Germany 15cm sIG 33 Gw II (Bison)

World War 2 Tank and Gun Database

The 15cm sIG 33 Gw II was a Self Propelled Artillery vehicle designed in 1939, manufactured by Alkett, it was based on the fully tracked PzKpfw II Ausf B chassis and was in use from 1941 to 1945. It was commonly called a Bison.

General Details (SP Artillery)

Specifications
Operational Date(s)	1941 - 1945
Quantity Produced	12
Weight	11.2 tonne
Crew	4
M.G's small	1
M.G's large(>10mm)	n/a
Length	4.81 mtr
Width	2.28 mtr
Height	2.30 mtr
Engine Details/Performance
Max Road Speed	25 mph
Max Cross Country Speed	12 mph
Range Road	100 miles
Range Cross Country	40 miles
Fuel Type	Petrol
Fuel Capacity	unknown
Horse Power	140 hp
Power/Weight	12 hp/tonne

General Information

The 15cm sIG 33 Gw II was a Self Propelled Artillery vehicle designed in 1939, manufactured by Alkett, it was based on the fully tracked PzKpfw II Ausf B chassis and was in use from 1941 to 1945. It was commonly called a Bison.

The vehicle was powered by Bussing-NAG 'petrol' petrol powerplant producing 140 HP which could drive the vehicle on roads at up to 25 mph with a range of about 100 miles before refuelling. Its cross country performance was good providing a max speed of about 12 mph and a range of about 40 miles.

It was armed with 1 light machine gun. Its main armament consisted of a 15cm sIG 33 L/11 which could penetrate 0 mm of flat plate at 200 metres

This vehicle was based on an extended PzKpfw II Ausf B with a chassis extended by 60 cm that allowed an extra roadwheel to be added to the vehicle.

Armour Details

Turret
Front	n/a
Side	n/a
Rear	n/a
Top	n/a

Superstructure
Front	30mm	@	9°	(30mm)
Side	15mm	@	30°	(17mm)
Rear	15mm	@	10°	(15mm)
Top	5mm	@	90°	(5mm)

Hull
Front	30mm	@	15°	(31mm)
Side	15mm	@	0°	(15mm)
Rear	15mm	@	15°	(16mm)
Top	5mm	@	90°	(5mm)

Armour (x)mm @ (y)° (Effective mm @ 0°)

Effective Armour - Maximum 31 mm - Minimum 5 mm


Weapon Details
	15cm sIG 33 L/11 15cm schwere Infanteriegeschutz 33 L/11 (translates as Heavy Artillery)

		History
		Standard German army heavy infantry gun originally issued in 1927 was still being produced at the end or the war. This gun was also mounted on a number of motorised chassis such as the 15cm s.I.G 33 Gw II(A,B,C,F).
		Manufacturer	Rheinmetal
		Manufactured	1927 - 1945
		Calibre	150mm
		Length	L/11
		Rate of Fire	3rpm

Ammunition Details
Name/Id	Calibre Weight MVelocity					Explosive Content
15cm I Gr 33 (HE High Explosive)	150mm 38Kg 240M/Sec					8.300Kg explosive
Maximum Range 4700 Mtr
Range(Mtr)	500	1000	1500	2000	2500	3000	3500	4000
Flight Time(Secs)	2.22	4.72	7.54	10.7	14.24	18.19	22.59	27.48
lateral dispersion means the side to side variation of the shell from the aiming point
50%(CEP) of shells land within +/- (mtr)	0.13	0.27	0.40	0.53	0.67	0.80	0.93	1.07
80% of shells land within +/- (mtr)	0.17	0.35	0.51	0.68	0.86	1.02	1.19	1.37
95% of shells land within +/- (mtr)	0.25	0.53	0.78	1.04	1.31	1.57	1.82	2.10
range dispersion means the back to front variation of the shell from the aiming point
50%(CEP) of shells land within +/- (mtr)	0.17	0.33	0.50	0.67	0.83	1.00	1.17	1.33
80% of shells land within +/- (mtr)	0.22	0.42	0.64	0.86	1.06	1.28	1.50	1.70
95% of shells land within +/- (mtr)	0.33	0.65	0.98	1.31	1.63	1.96	2.29	2.61
Direct Fire
Range(Mtr)	100	200	400	800	1200	1600	2000	2400
Flight Time(Secs)	0.42	0.85	1.75	3.8
Hit Probability(%)	98	92	68	15
Blast/Fragmentation Effects
Burst radius Infantry in open 99% kill	6 mtr	Burst radius Infantry in open 66% kill						12 mtr
Burst radius Infantry in open 33% kill	30 mtr	Armour Penetration inc roof at 2 mtr						24 mm
An explosion within 6 mtr of infantry in the open will cause 99% casualties - lethal.
An explosion within 12 mtr of infantry in the open will cause > 66% casualties and could damage some AFV's.
An explosion within 30 mtr of infantry in the open will cause 33% casualties.
The blast effect of this shell exploding within 2 mtr of an armoured vehicle will penetrate 24 mm of the tank armour including the roof.

Range(Mtr)	100	200	400	800
15cm I Gr 39 Hl/A (HEAT High Explosive Anti-Tank)	150mm 25Kg 600M/Sec
Quoted Penetration 185mm @ 500mtr/0°
Flight Time(Secs)	0.17	0.34	0.68	1.4
Penetration(mm@30°)	185	185	185	185
Penetration(mm@0°)	185	185	185	185
Hit Probability(%)	98	98	95	82

About Penetration Figures

All penetration figures in this database are calculated to a common standard based on German WWII testing criteria (complete penetration with functioning fuze). This allows direct comparison between all nations' guns.

Original national test figures would be higher for some nations due to different criteria:

German: 1.00? (baseline - strictest)
British: 1.02? (slightly looser)
American: 1.05? (50% mass through plate)
Soviet: 1.10? (75% mass through plate)

For example, a Soviet gun showing 159mm here would be published as ~175mm in Soviet documents, and a German gun showing 120mm would be published as 120mm in German documents. The 159mm figure is directly comparable to the German 120mm - the Soviet gun really was more powerful.

National Testing Standards
German:	1.00? - Complete penetration, fuze functions (strictest)
British:	1.02? - Complete penetration
American:	1.05? - 50% of shell mass through plate
Soviet:	1.10? - 75% of shell mass through plate
All database figures are normalized to German standard for direct comparison. Multiply by the factor above to see original national test figures.

Hit probability is based on a static 2 x 2.4 metre panel at 0 degrees(vertical) at the range specified.

The data that has been used to create these records has come from Wikipedia, The Lone Sentry, The Bundes Archive and numerous books and websites that have provided the detailed information that has not been available anywhere else. The information we use to calculate the penetration tables, flight times and the hit probability comes from the Gun Calibre, the Shell Mass(Kg) and the muzzle velocity, plus range reductions to allow for gravity and wind resistance. This calculation originally came from a pre-war Krupp calculation which has been modified, and seems to fit the actual test results.