Panzer I Variants - 15 Cm SIG 33 (Sf) Auf Panzerkampfwagen I Ausf B

15 Cm SIG 33 (Sf) Auf Panzerkampfwagen I Ausf B

This vehicle was sometimes known as the Bison. The larger Ausf B chassis made possible the mounting of heavier guns with removal of the turret. The largest was the 150 mm heavy infantry gun, the sIG 33. This mammoth piece was relatively short and barely fit inside a tall superstructure that was constructed up to the vehicle's 2.8 m height and over the tracks to their full 2.06 m width. The superstructure armor was light—only 13 mm—and only protected the front and sides. The heavy resulting weight of 8.5 tons overstressed the chassis; the vehicle was not a great success. 38 were converted from Ausf B tanks in February 1940. They served with six heavy SP infantry gun companies, with survivors in service into 1943. The sIG mounting was capable of 25 ° of traverse and 75 ° of elevation, and could be depressed to −4 °. It used a Rblf36 sight. Ammunition was carried separately, there being no room for onboard shell storage. The sIG would be mounted more successfully on larger chassis as the war progressed.