3.7 cm FlaK 43

3.7 cm Flak 43
300px A 3.7 cm Flak 43 Zwilling
Type	Anti-aircraft cannon
Place of origin	Nazi Germany
Service history
In service	1943—45
Used by	Nazi Germany
Wars	World War II
Production history
Designer	Rheinmetall
Produced	1943—45
Variants	3.7 cm Flak 42 Zwilling
Specifications
Weight	1,248 kilograms (2,751 lb)
Barrel length	2.13 metres (84 in) L/57 (length of bore)
Shell	37 × 263 mm. B
Caliber	3.7 centimetres (1.5 in)
Barrels	1 or 2
Breech	gas-operated bolt
Carriage	three-legged platform
Elevation	-7° 30' to +90°
Traverse	360°
Rate of fire	150 rpm (practical)
Muzzle velocity	770–1,150 m/s (2,500–3,800 ft/s)
Effective range	2,000 metres (6,600 ft) (max. effective ceiling FlaK 18/36/37) 4,200 metres (13,800 ft) (max. effective ceiling FlaK 43)
Maximum range	6,585 metres (7,201 yd) (max. ground range)
Feed system	8-round clips

The 3.7 cm FlaK 43 was one of a series of medium-caliber anti-aircraft cannon produced by Nazi Germany and which saw widespread service in the Second World War. The cannon was fully automatic and effective against aircraft flying at altitudes of 4200 meters and lower. The cannon was produced in both towed and self-propelled versions. Unbound by flexible doctrine, the Germans used the Flak 43, among other anti-aircraft pieces, in ground support roles as well. With Germany's defeat, production of the Flak 43 ceased, and overall, 37-mm caliber anti-aircraft cannon fell into gradual disuse, being replaced by existing 40-mm Bofors guns, and later, 35-mm anti-aircraft pieces produced by Switzerland.

Earlier guns

The original 37 mm gun was developed by Rheinmetall in 1935 as the 3.7 cm Flugzeugabwehrkanone 18. It was essentially an enlarged version of the 2 cm FlaK 30 firing a 37 mm shell from an L/89 barrel. Like the Flak 30, it used a mechanical bolt for automatic fire, but nevertheless featured a fairly good rate of fire, about 160 rounds per minute. The complete gun, including the wheeled mount, weighed 1,757 kilograms (3,874 lb).

The Flak 18 was produced only in small numbers, and production had already ended in 1936 in favor of well known 2 cm Flakvierling 38, a four-barrel development of the Flak 30. Development continued, however, resulting in a lighter two-wheel mount produced as the 3.7 cm Flak 36 that cut the complete weight to 1,544 kilograms (3,404 lb). A new sighting system introduced the next year produced the 3.7 cm Flak 37 that was otherwise similar. It appears existing weapons were brought up to the Flak 37 standard, while new production started in 1942 and produced 1178 before production ended in 1944. The Flak 37 was known as 37 ITK 37 in Finland.

FlaK 43

File:Bundesarchiv Bild 101I-301-1957-34, Nordfrankreich, Zwillings-Flak.jpg

German soldiers carry ammunition for the 3,7 cm Flakzwilling 43.

As Allied air power grew dramatically during the mid-period of the war, the 20 mm quad-mount proved to have too little power and the 37 mm was turned to as its replacement. Not content with the existing versions, Rheinmetall-Borsig and Krupp were asked to produce a new version that was less expensive.

Krupp initially won the contract, but at the last moment the Krupp design developed weaknesses and Rheinmetall-Borsig got the award. This immediately resulted in the factional wrangling in the Nazi party that often beset German wartime industrial production, so by the time Rheinmetall-Borsig was actually able to go ahead well over a year had passed. The design partially able to made up for the delay, however, as it was produced with stampings, welding and simple components in the same way as submachine guns. The production time for a gun was cut by a factor of four.

The new 3.7 Flak 43 was a dramatic improvement over the older models. A new gas-operated breech improved the firing rate to 250 RPM, while at the same time dropping in weight to 1247 kg. It was also produced in a twin-gun mount, the 3.7 cm Flakzwilling 43, although this version was considered somewhat unwieldy and top-heavy.

The Flak 37 could be found in some numbers mounted to the ubiquitous Sd.Kfz. 7 or (later) the sWS. The newer Flak 43 was almost always used in a mobile mounting. Most famous of these were the converted Panzer IV's, first the "interim" Möbelwagen, and later the Ostwind, which was considered particularly deadly.

Compared to its closest Allied counterpart, the 40 mm Bofors, the Flak 43 had over double the firing rate, could set up in much smaller spaces, and was considerably lighter when considering the gun and mount together. Although the weapon was complete in 1942, production did not start until 1944. About 928 single and 185 double versions were produced by end of the war.

References

• Gander, Terry and Chamberlain, Peter. Weapons of the Third Reich: An Encyclopedic Survey of All Small Arms, Artillery and Special Weapons of the German Land Forces 1939-1945. New York: Doubleday, 1979 ISBN 0-385-15090-3
• Hogg, Ian V. German Artillery of World War Two. 2nd corrected edition. Mechanicsville, PA: Stackpole Books, 1997 ISBN 1-85367-480-X

External links

• 3.7 cm FlaK 43 in U.S. Ordnance Catalog

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