15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf)

15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf)
Type	heavy assault gun
Place of origin	Nazi Germany
Service history
In service	1942 - 1943
Used by	Nazi Germany
Wars	World War II
Production history
Manufacturer	Alkett
Produced	1941
No. built	12
Specifications
Mass	11.2 tonnes (11.0 long tons; 12.3 short tons)
Length	5.41 metres (17.7 ft)
Width	2.6 metres (8.5 ft)
Height	1.9 metres (6.2 ft)
Crew	4
Armor	30 mm - 5 mm
Main armament	1× 15 cm sIG 33
Secondary armament	1× 7.92 mm Maschinengewehr 34
Engine	Bussing-NAG engine
Transmission	6 forward, 1 reverse gears
Suspension	leaf-spring
Operational range	190 kilometres (120 mi)
Maximum speed	40 kilometres per hour (25 mph)

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 centimetres (24 in), which required adding a sixth roadwheel, and widened by 32 centimetres (13 in) to better accommodate the gun while preserving its low silhouette. 15 millimetres (0.59 in) 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-centimetre (5.9 in) 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.

References

• Chamberlain, Peter, and Hilary L. Doyle. Thomas L. Jentz (Technical Editor). Encyclopedia of German Tanks of World War Two: A Complete Illustrated Directory of German Battle Tanks, Armoured Cars, Self-propelled Guns, and Semi-tracked Vehicles, 1933–1945. London: Arms and Armour Press, 1978 (revised edition 1993) ISBN 1-85409-214-6
• Trojca, Waldemar and Jaugitz, Markus. Sturmtiger and Sturmpanzer in Combat. Katowice, Poland: Model Hobby, 2008 ISBN 978-83-60041-29-1
• "Sturmpanzer II Bison". Achtung Panzer!. Archived from the original on 28 August 2010. http://web.archive.org/web/20100828113619/http://www.achtungpanzer.com/sig33.htm. Retrieved 27 September 2010. 

External links

• Panzers of the Reich
• wwiivehicles.com
• "Gw. II für 15 cm s.I.G. 33: S.P. Heavy Infantry Howitzer" (U.S. World War II intelligence report)