Operation Bellicose
Operation Bellicose was an attack by Avro Lancaster bombers of the Royal Air Force on a German radar factory housed in the former Zeppelin Works at Friedrichshafen and the Italian naval base at La Spezia. It was the first shuttle bombing raid in the Second World War and the second use of a Master Bomber. In early June 1943, Central Interpretation Unit photo interpreter, Claude Wavell, identified a stack of ribbed baskets at the Zeppelin Works as Würzburg radar reflectors. After Winston Churchill viewed the photos at RAF Medmenham on 14 June, No. 5 Group RAF received the surprise orders on 16 June to attack Friedrichshafen during the next full moon.
On approach to the target, Wing Commander Gomm assumed control of the operation when the aircraft of Group Captain Slee, the master bomber, developed trouble. The main force was ordered to bomb from rather than the planned due to heavy flak. In the first phase, the Pathfinder Force and Wing Commander Gomm dropped Target Indicator bombs for the main force to aim at. In the second phase, as dust and smoke obscured the TIs, Gomm ordered the main force to use 'time-and-distance' bombing runs from a location on the Lake Constance shore, along a measured distance to the target.
The bombers damaged the radar factory and destroyed the unsuspected V-2 rocket production line also housed in the Zeppelin Works, so that Bellicose accidentally became the first Allied air blow against the German V-weapons programme. No Lancasters were lost and from Friedrichshafen, the aircraft continued to the United States Army Air Forces base at Maison Blanche, Algeria. On 23–24 June, eight of the original force of sixty Lancasters remained in Algeria for repairs and the remaining 52 bombed the Italian naval base at La Spezia, damaging an oil depot and an armaments store, then flew to Britain, again without loss.
Background
The Zeppelin shed, and high, had been built at Friedrichshafen-Löwenthal airfield in 1930–1931 and used by the Zeppelin company's last and largest airships, the LZ 127 Graf Zeppelin, LZ 129 Hindenburg and LZ 130 Graf Zeppelin II. After the Hindenburg was destroyed by fire in New Jersey in 1937 and the two Graf ships were broken up for scrap at Frankfurt in 1940, the vast hangar fell into disuse. In early 1943 it was dismantled and transported in sections on a specially laid track to the industrial suburbs of Friedrichshafen, where it was reconstructed.British aerial reconnaissance of southern Germany was mainly carried out by de Havilland Mosquito PR IV and PR VIII aircraft of 540 Squadron from RAF Benson, Oxfordshire. The photographs were sent for assessment to the Central Interpretation Unit at Danesfield House near Medmenham, Buckinghamshire, from Benson. At the beginning of June 1943, Squadron Leader Claude Wavell, head of G Section at Medmenham, noticed stacks of ribbed metalwork lying outside the Zeppelin shed in recent 'covers' of Friedrichshafen. The pattern of the stacks had changed between photographic sorties, implying activity, and Wavell identified the metalwork as parts for the distinctive lattice reflector dishes of Giant Würzburg radar sets.
The appearance and size of Würzburg-Riese dishes had been known to British intelligence since 2 May 1942, when Flight Lieutenant 'Tony' Hill, in a Spitfire PR IV of 1 Photographic Reconnaissance Unit from Benson, had taken low-level oblique pictures of a German radar station at Domburg on Walcheren Island, Netherlands. The pictures showed two Würzburg-Riese, pointed in different directions, so that the analysts got both a profile and a more full-face view. In the profile shot, a startled Luftwaffe member was standing at the foot of the ladder to the control cabin behind the dish, giving scale to the picture. A previous oblique by Hill, taken on 15 December 1941, had shown an example of the original, much smaller Würzburg set, with a sheet-metal dish, on a Normandy clifftop. This led to Operation Biting, the Bruneval Raid of 27–28 February 1942, in which C Company of 2nd Battalion, Parachute Regiment under Major John Frost, parachuted from Armstrong Whitworth Whitley bombers of 51 Squadron, stole the Würzburg and brought it to England aboard Motor Gun Boat 312 of the Royal Navy.
In radar matters, Medmenham reported to Dr Reginald Victor Jones, Assistant Director of Intelligence at the Air Ministry. Jones's department, drawing on information from air reconnaissance, PoW interrogations, resistance agents in France and Belgium, Enigma cipher decrypts, and the monitoring of Luftwaffe radio traffic and radar signals by RAF ground stations and specially equipped bombers known as Ferrets, had built up a detailed knowledge of the German air-defence system. The Würzburg-Riese was similar in signal to the original Bruneval Würzburg, operating at 560 MHz, but it was more precise and longer-ranging due to its more powerful transmitter and its much larger reflector dish. By 1943, while the original Würzburg was still in service with flak and searchlight batteries, the Luftwaffe used the Würzburg-Riese for ground-controlled interception, vectoring German night fighters onto British bombers. The Würzburg-Riesen were installed in pairs, as seen in Hill's Walcheren pictures, because one set tracked the bomber while the other tracked the fighter, until the fighter's airborne radar acquired the target.
Jones mentioned the Friedrichshafen findings to Prime Minister Winston Churchill's chief scientific adviser, Lord Cherwell, in whose Oxford laboratory Jones had once worked as a researcher. According to Wavell, Churchill visited Medmenham, viewed the Friedrichshafen covers, and asked, "Have we been there yet?" Wavell said no; the RAF had not bombed Friedrichshafen. Cherwell had spoken to the Chief of Air Staff, Air Chief Marshal Sir Charles Portal and with the Prime Minister's interest engaged, Operation Bellicose was ordered.
Arthur Harris, as Air Officer Commanding-in-Chief RAF Bomber Command, was in the midst of the Battle of the Ruhr, a campaign against the industrial conurbations of north-west Germany carried out from March to July 1943. These attacks, on targets only ninety minutes' flying time from Bomber Command bases, made use of the short spring and summer nights and also exploited the Oboe radar-ranging device, which enabled high-flying Mosquito bombers of No.8 Group to place their pyrotechnic TI bombs accurately. Reliant on signals from ground stations, Oboe was restricted by the curvature of the Earth to a range of. Beyond Oboe range, the Pathfinders normally used a combination of visual methods and airborne ground-mapping H2S radar, with much less consistent results.
Harris opposed 'precision' bombing as a general policy, in part because he felt it made bomber operations too predictable, saying,
Harris knew that his area bombing campaign against the Ruhr was incurring the same problem, and said,
Since 10 June 1943, Harris had been under an Air Staff order known as the Pointblank Directive, which required him to give priority to targets associated with the German fighter force. This directive arose from the Combined Chiefs of Staff Conference in Washington, DC, in May. As Harris later wrote,
As a radar factory, the Zeppelin shed at Friedrichshafen was a valid and important Pointblank target, but an added attraction, in Harris's view, was its great distance from England,
Prelude
Plan
The obvious difficulty was that, with the target lying some from Bomber Command bases as the crow flies, or by the best indirect tactical route, it was impossible for bombers to fly there and back in darkness at midsummer. The coast of North Africa was within range of Lancaster bombers and the USAAF agreed to receive the bombers at Blida and Maison Blanche, two American bases in Algeria. Although the Americans were not equipped to service Lancasters properly, they would at least be able to refuel and re-arm them. Harris's orders at this time required him to attack Italian targets when possible, as part of the government's policy to knock Italy out of the war, so he decided that the Friedrichshafen force would bomb the Italian naval base of La Spezia at dusk on the return flight to England.Harris assigned the operation to 5 Group. Harris had commanded 5 Group earlier in the war. Under his successor, Air Vice-Marshal John Slessor, it became the first bomber group to begin re-equipping with Lancasters and under Air Vice-Marshal Alec Coryton it had gained a reputation for daring low-level attacks. First came the Augsburg raid of 17 April 1942, when six Lancasters of 44 Squadron and another six of 97 Squadron were dispatched in daylight to bomb the MAN factory producing diesel engines for U-boats, with the loss of seven from the twelve aircraft. Next was Operation Robinson, the Le Creusot raid of 17 October 1942, when 94 Lancasters, led by Wing Commander Leonard Slee of 49 Squadron, made a dusk attack on the Schneider-Creusot munitions complex in Burgundy, flying at tree top height from the Bay of Biscay and returning to England in darkness, for the loss of only one aircraft. Reconnaissance pilot Tony Hill, whose pictures had done so much for British understanding of enemy radar, was shot down while attempting to take post-strike photographs of Le Creusot on 21 October. The Germans recovered him alive from the wreckage of the Spitfire and R. V. Jones, hearing this from the French Resistance, began to organise a rescue operation by special agents but Hill died of his injuries before it could be put into effect.
Cochrane, who took over 5 Group from Coryton in February 1943, soon oversaw Operation Chastise, the Dams Raid of 16/17 May, for which Harris ordered the creation of the special 617 Squadron. The successful part of this operationthe attacks on the Möhne and Eder damshad been controlled over Very high frequency Radiotelephone by Wing Commander Guy Gibson. Cochrane decided to use the same method at Friedrichshafen and appointed Leonard Slee, to lead the raid, with Wing Commander Cosme Gomm of 467 Squadron RAAF as his deputy. Although Gomm led a nominally Australian unit, he came from Brazil, his parents lived in São Paulo and only two of his crew were Australian.