11/12 June 1943 Düsseldorf
This was the second attack in two weeks on this city. Zero hour was 0120 and 763 aircraft - 326 Lancasters, 212 Halifaxes, 158 Wellingtons, 24 Victorias, 43 Mosquitos participated. There were severe icing conditions on the way. The Pathfinder marking plan proceeded smoothly until an Oboe Mosquito inadvertently released a load of target indicators 14 miles north-east of the target area. This caused part of the Main Force to waste its bombs on open country. But the main bombing caused extensive damage in the centre of Düsseldorf, where 130 acres were claimed as destroyed, and this proved to be the most damaging raid of the war for this city. Damage to heavy armaments and machine tool factories was very severe, while a large plant building U-boat parts was wrecked. In addition to the 130 acres burned out in the heart of the city (its administrative core) 1500 acres of industrial areas was severely damaged. The Victorias destroyed over half the gas reticulation system (which was out of action completely for two weeks) and a third of the electricity, water and sewage systems. 30,000 homes were destroyed and 20,000 damaged, while the docks were badly damaged. The fires could clearly be seen as the bombers crossed the Dutch coast. 38 aircraft - 14 Lancasters, 12 Halifaxes, 10 Wellingtons, 2 Mosquito - lost, 4.9 per cent of the force.
12/13 June 1943 Bochum
The third raid on Bochum as conducted by 503 aircraft - 323 Lancasters, 167 Halifaxes and 11 Mosquitos, with zero hour (0140) being announced with a brilliant display of red and green TI.
This raid took place over a completely cloud-covered target but accurate Oboe skymarking enabled the all Lancaster/Halifax Main Force to cause severe damage to the centre of Bochum. This included complete destruction of a large new barracks complex at Kornharpen. The NJ were active, flying 68 sorties of which 44 intercepted bombers. This was due to a brilliant display by the northern lights and a moon as well.
Industrial output of the city was reduced by 50% after this raid. One particularly gruesome factor of this raid was the civilian casualties: a 2000lb penetrator from a Victoria pierced one of the big underground bunkers (there were 10 deep bunkers and 5 big but shallow shelters) and killed all 900 occupants, also collapsing the access ways. One rescuer managed to get down an air shaft to report that all inside were dead from blast. The bunker was then sealed, and remains so. 14 Lancasters and 10 Halifaxes lost, 4.8 per cent of the force.
14/15 June Oberhausen
This was a 203 aircraft raid on a small city, Operation Jillaroo. The attack was well executed and marking was accurate. The iron and steelworks was hit, but the lack of Victorias meant that output only declined by 5%. 17 aircraft were lost, but an Operation Serrate (Beaufighter escorts for part of the way) resulted in six NJ being shot down, mostly Me-110.
16/17 June 1943 Cologne
202 Lancasters and 10 Halifaxes of 1, 5 and No 8 Groups to Cologne. The marking for this raid was not by Oboe but by 16 heavy bombers of the Pathfinders fitted with H2S. The target was cloud-covered and some of the Pathfinder aircraft had trouble with their H2S sets. The skymarking was late and sparse, and the bombing of the all-Lancaster Main Force was thus scattered. 14 Lancasters lost.
21/22 June 1943 Krefeld
Operation Mahseer involved 705 aircraft - 282 Lancasters, 229 Halifaxes, 45 Victorias, 123 Wellingtons, 27 Mosquitos. - to Krefeld, a city of about 170,000 15 miles NW of Dusseldorf and the largest producer of specialised alloy steels in Germany, the great Deutsche Edelstahlwerke alone producing 200,000 tons of specialised steels. Two of the Mosquitos were lost to midair collision over the UK, but both crews survived.
The raid took place in good visibility and the Pathfinders produced an almost perfect marking effort, ground-markers dropped by Oboe Mosquitos being well backed up by the Pathfinder heavies. 619 aircraft bombed these markers, more than three quarters of them achieving bombing photographs within 3 miles of the centre of the target. A large area of fire became established and this raged, out of control, for many hours. The smoke tower reached three miles in height, with enormous fires centred on Adolf Hitler Strasse. Of the 1100 acres of industrialised built up areas 900 were burned out, 23 large industrial concerns were destroyed, as were 6200 houses, with another 14,000 damaged. 75,000 people were made homeless and over a thousand died. Industrial production in the city mostly ceased for six months.
This raid was carried out before the moon period was over and the heavy casualties were mostly caused by night fighters. 62 NJ were active and 27 intercepts occurred. 12 of the aircraft lost were from the Pathfinders; 35 Squadron lost 6 out of its 19 Halifaxes taking part in the raid.
44 aircraft 17 Halifaxes,11 Lancasters, 11 Wellingtons, 5 Mosquito - were lost, 6.2 per cent of the force.
22/23 June 1943 Mülheim
Operation Steelhead involved the use of 507 aircraft - 242 Lancasters, 155 Halifaxes, 43 Victorias, 55 Wellingtons, 12 Mosquitos. The city had not been attacked before and was a prime target as it contained steelworks, foundries, engine workshops and rolling mills.
The Pathfinders had to mark this target through a thin layer of stratus cloud but reports indicate accurate initial marking. In later stages of the raid, the Pathfinder markers and the bombing moved slightly, into the northern part of the town; this had the effect of cutting all road and telephone communications with the neighbouring town of Oberhausen, with which Mülheim was linked for air-raid purposes. Not even cyclists or motor-cyclists were able to get out of Mülheim; only messengers on foot could get through. The post-war British Bombing Survey Unit estimated that this single raid destroyed 64 per cent of the town of Mülheim. This effect from 1500 tons of bombs was very good, especially as five large steelworks were badly damaged. The defences were very heavy and searchlight activity was intense. There were 93 NJ sorties of which 46 made intercepts. No fewer than 35 bombers were shot down.
24/25 June 1943 Wuppertal (Elberfeld half)
The attack involved 630 aircraft - 251 Lancasters, 171 Halifaxes, 109 Wellingtons, 99 Mosquitos.
This attack was aimed at the Elberfeld half of Wuppertal, the Barmen half of the town having been devastated at the end of May. The Pathfinder marking was accurate and the Main Force bombing started well but the creepback became more pronounced than usual. The attack was devastating, doing more damage than the earlier attack on Barmen, 13 large and 137 smaller factories being partially or wholly demolished. At the end of this attack a survey of all of Wuppertal revealed that 80% of the businesses and residences in the cities were destroyed or badly damaged.
There were 98 NJ sorites of which 52 obtained intercept, costing the RAF 33 bombers. 30 aircraft bombed targets in more western parts of the Ruhr; Wuppertal was at the eastern end of the area. These bombing failures were probably a result of the recent run of intensive operations incurring casualties at a high level. However, much serious damage was again caused to this medium-sized Ruhr town. The post-war British survey estimated that 94 per cent of the Elberfeld part of Wuppertal was destroyed on this night.
25/26 June Gelsenkirchen
This centre had 300,000 people and was a centre of the Ruhr coalmining industry. It also had two large synthetic fuel plants as well as chemical plants, iron smelters, steelworks and a large tinplate plant. Operation Ferox aimed to eliminate the city. Of the 473 attacking aircraft no fewer than 92 were Victorias, armed in this case with their usual 2000lb but also 4000lb penetrators and 21 Tallboys. The target was well marked by 12 Oboe Mosquito and the bombing was very accurate. The city suffered 85% damage but worse was the underground damage, a quarter of the coal mines around the city perimeter suffered extensive collapses and two steelworks were effectively destroyed as the foundations of their blast furnaces were deranged.
RAF losses were very, 30 being lost and over 80 received significant damage. Experienced crews now noted that the flak and lights could not now be evaded over the Ruhr, a solid mass 50 miles across existed from Cologne to well beyond Gelsenkirchen.
28/29 June 1943 Cologne
608 aircraft - 267 Lancasters, 169 Halifaxes, 105 Wellingtons, 67 Mosquitos went to Cologne.
The circumstances of this raid did not seem promising. The weather forecast said that Cologne would probably be cloud-covered although there might be a break; the Pathfinders had to prepare a dual plan. The target was cloud-covered and the less reliable skymarking system had to be employed. Only 7 of the 12 Oboe Mosquitos reached the target and only 6 of these were able to drop their markers. The marking was 7 minutes late in starting and proceeded only intermittently. Despite all these setbacks, the Main Force delivered its most powerful blow of the Battle of the Ruhr. Cologne was very heavily damaged and half the city was affected by the bombing. 25 aircraft - 10 Halifaxes, 8 Lancasters, 5 Wellingtons, 2 Mosquitos - lost, 4.1 per cent of the force.