Sheffield Blitz The Sheffield Blitz is the name given to the worst nights of German Luftwaffe bombing in Sheffield , England , during the Second World War . It took place over the nights of 12 December and 15 December 1940 . In 1940 Sheffield was a city of about 560 , 000 people and contained many heavy industries , primarily centred around steel and armaments . The Vickers works was host at the time to the only drop hammer in the country , made in Germany by Beche , capable of forging crankshafts for the Rolls Royce Merlin engine which powered the Supermarine Spitfire fighter plane and later in the war the Avro Lancaster bomber . The hammer itself weighed 15 tons and was housed in a 200 ton mounting . It was manned by 16 men working in two shifts . The hammer produced 168 forgings a day which was one of the three operations necessary to make a crankshaft . Hadfields steelworks was also the only place in the UK at that time where 18 inch armour piercing shells were made . Most of the factories were located in the East end of the city beside the River Don . Documents captured at the end of the war showed that the targets for the raids included the Atlas Steelworks , Brown Bayley Steelworks , Meadowhall Iron Works , River Don Works , Darnall Wagon Works , Tinsley Park Collieries , East Hecla Works and Orgreave Coke Ovens . The full moon was on 14 December 1940 and both blitz nights were cold and clear . The German code name for the operation was Crucible . 12 December raid . On the afternoon of 12 December British monitoring stations detected X Verfahren ( sometimes called X - Gerät ) radio beams being laid across northern England and calculated that the likely target of the coming raid would be Sheffield . The yellow alert was received at 6 . 15pm followed by the purple alert at 6 . 45pm . The red alert was sounded at 7pm . The attack was made by three main groups of aircraft flying from airfields in northern France , including Cambrai . 13 Heinkel 111s from Kampfgruppe 100 , the German Pathfinder unit arrived over the city at 7 . 41 p . m . and dropped 16 SC50 high explosive bombs , 1 , 009 B1 E1 ZA incendiaries and 10 , 080 B1 E1 incendiaries . The first incendiaries were dropped over the suburbs of Norton Lees and Gleadless . The first main group was made up of three waves of 36 Junkers 88 s and 29 Heinkel 111 s . The second group was made up of 23 Junkers 88s , 74 Heinkel 111s and 7 Dornier 17 s . The last group was made up of 63 Junkers 88s and 35 Heinkel 111s , a total of 280 aircraft . At about 9 . 30 p . m . a stick of bombs fell on Campo Lane and Vicar Lane , demolishing the West end of the Cathedral . At about 10 . 50 p . m . a 500 kg bomb fell on and destroyed the C & A building opposite the Marples Hotel in Fitzalan Square . At 11 . 44 p . m . , The Marples Hotel itself received a direct hit . It is not known exactly how many people were killed but approximately 70 bodies were recovered from the rubble . This was the single biggest loss of life in the attacks . The majority of the bombs on this night fell on the City Centre or on residential districts with the last bombs falling at 4am . 15 December raid . The second night of the Blitz saw the first use of a new German policy for their pathfinders . High explosive bombs were no longer carried and were replaced by incendiaries . On this night the pathfinder force was made up of 16 Heinkel 111s that dropped 11 , 520 B1 E1 incendiaries between 7 p . m . and 7 . 50 p . m . The 15 large and numerous small fires started were visible from 150 km away . The main raid was carried out by 50 Heinkel 111s and 11 Dornier 17s . The raid finished at 10 . 15 p . m . . Many steelworks received hits , including Hadfields , Brown Bayleys and Steel , Peech and Tozer Ltd , although the damage was not serious enough to affect production . Aftermath . In total over 660 people were killed , 1 , 500 injured and 40 , 000 made homeless . 3 , 000 homes were demolished with a further 3 , 000 badly damaged . A total of 78 , 000 homes received damage . Six George Medal s were awarded to citizens of Sheffield for their bravery during the raids . 134 victims of the raids were buried in a communal grave in City Road Cemetery . Some steel works were badly damaged and unable to continue production for a while , among which was Cockers , on the banks of the river . King George VI and Queen Elizabeth toured the city soon after the raids to inspect the damage and boost morale amongst survivors . Prime Minister Winston Churchill also toured the blitzed city , speaking through loudspeakers to a 20 , 000 - strong crowd in Town Hall Square and giving his signature ' V ' for ' Victory ' V sign .