Davis cannon

from Wikipedia, the free encyclopedia
Davis cannon on a Curtiss HS flying boat . The shooting machine gun is attached above the gun barrel.
Charging process
Principle: 1) tube, 2) projectile, 3) propellant charge, 4) counter mass
Sectional images of the ammunition
British attempts at firing on an improvised gun carriage.
Davis cannon on a US submarine hunter (behind the lifeboat, recognizable by the distinctive C-shaped handle)

The Davis cannon or the Davis gun was the first recoilless gun . The Davis cannon worked on the principle of the counter mass d. H. when the projectile was fired, the countermass was hurled in the opposite direction. The light and recoilless weapon seemed ideal for the fragile aircraft of the time. However, it was only used to a limited extent by the United Kingdom and the United States during World War I. Various design disadvantages and the further development of weapon technology made the Davis cannon obsolete.

Development and technology

The developer was Cleland Davis, an officer of the United States Navy . Davis was a weapons expert and was familiar with, among other things, the field test of the M1895 Colt-Browning machine gun in the Spanish-American War .

When the powered aircraft became practicable at the beginning of the 20th century , ideas quickly arose as to how it could be used militarily . Davis dealt with how one could fight point targets on the ground or on the water from an airplane . A conventional gun generated too much recoil for the fragile aircraft of the time . Davis had an idea how to neutralize the recoil. A counter mass should be hurled in the opposite direction of the projectile ; this would cancel out the two forces and the weapon would be recoil-free. From 1906 he worked on his invention. From 1911 to 1913 he applied for several patents. The first experiments took place in October 1912. The principle of a counter-mass cannon was known per se for a long time; one of the first known designs comes from Leonardo Da Vinci . However, no operational weapon based on this principle has yet been developed.

In the first version, the tube served as a counterweight. That made the gun single-shot because it could no longer be reloaded. The next evolution was a tube that was open on both sides, which could be divided in the middle and the rear half opened for reloading. The connection between the two pipes was a screw lock . The ammunition consisted of the projectile, the propellant charge and the counterweight in a cartridge case . The propellant charge accelerated the projectile and the countermass from the cartridge case in opposite directions. Initially, the gun had a smooth barrel . Davis found that the barrel could be rifled if the rotation of the bullet was canceled by an opposite rotation of the counter mass.

The test models were equipped with an electric lighter . The operational models, on the other hand, had a conventional lighter based on the percussion principle . The position of the detonator was unusual; not on the bottom of the cartridge as is conventional , but on its side. Therefore, the cartridge had to be positioned so that the detonator was under the firing pin. To ensure this, it had a centering nose that fitted into a bulge in the cartridge chamber. The cartridge was a rim cartridge ; the rim prevented the cartridge from sliding further into the barrel. Instead of a massive cartridge base, there was only a thin cap made of tin or brass. The counterweight was thrown backwards through this cartridge base. This consisted of shotgun pellets poured into Vaseline . There was also another type of ammunition in which the cartridge case formed the counterweight and was ejected completely backwards.

The Davis cannon had a new type of aiming device. A Lewis machine gun was mounted on the barrel of the gun as a sighting weapon. The shooter fired the machine gun until the projectiles hit the target. Only then did he pull the trigger on the gun. A stop on the mount ensured that it was only possible to fire downwards; the counter mass was thrown over the aircraft, as otherwise the counter mass could have damaged the aircraft.

The weapon was available in different calibers , indicated either as bullet weight or diameter: 2pdr (0.91 kg), 6 pdr (2.72 kg), 9 pdr (4.08 kg), 12 pdr (5.4 kg), 2.25 inch (57 mm), 3 inch (76 mm), 5 inch (127 mm). In addition, there were different bullets with conventional point and flat head bullets, which were ascribed better penetration.

commitment

Even before the First World War, the British were testing smooth-barreled Davis cannons. The accuracy at the time was not satisfactory. After the outbreak of war, the British Admiralty ordered some Davis cannons from the General Ordnance Company in Connecticut for testing purposes. The tests carried out from a flying boat were promising and 300 guns were ordered. The Royal Naval Air Service planned to use the weapon against German submarines and mounted it on some Curtiss HS-2L flying boats and four HP O / 100 bombers. On the western front , these bombers were used against ground targets such as supply convoys and railways. The British officially withdrew the Davis cannon in February 1918, probably as early as August 1917, because it has not been mentioned in the operational reports since then.

The British are making further attempts with the Royal Aircraft Factory BE2 , which served as an interceptor for Zeppelins . However, this plane was too small for the Davis cannon. A larger aircraft, the Robey-Peters Gun-Carrier , was specially designed to carry the weapon, but after the prototype crashed, that project was no longer pursued. Another weapon platform for anti-zeppelin defense was supposed to be the Supermarine Nighthawk , but work on the prototype was canceled due to insufficient airspeed. The British considered equipping armored vehicles with this weapon.

The United States Navy tried the Davis cannon only from 1917; 149 pieces were ordered. The weapon was installed on some flying boats and was intended to be used against submarines. Also a new American aircraft, the Naval Aircraft Factory N-1, was supposed to carry the weapon, but after two crashes this project was canceled. The Davis cannons were dismantled from the aircraft by 1920 at the latest. Some anti-submarine boats of the SC-1 class were equipped with it. There were also considerations to use the Davis cannon on troop transports and submarines (as a deck gun). The United States Army made no move to use the weapon on land.

Ultimately, the Davis cannons were only used operationally to a very limited extent. Neither the British nor the Americans were happy with the weapon. The ammunition's effect against submarines was unsatisfactory. Variants with smaller calibers were too weak to damage the hull, variants with larger calibres (such as the 5 inch) were too big for the aircraft of the time. The ammunition was heavy and large because of the counter mass. 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.

Aftermath

The Davis cannon was the only operational recoilless gun in World War I. After the armistice, the concept was no longer pursued in the United States. It was not until the Second World War that recoilless guns were used again by the Soviet Union and the German Reich . Although the German Reich developed prototypes based on counter-masses, the principle without counter-masses prevailed. The counter pulse was generated by the powder gases of the propellant charge. With some recoilless anti-tank weapons (e.g. the Panzerfaust 3 ) the countermass principle is used again. The advantage is that these weapons can also be fired from closed spaces.

Despite the limited success of the weapon, the name Davis remained associated with the principle of the counter-mass cannon.

Preserved copies

The few surviving specimens of the Davis cannon can be seen in the National Museum of Naval Aviation in Pensacola and the Imperial War Museum in London .

Patents

Web links

Commons : Davis gun  - collection of images, videos and audio files

Individual evidence

  1. ↑ Beat P. Kneubuehl : Ballistics: Theory and Practice , Springer-Verlag , 2018, ISBN 978-3-662-58300-5 , p. 117 books.google.de
  2. ^ Scientific Society for Aviation : Yearbook of the Scientific Society for Aviation e. V: 1912 / 13-1916, 1918-1929 , Verlag J. Springer, p. 117 books.google.de
  3. ↑ a b c d e f 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 ibiblio.org
  4. ^ A b c Rob Langham: Bloody Paralyser: The Giant Handley Page Bombers of the First World War. Fonthill Media Verlag, 2017, pp. 51–52 books.google.de
  5. ↑ a b c d e f A. B. Fire: The US Navy in World War I: Combat at Sea and in the Air. Praeger Publishing, 1999, pp. 135-137 books.google.de
  6. ↑ Naval Weapons Bureau: United States Naval Aviation, 1910-1960. 1961, p. 6 [c]
  7. ↑ Nuri Y. Olcer, Sam Lévin: Recoilless Rifle Weapon Systems. US Department of Defense, Army Materiel Command, 1976, pp. 1-3 books.google.com
  8. ^ A b c Charles E. Lucke, Great Lakes Naval Training Center, Navy Gas Engine School: United States Navy Aviation Mechanics 'Training System for Miscellaneous Maintenance Force: Course Manual for Gunner's Mates' (A) (armorers) Course, 1919, p 208-221 books.google.de
  9. ↑ a b United States Department of the Navy , Bureau of Ordnance: Navy Ordnance Activities: World War, 1917-1918 , Verlag United States Government Printing Office , 1920, p. 142 books.google.de
  10. ↑ a b c d e f Norman Friedman: Naval Weapons of World War One. Seaforth Publishing, 2011, ISBN 978-1-84832-100-7 , pp. 120, 194-196 books.google.de
  11. ↑ a b c Robert Guttman: The Navy's Flying Cannon on historynet.com, May 2017.
  12. ^ Jon Guttman: Zeppelin vs. British Home Defense 1915-1918. Verlag Osprey Publishing , 2018, ISBN 978-1-4728-2034-1 , p. 34 books.google.de
  13. ↑ Nuri Y. Olcer, Sam Lévin: Recoilless Rifle Weapon Systems. Publishing United States Army Materiel Command , 1976, pp 1-3 books.google.com
  14. ↑ Edward L. Oliver: Antiarmor. In: Infantry Vol. 74 No. 2, Department of the Army , March-April 1984, pp. 19-20 books.google.de
  15. ↑ How it Works: Science and Technology, Volume 11 , Marshall Cavendish Verlag , 2003, ISBN 0-7614-7325-4 , p. 1485 books.google.de
  16. ↑ Larry O. Seamons: A davis gun penetrator launch system. In: The Shock and Vibration Bulletin 1975, p 81-85 books.google.de
  17. ↑ Davis Recoilless Gun in National Naval Aviation Museum
  18. ^ Ian Hogg: The Guns 1939-45. Ballantine Books, 1970, pp. 140-41 excerpt