Battle of the Ruhr


The Battle of the Ruhr of 1943 was a 5-month British campaign of strategic bombing during the Second World War against the Ruhr Area in Nazi Germany, which had coke plants, steelworks, and 10 synthetic oil plants. The campaign bombed 26 major Combined Bomber Offensive targets. The targets included the Krupp armament works, the Nordstern synthetic-oil plant, and the Rheinmetal–Borsig plant in Düsseldorf. The latter was safely evacuated during the Battle of the Ruhr. Although not strictly part of the Ruhr area, the battle of the Ruhr included other cities such as Cologne which were within the Rhine-Ruhr region and considered part of the same "industrial complex". Some targets were not sites of heavy industrial production but part of the production and movement of materiel.
Although the Ruhr had always been a target for the RAF from the start of the war, the organized defences and the large amount of industrial pollutants produced that gave a semi-permanent smog or industrial haze hampered accurate bombing. The Germans also built large-scale night-time decoys like the Krupp decoy site which was a German decoy-site of the Krupp steel works in Essen. During World War II, it was designed to divert Allied airstrikes from the actual production site of the arms factory.
Before the Battle of the Ruhr ended, Operation Gomorrah began the "Battle of Hamburg". Even after this switch of focus to Hamburg, there would be further raids on the Ruhr area by the RAF—in part to keep German defences dispersed, just as there had been raids on areas other than the Ruhr during the battle.

Offence and defence

The British bomber force consisted mainly of the twin-engined Vickers Wellington medium bomber and the four-engined "heavies", the Short Stirling, Handley Page Halifax and Avro Lancaster. The Wellington and Stirling were the two oldest designs and limited in the type or weight of bombs carried. The Stirling was also limited to a lower operational height. Bombers could carry a range of bombs—Medium Capacity bombs of about 50% explosive by weight, High Capacity "Blockbusters" that were mostly explosive, and incendiary devices. The combined use of the latter two were most effective in setting fires in urban areas.
British raids were by night—the losses in daylight raids having been too heavy to bear. By this point in the war, RAF Bomber Command were using navigation aids, the Pathfinder force and the bomber stream tactic together. Electronic navigation aids such as "Oboe", which had been tested against Essen in January 1943, meant the Pathfinders could mark the targets despite the industrial haze and cloud cover that obscured the area by night. Guidance markers put the main force over the target area, where they would then drop their bombloads on target markers. The bomber stream concentrated the force of bombers into a small time window, such that it overwhelmed fighter defences in the air and firefighting attempts on the ground. For most of the Battle of the Ruhr the Oboe de Havilland Mosquitoes came from one squadron, No. 109. The number of Oboe aircraft that could be used at any time was limited by the number of ground stations.
The USAAF had two 4-engined heavy bombers available: the Boeing B-17 Flying Fortress and Consolidated B-24 Liberator—neither of these American heavy bomber designs had a bomb bay suitable to carry the RAF's blockbuster bombs or anything comparable. USAAF raids were by daylight, the closely massed groups of bombers covering each other with defensive fire against fighters. Between them, the Allies could mount "round the clock" bombing. The USAAF forces in the UK were still increasing during 1943 and the majority of the bombing was by the RAF.
The German defence consisted of anti-aircraft weapons and day and night fighters. The Kammhuber Line used radar to identify the bomber raids and then controllers directed night fighters onto the raiders. During the battle of the Ruhr, Bomber Command estimated about 70% of their aircraft losses were due to fighters. By July 1943, the German night fighter force totalled 550.
Through the summer of 1943, the Germans increased the ground-based anti-aircraft defences in the Ruhr Area; by July 1943 there were more than 1,000 large flak guns and 1,500 lighter guns. This was about one-third of all anti-aircraft guns in Germany. Six-hundred thousand personnel were required to man the AA defences of Germany. The British crews called the area sarcastically "Happy Valley" or the "valley of no Return".

Bombing operations

DateTarget location
1943-03-055 MarchEssen The opening of the battle of the Ruhr began with a 442 aircraft attack on Essen, the primary city targeted by the British Area bombing directive. Three waves of bombers dropped their incendiary and time-delayed bombs in under an hour. Only 153 aircraft bombed within three miles of the aiming point despite the target area marking by Pathfinders using Oboe. Fourteen aircraft were lost.
1943-03-99/10 MarchRuhr 8 Mosquitoes sent to Ruhr
1943-03-1010/11 MarchEssen and Mulheim 2 Mosquitoes.
1943-03-1212/13 MarchEssen Raid by 457 aircraft – 158 Wellingtons, 156 Lancasters, 91 Halifaxes, 42 Stirlings, 10 Mosquitos on Krupp factory in Essen. 23 aircraft were lost.
1943-03-2626/27 MarchDuisburg Duisburg was attacked with a large force; cloud cover and problems with the Oboe Mosquitoes gave a "widely scattered raid"
1943-03-2929/30 MarchBochum 149 Wellingtons with marking by 8 Oboe Mosquitoes; raid was a failure due to cloud and problems skymarking – 12 aircraft were lost. This raid occurred on the same night as a major raid on Berlin.
1943-04-33/4 AprilEssen Essen was targeted by 956 dispatched bombers – 797 bombers attacked and 12 different cities were hit.
1943-04-88/9 AprilDuisburg 392 aircraft sent to Duisburg. 19 aircraft lost.
1943-04-99/10 AprilDuisburg 104 Lancasters with 5 Mosquitoes. "Scattered attack", 8 aircraft lost.
1943-04-2626/27 AprilDuisburg 561 aircraft attacked Duisburg for 3% aircraft loss. Many buildings destroyed but most of the bombs had fallen to the north-east of Duisburg.
1943-04-3030 April/1 MayEssen 305 aircraft with skymarking by Oboe-equipped Mosquito due to expected cloud.
1943-05-1717 MayMöhne and Eder Dams Operation Chastise; 14 bombers use bouncing bombs to breach the Möhne and Eder Dams, but fail to disrupt the water supply or hydroelectrical power to the Ruhr Area more than briefly. 6 aircraft were lost.
1943-05-4 4/5 MayDortmund 596 aircraft in the first major attack on Dortmund.
1943-05-1313/14 MayBochum 442 bombers of which 24 were lost. Bombing off target possible due to decoy markers.
1943-05-2323/24 MayDortmund 826 bombers raided Dortmund dropping 2,000 tons of HE and incendiary bombs in an hour. Hoesch steelworks "ceased production" RAF loss 4.8%.
1943-05-2525/26 MayDüsseldorf 729 against Düsseldorf. Two layers of cloud and decoy fires caused widely spread bombing. 26 bombers lost.
1943-05-2727/28 MayEssen 518 against Essen with 23 lost. Scattered bombing led to damage to parts of Essen and 10 other towns
1943-05-2929/30 MayWuppertal 719 bombers attacked Wuppertal; Oboe marking was used, and being relatively close to the UK maximum payloads were carried. With only light defences, the bombing force was able to deliver their bombs accurately of the old town burned down when a firestorm takes hold. "Five of the six major factories" were destroyed, as were the homes of 100,000.
1943-06-1111/12 JuneDüsseldorf 783 aircraft. Although initial marking was spot on for the first wave a backup marker Mosquito dropped target indicators off target to the north-east; with the effect that part of the bombing fell there. of Düsseldorf claimed as destroyed. 38 aircraft lost.
12/13 June 1943Bochum 503 aircraft with targeting by Oboe skymarking. "severe damage to the centre of Bochum". 24 aircraft lost.
14/15 JuneOberhausen 197 Lancasters plus Oboe Mosquitoes which skymarked as cloud covered target. 8.4% aircraft loss.
16/17 JuneCologne 212 bombers. Marking by Pathfinder's heavy bombers with H2S. Cloud cover and equipment trouble gave scattered bombing. 14 bombers lost.
17/18 JuneCologne and Ruhr 3 Mosquitoes; no aircraft lost.
19/20Cologne, Duisburg and Düsseldorf 6 Mosquitoes; no aircraft lost
21/22 JuneKrefeld A 705 aircraft raid on a moonlit night; 44 aircraft were lost. Oboe Mosquitoes marked the ground in good visibility, the main force started a fire that "raged out of control, for several hours".
1943-06-2222 JuneHuls USAAF daylight raid on synthetic rubber plant
22/23 JuneMülheim 557 aircraft, marking through cloud layer. According to the post-war British Bombing Survey Unit, this raid destroyed 64% of the town.
24/25 JuneWuppertal 630 aircraft, post-war British estimates 94% of Elberfeld destroyed by this raid
1943-06-25 25/26 JuneGelsenkirchen, Nordstern oil plant 473 RAF bombers unsuccessfully attack the Nordstern synthetic-oil plant at Gelsenkirchen due to cloud and "unserviceable" equipment on 5 of the 12 Oboe-equipped Mosquitoes
28/29 JuneCologne 608 aircraft with 25 lost. Only half the Oboe Mosquitoes sent were able to skymark.
1943-07-9 9/10 JulyGelsenkirchen 418 bombers unsuccessfully attack Gelsenkirchen – Oboe equipment failed to operate in 5 of the Mosquitoes and a 6th marked north of the target.
1943-07-25 25/26 JulyEssen A force of 600 bombers dropped their bombs on Essen over a period of less than an hour. Goebbels recorded in his diary "last raid....complete stoppage of production in the Krupps works".
1943-07-3030/31 JulyRemscheid The last raid of the Battle of the Ruhr attacked Remscheid with 273 aircraft. 15 aircraft were lost

During the battle other German targets received large attacks.
In his study of the German war economy, Adam Tooze stated that during the Battle of the Ruhr, Bomber Command severely disrupted German production. Steel production fell by 200,000 tons. The armaments industry was facing a steel shortfall of 400,000 tons. After doubling production in 1942, production of steel increased only by 20 percent in 1943. Hitler and Speer were forced to cut planned increases in production. This disruption resulted in the Zulieferungskrise. The increase of aircraft production for the Luftwaffe also came to an abrupt halt. Monthly production failed to increase between July 1943 and March 1944. "Bomber Command had stopped Speer's armaments miracle in its tracks".
, 1945
At Essen after more than 3,000 sorties and the loss of 138 aircraft, the "Krupp works...and the town...itself contained large areas of devastation", and Krupp never restarted locomotive production after the second March raid.
Operation Chastise caused some temporary effect on industrial production, through the disruption of the water supply and hydroelectric power. The Eder Valley dam "had nothing whatsoever" to do with supplying the Ruhr Area. A backup pumping system had already been put in place for the Ruhr, and Speer's Organisation Todt rapidly mobilized repairs, taking workers from the construction of the Atlantic Wall. The destruction of the Sorpe dam would have caused significantly more damage but since it was a stronger design less likely to be breached it was effectively a secondary target.