighter and six squadrons of twin-engined Bristol Blenheim IF's. One squadron was equipped with ancient Gloster Gladiator biplanes, but saw no action during the period of the Battle of Britain. In the hectic weeks of the Battle itself, there was little time to re-equip the squadrons in the front line and, other than the early withdrawal of the Defiants, the disposition of the RAF's fighters remained substantially unchanged up to the end of the Battle. Thus, it was the Hurricane that bore the brunt of the fighting in the air, and was responsible for the major share of losses inflicted on the Luftwaffe, although the Spitfire was to capture the public imagination as the fighter