The Thousand Bomber raids, 30/31 May (Cologne) to 17 August 1942 Sir Arthur Harris knew that the future of Bomber Command was still in doubt and he approached both Winston Churchill and Sir Charles Portal with the bold idea of assembling a force of 1,000 bombers and sending them out in one massive raid on a German city. Churchill and Portal were both impressed and they agreed. Although Harris had only a little over 400 aircraft with trained crews which were regularly used for front-line operational work, he did have a considerable number of further aircraft in the conversion units attached to groups with four engined aircraft and in Bomber Command’s own operational training units 91 and 92 Groups. This secondary Bomber Command strength could be crewed by a combination of instructors, many of them ex-operational, and by men in the later stages of their training. To complete the 1,000 aircraft required, Harris asked for the help of his fellow commanders in chief in Coastal Command and Flying Training Command. Both officers were willing to help. Sir Philip Joubert of Coastal Command immediately offered to provide 250 bombers, many of them being from squadrons which had once served in Bomber Command. Flying Training Command offered fifty aircraft but many of these were later found to be insufficiently equipped for night bombing and only four Wellingtons were eventually provided from this source.

All now looked well. The target figure of 1,000 bombers was easily covered and detailed planning for the operation commenced. The tactics to be employed were of major concern, not only for the success of this unprecedented raid but as an experiment upon which future operations could be based. The tactics eventually adopted would form the basis for standard Bomber Command operations for the next two years and some elements would remain in use until the end of the war.

The major innovation was the introduction of a bomber stream in which all aircraft would fly by a common route and at the same speed to and from the target, each aircraft being allotted a height band and a time slot in the stream to minimize the risk of collision. The recent introduction of Gee made it much easier for crews to navigate within the precise limits required for such flying, although there would always be wayward crews who would drift away from the stream. The hoped-for advantage from the bomber stream was that the bomber force could pass through the minimum number of German radar night-fighter boxes. The controller in each box could only direct a maximum of six potential interceptions per hour. The passage of the stream through the smallest number of boxes would, therefore, reduce the number of possible interceptions, particularly if the bomber stream could be kept as short as possible and pass through the belt of boxes quickly. This led on to the next decision, to reduce still further the time allowed for the actual bombing at the target. Where four hours had been allowed earlier in the war for a raid by 100 aircraft and two hours had been deemed a revolutionary concentration for 234 aircraft at Lubeck, only 90 minutes were allowed for 1,000 aircraft in this coming operation.

The big fear in these matters was always that of collisions but, on this occasion, this was accepted in return for the opportunity to allow the bomber stream to pass through the night fighter boxes quickly, to swamp the Flak defences at the target and, above all, to put down such a concentration of incendiary bombs in a short period that the fire services would be overwhelmed and large areas of the city would be consumed by conflagrations. As in previous raids, the coming operation would be led by experienced crews whose aircraft were equipped with Gee; 1 and 3 Groups were selected to provide these raid leaders in the Thousand Plan.

But, as the planning period came to an end, potential disaster struck. The Admiralty refused to allow the Coastal Command aircraft to take part in the raid. This was obviously a step in the long-running battle between the R.A.F. and the Royal Navy over the control of maritime air power and the Admiralty realized that a success for this grandiose Bomber Command plan was not likely to help their prospects for building up a force of long-range aircraft for the war against the U-boat. They were quite correct in that belief. Harris now appeared to be falling well short of the dramatic figure of 1,000 aircraft with which he intended to carry out what was evidently a massive public-relations exercise.

Bomber Command redoubled its efforts. Every spare aircrew member and aircraft was gathered in by the operational squadrons but the decisive reinforcement came from Bomber Command’s own training units, which committed more crews from the bottom half of their training courses. Every effort was made to provide the training crews with at least an experienced pilot but forty-nine aircraft out of the 208 provided by 91 Group would take off with pupil pilots. When the operation was eventually mounted, 1,047 bombers would be able to take off, all but the four from Training Command being provided by Bomber Command’s own resources, in spite of the fearful risk of sending so many untrained crews. When Churchill and Harris discussed the possible casualty figures, Churchill said that he would be prepared for the loss of 100 aircraft. The force about to be dispatched was more than two and a half times greater than any previous single night’s effort by Bomber Command. In addition to the bombers, forty-nine Blenheims of 2 Group reinforced by thirty-nine aircraft of Fighter Command and fifteen from Army Co-operation Command would carry out Intruder raids on German night-fighter airfields near the route of the bomber stream.

Final orders were ready on 26 May with the full moon approaching. The force stood ready, waiting for the weather. Harris hoped to use the 1,000-bomber force more than once if conditions permitted, before the extra aircraft gathered together were dispersed to their normal locations. His first choice of target was Hamburg, the second largest city in Germany, a great port and, an attraction for the Admiralty, builder of about 100 U-boats each year. But the weather over Germany was unfavourable for three days running and, on 30 May, Harris had to decide to send the bombers to his second target choice – Cologne, the third largest city in Germany.

Soon after noon on that day, the order to attack Cologne went out to the groups and squadrons and the raid took place that night.

The first 1,000-bomber raid was a great success but a follow-up to Essen two nights later was not. The moon phase then passed and the training aircraft returned to their normal work, but they were recalled once more for a further massive raid on Bremen during the end of the June moon period, although the figure of 1,000 aircraft was not quite reached on that raid. Harris had originally hoped to assemble 1,000 aircraft for one or two raids in every moon period but he abandoned this idea and the full thousand operation using so many training aircraft was not carried out again after the Bremen raid, although smaller numbers of training aircraft were called upon from time to time later in the year.

The 1,000-bomber raids certainly made their mark on history and were another great turning point in Bomber Command’s war. The new tactics were mainly successful; there were never any serious casualties through collision and the time over target would progressively be shortened until 700 or 800 aircraft regularly passed over the city they were bombing in less than twenty minutes! The morale of Bomber Command was certainly uplifted by this great demonstration of air power and by the wide publicity, which followed. That same publicity also confirmed Bomber Command’s future as a major force and it can be said that, although there were bad as well as good times to come, Bomber Command never looked back after the 1,000 bomber raids. These events also placed Sir Arthur Harris firmly in the public eye where, as Bomber Harris, he would remain for the rest of his life.

The rest of the midsummer weeks passed with the front-line squadrons being pressed hard when the weather and moon conditions were favourable – and sometimes when they were not so favourable. The shorter nights again restricted raids to the coastal targets, the Ruhr and the Rhineland. There was another concentration of sustained effort against Essen in June, but this important target remained elusive of Bomber Command success. A similar campaign against Duisburg fared little better. There were minor operational changes. Harris started to restrict the practice whereby freshmen crews were introduced to operations gradually by being sent to lightly defended, close-range targets on the French coast. New crews were still allowed their one leaflet flight to France or Belgium but after that they were expected to go to any target in Europe. Harris was forced to agree to the temporary detachment of six more squadrons – even one of Lancasters – and one of his operational training units to Coastal Command to help with the U-boat war. There was a further draining away of operational effort when that unsatisfactory new aircraft, the Manchester, disappeared from 5 Group’s order of battle at the end of June – although the Lancasters being sent to this group would soon more than replace the loss. There were only minor changes in 2 Group although one feature was to be the portent of a brilliant future for a new type of aircraft. In the early morning after the first 1,000 bomber raid, five small twin-engined bombers of wooden construction flew to the smoking city of Cologne to take photographs and throw a few more bombs into that unhappy place. The De Havilland Mosquito had arrived. By the time the war ended, this aircraft would perform an undreamt-of range of tasks for Bomber Command.

30/31 May 1942 – The first thousand-bomber raid, Cologne 1,047 aircraft were dispatched, this number being made up as follows: • 1 Group – 156 Wellingtons • 3 Group – 134 Wellingtons, 88 Stirlings = 222 aircraft • 4 Group – 131 Halifaxes, 9 Wellingtons, 7 Whitleys = 147 aircraft • 5 Group – 73 Lancasters, 46 Manchesters, 34 Hampdens = 153 aircraft • 91 (O. T. U.) Group – 236 Wellingtons, 21 Whitleys = 257 aircraft 92 (O. T. U.) Group – 63 Wellingtons, 45 Hampdens = 108 aircraft Flying Training Command – 4 Wellingtons

Aircraft totals: 602 Wellingtons, 131 Halifaxes, 88 Stirlings, 79 Hampdens, 73 Lancasters, 46 Manchesters, 28 Whitleys = 1,047 aircraft

The exact number of aircraft claiming to have bombed Cologne is in doubt; the Official History says 898 aircraft bombed but Bomber Command’s Night Bombing Sheets indicate that 868 aircraft bombed the main target with 15 aircraft bombing other targets. The total tonnage of bombs was 1,455 two-thirds of this tonnage being incendiaries.

German records show that 2,500 separate fires were started, of which the local fire brigade classed 1,700 as large but there was no sea of fire as had been experienced at Lubeck and Rostock because Cologne was mainly a modern city with wide streets. The local records contained an impressive list of property damaged: 3,330 buildings destroyed, 2,090 seriously damaged and 7,420 lightly damaged. More than 90 percent of this damage was caused by fire rather than high-explosive bombs. Among the above total of 12,840 buildings were 2,560 industrial and commercial buildings, though many of these were small ones. However, 36 large firms suffered complete loss of production, 70 suffered 50-80 per cent loss and 222 up to 50 per cent. Among the buildings classed as totally destroyed were: 7 official administration buildings, 14 public buildings, 7 banks, 9 hospitals, 17 churches, 16 schools, 4 university buildings, 10 postal and railway buildings, 10 buildings of historic interest, 2 newspaper offices, 4 hotels, 2 cinemas and 6 department stores. Damage was also caused to 12 water mains, 5 gas mains, 32 main-electricity cables and 12 main telephone routes. The only military installation mentioned is a Flak barracks. In domestic housing, the following dwelling units (mainly flats/apartments) are listed: 13,010 destroyed, 6,360 seriously damaged, 22,270 lightly damaged. These details of physical damage in Cologne are a good example of the results of area bombing. Similar results can be expected in those of Bomber Command’s raids, which were successful during following years. The estimates of casualties in Cologne are, unusually, quite precise. Figures quoted for deaths vary only between 469 and 486. The 469 figure comprises 411 civilians and 58 military casualties, mostly members of Flak units. 5,027 people were listed as injured and 45,132 as bombed out. It was estimated that from 135,000 to 150,000 of Cologne’s population of nearly 700,000 people fled the city after the raid. The R.A.F. casualties were 41 aircraft were lost, including 1 Wellington, which was known to have crashed into the sea. The 41 lost aircraft were: 29 Wellingtons, 4 Manchesters, 3 Halifaxes, 2 Stirlings, 1 Hampden, 1 Lancaster, 1 Whitley. The total loss of aircraft exceeded the previous highest loss of 37 aircraft on the night of 7/8 November 1941 when a large force was sent out in bad weather conditions, but the proportion of the force lost in the Cologne raid – 3.9 per cent – though high, was deemed acceptable in view of the perfect weather conditions which not only led to the bombing success but also helped the German defences.

Bomber Command later estimated that 22 aircraft were lost over or near Cologne 16 shot down by Flak, 4 by night fighters and 2 in a collision; most of the other losses were due to night-fighter action in the radar boxes between the coast and Cologne. Bomber Command also calculated the losses suffered by each of the three waves of the attack – 4.8, 4.1 and 1.9 per cent – and assumed that the German defences were progressively overwhelmed by bombing and affected by smoke as the raid went on. Further calculations showed that the losses suffered by the operational training unit crews – 3.3 per cent – were lower than the 4.1 per cent casualties of the regular bomber groups and also that those training aircraft with pupil pilots suffered lower casualties than those with instructor pilots! Another Victoria Cross was awarded for an action on this night.

A Manchester of 50 Squadron, piloted by Flying Officer L.T Manser, was caught in a searchlight cone and seriously damaged by Flak on the approaches to Cologne. Manser held the plane steady until his bomb load was released and, despite further damage, set course for England although he and his crew could have safely baled out after leaving the target area.

But the Manchester steadily lost height and, when it became obvious that there was no hope of reaching England, Manser ordered his crew to bale out, which they all did safely. In holding the plane steady for the last man to leave, Manser lost the opportunity to save himself and was killed. He is buried at Heverlee War Cemetery in Belgium.

Intruder operations

In a major effort to help the bomber force attacking Cologne, 34 Blenheims of 2 Group, 15 Blenheims of Army Co-Operation Command and 7 Havocs of Fighter Command attempted to attack German night-fighter airfields alongside the bomber route. No particular success was gained by these Intruders and 2 of the Blenheims were lost.

Total effort for the night: 1,103 sorties, 43 aircraft (3.9 per cent) lost. (The 7 Havoc sorties of Fighter Command are included in these figures but have not been added to the statistics at the end of the current period of the diary because they did not take place directly under Bomber Command control.)