Red King and Red Queen were experimental

revolver cannon A revolver cannon is a type of autocannon, commonly used as an aircraft gun. It uses a cylinder with multiple chambers, like those of a revolver handgun, to speed up the loading-firing-ejection cycle. Some examples are also power-driven, to fur ...

anti-aircraft gun Anti-aircraft warfare, counter-air or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It includes surface based, ...

s developed for the

British Army The British Army is the principal land warfare force of the United Kingdom, a part of the British Armed Forces along with the Royal Navy and the Royal Air Force. , the British Army comprises 79,380 regular full-time personnel, 4,090 Gurk ...

during the 1950s. Red King was a two-barrel design from Oerlikon, Red Queen was a single-barrel water-cooled design. The project was cancelled with the introduction of the Bofors 40 mm/L70, which became the standard anti-aircraft gun for the Army until it was replaced by the

Rapier missile Rapier is a surface-to-air missile developed for the British Army to replace their towed Bofors 40/L70 anti-aircraft guns. The system is unusual as it uses a manual optical guidance system, sending guidance commands to the missile in flight over ...

in the 1970s.

History

Red King

In the late 1940s the

began the process of replacing their

Bofors 40 mm L/60 gun The Bofors 40 mm Automatic Gun L/60 (often referred to simply as the "Bofors 40 mm gun", the "Bofors gun" and the like, see name) is an anti-aircraft autocannon, designed in the 1930s by the Swedish arms manufacturer AB Bofors. The gu ...

guns. The introduction of higher-performance aircraft, especially jet-powered

fighter-bomber A fighter-bomber is a fighter aircraft that has been modified, or used primarily, as a light bomber or attack aircraft. It differs from bomber and attack aircraft primarily in its origins, as a fighter that has been adapted into other roles, wh ...

s and

light bomber A light bomber is a relatively small and fast type of military bomber aircraft that was primarily employed before the 1950s. Such aircraft would typically not carry more than one ton of ordnance. The earliest light bombers were intended to dro ...

s, proved to fly so fast that they exited the effective range of the Bofors before it could get enough rounds out to have a reasonable possibility of hitting the target. A gun with higher ballistic performance would increase the range, and thus reaction time, and a much higher firing rate was also desirable. Oerlikon heard of the concept and proposed an entirely new

using a 42 mm calibre round fired from a twin-barrel gun operated by a single seven-chamber. The Army was interested and offered a development contract in 1950. Oerlikon assigned the project the name "421 RK", for "42mm, model 1, Revolver Kanon", which was given the

Ministry of Supply The Ministry of Supply (MoS) was a department of the UK government formed in 1939 to co-ordinate the supply of equipment to all three British armed forces, headed by the Minister of Supply. A separate ministry, however, was responsible for aircr ...

rainbow code The Rainbow Codes were a series of code names used to disguise the nature of various British military research projects. They were mainly used by the Ministry of Supply from the end of the Second World War until 1958, when the ministry was broke ...

"Red King".

Red Queen

For reasons that are not recorded in available materials, in 1952 the Army decided to design their own AA gun of similar performance. This was assigned the name "Red Queen". They kept the same 42 mm shell but introduced a shorter and wider cartridge case, likely to ease operation of the chamber. In contrast to Red King, a single water-cooled barrel was used. A large disk-shaped magazine on the left side of the barrel, as seen from behind, carried the rounds.

Cancellation

Both projects appear to have had low priority and little documentation on either appears after 1957. 421RK continued to at least 1958, while Red Queen appears to have been abandoned before then due to development problems. The last mention of either project is in a 1960 memo about leftover test rounds for the Red King.

Notes

References