ADEN cannon

British testing of German 30 mm mine shell on a Bristol Blenheim. Single shot test.

During World War II, the German firm Mauser began development of a radically new 20 mm autocannon using a motorised firing mechanism in order to improve the rate of fire. The weapon was designed for 20mm mine shell rounds (designated the Mauser MG 213 and for 30mm rounds (the Mauser MK 213). However, production of the MK 213 never commenced due to development problems such as excessive barrel wear, not to mention the Allied Combined Bomber Offensive campaign against German industry.[7] At the end of the war only 5 prototypes (V1 to V5) of either 20 mm MG 213 or 30 mm MK 213 were finished.[7]

In the post-war era, the MK 213 became well known in armament circles, and a number of companies took up development. This included the Armament Development Establishment in the UK and GIAT in France. A common 30×111mm round[2][3] was developed that offered a dramatic improvement in muzzle velocity from the MK 108's 540 m/s to the new design's 790 m/s (2,600 ft/s). This was only slightly lower than contemporary 20 mm cannon like the Hispano Mk. V's 840 m/s (2,800 ft/s), making the new round suitable for use during dogfights as well as against larger targets. The mechanism improved the rate of fire from the Mk. V's 750 rpm to 1,300 rpm, a significant improvement.[1] The new weapon was quickly developed and production was set up at the Royal Small Arms Factory in Enfield. The name ADEN was created by combining the two first initials of Armament Development Establishment with the first two letters of Enfield, producing ADEN.[2]

The ADEN cannon entered service on the British Hawker Hunter in 1954, and was subsequently used on every British gun-armed aircraft until the advent of the Panavia Tornado in the 1980s.[5] The last version to see production was the Mk. 4. An improved version, the Mk. 5, incorporates a multitude of small changes to improve reliability and increase rate of fire to 1,500–1,700 rounds per minute. No new Mk 5s were built, but many older weapons were converted, being redesignated "Mk 5 Straden".[1]

GIAT also introduced their version of the design as the DEFA cannon; the two weapons are very similar.[5]

The Aden is belt feed using a disintegrating belt of open type links.

• Type: Single-barrel aircraft autocannon
• Action: Revolver drum with 5 chambers[10]
• Operation: Gas operation[1]
• Cocking-system: Pneumatic[1]
• Priming: Electronic firing[1]
• Firing-system: Electrical 26 volts DC
• Rifling: Progressive RH parabolic twist, 16 grooves[1]
• Cartridge: 30 × 111 mm[2][3]
• Calibre: 30 mm (1.18 in)
• Weight of complete weapon: 87.1 kg (192 lb), 196 kg (432 lb) with 200 rounds[5]
• Length of complete weapon: 1,590–1,639 mm (5 ft 2.6 in – 5 ft 4.5 in)[1][10]
• Weight of barrel: 12.25 kg (27.0 lb)[1]
• Length of barrel: 1,080 mm (3 ft 6.5 in)[1]
• Recoil load: 31.4 kN
• Rate of fire: 1,200–1,500 rpm (ADEN Mk. 4),[10] 1,500–1,700 rpm (ADEN Mk.5)

Ammunition

Swedish 30 mm High Explosive Mk.3Z[11][3]
30 mm mgr m/55[lower-alpha 1]

Swedish 30 mm Practice Mk.2Z[11][3]
30 mm övnprj m/55[lower-alpha 2]

Ammunition for the ADEN included.[2][3]

High Explosive (High Explosive Mk.3Z[lower-alpha 3] [3])

• Projectile type: "High-Explosive, High-Capacity"[11]
• Fuze type: Nose fuze[11]
• Explosive filling: 52.5 g (1.85 oz)[10] Torpex 5[3] (Hexotonal)[11]
• Cartridge weight: 440 g (15.5 oz)[2]
• Projectile weight: 220 g (7.76 oz)[2]
• Propellant weight: 46 g (1.62 oz)[2]
• CU-pressure: 2930 bar[2]
• Muzzle velocity: 795 m/s (2,610 ft/s) [lower-alpha 4] [2]

Armour-piercing (30 mm pprj m/55[lower-alpha 5] Sweden[2])

• Projectile type: Armour-Piercing, Composite Rigid[10]
• Fuze type: None[10]
• Core type: Tungsten penetrator[10]
• Cartridge weight: 511 g (18.0 oz)[2]
• Projectile weight: 270 g (9.52 oz)[2]
• Core weight: 150 g (5.29 oz)[10]
• Propellant weight: 47 g (1.66 oz)[2]
• CU-pressure: 2930 bar[2]
• Muzzle velocity: 795 m/s (2,610 ft/s)[lower-alpha 4][2]

Target practice (Practice Mk.2Z[lower-alpha 6], UK )[3]

• Projectile type: Inert solid metal plug in place of fuze and explosive charge[11]
• Cartridge weight: 440 g (15.5 oz)[2]
• Projectile weight: 220 g (7.76 oz)[2]
• Core weight: 80.5 g (2.84 oz)[11][2]
• Propellant weight: 46 g (1.62 oz)[2]
• CU-pressure: 2930 bar[2]
• Muzzle velocity: 795 m/s (2,610 ft/s)[lower-alpha 4][2]

• Mauser BK-27 – comparable German design
• M39 cannon – comparable US design
• Oerlikon KBA - comparable Swiss design
• R-23 cannon – comparable Russian design
• VENOM LR 30 mm – 21st century derivative, designed to fire from RCWS

• Mauser and Aden Cannon (RAF source)