Schwerer Gustav

Schwerer Gustav (English: Heavy Gustaf, or Great Gustaf) and Dora were the names of two German 80 cm K (E) railway guns. They were developed in the late 1930s by Krupp as siege artillery for the explicit purpose of destroying the main forts of the French Maginot Line, the strongest fortifications then in existence. The fully assembled guns weighed nearly 1,350 tonnes, and could fire shells weighing seven tonnes to a range of 47 km. The guns were designed in preparation for the Battle of France, but were not ready for action when the battle began, and in any case the Wehrmacht's Blitzkrieg offensive through Belgium rapidly outflanked and isolated the Maginot Line's World War I-era static defenses, forcing them to surrender uneventfully and making their destruction unnecessary. Gustav was later employed in the Soviet Union at the siege of Sevastopol during Operation Barbarossa, where among other things, it destroyed a munitions depot buried in the bedrock under a bay. The guns were moved to Leningrad, and may have been intended to be used in the Warsaw Uprising like other German heavy siege pieces, but the rebellion was crushed before they could be prepared to fire. Gustav was later captured by US troops and cut up, whilst Dora was destroyed near the end of the war in 1945 to avoid capture by the Red Army.

It was the largest-calibre rifled weapon ever used in combat, the heaviest mobile artillery piece ever built in terms of overall weight, and fired the heaviest shells of any artillery piece. It is only surpassed in calibre by the British Mallet's Mortar and the American Little David mortar (both 36 inch; 914 mm).

Development
In 1934 the German Army High Command (OKH) commissioned Krupp of Essen to design a gun to destroy the forts of the French Maginot Line which were nearing completion. 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. Krupp engineer Erich Müller calculated that the task would require a weapon with a calibre of around 80 cm, firing a projectile weighing 7 tonnes from a barrel 30 metres long. The weapon would have a weight of over 1000 tonnes. The size and weight meant that to be at all movable it would need to be supported on twin sets of railway tracks. In common with smaller railway guns, the only barrel movement on the mount itself would be elevation, traverse being managed by moving the weapon along a curved section of railway line. Krupp prepared plans for calibres of 70 cm, 80 cm, 85 cm, and 1 m.

Nothing further happened until March 1936 when, during a visit to Essen, Adolf Hitler enquired as to the giant guns' feasibility. No definite commitment was given by Hitler, but design work began on an 80 cm model. The resulting plans were completed in early 1937 and approved. Fabrication of the first gun started in mid-1937. Technical complications in the forging of such massive pieces of steel made it apparent that the original completion date of early 1940 could not be met.

Krupp built a test model in late 1939 and sent it to the Hillersleben firing range for testing. Penetration was tested on this occasion. Firing at high elevation, the 7.1 tonne shell was able to penetrate the specified seven metres of concrete and the one metre armour plate. When the tests were completed in mid-1940 the complex carriage was further developed. Alfried Krupp, after whose father the gun was named, personally hosted Hitler at the Rügenwald Proving Ground during the formal acceptance trials of the Gustav Gun in early 1941.



Two guns were ordered. The first round was test-fired from the commissioned gun barrel on 10 September 1941 from a makeshift gun carriage on the Hillersleben firing range. In November 1941 the barrel was taken to Rügenwald, where 8 further firing tests were carried out using the 7,100 kilogram armour-piercing (AP) shell out to a range of 37,210 metres.

In combat, the gun was mounted on a specially designed chassis, supported by eight bogies on two parallel sets of railway tracks. Each of the bogies had 5 axles, giving a total of 40 axles (80 wheels). Krupp christened the gun Schwerer Gustav (Heavy Gustav) after the senior director of the firm, Gustav Krupp von Bohlen und Halbach.

The gun could fire a heavy concrete-piercing shell and a lighter high-explosive shell. A super-long-range rocket projectile was also planned with a range of 150 km, that would require the barrel being extended to 84 metres.

In keeping with the tradition of the Krupp company, no payment was asked for the first gun. They charged seven million Reichsmark for the second gun Dora, named after the senior engineer's wife.

Schwerer Gustav
In February 1942, Heavy Artillery Unit (E) 672 reorganised and went on the march, and Schwerer Gustav began its long ride to the Crimea. The train carrying the gun was of 25 cars, a total length of 1.5 kilometres. The gun reached the Perekop Isthmus in early March 1942, where it was held until early April. A special railway spur line was built to the Simferopol-Sevastopol railway 16 km north of the target, at the end of which four semi-circular tracks were built specially for the Gustav to traverse. Outer tracks were required for the cranes which assembled Gustav.

The siege of Sevastopol was the gun's first combat test. Installation began in early May, and by 5 June the gun was ready to fire. The following targets were engaged:
 * 5 June
 * Coastal guns at a range of 25,000 m. Eight shells fired.
 * Fort Stalin. Six shells fired.
 * 6 June
 * Fort Molotov. Seven shells fired.
 * "White Cliff" aka "Ammunition Mountain": an undersea ammunition magazine in Severnaya ("Northern") Bay. The magazine was sited 30 metres under the sea with at least 10 metres of concrete protection. After nine shells were fired, the magazine was ruined and one of the boats in the bay sunk.
 * 7 June
 * Firing in support of an infantry attack on Sudwestspitze, an outlying fortification. Seven shells fired.
 * 11 June
 * Fort Siberia. Five shells fired.
 * 17 June
 * Fort Maxim Gorki and its coastal battery. Five shells fired.

By the end of the siege on 4 July the city of Sevastopol lay in ruins, and 30,000 tons of artillery ammunition had been fired. Gustav had fired 48 rounds and worn out its original barrel, which had already fired around 250 rounds during testing and development. The gun was fitted with the spare barrel and the original was sent back to Krupp's factory in Essen for relining.

The gun was then dismantled and moved to the northern part of the eastern front, where an attack was planned on Leningrad. The gun was placed 30 km from the city near the railway station of Taizy. The gun was fully operational when the attack was cancelled. The gun then spent the winter of 1942/43 near Leningrad.

The gun appears to have been destroyed to prevent its capture some time before 22 April 1945, when its ruins were discovered in a forest 15 km north of Auerbach about 50 km southwest of Chemnitz.

Dora
Dora was the second gun to be produced. It was deployed briefly against Stalingrad, where the gun arrived at its emplacement 15 km to the west of the city sometime in mid-August 1942. It was ready to fire on 13 September. It was quickly withdrawn when Soviet encirclement threatened. When the Germans began their long retreat they took Dora with them. Dora was broken up before the end of the war, being discovered in the west by American troops some time after the discovery of Schwerer Gustav.

Langer Gustav
The Langer Gustav was a long cannon with 52 centimetre caliber and a 43 metre barrel. It was intended to fire super-long-range rocket projectiles weighing 680 kilograms to a range of 190 kilometres. This gave it the range to hit London. It was never completed after being damaged during construction by one of the many RAF bombing raids on Essen.

Landkreuzer P. 1500 Monster Project
The Monster was to be a 1,500 tonne mobile, self-propelled platform for an 80-cm K (E) gun, along with two 15 cm sFH 18 heavy howitzers, and multiple MG 151 autocannons normally used on combat aircraft. It was deemed impractical, and in 1943 was canceled by Albert Speer. It never left the drawing board and no progress was made. It would have easily surpassed the Panzer VIII Maus (heaviest tank ever built) and the Landkreuzer P. 1000 Ratte (never built) in weight and size.

Models

 * 80 cm "Schwerer Gustav" (Heavy Gustav) - Deployed in March 1942 against Sevastopol.
 * 80 cm "Dora" - Deployed against Stalingrad in September 1942. Possibly never fired.
 * 52 cm "Langer Gustav" (Long Gustav) - Started but not completed.