An SPG with a cabin arrangement, combining high protection and firepower in the most compact possible dimensions and a weight of 45 tons. One of the main goals in the vehicle's development was to increase traverse limits without any turning of the hull. This led to a new design for the fighting compartment. The project called for mounting a 105 mm or 120 mm rifled gun. A muzzle brake was even planned for the latter.
Creation of a prototype brought to light numerous disadvantages. The mobility was fairly mediocre, and fuel consumption was enormous. Mounting the large guns was also difficult, since the barrel had an overhang of more than four meters, creating problems when traversing rough terrain and demanding greater attention from the driver. Also, the heavy weight and large size of the 120 mm gun overloaded the front end of the vehicle and led to rapid wear and tear of the front support units. Work on the project was canceled.