Recoilless gun
A recoil-free gun is a military weapon in which the recoil is counterbalanced or greatly reduced by suitable measures. Recoilless guns come in many sizes; from the light shoulder weapon , to mounted guns with operating crew, to guns on self-propelled guns .
principle
When a projectile is fired from a firearm , an impulse is transmitted to the weapon - according to the principle of conservation of momentum. This determines the strength of the recoil.
The speed of the recoil movement of the weapon results from the mass of the projectile, its speed, the ratio of the weapon mass to the projectile mass and the rocket effect of the powder gases flowing out of the barrel . Their energy can be estimated because the mass of the propellant used is known and the speed of the powder gases can be empirically set at around 1200 m / s ± 10%.
With recoil-free weapons, this rocket effect is used to compensate for the recoil caused by the projectile by allowing the greater part of the powder gases to flow out of the weapon against the direction of flight of the projectile. However, this also results in a larger cloud of combustion, through which the position of the fire is usually cleared up quickly.
Historical development
The development of guns with increasingly powerful effects led to the problem that these weapons also became heavier and heavier. Because of the strong recoil, even when using muzzle brakes and hydraulic barrel return , it was necessary to construct increasingly stronger mounts and beds. Transport and operation of such guns became more and more complex.
Counter-mass cannon
The counter-mass cannon is a forerunner of the recoilless gun. One of the first known designs comes from Leonardo Da Vinci (1452–1519).
Shortly before the First World War , the US Navy developed the Davis counter-mass cannon . The propellant charge was placed between two tubes . In one was the actual bullet, in the other a counterweight equal in weight to the bullet, made from a mixture of fat and shotgun shot . By igniting the propellant charge, the projectile was fired in the target direction and the countermass was ejected backwards at the same speed. The cannons were only used operationally to a very limited extent as aircraft armament during the war. The counterweight that was thrown backwards remained a dangerous risk. The barrel of the weapon was unwieldy at up to 3 m. Ultimately, better aerial bombs and their dropping systems made the Davis cannon obsolete.
Rheinmetall-Borsig developed several prototypes of counter-mass guns as aircraft armament in Germany during World War II. The SG 104 special device was an 11 m long pipe that was installed under the Dornier Do 217 bomber . With a total weight of 3.4 t, it should fire a 680 kg projectile against capital ships . As a major problem, the set pressure wave of the muzzle blast out. In addition, the special devices SG 113 and SG 116 were tested. These weapons should be used to fire at ground targets from above or air targets from below.
The principle of the counter mass was later rediscovered for light recoilless anti-tank weapons. The Yugoslav RB M57 , introduced in 1957, used sand as a counterweight. The crossbow developed in the late 1980s , like its successor Matador , knocked out bits of plastic . A version of the FFV AT4 specially developed for house warfare uses salt water as a counter mass. The use of a counter mass in a light anti-tank hand weapon is primarily intended to minimize the dangerous back beam. The weapons can be shot from confined spaces without endangering the shooter.
Soviet Union
Even before the turmoil of the February Revolution of 1917, the Russian mathematician Dmitri Pawlowitsch Rjabuschinski laid the theoretical foundations for recoilless guns without countermass. In the interwar period , Leonid Wassiljewitsch Kurtschewski built on this work and developed the first recoilless guns. Many prototypes and also some weapons, e.g. B. u. a. the 76-mm dynamo-reactive cannon and a cannon as aircraft armament were ready for use. However, the guns were unreliable and had too low a muzzle velocity . Kurtschewski and his supporters actually wanted to achieve a change in armament from conventional to recoilless guns and overestimated themselves in the process. As a result, all recoilless guns were eliminated from the Soviet armed forces by mid-1941. The recoil-free principle was so discredited in the Soviet Union that no further development took place in the following years.
Germany
A well-known development are the so-called light guns. This system used a cartridge with a plastic base ( Bakelite ) that was destroyed by the explosion of the propellant charge. The gases escaped through an opening at the end of the gun, which was shaped as a Laval nozzle . The ignition device was on the side of the cartridge. This design was used with the 7.5 cm light gun 40 , the 10.5 cm light gun 40 and the 10.5 cm light gun 42, among others by German paratroopers in the airborne battle of Crete .
Great Britain
The closure of the system invented by Sir Dennistoun Burney corresponded to that of conventional cannons , but with holes in the chamber, which was surrounded by a second chamber, which opened into gas outlet openings for discharging the propellant gases.
The sleeves of the cartridges had holes that were closed with brass covers.
When the powder of the propellant charge was ignited, the strips tore and the gas flowed out of the holes into the chamber and through the gas outlet openings to the outside.
United States
With Kromuskit, Kroger and Musser developed a system similar to Burney's for the USA. Kromuskit also uses perforated cartridges that allow propellant gas to escape into an annular chamber and then further through openings at the end of the gun.
In addition, the guide ring of the grenades had pre-stamped pulls so that less force was required to push the projectile through the pipe pulls. This made the construction even easier.
disadvantage
The exhaust jet emerging at the rear of recoilless guns must be taken into account when choosing the position and makes it relatively easy to detect a firing gun through the recoil jet and the resulting cloud of propellant charge.
The need for propellant is much greater than with conventional cannons, since only about 20% of the propellant is available for projectile propulsion and the rest of the propellant escapes to the rear.
Using the principle for portable weapons
The principle of the recoilless gun can also be used for portable recoilless anti-tank guns . The Germans used the fist cartridge as early as 1942 and the bazooka from 1943 . The Bundeswehr also used weapons based on this principle with the Panzerfaust 44 , the Carl Gustav or the Panzerfaust 3 , as did the armies of the Soviet sphere of influence, for example with the RPG-2 .
Some more modern developments like the Soviet-Russian RPG-7 represent a combination of recoilless gun and rocket launcher. Here the projectile is a rocket ; their propellant is ignited only after leaving the launch tube at some distance, so as not to endanger the shooter by the flame beam. During the launch, this is also a recoilless gun.
Recent developments
In some newer designs, instead of or in addition to the combustion exhaust gases, a large number of plastic pellets are expelled rearward. Since these have a greater density than gas, a correspondingly lower exit velocity is sufficient to compensate for the recoil. Both the flashback and the consumption of propellant are greatly reduced. Examples of this technology are the Panzerfaust 3 or the anti-tank weapon crossbow . With the latter, the plastic beads are ejected through a piston, which then seals the end of the tube; this even completely prevents the escape of telltale combustion gases.
Civil use
The principle of the counter-mass cannon was also used for research purposes. The Sandia National Laboratories led in 1975 penetration tests of the soil by using a device working on the principle.
literature
- John Batchelor, Ian Hogg : Artillery. The gun, railway guns, coastal guns, flak, anti-tank guns, self-propelled guns, recoilless guns, detonators. = The history of the artillery. Wilhelm Heyne Verlag, Munich 1977, ISBN 3-453-52068-8 .
Web links
Individual evidence
- ^ David Miller, Christopher F. Foss: Modern Land Combat , Portland House, 1987, ISBN 0517638541 pp. 36-37
- ↑ Nuri Y. Olcer, Sam Lévin: Recoilless Rifle Weapon Systems , published by US Department of Defense, Army Materiel Command, 1976 S. 1-3 [1]
- ↑ George M. Chinn: The Machine Gun: History, Evolution, and Development of Manual, Automatic, and Airborne Repeating Weapons , Department of the Navy , 1951 pp. 495-499 [2]
- ^ Rob Langham: Bloody Paralyser: The Giant Handley Page Bombers of the First World War , Fonthill Media, 2017 pp. 51–52 [3]
- ↑ George M. Chinn: The Machine Gun: History, Evolution, and Development of Manual, Automatic, and Airborne Repeating Weapons , Department of the Navy , 1951 pp. 495-499 [4]
- ^ Ian Hogg: German Secret Weapons of the Secret World War: The Missiles, Rockets, Weapons & New Technology of the Third Reich , Verlag Frontline Books, 2015 ISBN 9781473877672 , p. 44 [5]
- ↑ Paul Newhouse: Rocket vs. Recoilless , in: "Small Arms Defense Journal" August 17th, 2011 V1N3, Volume 1
- ^ David MO Miller, Christopher F. Foss: Modern Land Combat , Verlag Salamander Books, 1987, ISBN 0517638541 p. 162
- ↑ Syed Ramsey: Tools of War: History of Weapons in Modern Times , Verlag Vij Books India, 2016, ISBN 9789386019837 p. 208 [6]
- ↑ Nigel Cawthorne: The Mammoth Book of Inside the Elite Forces , Verlag Hachette UK, 2012, ISBN 9781780337319 p. 212 [7]
- ↑ Nuri Y. Olcer, Sam Lévin: Recoilless Rifle Weapon Systems , Verlag US Department of Defense, Army Materiel Command, 1976 pp. 1–3 [8]
- ^ Peter G. Dancey: Soviet Aircraft Industry. Fonthill Media, 2017, ISBN 9781781552896 , p. 87 [9]
- ↑ Leonid Kurchevsky - Dynamo-Reactive Gun DRP in: GlobalSecurity.org
- ↑ Larry O. Seamons: A Davis gun penetrator launch system in: The Shock and Vibration Bulletin 1975 pp. 81–85 [10]