The Gustav Gun, officially known as the Schwerer Gustav, was a massive railway gun developed by Nazi Germany during World War II. Designed by the German arms manufacturer Krupp, it was intended for long-range bombardment of fortified positions, particularly the Maginot Line. The gun was capable of firing shells weighing up to 7 tons over distances of up to 47 kilometers (29 miles). Weighing nearly 1,350 tons, the Gustav Gun was one of the largest artillery pieces ever constructed. It required a specialized railway system for transport and was operated by a crew of over 250 men. Despite its impressive size and firepower, the gun was used only in a limited capacity during the war, primarily in the siege of Sevastopol.