Sd.Kfz. 8

The Sonderkraftfahrzeug 8 ("special motorized vehicle 8") was a German half-track that saw widespread use in World War II. Its main roles were as a prime mover for heavy towed guns such as the 21 cm Mörser 18, the 15 cm Kanone 18 and the 10.5 cm FlaK 38. Approximately 4,000 were produced between 1938 and 1945. It was used in every campaign fought by the Germans in World War II, notably the Invasion of Poland, the Battle of France, the Balkans Campaign, the Eastern Front, the North African Campaign, the Battle of Normandy and the Italian Campaign.

Description
The ''Sd.Kfz. 8'' had a ladder frame chassis. Power was provided by a Maybach 12-cylinder, water-cooled, 8.52 litre (520 cu in) HL 85 TUKRM gasoline engine of 185 hp. It had a semi-automatic ZF transmission with four forward and one reverse gears. The driver selected the desired gear and initiated the shift by depressing the clutch. It had two fuel tanks, one of 40 l and the other of 210 l capacity.

Both tracks and wheels were used for steering. The steering system was set up so that shallow turns used only the wheels, but brakes would be applied to the tracks the farther the steering wheel was turned. The drive sprocket had rollers rather than the more common teeth. The rear suspension consisted of six double roadwheels, overlapping and interleaved in the usual Schachtellaufwerk system used for German half-track vehicles, mounted on swing arms sprung by torsion bars. An idler wheel, mounted at the rear of the vehicle, was used to control track tension. The front wheels had leaf springs and shock absorbers.

The upper body had a crew compartment with three bench seats, one for the driver and his assistant, and two others for the crew. The rear cargo area contained storage compartments, one on each side and two in the rear. The windshield could fold forward and was also removable. A convertible canvas top was mounted above the rear storage compartments. It fastened to the windshield when erected.

The ''Sd.Kfz. 8 was initially designed to have a towing capacity of 12 t, but the wartime DB 10'' could tow 14 t.

Design and development
Preliminary design of all the German half-tracks of the early part of the war was done by Dipl.Ing. Ernst Kniepkamp of the "Military Automotive Department" (Wa Prüf 6) before the Nazis took power in 1933. His designs were then turned over to commercial firms for development and testing. Daimler-Benz had been working on its own half-track design during 1931—32, the ZD.5. It weighed 9.3 t, used a twelve-cylinder, 150 hp Maybach DSO 8 gasoline engine and its upper body had three bench seats behind the driver. Its suspension was based on the World War I-era Marienwagen II and bore absolutely no relation to the interleaved roadwheels and torsion bars used by the various models of the ''Sd.Kfz. 8''.

Daimler-Benz combined the best of both designs in the DB s7 prototype which appeared in 1934. It used the same engine as the ZD.5, but otherwise bore little resemblance to the older model other than an upper body that had two bench seats for the crew behind the driver's seat. This upper body remained the same over the life of the ''Sd.Kfz. 8. It weighed 14.4 t and could pull loads of 12 t. An improved version was introduced in 1936 as the DB s8''. The heavier (15 t) DB 9 model appeared in 1938. It used the Maybach HL 85 TUKRM engine, could carry a 800 kg payload and could tow a 14 t load. Daimler-Benz tried unsuccessfully to use their diesel OM 48/1 engine, but it was repeatedly rejected by the Army Weapons Office. The DB 10 was a refined version of the DB 9 and was introduced in October 1939 and was produced for the duration of the war.

Variants
Ten 8.8 cm Flak 18 anti-aircraft guns were mounted on pedestals on DB s8 and DB 9 chassis in 1939 as the 8.8 cm Flak 18 (Sfl.) auf Zugkraftwagen 12t (Sd.Kfz. 8) for anti-tank duties. A gun shield was provided for the 88, but the gun crew had no other protection. The driver's cab was replaced by a lower, armored cupola and the engine compartment was lightly (14.5 mm) armored. The vehicle weighed 20 t, was 7.35 m long, 2.8 m tall and 2.65 m wide. The gun could fire directly ahead without any problem, but traverse was limited to 151° to each side by the gun shield. Elevation was between -3° and +15°. All ten were assigned to the first company of the anti-tank battalion Panzerjäger-Abteilung 8 which participated in the Invasion of Poland in 1939, the Battle of France in 1940 and Operation Barbarossa in 1941. The company was redesignated as Panzerjäger-Kompanie ("Anti-Tank Company") 601 in January 1942 and then as the third company of Anti-Tank Battalion 559 the following April. It reported that the last three vehicles had been lost by March 1943.

Production and use
Daimler-Benz and Krupp were the main builders of the ''Sd.Kfz. 8'' during the war, but Krauss-Maffei produced 315 in 1940—41 and Škoda joined in the last years of the war. 1615 were on hand on 20 December 1942. 507 were built in 1943 and 602 in 1944. Approximately 4000 were built in total. The ''Sd.Kfz. 8'' was used by Czechoslovakia after the war, but it is not known if production continued at Škoda or when they were finally discarded.

Unlike most of the other German half-tracks, the ''Sd.Kfz. 8'' was almost always used as a tractor for heavy artillery pieces and was not modified for other roles.