As World War 2 (1939-1945) raged on for Germany, it was pressed upon the Wehrmacht (Army) service that its fleet of standardized halftrack prime mover vehicles were proving rather expensive and complicated to continue to produce en mass. Therefore, in 1942, it was decided to pursue a low-cost alternative and this charge fell to Bussing-NAG that year and, by the fall of 1943, a new system was readied for production. The product became the 'schwere Wehrmacht Schlepper' (or 'sWS') and was on the lines of two assembly plants - Bussing-NAG in Berlin and the Kolin Works at Ringhoffer-Tatra.
It was a heavy-class (6-ton range) halftrack system utilizing a traditional halftrack vehicle arrangement with a steerable, truck-like pair of wheels at front and a tank-like track-and-wheel arrangement under the rear of the chassis. The forward compartment contained the driver's position and a passenger seat (open-air). The rear of the vehicle could be arranged to accept various loads including troop benches and anti-aircraft gun systems. Power was from a single Maybach HL42 TRKMS six-cylinder, liquid-cooled gasoline-fueled engine of 100 horsepower (3,000rpm) and performance included a maximum road speed of 27 kmh with a range out to 300 kilometers (100km off-road). Dimensions included an overall length of 6.68 meters, a width of 2.5 meters and a height of 2.8 meters. No communications suite (radio) was fitted.
Beyond the base operational model for transporting troops was a dedicated MEDEVAC version with provision for stretchers and support staff. A frontline resupply variant held an armored front cab and protected engine compartment. One proposed form of this model was to feature an anti-aircraft gun (as the 3.7cm FlaK 43 auf sWS). There was also a rocket-projecting armored vehicle which seated a 10-tube launcher arrangement for 15cm battlefield rockets and an operating crew of five. Reloads were stowed within the hull of this variant (designated 15cm Panzerwerfer 42 (Zehuling) auf sWS).
The sWS was to become the new standardized prime mover halftrack for the German Army going forward. However, it too proved a complex and expensive piece of machinery to produce in the numbers required and therefore saw only 1,000 or so units completed before war's end. After that, a stock was taken on by the Czechoslovakian Army and used for a time longer.