The Schwerer Gustav (lit. "Heavy Gustav") was a German 800 mm super-heavy railway gun developed by Nazi Germany prior to World War II. It was the largest artillery piece ever fielded in combat, as well as the largest artillery by caliber size to enter service.
Originally intended to counter the French's Maginot line of fortifications, the gun never saw use during the Battle of France due to the German army simply outflanking the line and ignoring the defense almost entirely. The gun later saw service as anti-fortification artillery on the Eastern Front.
The artillery was incredibly powerful, and was capable of defeating with one hit any fortification in existence at the time. However its deployment was hampered by the immense amount of resources, time and personnel it needed to operate. It weighed over 1,350 tons and required over 2,500 servicemen just to lay down the track and prepare its firing position. It also had a very poor rate of fire of one or two shots per hour.
Two of these railway guns were built; the first was named "Schwerer Gustav" while the second was named "Dora". Both were destroyed at the end of the war by Germany to prevent capture by allied forces.
