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Sd.Kfz. 7 on Militracks 2010, Overloon
|Type||Half-track artillery tractor|
|Place of origin||Nazi Germany|
|In service||1938 - 1945 (Nazi Germany)|
|Used by||Nazi Germany, Italy, Bulgaria, Yugoslav Partisans (captured) Czechoslovakia (postwar), Allies (postwar)|
|Wars||World War II|
|Manufacturer||Krauss-Maffei, Borgward, Österreichische Saurer-Werke AG, Breda (Breda 61)|
|Unit cost||36,000 Reichsmark|
|Produced||1938 - 1944|
|Variants||Sd.Kfz. 7/1, Sd.Kfz. 7/2, Feuerleitpanzer auf Zugkraftwagen 8t, Breda 61|
|Length||6.85 m (22 ft 6 in)|
|Width||2.35 m (7 ft 9 in)|
|Height||2.62 m (8 ft 7 in)|
|Engine||Maybach HL 62 TUK, six-cylinder petrol
135 PS, (133 hp, 99 kW)
|Payload capacity||1,800 kg|
|Fuel capacity||215 liters|
|250 km (160 mi) on roads
120 km (75 mi) off-road
|Speed||50 km/h (31 mph) on roads|
The Sd.Kfz. 7 was a half-track military vehicle used by the German Wehrmacht Heer, 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 Sd.Kfz. 7 mittlerer Zugkraftwagen 8t, "medium towing motor vehicle 8t".)
Development of the Sd.Kfz. 7 can be traced back to a 1934 Wehrmacht requirement for an eight-tonne (7.87 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. Because of its heavy power, it often found use as a recovery vehicle.
The vehicle could carry gun crews of up to 12 men in theatre-type seats. Under the seats was storage room for various tools, and the whole vehicle was spacious enough to carry their kit. The rear of the vehicle housed an enclosed compartment for storage of ammunition, though a second ammunition carrier was desirable. The tractor could tow loads up to 8,000 kg (17,600 lb) in weight. Most were fitted with a winch that could pull up to 3450 kg. It had a payload of 1800 kg. 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 HL 62 engine was replaced with Maybach HL 64.
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 iconic Sd.Kfz.7 was used throughout the war. Sd.Kfz. 7 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 POW's 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 (8 mm thickness). There were also conversions made mounting a single 2 cm anti-aircraft gun. Trial vehicles mounting a 5 cm FlaK 41 were produced but proved unsuccessful, and did not enter serial production.
A variant with an armored superstructure based on the Sd.Kfz. 7, the Feuerleitpanzer auf Zugkraftwagen 8t, was used by launch crews of the V-2 ballistic missile. This was necessary as the V-2 sometimes malfunctioned and exploded on the launch pad. It was also used to tow the launch pad in place. Bunkers were not used as the V-2 was transported to widely dispersed launchpads by carriage on Meillerwagen trailers that could erect them atop the launchstands/flame deflectors that each dispersed launchpad facility was equipped with for surprise launches, to dissuade Allied air attacks.
British Improved Copy
The British company Bedford Motors (a subsidiary of Vauxhall Motors) built an improved copy of Nazi Germany's 8 ton half track prime mover. Designated the Bedford Tractor (BT) and codenamed Traclat (Tracked Light Artillery Tractor) this was to be a 'go anywhere' artillery tractor for 17 pounder, 25 pounder and Bofors 40 mm guns but, so far as possible, built using existing parts and production capacity.
In 1943 the Ministry of Supply asked Vauxhall Motors to construct a three-quarter tracked vehicle using a similar track and rear suspension system to that of the Sd.Kfz.7 medium artillery tractors. To this end a number of captured half-tracks were shipped back to Britain from Libya. Morris put them through a trials and evaluation programme with a view to developing a similar machine for British use. Six prototypes were built for trials in 1944 but the war in Europe ended before mass production could be considered.
Unlike the German original the Traclat was powered by two off-the-shelf Bedford engines mounted side-by-side and geared to a common shaft but like the original when the steering wheel went beyond a gentle turn power was diverted progressively to the outermost wheel and track.
In some ways the Traclat was superior to its progenitor: the ammunition lockers were accessible from outside of the vehicle and it also had automatic steering. By early 1945 Vauxhall motors had supplied prototypes to the Fighting Vehicle Proving Establishment (FVPE) for official trials in conditions ranging from arctic to tropical and the vehicles proved excellent, being able to climb a one-in-two gradient and wade in water six feet deep but the war ended before mass production could be contemplated.
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 (unsurprisingly) 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 since 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).
Allied use of Sd Kfz 7
- Sd.Kfz. 7
Basic Sd.Kfz. 7 prime mover, with open bodywork and theatre-type seating for gun crews. No armor.
- Sd.Kfz. 7/1
- Sd.Kfz. 7/2
- Feuerleitpanzer auf Zugkraftwagen 8t
Observation and command post for the V-2 ballistic missile. Unknown numbers produced.
- Breda 61
- Bishop, Chris (editor), The Encyclopedia of Weapons of World War II, Sterling Publishing Company, Inc. (2002), ISBN 1586637622 p.78-79
- Lepage, Jean-Denis, German Military Vehicles of World War II: An Illustrated Guide to Cars, Trucks, Half-Tracks, Motorcycles, Amphibious Vehicles and Others McFarland (2007), ISBN 9780786428984, p. 141-142
- Mittlerer Zugkraftwagen 8t Sd.Kfz.7 achtungpanzer.com accessed 2012-07-22
- Jentz, Thomas L. (1998). Panzer Tracts 12 - Flak Selbstfahrlafetten and Flakpanzer. Panzer Tracts. pp. 15–21.
- Ellis, Chris; Bishop, Denis (1971). Military Transport of World War II. 167 High Holborn London WC1V 6PH: Blandford. pp. 130–131. ISBN 0-7137-0702-X.
- Classic Military Vehicle Magazine Issue 46 March 2005