After the invasion of Russia, it was realized that more powerful and mobile anti-tank capability was needed at the front.
Captain Alfred Becker, 227th Infantry Division, was stationed in France and designed vehicles that married captured chassis with captured artillery guns. This caught the notice of the German High Command and in the summer of 1942, Becker was transferred to Alkett in Berlin. He was then dispatched to Paris to convert enough vehicles to equip two panzer divisions.
The Weapons Department ordered on May 25, 1942, that the Lorraine Schlepper chassis was to be developed into a self-propelled mount for anti-tank and artillery guns.
Idler was mounted in rear, and drive sprocket in front.
The Pak 40 was placed in an armored structure that used the original gun shield.