Fuze — Mediated Wiki

{{Short description|Device which initiates munition explosion}} {{About|trigger devices for military munitions|simple burning fuzes|Fuse (explosives)|other uses|Fuze (disambiguation)}} {{Redirect|Exploder|the electric device used to detonate explosives|blasting machine|other uses}}

In military [[munition]]s, a '''fuze''' (sometimes spelled '''fuse''') is the part of the device that initiates its function. In some applications, such as [[torpedo]]es, a fuze may be identified by function as the '''exploder'''.<ref>{{cite book| title=Naval Ordnance |last=Fairfield |first=Arthur P.|author-link=Arthur P. Fairfield |publisher=Lord Baltimore Press |page=24 |year=1921}}</ref> The relative complexity of even the earliest fuze designs can be seen in [[Cutaway drawing|cutaway diagrams]].

A fuze is a device that [[detonate]]s 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.<ref>{{Cite report|url=http://www.dtic.mil/ndia/2004fuze/hiebel.pdf |title=Self Destruct Fuze for M864 Projectiles/MLRS Rockets|first1=Mike|last1=Hiebel|first2=Ilan|last2=Glickman|publisher=[[Alliant Techsystems]]|date=27–28 April 2004|archive-url=https://web.archive.org/web/20090319014431/http://www.dtic.mil/ndia/2004fuze/hiebel.pdf |archive-date=2009-03-19 |url-status=dead }}</ref><ref>{{cite journal |first=C. G. |last=Young |title=Notes on Fuze Design |date=November 1920 |location=Fort Monroe, VA |journal=Journal of the United States Artillery |volume=53 |issue=5 |pages=484–508 |url=https://books.google.com/books?id=8w9LAAAAYAAJ&pg=PA500 }}</ref> 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.<ref>{{harvnb|Young|1920|p=488}}</ref>

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]].

== Name== The word derives from Italian ''fuso'', itself derived form Latin ''fūsus'', spindle, applied to the spindle-shaped tube originally used to detonate a bomb. "Fuse" is attested from 1647.<ref>{{Cite OED|fuse|id=7238375419}}</ref>

Some professional publications about explosives and munitions distinguish the "fuse" and "fuze" spellings.<ref>{{harvnb|Ministry of Defence (Army Dept.)|1968|p=33,35}}</ref><ref>{{cite book |first1=Rudolf |last1=Meyer |first2=Josef |last2=Koehler |first3=Axel |last3=Homburg |title=Explosives |url=https://archive.org/details/Explosives._6th_Edition |edition=sixth, completely revised |publisher=Wiley-VCH Verlag GmbH |location=Weinheim |date=2007 |isbn=978-3-527-31656-4 |page=[https://archive.org/details/Explosives._6th_Edition/page/n157 145]}}</ref> Where a distinction is made usages are: :'''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.)<ref>{{harvnb|Ministry of Defence (Army Dept.)|1968|p=33}}</ref><ref name=garner>"A ''fuse'' is a wick or other combustible cord for an old-fashioned explosive. A ''fuze'' is for more high-tech explosives: it's a mechanical or electronic device used for detonations."{{Cite book|title = The Oxford Dictionary of American Usage and Style|url = http://www.oxfordreference.com/view/10.1093/acref/9780195135084.001.0001/acref-9780195135084-e-1056?rskey=D8fWCd&result=43|isbn=9780195135084|last = Garner|first = Bryan A.|year = 2000| publisher=Oxford University Press }}</ref> :'''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.)<ref>{{harvnb|Ministry of Defence (Army Dept.)|1968|p=35}}</ref><ref name=garner/>

Historically, it was spelled with either 's' or 'z', and both spellings can still be found.<ref>{{cite web |title=Proximity fuze |url=http://www.oxfordreference.com/view/10.1093/oi/authority.20110803100351574 | publisher = Oxford Reference |quote=citing The Oxford Companion to World War II Edited by: I. C. B. Dear and M. R. D. Foot. Oxford University Press 2001 ISBN 9780198604464}}</ref>

== Munition types ==

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 : [[Artillery fuze]]s 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 [[Proximity fuze|detection of proximity]] to the target, or a combination of these. ; Grenades : Requirements for a [[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 bombs : 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.<ref>{{cite web |url=https://stephentaylorhistorian.com/2018/03/03/british-bombs-fuzes-pistols-and-detonators-of-ww2/ |title=British bombs | work = Fuzes, Pistols and Detonators of WW2 |publisher =Stephen Taylor WW2 Relic Hunter |date=3 March 2018 |access-date= 23 April 2018}} Article has a great many illustrations and descriptions of bomb fuzes and pistols.</ref> The pistol may be considered a part of the mechanical fuze assembly. ; Landmines : 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 mines : 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.

== Activation mechanisms ==

=== Time === [[File:Broken wooden Fuze from Ingolstadt.jpg|thumb|Wooden grenade fuse from the 17th Century, broken open vertically, with preserved delay charge.]] Time fuzes detonate after a set period of time by using one or more combinations of mechanical, electronic, [[pyrotechnic]] or even [[pencil detonator|chemical timers]]. Depending on the technology used, the device may [[self-destruct]]<ref>{{Cite conference|url=http://www.dtic.mil/ndia/2003fuze/strickland.pdf |title=Adding an Electronic Self-Destruct Mode to the M230 Fuze|first=Shala M.|last=Strickland|conference=47th Annual Fuze Conference|date=8–10 April 2003|archive-url=https://web.archive.org/web/20090319014342/http://www.dtic.mil/ndia/2003fuze/strickland.pdf |archive-date=2009-03-19 |url-status=dead }}</ref> (or render itself safe without detonation<ref>{{cite web |url=http://www.defensetech.org/archives/002534.html |title=Miniature Bomb, Heavyweight Punch|access-date=29 December 2014 |url-status=usurped |archive-url=https://web.archive.org/web/20090925001412/http://www.defensetech.org/archives/002534.html |archive-date=25 September 2009 }}</ref>) some seconds, minutes, hours, days, or even months after being deployed.

Early artillery time fuzes were nothing more than a hole filled with gunpowder leading from the surface to the centre of the projectile. The flame from the burning of the gunpowder propellant ignited this "fuze" on firing, and burned through to the centre during flight, then igniting or exploding whatever the projectile may have been filled with.

By the 19th century devices more recognisable as modern artillery "fuzes" were being made of carefully selected wood and trimmed to burn for a predictable time after firing. These were still typically fired from smoothbore muzzle-loaders with a relatively large gap between the shell and barrel, and still relied on flame from the [[gunpowder]] propellant charge escaping past the shell on firing to ignite the wood fuze and hence initiate the timer.

In the mid-to-late 19th century adjustable metal time fuzes, the fore-runners of today's time fuzes, containing burning gunpowder as the delay mechanism became common, in conjunction with the introduction of [[Rifling|rifled]] artillery. Rifled guns introduced a tight fit between shell and barrel and hence could no longer rely on the flame from the propellant to initiate the timer. The new metal fuzes typically use the shock of firing ("setback") and/or the projectiles's rotation to "arm" the fuze and initiate the timer : hence introducing a safety factor previously absent.

As late as World War I, some countries were still using hand-grenades with simple [[black match]] fuses much like those of modern fireworks: the infantryman lit the fuse before throwing the grenade and hoped the fuse burned for the several seconds intended. These were soon superseded in 1915 by the [[Mills bomb]], the first modern hand grenade with a relatively safe and reliable time fuze initiated by pulling out a safety pin and releasing an arming handle on throwing.

Modern time fuzes often use an electronic delay system.

=== Impact === {{Main|Contact fuze}}

Impact, percussion or contact fuzes detonate when their forward motion rapidly decreases, typically on physically striking an object such as the target. The detonation may be instantaneous or deliberately delayed to occur a preset fraction of a second after penetration of the target. An instantaneous "superquick" fuze will detonate nearly instantly on the slightest physical contact with the target. A fuze with a '''graze''' action will also detonate on change of direction caused by a slight glancing blow on a physical obstruction, such as the ground.

Impact fuzes in artillery usage may be mounted in the shell nose ("point detonating") or shell base ("base detonating").

=== Inertia ===

Inertial fuzes are triggered when the entity carrying them (for example, a [[torpedo]], air-dropped bomb, [[sea mine]], or [[Booby trap#Military booby traps|booby trap]]) experiences a sudden (or gradual, depending on the design) acceleration, deceleration, or impact. In this way they are both similar to and different from impact fuzes. Whereas impact fuzes usually require physical contact with, or an impact against a hard surface, inertial fuzes can trigger from any change of momentum. This allows them to be mounted deep inside the entity carrying them, rather than on its exterior. Designs can be varied. Some can be ''passively safe'', ignoring all changes of momentum below a certain threshold, thereby functioning similarly to impact fuzes without the limitation of being externally mounted. Other designs can be ''passively dangerous'', using other energy sources such as gravity or an electrical battery to greatly amplify slight changes in inertia over time. One easy way of visualizing a passively safe inertial fuze is to picture a marble in a bowl - the device is triggered when the marble rolls to the rim of the bowl. In contrast, a passively dangerous inertial fuze would be similar to a marble on a smooth, flat plate. The former uses gravity to actively suppress weak forces acting on the marble, whereas the latter uses gravity to actively amplify them. Passively dangerous inertial fuzes are commonly employed in [[anti-handling device]]s.

For comparatively low-velocity munitions such as torpedoes, inertial fuzes of the pendulum and swing-arm types have been used historically. An early example of a pendulum fuze can be seen in the design of the [[Brennan torpedo]]. Inertial fuzing is also used in the design of [[High-explosive squash head|HESH]] munitions, since their concept precludes the use of contact fuzing.

=== Proximity === {{Main|Proximity fuze}} [[File:MK53 fuze.jpg|thumb|right|Mk 53 [[Proximity fuze]] for an [[artillery shell]], c. 1945]]

[[Proximity fuze]]s cause a [[missile]] warhead or other munition (e.g. air-dropped bomb, [[sea mine]], or [[Magnetic pistol|torpedo]]) 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 detonation === [[File:EOD clears Warren Grove Gunnery Range 150501-Z-AL508-054.jpg|thumb|right|A modern multichannel radio remote detonator, in 2015.]] Detonation can be triggered from distant sources of interaction. This can be accomplished both by mechanical and electronic means. Electronic or electrical [[remote detonators]] use [[wire]]s or [[electromagnetic radiation]] (such as radio waves or infrared light) to remotely command the device to detonate. This can be achieved by either a deliberate command from a transmitter apparatus, or by autonomous transmission of a signal, or sensing of an interruption of a continuous signal. A simple example of an electrical wired remote detonator is known as a [[blasting machine]], a device used since the 19th century. Vast and sophisticated systems like [[Dead Hand]] could also technically fall within this category.

Mechanical remote detonators use some type of [[Linkage (mechanical)|mechanical linkage]], usually a lanyard or [[tripwire]], but sophisticated rigid linkages are also a possibility. Lanyards have been commonly employed by [[Friction primer|artillery pull primers]].<ref>{{cite web|title=Pull Primers|website=Standing Well Back|url=https://www.standingwellback.com/pull-primers/|date=8 December 2012|access-date=25 January 2025}}</ref> Lanyards continue to be used to trigger primer detonations in modern emplaced artillery, for safety reasons.<ref>{{cite web|title='Pull string, go boom': Texan participates in artillery battalion fire exercise|website=Defense Visual Information Distribution Service|url=https://www.dvidshub.net/news/122710/pull-string-go-boom-texan-participates-artillery-battalion-fire-exercise|date=26 March 2014|access-date=25 January 2025}}</ref> Such devices are no longer of the friction primer type, using modern impact or electronic [[Primer (firearms)|primer]] ignition systems.

=== Barometric ===

Barometric fuzes cause a bomb to detonate at a certain pre-set altitude above [[sea level]] by means of a [[radar]], [[barometer|barometric]] [[altimeter]] or an [[infrared]] [[Rangefinding telemeter|rangefinder]].

=== Combinations === [[File:Aufschlagzuender G7a.JPG|thumb|right|The contact fuze of a [[G7a torpedo]], a hybrid design using both impact and swing-arm inertial triggering.]] A 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 mine]]s may require simultaneous detection of a series arrangement of [[Acoustic signature|acoustic]], [[magnetic]], and/or [[pressure]] sensors to complicate mine-sweeping efforts.<ref name="frieden">Frieden, David R. ''Principles of Naval Weapons Systems'' Naval Institute Press (1985) {{ISBN|0-87021-537-X}} pp.405-427</ref>

== Safety and arming mechanisms == [[File:Sd2 opened.jpg|thumb|SD2 [[Butterfly bomb]] c. 1940 - wings rotate as bomb falls, unscrewing the arming spindle connected to the fuze]]

The multiple safety/arming features in the [[M734 fuze]] used for [[Mortar (weapon)|mortars]] are representative of the sophistication of modern [[electronics|electronic]] fuzes.

Safety/arming mechanisms can be as simple as the spring-loaded safety levers on [[M67 grenade|M67]] or [[RGD-5]] [[grenade]] fuzes, which will not initiate the explosive train so long as the pin is kept in the grenade, or the safety lever is held down on a pinless grenade. Alternatively, it can be as complex as the electronic timer-countdown on an influence sea mine, which gives the vessel laying it sufficient time to move out of the blast zone before the magnetic or acoustic sensors are fully activated.

In modern artillery shells, most fuzes incorporate several safety features to prevent a fuze arming before it leaves the gun barrel. These safety features may include arming on "setback" or by centrifugal force, and often both operating together. Set-back arming uses the [[inertia]] of the accelerating artillery shell to remove a safety feature as the projectile accelerates from rest to its in-flight speed. Rotational arming requires that the artillery shell reach a certain [[Revolutions per minute|rpm]] before [[centrifugal force]]s cause a safety feature to disengage or move an arming mechanism to its armed position. Artillery shells are fired through a [[rifled barrel]], which forces them to spin during flight.

In other cases the bomb, [[Land mine|mine]] or projectile has a fuze that prevents accidental initiation e.g. stopping the rotation of a small [[Propeller (aircraft)|propeller]] (unless a lanyard pulls out a pin) so that the striker-pin cannot hit the [[detonator]] even if the weapon is dropped on the ground. These types of fuze operate with aircraft weapons, where the weapon may have to be jettisoned over ''friendly'' territory to allow a damaged aircraft to continue to fly. The crew can choose to jettison the weapons ''safe'' by dropping the devices with safety pins still attached, or drop them ''live'' by removing the safety pins as the weapons leave the aircraft.

Aerial bombs and [[depth charge]]s can be ''nose'' and ''tail'' fuzed using different detonator/initiator characteristics so that the crew can choose which effect fuze will suit target conditions that may not have been known before the flight. The arming switch is set to one of ''safe'', ''nose'', or ''tail'' at the crew's choice.

Base fuzes are also used by artillery and tanks for shells of the 'squash head' type. Some types of armour piercing shells have also used base fuzes, as have nuclear artillery shells.

The most sophisticated fuze mechanisms of all are those fitted to [[nuclear weapons]], and their safety/arming devices are correspondingly complex. In addition to [[permissive action link|PAL]] protection, the fuzing used in nuclear weapons features multiple, highly sophisticated environmental sensors e.g. sensors requiring highly specific acceleration and deceleration profiles before the warhead can be fully armed. The intensity and duration of the acceleration/deceleration must match the environmental conditions which the bomb/missile warhead would actually experience when dropped or fired. Furthermore, these events must occur in the correct order. As an additional safety precaution, most modern nuclear weapons utilize a timed two point detonation system such that ONLY a precisely firing of both detonators in sequence will result in the correct conditions to cause a fission reaction {{citation needed|date=September 2020}}

Note: some fuzes, e.g. those used in air-dropped bombs and landmines may contain [[anti-handling device]]s specifically designed to kill [[explosive ordnance disposal|bomb disposal]] personnel. The technology to incorporate [[booby-trap]] mechanisms in fuzes has existed since at least 1940 e.g. the German ZUS40 anti-removal bomb fuze.<ref>{{cite web|url=http://www.bocn.co.uk/vbforum/zus-40-anti-t4053.html?s=10c72e0dc5c219f648dadbd6b7ab792c&|title=ZUS 40 (Anti withdrawal device 40) Germany WW2|work=Inert Ordnance Collectors|date=22 January 2008 |access-date=29 December 2014}}</ref>

== Reliability ==

A fuze must be designed to function appropriately considering relative movement of the munition with respect to its target. The target may move past stationary munitions like [[land mine]]s or naval mines; or the target may be approached by a rocket, torpedo, artillery shell, or air-dropped bomb. Timing of fuze function may be described as ''optimum'' if detonation occurs when target damage will be maximized, ''early'' if detonation occurs prior to optimum, ''late'' if detonation occurs past optimum, or ''dud'' if the munition fails to detonate. Any given batch of a specific design may be tested to determine the anticipated percentage of ''early'', ''optimum''. ''late'', and ''dud'' expected from that fuze installation.<ref name="frieden"/>

Combination fuze design attempts to maximize ''optimum'' detonation while recognizing dangers of ''early'' fuze function (and potential dangers of ''late'' function for subsequent occupation of the target zone by friendly forces or for gravity return of anti-aircraft munitions used in defense of surface positions.) Series fuze combinations minimize ''early'' function by detonating at the latest activation of the individual components. Series combinations are useful for safety arming devices, but increase the percentage of ''late'' and ''dud'' munitions. Parallel fuze combinations minimize ''duds'' by detonating at the earliest activation of individual components, but increase the possibility of premature ''early'' function of the munition. Sophisticated military munition fuzes typically contain an arming device in series with a parallel arrangement of sensing fuzes for target destruction and a time fuze for self-destruction if no target is detected.<ref name="frieden"/>

== Gallery == {{cleanup gallery|date=August 2024}}

<gallery class="center" widths="137px" heights="137px"> File:Bombing_up_106_Squadron_Lancaster_WWII_IWM_CH_12541.jpg|[[Avro Lancaster]] at [[RAF Metheringham]]. Note the "Fuzed" status, chalked on the nose of each bomb File:British_20_mm_Oerlikon_shell_diagrams.jpg|[[Oerlikon 20 mm cannon]] fuze File:QF2pdrVickersHVShell1943.jpg|Cross-sectional views of [[QF 2-pounder naval gun]] shells, showing percussion fuzes. File:M107_Shells.JPEG|Fuzes fitted to [[M107 projectile|M107]] 155mm artillery shells, c. 2000 File:White_Phosphorous_mortar_round.jpg|Fuzed 81mm [[white phosphorus]] [[mortar shell]] in 1980. Note spelling of "fuze" on adjacent boxes File:Multiple fuzes.gif|An assortment of fuzes for [[artillery]] and [[Mortar (weapon)|mortar]] shells File:British 4 inch 35 lb star shell 1943 diagram.jpg|British World War II 4-inch naval illuminating shell, showing time fuze (orange, top), illuminating compound (green) and parachute (white, bottom) File:No145MkIPercussionFuzeDiagram.jpg|Fuze for a [[Stokes mortar]] shell File:No63FuzeMkIC.jpg|British No. 63 Mk I Time and Percussion fuze, c. 1915, used in [[Shrapnel shell|shrapnel]] shells File:No100FuzeDiagram.jpg|British No. 100 Graze Fuze for high-explosive shell, [[World War I]]. File:No110MkIIIPercussionFuzeDiagram.jpg|British Percussion Fuze No. 110 Mk III, World War I, used in trench mortars File:No131DAImpactFuzeMkVIDiagram.jpg|British No. 131 D.A. (Direct Action) Impact Fuze, Mk VI, [[World War I]], used in anti-aircraft artillery File:No16DMkIVNBasePercussionFuzeLarge.jpg|British No. 16 D Mk IV N Base percussion fuze, c. 1936 File:No45PDAImpactFuzeDiagram.jpg|British No. 45 P Direct Action Impact Fuze, World War I, used in [[howitzer]] shells File:Type_99_grenade.jpg|Cut-away diagram of [[Empire of Japan|Japanese]] [[Type 99 Grenade]] showing fuze mechanism. c. 1939 File:M2A4_mine_M6A1_fuze.jpg|Cut-away diagram of a US [[M2 mine|M2A4]] [[bounding mine]] showing the M6A1 pressure/pull fuze. c. 1950 File:Russian_-_VPF_pull_fuze.jpg|[[USSR]] pull-fuze designed for [[booby-trap]] or [[anti-handling device|anti-handling]] purposes. c. 1950s. Detonator assembly is inserted into explosives File:Russian_-_MUV_pull_fuze.jpg|Alternative design of USSR booby-trap pull-fuze, usually connected to a [[tripwire]]. c. 1950s File:Russian_MV-5_pressure_fuze.jpg|USSR pressure fuze for booby-trap purposes e.g. victim steps on loose floorboard with fuze (connected to [[trinitrotoluene|TNT]] explosives) concealed underneath. c. 1950s File:TC24_Italian_landmine_cutaway.png|Italian [[TC/2.4 mine]] c. 1980s showing central location of mechanical pressure fuze File:Smine-diagram.jpg|German [[S-mine]] dating from [[World War II]] showing fuze well into which a 3-pronged fuze would be screwed File:Smine-sensor.jpg|Fuze for a German [[S-mine]], which would be screwed into the fuze well on the mine File:M1-M4_mine_cutaway.JPG|M4 anti tank mine, showing main fuze in the centre, plus 2 additional fuze pockets (both empty) which provide the option to fit [[anti-handling device]]s File:Landmine_anti-handling_devices.png|Typical configuration of a pull fuze and/or pressure-release fuze attached to [[M15 mine|M15 anti-tank landmines]] File:Torpedo exploder Mark 6 Mod 1.jpg|The problem-prone [[Mark 6 exploder|Mark 6 magnetic influence exploder]] for the [[Mark 14 torpedo|Mark 14 submarine torpedo]] was secretly developed with limited testing between the world wars </gallery>

== See also == * {{annotated link|Artillery fuze}} * {{annotated link|Black match}} * {{annotated link|Contact fuze}} * {{annotated link|Slow match}}

== References ==

== Sources ==

* [https://web.archive.org/web/20100209173804/http://armyapp.dnd.ca/ael/pubs/B-GL-371-006-FP-001.PDF Canada. Army Electronic Library. Field Artillery Volume 6. Ballistics and Ammunition. B-GL-306-006/FP-001 1992-06-01] * {{ cite book |last=Ministry of Defence (Army Dept.) |author1-link=Ministry of Defence (United Kingdom) |year=1968 |id=A 32/ARTS/R & D/678 |title=Explosives Terms and Definitions }}

== External links == {{commons category|Fuzes}}

* [https://web.archive.org/web/20090304201236/http://www.kdi-ppi.com/products/index.htm A range of modern munitions fuzes, together with detailed technical specifications] * [http://www.lexpev.nl/downloads/bombfuzedata1945.pdf Bomb fuze data - US guide dated 1945] * [http://www.globalsecurity.org/wmd/intro/safe.htm Safing, Arming, Fuzing, and Firing (SAFF) info from Globalsecurity.org] * [https://web.archive.org/web/20091210112547/http://www.ordnance.org/fuzes.htm Tutorial regarding fuzes for air-dropped bombs] * [https://web.archive.org/web/20090319014341/http://web.ukonline.co.uk/stephen.johnson/arms/fusb1.jpg Internal view of 1940s aerial bomb fuze, featuring 2 strikers held back by single screw-thread and 2 creep springs] * [http://www.90thidpg.us/Equipment/Weapons/index.html 90th Infantry Division Preservation Group] - page on 81mm Mortar Fuzes * {{ citation |last=Farmer |first=William C. |title=Ordnance Field Guide |date=1945 |volume=III |publisher=Military Service Publishing |location=Harrisburg, PA |url=https://archive.org/details/OrdnanceFieldGuideV3 |ref=none | pages = cf 7, "Introduction to Fuzes" }}

[[Category:Fuzes]] [[Category:Military slang and jargon]] [[Category:Artillery]] [[Category:Ammunition]]