Fuse (explosives)

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A smoke bomb with a lit fuse Smoke bomb with burning fuse.jpg
A smoke bomb with a lit fuse

In an explosive, pyrotechnic device, or military munition, a fuse (or fuze) is the part of the device that initiates function. In common usage, the word fuse is used indiscriminately. However, when being specific (and in particular in a military context), the term fuse [1] describes a simple pyrotechnic initiating device, like the cord on a firecracker whereas the term fuze [2] [ unreliable source? ] [3] [4] is used when referring to a more sophisticated ignition device incorporating mechanical and/or electronic components, such as a proximity fuze for an M107 artillery shell, magnetic or acoustic fuze on a sea mine, spring-loaded grenade fuze, [5] [6] [7] pencil detonator, or anti-handling device. [8]

Contents

History

A burning length of fuse Fuse burning.jpg
A burning length of fuse

Documented evidence suggests that the earliest fuses were first used by the Song Chinese between the 10th and 12th centuries. After the Chinese invented gunpowder, they began adapting its explosive properties for use in military technology. By 1044 they were using gunpowder in simple grenades, bombs, and flamethrowers. [9]

The simplest form of fuse is the burning fuse, believed to date back to the 10th century and originating during the medieval Chinese Song dynasty. This simple fuse consisted of lightweight paper filled with loose gunpowder, and served as a means of delaying ignition in fireworks. This simple form of burning fuse can still be found today in many modern fireworks. A version of this simple fuse is called visco fuse, and consists of the burning core coated with wax or lacquer for durability and water resistance. Early fuses for grenades also consist of a wooden plug with a longitudinal hole filled with a slow burning gunpowder mixture inserted into the grenade. Such fuses were in use until the 18th century. [10] The commercial and military version of a burning fuse referred to as safety fuse (invented by William Bickford) is a textile tube filled with combustible material and wrapped to prevent external exposure of the burning core. Safety fuses are used to initiate the detonation of explosives through the use of a blasting cap.

Fuses

Modern day safety fuses are often used in mining and military operations, to provide a time-delay before ignition, and they more often than not are used to initiate an explosive detonator, thereby starting an explosive chain reaction to detonate a larger more stable main charge. Safety fuses are typically colored green or black (military) or fluorescent orange (commercial) to distinguish them from detonating cords such as Primacord, which are brightly colored or transparent.

Usage

Fuses are found in pyrotechnics, model cannons, matchlock firearms, some improvised explosive devices, and many forms of fireworks.

Types

Burning fuses

See also

Related Research Articles

Fireworks Low explosive pyrotechnic devices for entertainment

Fireworks are a class of low explosive pyrotechnic devices used for aesthetic and entertainment purposes. The most common use of a firework is as part of a fireworks display, a display of the effects produced by firework devices.

Detonator Device used to trigger an explosion

A detonator, frequently a blasting cap, is a device used to trigger an explosive device. Detonators can be chemically, mechanically, or electrically initiated, the last two being the most common.

Pyrotechnics Science of creating combustibles and explosives for entertainment

Pyrotechnics is the science and craft of creating such things as fireworks, safety matches, oxygen candles, explosive bolts and other fasteners, parts of automotive airbags, as well as gas-pressure blasting in mining, quarrying, and demolition. This trade relies upon self-contained and self-sustained exothermic chemical reactions to make heat, light, gas, smoke and/or sound. The name comes from the Greek words pyr ("fire") and tekhnikos.

Shell (projectile) Payload-carrying projectile

A shell, in a military context, is a projectile whose payload contains an explosive, incendiary, or other chemical filling. Originally it was called a bombshell, but "shell" has come to be unambiguous in a military context. Modern usage sometimes includes large solid kinetic projectiles that is properly termed shot. Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used.

Sparkler Type of pyrotechnic device

A sparkler is a type of hand-held firework that burns slowly while emitting bright, intense colored flames, sparks, and other effects.

Slow match Slow-burning cord or twine fuse

Slow match, also called match cord, is the slow-burning cord or twine fuse used by early gunpowder musketeers, artillerymen, and soldiers to ignite matchlock muskets, cannons, shells, and petards. Slow matches were most suitable for use around black-powder weapons because a slow match could be roughly handled without going out, and only presented a small glowing tip instead of a large flame that risked igniting nearby gunpowder. Slow match of various types was one of the first kinds of artillery fuse.

Visco fuse

A visco fuse is a higher-quality fuse used for consumer fireworks. It is most commonly colored green or red, and is found as a twisted, coated strand. It is also used to create delays in the firing of multiple firework displays.

The military of the United States has used many different types of hand grenades since its foundation. Presented on this page is a basic overview.

A pyrotechnic composition is a substance or mixture of substances designed to produce an effect by heat, light, sound, gas/smoke or a combination of these, as a result of non-detonative self-sustaining exothermic chemical reactions. Pyrotechnic substances do not rely on oxygen from external sources to sustain the reaction.

A pyrotechnic initiator is a device containing a pyrotechnic composition used primarily to ignite other, more difficult-to-ignite materials, such as thermites, gas generators, and solid-fuel rockets. The name is often used also for the compositions themselves.

A plastic igniter cord (PIC) is a type of fuse used to initiate an explosive device or charge. In appearance igniter cord is similar to safety fuse and when ignited, an intense flame spits perpendicular to the cord at a uniform rate as it burns along its length. Igniter cord in the construction and demolition industry is similar to a safety fuse, consisting of a pyrotechnic composition at the core, wrapped with a nylon sheath to provide shape and finally wrapped again in an outer plastic shell to provide water resistance. Normally, igniter cord also consists of a metal wire at the very center of the pyrotechnic core which also runs the entire length of the cord; the pyrotechnic composition will react with the metal wire to increase the energetics of the fuse. There are two types of PICs: the fast type which has nominal burning speed of 30 cm per second, a diameter of about 3 mm, and is brownish in color; and the slow type, which has a diameter of 2 mm, is greenish in color, and has a nominal burning speed of 3 cm per second.

In military munitions, a fuze is the part of the device that initiates function. In some applications, such as torpedoes, a fuze may be identified by function as the exploder. The relative complexity of even the earliest fuze designs can be seen in cutaway diagrams.

Grenade Small bomb that can be thrown by hand

A grenade is an explosive weapon typically thrown by hand, but can also refer to a shell shot from the muzzle of a rifle or a grenade launcher. A modern hand grenade generally consists of an explosive charge ("filler"), a detonator mechanism, an internal striker to trigger the detonator, and a safety lever secured by a cotter pin. The user removes the safety pin before throwing, and once the grenade leaves the hand the safety lever gets released, allowing the striker to trigger a primer that ignites a fuze, which burns down to the detonator and explodes the main charge.

A pyrotechnic heat source, also called heat pellet, is a pyrotechnic device based on a pyrotechnic composition with a suitable igniter. Its role is to produce controlled amount of heat. Pyrotechnic heat sources are usually based on thermite-like fuel-oxidizer compositions with slow burn rate, high production of heat at desired temperature, and low to zero production of gases.

The safety fuse is a type of fuse invented and patented by English inventor William Bickford in 1831. Originally it consisted of a "tube" of gunpowder surrounded by a waterproofed varnished jute "rope." It replaced earlier and less reliable methods of igniting gunpowder blasting charges which had caused many injuries and deaths in the mining industry. The safety fuse burns at a rate of typically about 30 seconds per foot.

Artillery fuze

An artillery fuze or fuse is the type of munition fuze used with artillery munitions, typically projectiles fired by guns, howitzers and mortars. A fuze is a device that initiates an explosive function in a munition, most commonly causing it to detonate or release its contents, when its activation conditions are met. This action typically occurs a preset time after firing, or on physical contact with or detected proximity to the ground, a structure or other target. Fuze, a variant of fuse, is the official NATO spelling.

Thermalite is a specific type of fuse used in pyrotechnic applications. The product was designed to be used in cross matching safety fuses of the Bickford type. As safety fuse is designed to neither give nor take fire through the heavy fuse jacket, ignition may be achieved by punching a hole perpendicular to and through a safety fuse powder core, threading a piece of Thermalite or similar igniter cord through the hole, then gently squeezing the safety fuse with pliers or similar to bring the powder core into contact with the igniter cord. The Thermalite could be ignited by a match, or more certainly by a purpose made igniter, similar to a wire sparkler.

In firearms and artillery, the primer is the chemical and/or device responsible for initiating the propellant combustion that will push the projectiles out of the gun barrel.

Glossary of firelighting

This is an alphabetized glossary of terms pertaining to lighting fires, along with their definitions. Firelighting is the process of starting a fire artificially. Fire was an essential tool in early human cultural development. The ignition of any fire, whether natural or artificial, requires completing the fire triangle, usually by initiating the combustion of a suitably flammable material.

Fireworks policy in the United States Overview of the fireworks policy in the United States of America

Fireworks policy in the United States can be different in each jurisdiction.

References

  1. Davis, Tenney L. (1943). The Chemistry of Powder and Explosives. Vol. I & II (reprint ed.). Hollywood, California: Angriff Press. p. 6. ISBN   0913022-00-4.
  2. "Junghans Feinwerktechnik - Modern Fuzes for Today's Armed Forces". Army Technology. 2011-06-15. Archived from the original on 2012-05-29. Retrieved 2011-11-12.
  3. "Chapter 14 Fuzing". Fas.org. 2008-05-30. Retrieved 2011-11-12.
  4. http://www.janes.com/extracts/extract/jmvl/del02063.html%5B%5D
  5. "Grenade fuze - Patent 4063514". Freepatentsonline.com. 1977-12-20. Retrieved 2013-09-14.
  6. US 3618522,Henderson, John E.,"Dual Safety Grenade Fuze",published 1969-09-29,issued 1971-11-09, assigned to Hamilton Watch Company
  7. Ammunition Peculiar Equipment (APE) 1955 Grenade Fuze Tester MIL-STD-398 Test (PDF) (Report). U.S. Army Defense Ammunition Center and School. March 1996. ADA312253. Archived (PDF) from the original on June 30, 2016.
  8. "Archived copy" (PDF). Archived from the original (PDF) on 2009-03-19. Retrieved 2008-08-03.{{cite web}}: CS1 maint: archived copy as title (link)
  9. Crocker 2002 , p. 3
  10. Geibig, Alfred (2012), "Spreng- und Streugeräte, Schneide- und Fragmentierungsprojektile" [Explosive and Scattering Devices, Cutting and Fragmentation Projectiles], Die Macht Des Feuers: Ernstes Feuerwerk Des 15.-17. Jahrhunderts Im Spiegel Seiner Sächlichen Überlieferung[Might and fire: an object-based survey of serious fireworks of the 15th to the 17th centuries] (in German), Coburg: Kunstsammlungen der Veste Coburg, pp. 177–226, ISBN   978-3-87472-089-2
  11. DuPont Blaster's Handbook, Fifteenth Edition, Wilmington, Delaware, E.I. DuPont de Nemours and Company, Inc., 1969, pp 97-99