"Karl-Gerät" (040/041) (German literally "Karl-device"), also known as Mörser Karl, was a World War II German self-propelled siege mortar (Mörser) designed and built by Rheinmetall. Its heaviest munition was a diameter, shell, and the range for its lightest shell of was just over . Each gun had to be accompanied by a crane, a two-piece heavy transport set of railcars, and several modified tanks to carry shells.
Seven guns were built, six of which saw combat between 1941 and 1945. It was used in attacking the Soviet fortresses of Brest-Litovsk and Sevastopol, bombarded Polish resistance fighters in Warsaw, participated in the Battle of the Bulge, and was used to try to destroy the Ludendorff Bridge during the Battle of Remagen. One Karl-Gerät has survived and the remainder were scrapped after the war.
Development
In March 1936 Rheinmetall made a proposal for a super-heavy howitzer to attack the Maginot Line. Their initial concept was for a weapon that would be transported by several tracked vehicles and assembled on site, but the lengthy preparation time drove them to change it to a self-propelled weapon in January 1937. Extensive driving trials took place in 1938 and 1939 using the first Neubaufahrzeug tank prototype and a scale model to investigate the extremely high ground pressure and steering of such an enormous vehicle. Firing trials took place in June 1939. The full-scale driving trials were held at Unterlüss in May 1940. General Karl Becker of the Artillery was involved in the development, from whom the huge weapon gained its nickname.
In total, seven Karl-Gerät howitzers were manufactured. The first six had the nicknames "Adam" (later "Baldur"), "Eva" (later "Wotan"), "Thor", "Odin", "Loki", and "Ziu"; the seventh, the research and test weapon (Versuchs-Gerät), had no name. Delivery of the six production vehicles took place from November 1940 to August 1941.
In February 1941, discussions commenced concerning increasing the range of the weapon, and in May 1942, Gerät 041 barrels were ordered for the six vehicles. At a conference with Adolf Hitler in March 1943 it was stated that the first Gerät 041 would be delivered by June 1943, and the third, by mid-August. Only three of the Gerät 041 barrels were actually completed for mounting on Karl-Gerät Nr. I, IV and V, although any vehicle could be converted to use the smaller weapon.
Twenty-two Panzer IV Ausf. D, E and F chassis were modified with a superstructure capable of carrying four shells that replaced the turret and outfitted with a crane as Munitionsschlepper für Karl-Gerät ammunition transporters/loaders. Two or three of these Munitionsschlepper were assigned to each weapon.
Variants
Gerät 040: original model, armed with a short calibre barrel; Gerät 041: later model, armed with a long (L/11.55) calibre barrel.
Description
The 124-ton vehicle was propelled by a Daimler-Benz MB 503A 12-cylinder liquid-cooled gasoline engine or a Daimler-Benz MB 507C 12-cylinder liquid-cooled diesel engine, but this was mainly used for aiming (the mount had only 4 degrees of traverse on each side), as the engines provided a top speed of only . For longer distances the Karl-Gerät was disassembled using a special mobile crane into seven loads. The chassis was loaded onto a six-axle Culemeyer-Strassenroller lowboy trailer. The other parts of the gun were lighter and used four-axle trailers. If the trailer with the chassis on board had to cross a bridge that couldn't carry their combined weight the chassis had to be off-loaded and driven across under its own power.