Heavy self propelled gun on Panzer I chassis
German World War II armored fighting vehicles gallery
From the very first moments of World war II, German army was asking for a powerful self propelled gun able to destroy enemy strong points. Development of such machine was assigned to the Alkett company. Alkett`s designers decided to simply combine already existing elements – the chassis of obsolete light tank Panzer I Ausf. B and a 150 mm heavy infantry gun sIG 33.
The original tank hull and turret were removed and a new armored superstructure was erected on the chassis. It needed to be very tall to provide cover for the whole gun and its operators. The thickness of the armor was probably only 10 mm. The superstructure was open from the top, back and partly also from the sides. To get a protection from weather foulness it could have been covered with a waterproof canvas.
The sIG 33 gun was installed practically as it came – including the shield, wheels and massive brace. It was a powerful weapon but was pretty big and heavy for the light chassis. The original Panzer I Ausf. B weighted some 5,8 tons while the Sturmpanzer I had a mass of 8,5 tons which means more than 40% increase in weight. Therefore the chassis and engine were constantly overloaded and prone to mechanical breakdowns.