Sd.Kfz. 7

The Sd. Kfz. 7 was a half track military vehicle used by the German Army, Luftwaffe and Waffen SS during the Second World War. Sd. Kfz. is an abbreviation of the German word Sonderkraftfahrzeug, "special purpose vehicle". A longer designation is mittlerer Zugkraftwagen 8t, Sd. Kfz. 7, "medium towing motor vehicle 8t".

Development of the Sd. Kfz. 7 can be traced back to a 1934 Wehrmacht requirement for an eight tonne (8.3 tons) half track. Various trial vehicles were built by Krauss Maffei from 1934 to 1938. The production vehicle first appeared in 1938 and was intended to be used mainly as the tractor for the 8.8 cm FlaK gun and the 15 cm sFH 18 150 mm howitzer. Production was stopped in 1944. The vehicle was made by Krauss Maffei in Munich, the Saurerwerke in Vienna and the Borgward works at Bremen. The windscreen was able to fold down and a canvas roof could be erected. A number were also constructed with a hard top, but this was less common in service. A later simplified type appeared with a timber frame truck type layout, the ammunition being stored behind the driver's station and the gun crew having space on wooden benches behind. The running gear consisted of two front wheels with hydro pneumatic tires for steering and a track each side with 14 road wheels—7 per side, overlapping and interleaved in the common Schachtellaufwerk design for German half tracks—on each side of the vehicle; a drive sprocket was located at the front of each track system. Minor variations on the track and road wheel design and manufacture took place throughout the course of service, some being combined in the field as repairs took place. In 1943, the Maybach HL62 engine was replaced with a Maybach HL64. It was used as a recovery vehicle for lightly armored vehicles.

The use of half tracked prime movers for artillery was common in the German forces but not elsewhere. Compared to wheeled vehicles, half tracks are more difficult to maintain, they often suffer track breakages, and are slower on roads. However, they have better off road mobility compared to wheeled vehicles. The Sd. Kfz.7 was used throughout the war. They were seen during the 1940 Paris victory parade and the Sd. Kfz. 7 features in much German wartime propaganda footage, contributing to the myth of the mechanized Blitzkrieg. In fact, while produced in large numbers, there were never enough to fully equip the German forces. Typically, like many other types, the artillery elements of Panzer and mechanized infantry units (Panzergrenadier) received them, while other units continued to rely on horses to draw their guns. The Sd. Kfz. 7 saw extensive use in the North African Campaign where their tracks allowed them to drive through the desert sands far more effectively than trucks. Often, columns carrying troops or POWs would include at least two half tracks with one generally riding point in order to make a path through the sands that the trucks could follow. The Sd. Kfz. 7 also became the basis of a number of self propelled anti aircraft variants based on 20 mm and 37 mm flak types in use. The Sd. Kfz. 7/1 was armed with a 2 cm Flakvierling 38 quadruple anti aircraft gun system. The Sd. Kfz. 7/2 was armed with a single 3.7 cm FlaK 36 anti aircraft gun. On many of these variants, the driver's position and the engine cover was armored

In July 1946, the test vehicle was required to tow a 25 pounder gun and limber, pitted against a Crusader artillery tractor and an Alecto self propelled gun. While the Traclat gave the best performance, it bogged down in mud. A number of vehicles were shipped to Germany for more trials but this came to nothing, due to excessive cost, and because existing tractors were coping with combat conditions in Western Europe, there was no longer any requirement for series production. The paired standard Bedford engines produced a combined 136 bhp, with a combined fuel consumption of 3.5mpg(1.27 km/litre). The Traclat achieved a maximum road speed of 30 mph (48 km/h).