German night-fighters are duped

24th July 1943: As the Allies launch Operation Gomorrah - a series of bombing raids on Hamburg, hitting the city by night and day - they use a new technique

Before a big raid on any target, no members of ground crew work harder than the armourers. It is their job to transport all the bombs to the aircraft and then load them on to the bombers. These pictures taken before one of the great raids on Hamburg recently, show some of the actual bombs which were dropped on the famous centre of U-boat construction

Avro Lancasters of No 50 Squadron, Royal Air Force (No 5 Group), based at Skellingthorpe, Lincolnshire, England, flying in loose formation, 23rd July 1943

An image of the highly secret ‘Window’ taken during a raid later in the war.

A year earlier, Churchill had called for the “ruthless bombing” of Germany. Now the RAF and the USAAF were beginning to deliver it in large measure. Bomber Command had been engaged in the Battle of the Ruhr since March 1943, in which the major German industrial cities were laid waste in a coordinated plan.

Now an even more devastating blow was planned for just one city. It was intended to demonstrate the awesome destructive power that the bomber forces were now capable of - and by doing so send a message to every German as to what they could expect if the war continued. Not only would RAF Bomber Command make several successive trips to Hamburg but the USAAF would be making daylight attacks to maintain round-the-clock pressure on the defenders and rescue services.

The raid was considered so important that a new weapon was used operationally for the first time. 'Window' was very simple in concept - simply large bundles of tinned foil that were dropped by aircraft during the flight into the target. The effect of Window on the German radar was calculated to produce confusion. Luftwaffe night fighter pilot Wilhelm Johnen¹ was one of those on the receiving end on 24th July: