The Becker Type M2 20 mm cannon was a German autocannon developed for aircraft use during

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

by '' Stahlwerke Becker''. It was first mass-produced in 1916 and was installed in a variety of aircraft. It was the only German autocannon to see service in the air during the war. The Becker also served as the pattern for the famous Swiss-built

Oerlikon 20 mm cannon The Oerlikon 20 mm cannon is a series of autocannons, based on an original German Becker Type M2 20 mm cannon design that appeared very early in World War I. It was widely produced by Oerlikon Contraves and others, with various models em ...

, which is in service to this day, and in a later form, was the original inspiration, through the Swiss design after World War I, for the World War II German Luftwaffe's MG FF (''Maschinengewehr Flügel Fest'', "fixed wing-mount automatic ordnance") 20 mm autocannon design.

History

Design and development

The original design was based on the 19 mm Becker Cannon cartridge by the Conder brothers at ''Stahlwerke Becker'' of

Reinickendorf Reinickendorf () is the twelfth borough of Berlin. It encompasses the northwest of the city area, including the Berlin Tegel Airport, Lake Tegel, spacious settlements of detached houses as well as housing estates like Märkisches Viertel. Subdi ...

, Germany. Development commenced in 1913 and was therefore already advanced when the War Ministry issued a specification in June 1915 calling for an aircraft cannon of under 37 mm caliber and 70 kg weight capable of firing a 10-round burst. Tests commenced shortly thereafter with the weapon mounted in a

Gotha G.I The Gotha G.I was a heavy bomber used by the ''Luftstreitkräfte'' (Imperial German Air Service) during World War I. Design and development In mid-1914, Oskar Ursinus, the founder and editor of the German flying magazine ''Flugsport'', began des ...

, but proved unsatisfactory. Despite this, the potential of the gun was such that Spandau arsenal was engaged to help develop and fine-tune the design, leading to a production contract for 120 Becker Type M2 guns in June 1916. In addition to the orders for aircraft guns placed with Becker, Spandau and

MAN A man is an adult male human. Prior to adulthood, a male human is referred to as a boy (a male child or adolescent). Like most other male mammals, a man's genome usually inherits an X chromosome from the mother and a Y chromo ...

also received a contract to build Becker cannon for the Army. The Spandau works developed the gun further producing it as the ''Spandau Type 3 20 mm cannon'', which was heavier and had a slower rate of fire at 250 rpm.

Operational use

The main types to utilise the Type M2 were large, twin-engined aircraft, initially of ''IdFlieg's'' "G"-class ''Grossflugzeug'' category: the

Friedrichshafen G.III The Friedrichshafen G.III (factory designation FF.45) was a heavy bomber designed and manufactured by ''Flugzeugbau Friedrichshafen''. They were used by the German Imperial Air Service during World War I for tactical and limited strategic bomb ...

bomber and AEG G.IVk ground-attack machine. Tests in smaller, single-engined aircraft were not so successful but were carried out extensively through the rest of the war, commencing with an Albatros J.I in December 1917. Due to the gun's operating principles, it could not be synchronised and this posed an immediate problem for its installation in this type of aircraft. The solution adopted after the tests with the Albatros J.I was to mount the gun at an angle to fire downwards. Fitting the gun to a fighter with a pusher configuration was another obvious solution and trials were carried out with an

Albatros D.VI Albatros D.VI was the designation given to a prototype single-seat twin-boom pusher biplane built in 1917 in Germany. It was armed with a fixed LMG 08/15 machine gun and a fixed Becker Type M2 cannon. The aircraft's undercarriage was damaged ...

. Other intended installations were for an

AGO S.I The AGO S.I was a German prototype ground-attack aircraft built in October 1918 but possibly never flown before the end of World War I. It was a single-seat biplane A biplane is a fixed-wing aircraft with two main wings stacked one above th ...

and the Hansa (Caspar) D.I, but these were not carried out before the Armistice. Some rigid airships of the

Imperial German Navy The Imperial German Navy or the Imperial Navy () was the navy of the German Empire, which existed between 1871 and 1919. It grew out of the small Prussian Navy (from 1867 the North German Federal Navy), which was mainly for coast defence. Wilhel ...

, such as the most modern Zeppelin L 70 (LZ 112), were armed with the Becker cannon. Total production figures are not known but were in excess of 539 (111 by Becker and 428 by MAN); a total of 362 were surrendered to the Allies.

Postwar use and patterns

The patent for the gun was bought by SEMAG (''Seebach Maschinenbau

Aktiengesellschaft (; abbreviated AG, ) is a German word for a corporation limited by share ownership (i.e. one which is owned by its shareholders) whose shares may be traded on a stock market. The term is used in Germany, Austria, Switzerland (where it is equ ...

'') in 1921, who continued development with a more powerful cartridge as the ''SEMAG L''. After the collapse of SEMAG Oerlikon took over the SEMAG assets in 1924, marketing improved versions as the Oerlikon F, Oerlikon L and

Oerlikon S The Oerlikon 20 mm cannon is a series of autocannons, based on an original German Becker Type M2 20 mm cannon design that appeared very early in World War I. It was widely produced by Oerlikon Contraves and others, with various models empl ...

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

bought eight 20 mm Semag rifles. During the

Chaco War The Chaco War ( es, link=no, Guerra del Chaco, gn, Cháko ÑorairõParaguay Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to t ...

ans.

Description

The Type M2 was a slim weapon working on the principle of advanced primer ignition blowback. It weighed only 30 kg. It was fed by a somewhat awkward, curved box magazine, available in versions that held 10 or 15 rounds; the latter weighed another 5 kg. As the rate of fire was 325 rounds per minute, this magazine could be emptied very quickly. The muzzle velocity was 490 m/s, which was low compared to the rifle-calibre machine guns of the period such as the German

MG 08 The ''Maschinengewehr'' 08, or MG 08, was the German Army's standard machine gun in World War I and is an adaptation of Hiram S. Maxim's original 1884 Maxim gun. It was produced in a number of variants during the war. The MG 08 served during Wo ...

, but a respectable performance compared to other automatic cannon of the period, such as the Vickers QF 1 pounder pom-pom.

Applications

* Friedrichshafen G.I *

AEG G.IV The AEG G.IV was a biplane bomber aircraft used in World War I by Germany. It was developed from the AEG G.III, with refinements to power, bomb-load and dimensions. Coming into service in late 1916, it featured a bomb capacity twice as large as ...

* AEG J.II *

Albatros D.II The Albatros D.II was a German fighter aircraft used during World War I. After a successful combat career in the early ''Jagdstaffeln'', it was gradually superseded by the Albatros D.III. Design and development Albatros designers Robert Thelen, ...

* Albatros J.I *

Caspar D.I Caspar is a masculine given name. It may refer to: People * Caspar (magus), a name traditionally given to one of the Three Magi in the Bible who brought the baby Jesus gifts *Caspar Austa (born 1982), Estonian cyclist *Caspar Badrutt (1848–1904) ...

LVG C.V The LVG C.V was a reconnaissance aircraft produced in large numbers in Germany during World War I.Taylor 1989, 615 Design and development The C.V was a conventional two-bay biplane design of its day, with unstaggered wings of equal span and tan ...

Competing German designs

During World War I, at least two other German 20 mm autocannons were designed and saw limited production. One was the

2cm Ehrhardt CM or its variants may refer to: Arts and media Gaming * ''Championship Manager'', a popular football management simulation game * ''Chessmaster'', a chess computer program series Music * C minor, abbreviated Cm, a minor scale or chord based ...

, the other was the 19 mm (sometimes reported as 20 mm) Szakats.Chinn (1951), 523–525