Self propelled gun on Panzer IV chassis
German World War II armored fighting vehicles gallery
Based on practical experience with combat in urban areas, German infantry units were calling for means of direct artillery support, strong enough to destroy even the enemy hidden in buildings. Practically all existing self propelled guns had open fighting compartments and therefore could have not been used in urban areas, where the enemy fire was close and could come from any direction. Stug III assault gun, which was fully armored, was on the other hand armed with just a 75 mm gun and was not really able to take down buildings.
Development of a brand new assault gun was therefore started by Alkett company at the beginning of 1942. It used the chassis of Panzer IV medium tank and was armed with a 150 mm StuH 43 gun. Design was ready in August 1942 and serial production commenced in April 1943. New vehicle was called Sturmpanzer 43 but is much more known as Brummbär (grouch). It had a fully enclosed casemate superstructure and mass of over 28 tons. It was operated by a crew of five.
Original Brummbärs had no integral anti-infantry weapon which soon showed to be a significant drawback. Modernized version was therefore introduced in December 1943. It had a machine gun in a ball mount installed to the left of the main gun, a new commander cupola on the superstructure roof, new version of gun called StuH 43/1 and some other upgrades. Brummbär production continued until March 1945 with total score of more than 300 vehicles.