The Sturmpanzer, also known as the Brummbar, was a notable armored fighting vehicle of the Nazis during World War II.
Sturmpanzer was based on the Panzer IV chassis to be an armored infantry support gun, similar to a howitzer. The main weapon was a 150mm field howitzer and the vehicle’s primary mission was in support of ground troops, mainly in urban areas where its armament could be used to devastating effect against structures.
The Sturmpanzer was similar in appearance to a tank but did not have a traversing turret. Instead, its powerful howitzer armament was fitted within a fixed superstructure. Just over 300 vehicles were built and they were assigned to four independent battalions.
The Sturmpanzer fired the same shells as the 150 mm heavy infantry gun. Thirty-eight rounds, with separate propellant cartridges, could be carried. An MG 34 machine gun was carried that could be fastened to the open gunner’s hatch. Early vehicles carried an MP 40 sub-machine gun inside, which could be fired through firing ports in the side of the superstructure.
Armor on the superstructure was sloped on all sides including the roof with front plate armor completed at 100mm thick. Side armor along earlier models managed only 30mm of armor, making them somewhat vulnerable to Allied anti-tank weapons, particularly at close ranges in which the Sturmpanzer was intended to fight. The stout 15cm.
Power was supplied from a single Maybach HL 120 TRM series 12-cylinder engine of 300 horsepower. Later models introduced the Maybach HL 120 TRM 112 series 12-cylinder engine, again, of 300 horsepower. Range was out to only 130 miles so her strategic usefulness was somewhat limited.
Early vehicles were too heavy for the chassis, which led to frequent breakdowns of the suspension and transmission. Efforts were made to ameliorate this from the second series onwards, with some success.
The 60 examples of the original series were first delivered in Apr 1943. The second series of another 60 vehicles began production in Dec 1943. The first unit to take these guns to combat was Sturmpanzer-Abteilung 216 battalion, which trained in France and then saw combat at Kursk, Russia.
Combat experience in the Soviet Union showed that the primary guns were too heavy for the chassis, which caused unacceptable wear. This problem was improved, but never completely eliminated, with the third series, which saw a redesign of the primary weapon, reduction of hull armor, and new steel road wheels. Battalions equipped with Sturmpanzer vehicles would subsequently see action in Italy, France, Belgium, Poland, Hungary, and Germany. Overall, 306 Sturmpanzer vehicles were built between 1943 and 1945.