15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf)

Sometimes referred to as the Sturmpanzer II Bison, the 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) was a German self-propelled heavy infantry gun used during World War II. The 15 cm sIG 33 (Sf) auf Panzerkampfwagen I Ausf B built in time for the Invasion of France in 1940 had proven to be too heavy for their chassis as well as enormously tall. The same gun was mated to the Panzerkampfwagen II chassis in an attempt to drastically lower its height while using a stronger chassis. The prototype used a standard Panzer II Ausf. B chassis when it was built in February 1941, but this was too cramped for use. The chassis was lengthened by 60 cm, which required adding a sixth roadwheel, and widened by 32 cm to better accommodate the gun while preserving its low silhouette. 15 mm plates formed the front and sides of the open-topped fighting compartment, which was also open at the rear. Its sides were notably lower than the front which made the crew vulnerable to small arms fire and shell fragments. Large hatches were added to the rear deck to better cool the engine.

The 15 cm sIG 33 gun, for which 30 rounds were carried, could traverse a total of 5° left and right and used a Rblf36 sight.

Twelve were built at the end of 1941 and shipped to North Africa in early 1942 where they formed schwere Infanteriegeschütz-Kompanie (mot.S.) ("Heavy Self-propelled Infantry Gun Company") 707 and 708. The former was assigned to Schützen-Regiment 155 and the latter to Schützen-Regiment 200, both part of the 90. leichte Afrika-Division. Both companies fought until the Axis surrender in Tunisia in May 1943.