15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf)
The 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf), sometimes referred to as the Sturmpanzer II Bison, was a German assault gun used during World War II. The dozen vehicles produced were assigned to the 90th Light Infantry Division in North Africa during the war. Development The sIG 33 gun was used as direct-fire artillery in support of assaulting infantry. To improve its mobility 38 guns were mounted on a Panzerkampfwagen I chassis in February 1940. The 15 cm sIG 33 (Sf) auf Panzerkampfwagen I Ausf B that had participated in the Invasion of France in 1940 had proven to be too heavy for its chassis as well as being 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 , which required adding a sixth roadwheel, and widened by to better accommodate the gun while preserving its low silhouette. plates formed the front and sides of the open-topped fighting compartment, which was also open