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A proximity fuze (also called a VT fuze, for "variable time") is a fuze that is designed to detonate an explosive automatically when the distance to target becomes smaller than a predetermined value or when the target passes through a given plane. There are different sensing principles: Image File history File links Size of this preview: 423 × 599 pixel Image in higher resolution (506 × 717 pixel, file size: 60 KB, MIME type: image/jpeg) (All user names refer to en. ...
In an explosive device, a fuse (or fuze) is the part of the device that causes it to function. ...
This article is concerned solely with chemical explosives. ...
- radio frequency sensing
- optical sensing
- acoustic sensing
- magnetic sensing
Radio frequency sensing
Radio frequency sensing is the main sensing principle for shells and this is mostly in mind when one speaks of "proximity fuzes".
The WW2 patent works as follows: The shell contains a radio transmitter which uses the shell body as antenna and emits a continuous wave of roughly 180 - 220 MHz. As the shell approaches a reflecting object, an interference pattern is created. This pattern changes with shrinking distance: every half wavelength in distance, the transmitter is in or out of resonance. This causes a small oscillation of the radiated power and consecutively the oscillator supply current of about 200 - 800 Hz, the Doppler frequency. This signal is sent through a band pass filter, amplified, and triggers the detonation when it exceeds a given amplitude.
Before the fuze's invention, detonation had to be induced by direct contact, a timer set at launch, or an altimeter. All of these have disadvantages. Getting direct contact with a relatively small moving target is hard (even ignoring the effect of wind); to set a time- or height-triggered fuze one must measure the height of the target (or even predict the height of the target at the time one will be able to get a shell or missile in its neighbourhood). With a proximity fuze, all one has to worry about is getting a shell or missile on a trajectory that, at some time, will pass close by the target. This is still not a trivial task, but it is much easier than previous methods were. Exocet missile in flight A missile (see also pronunciation differences) is a projectile propelled as a weapon at a target. ...
A shell is a projectile, which, as opposed to a bullet, contains an explosive or other filling, though modern usage includes large solid projectiles previously termed shot (AP, APCR, APCNR, APDS, APFSDS and Proof shot). ...
Use of timing to produce air bursts against ground targets requires observers to provide information for adjusting the timing. This is not practical in all situations and is slow in any event. Proximity fuzes remove these problems.
The proximity fuze was invented in the UK in 1940, but developed mainly by the U.S. (with British collaboration) during World War II. Vannevar Bush, head of the U.S. Office of Scientific Research and Development (OSRD) during this war, credits it with three significant effects. It was important in defense from Japanese Kamikaze attacks in the Pacific. It was an important part of the radar-controlled anti-aircraft batteries that finally neutralized the German V-1 bomb attacks on England. Third, it was released for use in land warfare just in time for use in the Battle of the Bulge, where it decimated German divisions caught in the open. The Germans felt safe from timed fire because the weather prevented accurate observation. Bush cites an estimated seven times increase in the effect of artillery with this innovation. Motto: (Out Of Many, One) (traditional) In God We Trust (1956 to date) Anthem: The Star-Spangled Banner Capital Washington D.C. Largest city New York City None at federal level (English de facto) Government Federal constitutional republic - President George Walker Bush (R) - Vice President Dick Cheney (R) Independence from...
Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki TÅjÅ Casualties Military dead: 17,000,000 Civilian dead: 33,000...
Vannevar Bush (March 11, 1890 – June 30, 1974) was an American engineer and science administrator, known for his political role in the development of the atomic bomb, and the idea of the memex—seen as a pioneering concept for the World Wide Web. ...
In June of 1941, the Office of Scientific Research and Development (OSRD) superseded the committee structure [of the National Defense Research Committee (NDRC)]. The OSRD projects gave the United States and Allied troops more powerful and more accurate bombs, more reliable detonators, lighter and more accurate weapons, safer and more...
It has been suggested that Personnel involved in the development of World War II suicide attacks be merged into this article or section. ...
The Pacific Ocean (from the Latin name Mare Pacificum, peaceful sea, bestowed upon it by the Portuguese explorer Ferdinand Magellan)is the largest body of water on Earth – at 165. ...
The Vergeltungswaffe-1, V-1, also designated Fieseler Fi 103/FZG-76, known colloquially in English as the Flying bomb, Buzz bomb or Doodlebug, was the first guided missile used in war and the forerunner of todays cruise missile. ...
Motto: (French for God and my right) Anthem: God Save the King/Queen Capital London (de facto) Largest city London Official language(s) English (de facto) Unification - by Athelstan AD 927 Area - Total 130,395 km² (1st in UK) 50,346 sq mi Population - 2006 est. ...
Combatants United States United Kingdom Germany Commanders Dwight D. Eisenhower Bernard Montgomery Omar N. Bradley George S. Patton, Jr. ...
Optical sensing Optical sensing was also developed first in WW2, mainly for anti-aircraft missiles. It used then a toroidal lens, that concentrated all light out of a plane perpendicular to the missile's main axis onto a photo cell. When the cell current changed a certain amount in a certain time interval, the detonation was triggered.
Some modern air-to-air missiles make use of lasers. They project narrow beams of laser light perpendicular to the flight of the missile. As the missile cruises towards the target the laser energy simply beams out into space. However, as the missile passes its target some of the laser energy strikes the target and is reflected back towards the missile where detectors sense the reflected laser energy and trigger the missile warhead. A US Navy VF-103 Jolly Rogers F-14 Tomcat fighter launches an AIM-54 Phoenix long-range air-to-air missile. ...
For other uses, see Laser (disambiguation). ...
Acoustic sensing Acoustic sensing used a microphone in a missile. The characteristic frequency of an aircraft engine was filtered and triggered the detonation. This principle was applied in German anti-aircraft missiles, which were mostly still in development when the war ended.
Magnetic sensing Magnetic sensing can only be applied to detect huge masses of iron such as ships. It is being used in mines and torpedoes.
References - Pieces of the Action by Vannevar Bush, William Morrow and Co., inc. 1970
- An account of the development and initial introduction of proximity fuzes is given in The Deadly Fuze by Ralph B Baldwin (UK Edition published by Janes, 1980. ISBN 0-354-01243-6. Dr Baldwin was a member of the Johns Hopkins University team headed by Merle A Tuve that did most of the work.
Vannevar Bush (March 11, 1890 – June 30, 1974) was an American engineer and science administrator, known for his political role in the development of the atomic bomb, and the idea of the memex—seen as a pioneering concept for the World Wide Web. ...
The Johns Hopkins University, founded in 1876, is a private institution of higher learning located in Baltimore, Maryland, United States. ...
See also Look up Proximity fuze in Wiktionary, the free dictionary. The M734 Fuze consists of four types of detonation sequences: Proximity burst above 3 to 13 feet. ...
Wikipedia does not have an article with this exact name. ...
It has been suggested that French Wiktionary be merged into this article or section. ...
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