Schwere Wehrmachtschlepper

The Schwerer Wehrmachtschlepper (Heavy Military Tractor), or sWS, was a German World War II half-track vehicle used in various roles between 1943 and 1945. The unarmored models were used as supply vehicles and as tractors to haul artillery. Armored versions mounted anti-aircraft guns or a 10 barrel rocket launcher (Nebelwerfer). Less than a thousand were built before the end of the war, but production continued after the war of an improved model in the Tatra plant in Czechoslovakia.

On 7 May 1942 Hitler ordered development of a simple, low-speed, half-track, load-carrying vehicle for use on the Eastern Front. Büssing-NAG was selected to develop a new 5 t (4.9 long tons; 5.5 short tons) tractor (Zgkw. 5t neuer Art) to replace the earlier 5 tonne Sd.Kfz. 6 and 3 t (3.0 long tons; 3.3 short tons) Sd.Kfz. 11 half-tracks, as well as the various lesser-known vehicles of the same class. Production started in December 1943 at Büssing-NAG. Early examples used a truck-like, unarmored cabin similar to the earlier half-tracks it replaced, while later examples featured an armored cabin and engine compartment that looked similar to the Sd.Kfz. 251 armored personnel carrier. Like the earlier Demag-designed Sd.Kfz. 10, the sWS's suspension system consisted of five double roadwheels per side, overlapping and interleaved in the Schachtellaufwerk () layout, mounted on swing arms sprung by torsion bars. One idler wheel, mounted at the rear end of each track unit, was used to control track tension.

Tatra also joined in production, but together both factories produced only 825 vehicles in total. Tatra continued production of an improved vehicle after the war as the T809.