The gun's shells had to punch through seven metres of reinforced concrete or one full metre of steel armour plate, from beyond the range of French artillery. In 1934, the German Army High Command ( Oberkommando des Heeres (OKH)) commissioned Krupp of Essen to design a gun to destroy the forts of the French Maginot Line that were nearing completion. It was surpassed in calibre only by the unused British Mallet's Mortar and the American Little David bomb-testing mortar-both at 36 inches (91.5 cm)-but was the only one of the three to be used in combat.ĭevelopment Schwerer Gustav (black) compared to an OTR-21 Tochka SRBM launcher (red) (which launches projectiles of similar size and range) with human figures for scale It fired the heaviest shells of any artillery piece. Schwerer Gustav was the largest-calibre rifled weapon ever used in combat, and in terms of overall weight, the heaviest mobile artillery piece ever built. Gustav was destroyed by the Germans near the end of the war in 1945 to avoid capture by the Soviet Red Army. The gun was moved to Leningrad, and may have been intended to be used in the Warsaw Uprising like other German heavy siege pieces, but the uprising was crushed before it could be prepared to fire. Gustav was later deployed in the Soviet Union during the Battle of Sevastopol, part of Operation Barbarossa, where, among other things, it destroyed a munitions depot located roughly 30 m (98 ft) below ground level. The gun was designed in preparation for the Battle of France, but was not ready for action when that battle began, and in any case the Wehrmacht's Blitzkrieg offensive through Belgium rapidly outflanked and isolated the Maginot Line's static defences, which were then besieged with more conventional heavy guns until French capitulation.

The fully assembled gun weighed nearly 1,350 tonnes (1,490 short tons), and could fire shells weighing 7 t (7.7 short tons) to a range of 47 km (29 mi). It was developed in the late 1930s by Krupp in Rügenwalde as siege artillery for the explicit purpose of destroying the main forts of the French Maginot Line, the strongest fortifications in existence at the time. Schwerer Gustav (English: Heavy Gustav) was a German 80-centimetre (31.5 in) railway gun.

2 flak battalions to protect the gun from air attack.ġ round every 30–45 minutes or typically 14 rounds a day 1,350 tonnes (1,490 short tons 1,330 long tons)Ģ50 to assemble the gun in 3 days (54 hours), 2,500 to lay track and dig embankments.

Largest battle tank ever built