Battle of The Ruhr - Offence and Defence

Offence and Defence

See also: Defense of the Reich, Pathfinder (RAF), and Battle of the beams

The British bomber force was made up in the main 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 dropping 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 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 B-17 Flying Fortress and B-24 Liberator - neither carried a bomb similar to the blockbuster bomb. 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 was through 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 (88 mm calibre or greater) and 1,500 lighter guns (chiefly 20 mm and 37 mm calibre). 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".