Battle of Kursk guns and mortars. In 1943 an offensive by the Soviet Central, Bryansk and Western Fronts against Army Group Centre was abandoned shortly after it began in early March, when the southern flank of the Central Front was threatened by Army Group South. Soviet intelligence received information about German troop concentrations spotted at Orel and Kharkov, as well as details of an intended German offensive in the Kursk sector through the Lucy spy ring in Switzerland. The Soviets verified the intelligence via their spy in Britain, John Cairncross, at the Government Code and Cypher School at Bletchley Park, who clandestinely forwarded
Battle of Kursk total, the German forces had a total strength of 777,000–779,000 men, and the three attacking armies contained 438,271 combat soldiers. Army Group South was equipped with more armoured vehicles, infantry and artillery than the 9th Army of Army Group Center. The 4th Panzer Army and Army Detachment "Kempf" had 1,377 tanks and assault guns, while the 9th Army possessed 988 tanks and assault guns. German industry produced 2,816 tanks and self-propelled guns between April and June, of which 156 were Tigers and 484 Panthers. At Kursk, a total of 259 Panther tanks, about 211 Tigers, and 90 Ferdinands were used.