In military munitions, a fuze (sometimes fuse) 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.[1] The relative complexity of even the earliest fuze designs can be seen in cutaway diagrams.
Description
A fuze is a device that detonates a munition's explosive material under specified conditions. In addition, a fuze will have safety and arming mechanisms that protect users from premature or accidental detonation.[2][3] For example, an artillery fuze's battery is activated by the high acceleration of cannon launch, and the fuze must be spinning rapidly before it will function. "Complete bore safety" can be achieved with mechanical shutters that isolate the detonator from the main charge until the shell is fired.[4]
A fuze may contain only the electronic or mechanical elements necessary to signal or actuate the detonator, but some fuzes contain a small amount of primary explosive to initiate the detonation. Fuzes for large explosive charges may include an explosive booster.
Etymology
Professional publications about explosives and munitions distinguish the "fuse" and "fuze" spelling.[5][6] The UK Ministry of Defence states (emphasis in original):
- FUSE: Cord or tube for the transmission of flame or explosion usually consisting of cord or rope with gunpowder or high explosive spun into it. (The spelling FUZE may also be met for this term, but FUSE is the preferred spelling in this context.)[7]
- FUZE: A device with explosive components designed to initiate a main charge. (The spelling FUSE may also be met for this term, but FUZE is the preferred spelling in this context.)[8]
Oliver Hogg states the following about fuze:
- The word "fuze" is often spelt "fuse" by those unacquainted with artillery usage. This is incorrect. "Fuse", derived from fusus, the past participle of fundo, means "to melt", e.g., the term "fuse-wire" used in electrical circuits. "Fuze", on the other hand, is the shortened or modern method of spelling "fuzee", meaning a tube filled with combustible material. It is a derivation of fusus, a spindle and from the French fusee, a spindle full of thread. It is well to make this point at the outset.[9]
Historically, it was spelled with either 's' or 'z', and both spellings can still be found.[10] In the United States and some military forces,[11] fuze[12] is used[13][14][15][16] to denote a sophisticated ignition device incorporating mechanical and/or electronic components (for example a proximity fuze for an artillery shell, magnetic/acoustic fuze on a sea mine, spring-loaded grenade fuze,[17][18][19] pencil detonator or anti-handling device)[20] as opposed to a simple burning fuse.[21]
Fuze categorization by munition type
The situation of usage and the characteristics of the munition it is intended to activate affect the fuze design e.g. its safety and actuation mechanisms.
Artillery fuze
Artillery fuzes are tailored to function in the special circumstances of artillery projectiles. The relevant factors are the projectile's initial rapid acceleration, high velocity and usually rapid rotation, which affect both safety and arming requirements and options, and the target may be moving or stationary.
Artillery fuzes may be initiated by a timer mechanism, impact or detection of proximity to the target, or a combination of these.
Hand grenade fuze
Require
A fuze is a device that detonates a munition's explosive material under specified conditions. In addition, a fuze will have safety and arming mechanisms that protect users from premature or accidental detonation.[2][3] For example, an artillery fuze's battery is activated by the high acceleration of cannon launch, and the fuze must be spinning rapidly before it will function. "Complete bore safety" can be achieved with mechanical shutters that isolate the detonator from the main charge until the shell is fired.[4]
A fuze may contain only the electronic or mechanical elements necessary to signal or actuate the detonator, but some fuzes contain a small amount of primary explosive to initiate the detonation. Fuzes for large explosive charges may include an explosive booster.
Etymology
Professional publications about explosives and munitions distinguish the "fuse" and "fuze" spelling.[5][6] The UK Ministry of Defence states (emphasis in original):
- FUSE: Cord or tube for the transmission of flame or explosion usually consisting of cord or rope with gunpowder or high explosive spun into it. (The spelling FUZE may also be met for this term, but FUSE is the preferred spelling in this context.)[7]
- FUZE: A device with explosive components designed to initiate a main charge. (The spelling FUSE may also be met for this term, but FUZE is the preferred spelling in this context.)[8]
Oliver Hogg states the following about fuze:
- The word "fuze" is often spelt "fuse" by those unacquainted with artillery usage. This is incorrect. "Fuse", derived from fusus, the past participle of fundo, means "to melt", e.g., the term "fuse-wire" used in electrical circuits. "Fuze", on the other hand, is the shortened or modern method of spelling "fuzee", meaning a tube filled with combustible material. It is a derivation of fusus, a spindle and from the French fusee, a spindle full of thread. It is well to make this point at the outset.[9]
Historically, it was spelled with either 's' or 'z', and both spellings can still be found.[10] In the United States and some military forces,[11] fuze[12] is used[13][14][15][16] to denote a sophisticated ignition device incorporating mechanical and/or electronic components (for example a proximity fuze for an artillery shell, magnetic/acoustic fuze on a sea mineA fuze may contain only the electronic or mechanical elements necessary to signal or actuate the detonator, but some fuzes contain a small amount of primary explosive to initiate the detonation. Fuzes for large explosive charges may include an explosive booster.
Professional publications about explosives and munitions distinguish the "fuse" and "fuze" spelling.[5][6] The UK Ministry of Defence states (emphasis in original):
- FUSE: Cord or tube for the transmission of flame or explosion usually consisting of cord or rope with gunpowder or high explosive spun into it. (The spelling FUZE may also be met for this term, but FUSE is the preferred spelling in this context.)fusus, the past participle of fundo, means "to melt", e.g., the term "fuse-wire" used in electrical circuits. "Fuze", on the other hand, is the shortened or modern method of spelling "fuzee", meaning a tube filled with combustible material. It is a derivation of fusus, a spindle and from the French fusee, a spindle full of thread. It is well to make this point at the outset.[9]
Hi
Historically, it was spelled with either 's' or 'z', and both spellings can still be found.[10] In the United States and some military forces,[11] fuze[12] is used[13][14][15][16] to denote a sophisticated ignition device incorporating mechanical and/or electronic components (for example a proximity fuze for an artillery shell, magnetic/acoustic fuze on a sea mine, spring-loaded grenade fuze,[17][18][19] pencil detonator or anti-handling device)[20] as opposed to a simple burning fuse.[21]
Fuze categorization by munition type
The situation of usage and the characteristics of the munition it is intended to activate affect the fuze design e.g. its safety and actuation mechanisms.
Artillery fuzeArtillery fuze
Main ar
Artillery fuzes are tailored to function in the special circumstances of artillery projectiles. The relevant factors are the projectile's initial rapid acceleration, high velocity and usually rapid rotation, which affect both safety and arming requirements and options, and the target may be moving or stationary.
Artillery fuzes may be initiated by a timer mechanism, impact or detection of proximity to the target, or a combination of these.
Hand grenade fuze
Req
Artillery fuzes may be initiated by a timer mechanism, impact or detection of proximity to the target, or a combination of these.
Requirements for a hand grenade fuze are defined by the projectile's small size and slow delivery over a short distance. This necessitates manual arming before throwing as the grenade has insufficient initial acceleration for arming to be driven by "setback" and no rotation to drive arming by centrifugal force.
Aerial bomb fuze
Aerial bombs can be detonated either by a fuze, which contains a small explosive charge to initiate the main charge, or by a "pistol", a firing pin in a case which strikes the detonator when triggered.[22] The pistol may be considered a part of the mechanical fuze assembly.
Landmine fuze
The ma
The main design consideration is that the bomb that the fuze is intended to actuate is stationary, and the target itself is moving in making contact.
Naval mine fuze
Relevant design factors in naval mine fuzes are that the mine may be static or moving downward through the water, and the target is typically moving on or below the water surface, usually above the mine.
Fuze categorization by activation mechanism
Impact fuzes in artillery usage may be mounted in the shell nose ("point detonating") or shell base ("base detonating").
Proximity fuzes cause a missile warhead or other munition (e.g. air-dropped bomb or sea mine) to detonate when it comes within a certain pre-set distance of the target, or vice versa. Proximity fuzes utilize sensors incorporating one or more combinations of the following: radar, active sonar, passive acoustic, infrared, magnetic, photoelectric, seismic or even television cameras. These may take the form of an anti-handling device designed specifically to kill or severely injure anyone who tampers with the munition in some way e.g. lifting or tilting it. Regardless of the sensor used, the pre-set triggering distance is calculated such that the explosion will occur sufficiently close to the target that it is either destroyed or severely damaged.
Remote detonators
Remote detonators use wires or radio waves to remotely command the device to detonate.
Barometric fuze
Barometric fuzes cause a bomb to detonate at a certain pre-set altitude above sea level by means of a radar,
Remote detonators use wires or radio waves to remotely command the device to detonate.
Barometric fuze
Barometric fuzes cause a bomb to detonate at a certain pre-set altitude above sea level by means of a radar, barometric altimeter or an infrared rangefinder.
Combination fuzeA fuze assembly may include more than one fuze in series or parallel arrangements. The RPG-7 usually has an impact (PIBD) fuze in parallel with a 4.5 second time fuze, so detonation should occur on impact, but otherwise takes place after 4.5 seconds. Military weapons containing explosives have fuzing systems including a series time fuze to ensure that they do not initiate (explode) prematurely within a danger distance of the munition launch platform. In general, the munition has to travel a certain distance, wait for a period of time (via a clockwork, electronic or chemical delay mechanism), or have some form of arming pin or plug removed. Only when these processes have occurred will the arming process of the series time fuze be complete. Mines often have a parallel time fuze to detonate and destroy the mine after a pre-determined period to minimize casualties after the anticipated duration of hostilities. Detonation of modern naval mines may require simultaneous detection of a series arrangement of acoustic, magnetic, and/or pressure sensors to complicate mine-sweeping efforts.[25]
Fuze safety/arming mechanisms
References
- Notes