RAF raids on Hamburg and Berlin

War chronologies record under 12 May 1941 that the RAF bombed several German cities, including Hamburg, Emden and Berlin. That entry sums up several nights in a single sentence. Britain’s bomber force, Bomber Command, flew over the Reich only after dark, and in the first half of May, with bright nights and tolerable weather, it sent out its bombers almost without a break. On the night of 8–9 May its largest operation yet took off: according to the German chronology of the war at sea by Jürgen Rohwer and Gerhard Hümmelchen, 359 aircraft, of which 317 were sent against Hamburg and Bremen. On the night of 10–11 May about a hundred and ten bombers attacked Hamburg, and a small detachment flew on to Berlin. The following night, 11–12 May, 92 aircraft bombed Hamburg again and 81 attacked Bremen. The date of 12 May therefore really refers to the morning after that last night, which closed one of the most intensive series of British raids so far. Emden, mentioned in this context, was in those months the target of smaller, supplementary operations.

Bombers in the service of the Battle of the Atlantic

It was no accident that Hamburg and Bremen stood at the top of the target list. Since the autumn of 1940 the Chief of the Air Staff, Charles Portal, and the leadership of Bomber Command had been leaning towards raids on German cities, as the directive of 30 October 1940 showed. In January 1941 priority was given back to synthetic oil plants, but at the beginning of March the situation at sea forced the British to change course again. German U-boats and long-range Focke-Wulf Condor aircraft were sinking ships faster than the shipyards could replace them, and the Battle of the Atlantic had become a matter of survival for Britain. On 1 March Portal warned the head of Bomber Command, Air Marshal Richard Peirse, that a “very large part” of the bombers’ effort would be needed to get the Admiralty out of its difficulties. On 9 March, following a ruling by the Prime Minister, Winston Churchill, Bomber Command received a directive that for four months put the fight against the U-boats and long-range aircraft first. It quoted Churchill’s words: the U-boat at sea must be hunted and the U-boat in the shipyard or in dock must be bombed; the Focke-Wulfs and other aircraft attacking shipping must be destroyed in the air and “in their nests”.

In practice this meant the shipyards and aircraft factories on the North Sea coast. Hamburg, the Reich’s largest port, built submarines at the Blohm + Voss yard and several smaller ones. Bremen had shipyards building U-boats and the Focke-Wulf works where the Condors were made; the RAF had already bombed them in the first nights of the year. Emden, the port at the mouth of the Ems and the nearest to the British airfields, had the Nordseewerke shipyard, which in 1941 was beginning to launch submarines. The British official history of the bombing offensive records that in 1940–1941 Emden was attacked many times, usually by small forces, and that on the night of 31 March–1 April 1941 Bomber Command dropped on it the first 4,000-pound bombs (about 1,800 kilograms), later known as “cookies”. The surviving documents do not, however, make it possible to establish what damage these raids did there, and in Britain they were not rated highly.

At the same time the command did not give up attacking the capital of the Reich. Berlin, nearly a thousand kilometres from the British airfields, could be attacked only on longer, clear nights and with smaller forces. The largest operation against the capital, the raid of 23–24 September 1940, involved 119 aircraft and remained an exception. On the night of 9–10 April 1941 bombs hit the building of the State Opera on Unter den Linden, which partly burned down; Hitler ordered it to be rebuilt at once.

Three nights over northern Germany

In the spring of 1941 the backbone of Bomber Command consisted of the twin-engined Vickers Wellington, Armstrong Whitworth Whitley and Handley Page Hampden. From February and March the first new types were entering service: the four-engined Short Stirling and Handley Page Halifax and the twin-engined Avro Manchester, all still in single squadrons and plagued by faults. The British Bomber Command operations record states that on the night of 11–12 May 91 Wellingtons and one Stirling flew to Hamburg, and 48 Whitleys, 31 Hampdens and two Manchesters to Bremen. The breakdown captures the state of British bomber aviation in the spring of 1941 well: the new bombers were only a promise of things to come, and the air war over Germany was still being fought with aircraft designed before the war.

The operation of 8–9 May was the first in which Bomber Command sent out more than three hundred and fifty aircraft in a single night. Rohwer and Hümmelchen call it the heaviest night raid on Germany up to that time. The remaining aircraft attacked minor targets. In line with the tactics of the day, the bombers flew singly, at intervals, and each crew looked for its target on its own, navigating by compass, watch and whatever could be made out by moonlight. The estuaries of the Elbe and the Weser made Hamburg and Bremen easier to find, which is why these cities were attacked more readily than the smoke-shrouded Ruhr. Two nights later, on 10–11 May, about 110 aircraft returned to Hamburg. The operations record stresses that the night of 11–12 May was the most intensive of the month: both port cities were attacked simultaneously, and the bombs destroyed many houses, whereas industrial targets suffered little.

British losses on these nights were counted in single aircraft, but they were growing. The German defences were becoming more effective: Hamburg and Bremen had strong anti-aircraft artillery and searchlights, and over the Netherlands and the German coast a belt of night-fighter zones was taking shape under General Josef Kammhuber, in which ground radars guided fighters onto bombers heading back over the North Sea. Some aircraft were also lost without any enemy action, to icing, mechanical failure and running out of fuel on the way home.

The same night on both sides

The May operations fell in the last weeks of the great German night offensive against Britain. On those same nights the Luftwaffe was bombing Liverpool and Hull: according to Rohwer and Hümmelchen’s chronology, some 120 German aircraft flew to Hull on the night of 8–9 May, while the RAF was attacking Hamburg and Bremen. The night of 10–11 May was also the night of the last great raid on London, which killed nearly one and a half thousand people and reduced the chamber of the House of Commons to rubble. That same night, as the first bombs were already falling on London, Hitler’s deputy Rudolf Hess, who had taken off from Augsburg a few hours earlier, bailed out over Scotland. A comparison of the scale of the two offensives still told against the British: the Luftwaffe sent several hundred aircraft over London at once and in a single night killed more people there than died in German cities in whole series of British raids. German bombers had several times less distance to cover from France and Belgium to London than British bombers from England to Berlin.

The results

British communiqués spoke of fires in shipyards and ports, but the real effects were modest. The post-war official history of the bombing offensive, written by Charles Webster and Noble Frankland on the basis of German documents, records that in March 1941 bombs partly destroyed the administrative buildings of Blohm + Voss without any loss of production, and that in May fires in the shipyard, the machine shops and the boiler house at last caused some delay to it. In Hamburg three small vessels were destroyed and several factories damaged, “of no great importance”. According to surviving German figures from south-western Germany covering the period from May 1940 to May 1941, almost half the British bombs fell in open country, and of the rest most hit residential districts. On the ground the Germans sometimes counted only a fifth of the bombs that British crews reported having dropped on a given city. The occupants of the houses that were hit and workers on night shifts were killed, but reliable figures for the casualties of the individual May nights, consistent across several sources, cannot be given. British bombs did not stop the building of submarines in Hamburg or Bremen, which were entering service in growing numbers in 1941.

Place in the war

The May raids closed a period in which Britain’s bomber force divided its strength between shipyards, ports and aircraft factories as part of the Battle of the Atlantic. On 19 May 1941 the founder of the RAF, Marshal of the Royal Air Force Lord Hugh Trenchard, sent Churchill a memorandum arguing that Germany’s weakest point was the morale of its population and that the bombers should strike at German cities every night. The Chiefs of Staff accepted his diagnosis, though not all his conclusions; the First Sea Lord, Dudley Pound, considered the memorandum “a complete exaggeration”. When in June, after the German attack on the Soviet Union, the pressure in the Atlantic eased, a directive of 9 July 1941 turned Bomber Command against German rail transport and, explicitly, against the morale of the civilian population and industrial workers.

It soon became clear how little the earlier reports had been worth. The report by David Butt, commissioned by Churchill’s scientific adviser Frederick Lindemann and based on photographs taken by bomber cameras in June and July, showed in August 1941 that only about one crew in three that reported attacking dropped its bombs within eight kilometres of the target, and over the Ruhr only one in ten. The response was not to abandon raids on cities but to extend them. In November 1941 a failed operation against Berlin, in which several dozen bombers were lost, ended Peirse’s career, and in February 1942 command of Bomber Command passed to Arthur Harris, an advocate of area bombing. In July 1943 Hamburg endured Operation Gomorrah and a firestorm in which an estimated 34,000 people were killed, and Berlin was the target of a great bombing offensive in the winter of 1943–1944. Seen in that perspective, the raids of May 1941, large for their time, were still only a trial of strength.