Jagdtiger (Hunting Tiger) is the common name of a German heavy tank destroyer of World War II. The official German designation was Panzerjäger Tiger Ausf. B as it was based on a lengthened Tiger II chassis. The ordnance inventory designation was Sd. Kfz. 186. The 71-tonne Jagdtiger was the heaviest armored fighting vehicle used operationally during World War II and is the heaviest armored vehicle of any type to achieveproduction. The vehicle carried a 128 mm PaK 44 L/55 main gun, capable of out-ranging and defeating any fielded Allied tank. It saw service in small numbers from late 1944 to the end of the war on both the Western and Eastern Front. Tiger ace Otto Carius commanded a company of Jagdtigers. His post-war memoir provides a rare combat history of the Jagdtigers that were under his command. Although 150 were ordered, only between 77 and 88 were produced. Due to an excessive weight, the Jagdtiger was continuously plagued with mechanical problems. Today, three Jagdtigers survive in museums.\r
With the success of the StuG İ, Marder I, Marder II, and Marder İ in the tank destroyer role, the military leadership of Nazi Germany decided to use the chassis of existing armored fighting vehicles as the basis for self-propelled guns. German tank destroyers of World War II mostly used fixed casemates instead of moveable turrets to significantly reduce the cost, weight, and materials used for mounting large caliber guns.\r
In early 1942, a request was made by the Army General Staff to mount a 128 mm gun on a self-propelled armored chassis. On 18 May 1942, Adolf Hitler ordered that the 128 mm gun be utilized in the tank destroyer role, rather than for infantry support.[citation needed] Firing tests of the 128 mm gun showed to have a high percentage of hits; lower caliber guns, such as the 88 mm and 105 mm were also tested.\r
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By early 1943, a decision was made to install a 128 mm gun on a Panther or Tiger I chassis as a heavy assault gun. The Panther chassis was considered unsuitable after a wooden mockup of the design was constructed. On 20 October 1943, another wooden mockup was constructed on a Tiger II chassis, and presented to Hitler in East Prussia. Two prototypes were produced; a version with the eight road wheel Porsche suspension system (number 305001) and a version with the Henschel nine overlapping wheel suspension system (number 305002), as used on the production Tiger II. They were completed in February 1944. It was originally designated as Jagdpanzer VI, but was later named the Jagdtiger. It received the inventory ordnance number Sd.Kfz. 186.