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 Jagdtiger was the heaviest armored fighting vehicle used operationally during World War II and is the heaviest tank ever to achieve series production. 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 which had been 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.
With the success of the StuG III, Marder I, Marder II, and Marder III 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.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. Firing tests of the 128 mm gun showed to have a high percentage of hits; lower caliber heavy shells such as the 88 mm and 105 mm were also tested. 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.
The Jagdtiger was a logical extension of the creation of Jagdpanzer designs from tank designs, such as the Jagdpanther from the Panther tank. The Jagdtiger used a boxy casemate superstructure, with its sides completely integral with the hull's sides, on top of a lengthened Tiger II chassis. The resulting vehicle featured very heavy armor and the 128 mm PaK 44 L/55 gun, capable of defeating any tank fielded in World War II; even at very long ranges (over 3,500 m (2.2 mi)). It had 250 mm (9.8 in) armor on the front of the casemate and 150 mm (5.9 in) on the glacis plate. The main gun mount had a limited traverse of only 10 degrees; the entire vehicle had to be turned to aim outside that narrow field of fire. The Jagdtiger suffered from a variety of mechanical and technical problems due to its immense weight and under-powered engine. The vehicle had frequent breakdowns; ultimately more Jagdtigers were lost to mechanical problems or lack of fuel than to enemy action.
One hundred and fifty Jagdtigers were initially ordered but only between 77 to 88 were produced from July 1944 to May 1945. Eleven of them, serial numbers 305001 and 305003 to 305012, were produced with the Porsche suspension (eight road wheels); all following used the Henschel suspension with nine road wheels. Production figures vary depending on source and other factors such as if prototypes are included and if those made after VE day are included. Approximately 48 from July 1944 to the end of December 1944; 36 from January to April 1945, serial numbers from 305001 to 305088 (such as examples from May 1945, and pre-production prototypes, and whether incomplete chassis are counted). Some sources say no more vehicles were completed after February. Towards the end some were lacking important equipment and could not be used operationally, or could not be deployed to units.