Artillery fuze

An artillery fuze or fuse is the type of munition fuze used with artillery munitions, typically projectiles fired by guns (field, anti-aircraft, coast and naval), 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 (time fuze), or on physical contact with (contact fuze) or detected proximity to the ground, a structure or other target (proximity fuze). Fuze, a variant of fuse, is the official NATO spelling.

Terminology

Munitions fuzes are also used with rockets, aircraft bombs, guided missiles, grenades and mines, and some direct fire cannon munitions (small calibre and tank guns).

Broadly, fuzes function on impact (percussion fuzes) or at a pre-determined time period after firing (time fuzes). However, by the 18th century time fuzes were aimed to function in the air and in the 1940s proximity fuzes were introduced to achieve more precisely positioned airburst. Therefore, the terms ‘percussion’ and ‘airburst’ are generally used here unless ‘time’ fuzes are being explicitly described.

Early history

Solid cannonballs (“shot”) did not need a fuze, but hollow balls (“shells”) filled with something, such as gunpowder to fragment the ball hopefully on the target needed a time fuze. Early reports of shells include Venetian use at Jadra in 1376 and shells with fuzes at the 1421 siege of St Boniface in Corsica. In 1596 Sebastian Halle proposed both igniting the bursting charge by percussion and regulating the burning time of fuzes, this was considered visionary and nothing much happened until 1682. These early time fuzes used a combustible material that burnt for a time before igniting the shell filling (slow match). The problem was that precise burning times required precise time measurement and recording, which did not appear until 1672. Before this the proofmaster often tested the burning time of powder by reciting the Apostles' Creed for time measurement.[1]

It was not until around the middle of the following century that it was realised that the windage between ball and barrel allowed the flash from the propelling charge to pass around the shell. This led, in 1747, to ‘single-fire’ and eliminated the need to light the fuze before loading the shell. At this time fuzes were made of beech wood, bored out and filled with powder and cut to the required length. Experience taught that there was a minimum safe length. In 1779 the British adopted pre-cut fuze lengths giving 4, 4.5 and 5 seconds.[2]

The first account of a percussion fuze appears in 1650, using a flint to create sparks to ignite the powder. The problem was that the shell had to fall a particular way and with spherical shells this could not be guaranteed. The term ‘blind’ for an unexploded shell resulted. The problem was finding a suitably stable ‘percussion powder’. Progress was not possible until the discovery of mercury fulminate in 1800, leading to priming mixtures for small arms patented by the Rev Alexander Forsyth, and the copper percussion cap in 1818. The concept of percussion fuzes was adopted by Britain in 1842, many designs were jointly examined by the army and navy, but were unsatisfactory, probably because of the safety and arming features. However, in 1846 the design by Quartermaster Freeburn of the Royal Artillery was adopted by the army. It was a wooden fuze some 6 inches long and used shear wire to hold blocks between the fuze magazine and a burning match. The match was ignited by propellant flash and the shear wire broke on impact. A British naval percussion fuze made of metal did not appear until 1861.[3]

There was little standardisation, well into the 19th century, in British service, virtually every calibre had its own time fuze. For example, seven different fuses were used with spherical cased shot until 1850. However, in 1829 metal fuzes were adopted by the Royal Navy instead of wooden ones. At this time fuzes were used with shrapnel, common shell (filled with explosive) and grenades. All British fuzes were prepared by cutting to length or boring into the bottom from below. The problem was that this left the powder unsupported and fuze failures were common. The indefatigable Colonel Boxer suggested a better way : wooden fuze cones with a central powder channel and holes drilled every 2/10th of an inch. There were white and black painted fuzes for odd and even tenths, clay prevented the powder spilling out. In 1853 these were combined into a single fuze with dual channels, 2 inches long for howitzers and common shell, 1 inch for shrapnel.[4]

However, while the Boxer time fuze was a great advance various problems had to be dealt with over the following years. It also used a different fuze hole size to Freeburn’s percussion fuze, which became obsolete. They were replaced in army service in 1861 by those designed by Mr Pettman, these could be used with both spherical and non-spherical shells.[5]

The final Boxer time fuze, for mortars, appeared in 1867 and the army retained wooden fuzes although the navy used metal ones. There was a similar American wooden fuze.[6] However, in 1855 Armstrong produced his rifled breech loading (RBL) gun, which was introduced into British service in 1859. The problem was that there was little or no windage between the shell and the barrel, so the propelling charge could no longer be used to ignite the fuze. Therefore, a primer was added with a hammer suspended above it, the shock of firing released the hammer which initiated the primer to ignite the powder time train. Armstrong’s A pattern time fuze was introduced to British service in 1860 and the shorter length Borman fuzes in the United States.[7]

The introduction of RBL guns led to non-spherical projectiles, which landed nose first. This enabled percussion nose fuzes, but they had to cope with the spinning shell and centrifugal forces. This led, by about 1870, to percussion fuzes with a direct action firing pin and detonator and a magazine to boost the detonators sufficiently to initiate the shell’s main charge.[8]

Armstrong’s time fuze designs evolved rapidly, in 1867 the F pattern was introduced, this was the first ‘time and percussion’ (T & P) fuze. Its percussion function was not entirely successful and was soon replaced by the E Mk III fuze, made of brass it contained a ring of slow burning composition ignited by a pellet holding a detonator cap that was set back onto a firing pin by the shock of firing. It was the prototype of the T & P fuzes used in the 20th century, although initially it was only used with naval segment shells and it took some time for the army to adopt it for shrapnel.

Description

Since the second half of the 19th century, most artillery fuzes are fitted to the nose of the projectile. The base of the fuze is screwed into a recess, and its nose is designed to conform to the shape of the shell’s ogive. The depth of recess can vary with the type of shell and fuze. Artillery fuzes were sometimes specific to particular types of gun or howitzer due to their characteristics, notable differences in muzzle velocity and hence the sensitivity of safety and arming mechanisms. However, by World War 2, while there were exceptions, most fuzes of one nation could be used with any required artillery shell of that nation, if it could be physically fitted to it, although different army and navy procurement arrangements often prevented this. The exceptions were mortar bomb fuzes, and this continues.

An early action in NATO standardisation was to agree the dimensions and threads of the fuze recess in artillery projectiles to enable fuze interchangeability between nations. Modern artillery fuzes can generally be used with any appropriate artillery shell, including naval ones. However, smoothbore mortars constrain the choice of safety and arming mechanisms because there is no centrifugal force and muzzle velocities are relatively low. Therefore, shell fuzes cannot be used with mortar bombs, and mortar fuzes are unsuitable for the higher velocities of shells.

The fuze action is initiated by impact, elapsed time after firing or proximity to a target. In most cases the fuze action causes detonation of the main high explosive charge in a shell or a small charge to eject a carrier shell’s contents. These contents may be lethal, such as the now-obsolete shrapnel shell or modern sub-munitions, or non-lethal such as canisters containing a smoke compound or a parachute flare.

Fuzes normally have two explosive components in their explosive train: a very small detonator (or primer) struck by a firing pin, and a booster charge at the base of the fuze (sometimes called the 'magazine'). This booster is powerful enough to detonate the main charge in a high-explosive shell or the ejecting charge in a carrier shell. The two charges are typically connected by a 'flash tube'.

The safety and arming arrangements in artillery fuzes are critical features to prevent the fuze functioning until required, no matter how harsh its transport and handling. These arrangements use the forces created by the gun or howitzer firing – high acceleration (or ‘shock of firing’) and rotation (caused by the rifling in the gun or howitzer barrel) - to release the safety features and arm the fuze. Some older types of fuze also had safety features such as pins or caps removed by the user before loading the shell into the breach. Defective fuzes can function while the shell is in the barrel - a 'bore premature', or further along the trajectory.

Different fuze designs have different safety and arming mechanisms that use the two forces in various ways. The earliest ‘modern’ fuzes used wire sheared by the shock of firing. Subsequently, centripetal devices were generally preferred for use with low-velocity howitzer shells because the set-back was often insufficient. However, late 19th- and 20th-century designs used more sophisticated combinations of methods that applied the two forces. Examples include:

  • Centripetal force moving a bolt outwards, which allows another bolt to move backwards by inertia from acceleration.
  • Inertia from acceleration overcoming the pressure of a retaining spring to release a catch that allows an arm, plate, segmented sleeve or other bolt to move outwards by centrifugal force.
  • Centripetal force causing a plate holding a detonator to swing into alignment with a firing pin.
  • Centripetal force causing a barrier plate(s) or block(s) to overcome a spring(s) and swing out of the channel between the firing pin and detonator or between the detonator and the booster (or both).
  • Rotation causing a weighted tape to unwind from around a spindle and free the firing pin hammer.

Modern safety and arming devices are part of an overall fuze design that meets insensitive munitions requirements. This includes careful selection of the explosives used throughout the explosive train, strong physical barriers between the detonator and booster until the shell is fired and positioning explosive components for maximum protection in the fuze.

Types of artillery fuze

Percussion fuzes

No 1 DA Percussion Fuze Mk III Diagram
Early British "direct action" nose impact fuze of 1900 with no safety or arming mechanism, relying on heavy direct physical impact to detonate
305mmMortarBasePercussionFuzeEarlyModelDiagram
Base-detonating fuze for Austrian 30.5 cm howitzer, as used in defeating the Belgian forts at Liège in 1914
German 7.5-cm-PzGr. 39
German 7,5 cm Pzgr. 1939 : an armour-piercing shell with base detonating fuze (1), as fired by Panzer IV and Pak 40 anti-tank gun
Peuch-Remondy 24 31 Mod 1916 Fuze
French point-detonating fuze of 1916 with inertia plunger and 1/10 second delay, used with heavy trench mortar bombs

In the 20th century, most fuzes were 'percussion'. They may be 'direct action' (also called 'point detonating' or ‘super quick’) or 'graze'. They may also offer a ‘delay’ option. Percussion fuzes remain widespread particularly for training. However, in the 19th century combined ‘T & P’ fuzes became common and this combination remain widespread with airburst fuzes in case the airburst function failed or was set too ‘long’. War stocks in western armies are now predominantly 'multi-function' offering a choice of several ground and airburst functions.

Direct action fuzes

Direct action fuzes function by the fuze nose hitting something reasonably solid, such as the ground, a building or a vehicle, and pushing a firing pin into a detonator. The early British fuze at left is an example.

Direct action fuze designs are 'super-quick' but may have a delay option. 20th-century designs vary in the relative positions of their key elements. The extremes being the firing pin and detonator close to the nose with a long flash tube to the booster (typical in US designs), or a long firing pin to a detonator close to the booster and a short flash tube (typical in British designs).

Graze fuzes

Graze fuzes function when the shell is suddenly slowed down, e.g. by hitting the ground or going through a wall. This deceleration causes the firing pin to move forward, or the detonator to move backward, sharply and strike each other. Graze is the only percussion mechanism that can be used in base fuzes.

Delay fuzes

Direct action fuzes can have a delay function, selected at the gun as an alternative to direct action. Delay may use a graze function or some other mechanism. Special 'concrete piercing' fuzes usually have only a delay function and a hardened and strengthened fuze nose.

Base fuzes

Base fuzes are enclosed within the base of the shell and are hence not damaged by the initial impact with the target. Their delay timing may be adjustable before firing. They use graze action and have not been widely used by field artillery. Base fuzed shells were used by coast artillery (and warships) against armoured warships into the 1950s. They have also had some use against tanks, including with High Explosive Squash Head (HESH), also called High Explosive Plastic (HEP) used after World War 2 by 105mm artillery for self-defence against tanks and by tanks.

Airburst fuzes

Airburst fuzes, using a preset timing device initiated by the gun firing, were the earliest type of fuze. They were particularly important in the 19th and early 20th Centuries when shrapnel fuzes were widely used. They again became important when cluster munitions became a major element in Cold War ammunition stocks, and the moves to multi-function fuzes in the late 20th century mean that in some western countries airburst fuzes are available with every shell used on operations.

Time fuzes were essential for larger calibre anti-aircraft guns, and it soon became clear that igniferous fuzes were insufficiently accurate and this drove the development of mechanical time fuzes between the world wars. During World War 2 radio proximity fuzes were introduced, initially for use against aircraft where they proved far superior to mechanical time, and at the end of 1944 for field artillery.

Time fuzes

No211TimeFuzeDiagram
A British clockwork Time fuze for an artillery shell using the Thiel mechanism, circa 1936
Boxer Wood 9 second Time Fuze Diagrams
British "Boxer" wooden time fuze, 1870s, burned for maximum 9 seconds, adjusted by punching through applicable hole
No25MkIVTimeFuzeDiagram
British aluminium No. 25 Mk IV time fuze, using a burning gunpowder timer, circa 1914, used for star shells

Artillery Time fuzes detonate after a set period of time. Early time fuzes were igniferous (i.e. combustible) using a powder train. Clockwork mechanisms appeared at the beginning of the 20th century and electronic time fuzes appeared in the 1980s, soon after digital watches.

Almost all artillery time fuzes are fitted to the nose of the shell. One exception was the 1950s design US 8-inch nuclear shell (M422) that had a triple-deck mechanical time base fuze.

The time length of a time fuze is usually calculated as part of the technical fire control calculations, and not done at the gun although armies have differed in their arrangements. The fuze length primarily reflects the range to the target and the required height of burst. High height of burst, typically a few hundred metres, is usually used with star shell (illuminating shell) and other base ejecting shells such as smoke and cluster munitions, and for observing with high-explosive (HE) shells in some circumstances. Low airburst, typically about 10 metres, was used with HE. The height of burst with shrapnel depended on the angle of descent, but for optimal use it was a few tens of metres.

Igniferous time fuzes had a powder ring in an inverted ‘U’ metal channel, the fuze was set by rotating the upper part of the fuze. When the shell was fired the shock of firing set back a detonator onto a firing pin, which ignited the powder ring, when the burn reached the fuze setting it flashed through a hole into the fuze magazine, which then ignited the bursting charge in the shell. If the shell contained HE then the fuze had a gaine that converted the powder explosion into a detonation powerful enough to detonate the HE.

The problem with igniferous fuzes was that they were not very precise and somewhat erratic, but good enough for flat trajectory shrapnel (ranges were relatively short by later standards) or high bursting carrier shells. While improvements in powder composition helped, there were several complex factors that prevented a high degree of regularity in the field. Britain in particular encountered great difficulty in achieving consistency early in World War I (1914 and 1915) with its attempts to use its by-then obsolescent gunpowder-train time fuzes for anti-aircraft fire against German bombers and airships which flew at altitudes up to 20,000 feet. It was then discovered that standard gunpowder burned differently at differing altitudes, and the problem was then rectified to some extent by specially designed fuzes with modified gunpowder formulations.[9] Britain finally switched to mechanical (i.e. clockwork) time fuzes just after World War I which solved this problem. Residual stocks of igniferous fuzes lasted for many years after World War 2 with smoke and illuminating shells.

Before World War I Krupp, in Germany, started producing the Baker clockwork fuze. It contained a spring clock with an extra rapid cylinder escapement giving 30 beats per second.[10] During World War 1 Germany developed other mechanical time, i.e. clockwork, fuzes. These were less erratic and more precise than igniferous fuzes, critical characteristics as gun ranges increased. Between the wars five or six different mechanical mechanisms were developed in various nations.[11] However, three came to predominate, the Thiel pattern in British designs, Junghans pattern in United States and the Swiss Dixi mechanisms, the first two both originated in World War 1 Germany.[12] Mechanical time fuzes remain in service with many armies.

Mechanical time fuzes were just about good enough to use with field artillery to achieve the effective HE height of burst of about 10 metres above the ground. However, 'good enough' usually meant '4 in the air and 2 on the ground'. This fuze length was extremely difficult to predict with adequate accuracy, so the height of burst almost always had to be adjusted by observation.

Proximity fuzes

MK53 fuze
Mk 53 Proximity fuze for an artillery shell, circa 1945

The benefits of a fuze that functioned when it detected a target in proximity are obvious, particularly for use against aircraft. The first such fuze seems to have been developed by the British in the 1930s for use with their anti-aircraft ‘unrotated projectiles’ – rockets. These used a photo-electric fuze.[13]

During 1940-42 a private venture initiative by Pye Ltd, a leading British wireless manufacturer, worked on the development of a radio proximity fuze. Pye's research was transferred to the United States as part of the technology package delivered by the Tizard Mission when the United States entered the war.[14] These fuzes emitted radio waves and sensed their reflection from the target (aircraft or ground), the strength of the reflected signal indicated the distance to the target, when this was correct the fuze detonated.

For the first 18 months or so proximity fuzes were restricted to anti-aircraft use to ensure that none were retrieved by the enemy and copied. They were also called ‘variable time’ or VT to obscure their nature. They were finally released for field artillery use in December 1944 in Europe. While they were not perfect and bursts could still be erratic due to rain, they were a vast improvement on mechanical time in delivering a very high proportion of bursts at the required 10 metre height. However, VT fuzes went far deeper into the shell than other fuzes because they had a battery that was activated by the shock of firing. This meant the fuze recess had to be deeper, so to enable shorter non-VT fuzes the deep recess was filled with removable supplementary HE canisters.

After the war the next generation of proximity fuze included a mechanical timer to switch on the fuze a few seconds before it was due at the target. These were called controlled variable time’ (CVT) and reduced the incidence of early bursts. Later models had additional electronic counter measures.

Distance measuring fuzes

The mechanical distance fuze has had little use, Thompson’s pattern was trialled by the British but did not enter service. The fuzes operated by counting revolutions. It has the advantage of inherent safety and not requiring any internal driving force but depended on muzzle velocity and rifling pitch.[15] However, these are allowed for when calculating the fuze setting. Early 20th-century versions were sometimes called ‘flag fuzes’, so named due to the vane protruding from the nose of the fuze.[16]

Electronic time fuzes

In the late 1970s/early 1980s electronic time fuzes started replacing earlier types. These were based on the use of oscillating crystals that had been adopted for digital watches. Like watches, advances in electronics made them much cheaper to produce than mechanical devices. The introduction of these fuzes coincided with the widespread adoption of cluster munitions in some NATO countries.

Multi function fuzes

US21SecondCombinationFuze1915
US point detonating fuze of 1915 combining adjustable timer up to 21 seconds, using a gunpowder train, and impact mode
No80FuzeMkVL
No. 80 "Time & Percussion" fuze licensed from Krupp was Britain's main WWI shrapnel fuze. This igniferous fuze was set to lengths up to 22 time units before detonating and was also detonated by inertia on impact if that occurred before expiration of the timer. After World War I Britain had to pay Krupp large backdated licensing fees for its wartime use, mostly against Germany[17]

A fuze assembly may include more than one fuze function. A typical combination would be a T & P ("Time & Percussion") fuze with the fuze set to detonate on impact or expiration of a preset time, whichever occurred first. Such fuzes were introduced around the middle of the 19th century. This combination may function as a safety measure or as an expedient to ensure that the shell will be actuated no matter what happens and hence not be wasted. The United States called mechanical T & P fuzes ‘mechanical time super quick’ (MTSQ). T & P fuzes were normal with shrapnel and HE shells (including proximity fuzes), but were not always used with high bursting carrier shells.

However, in the early 1980s electronic fuzes with several functions and options started appearing. Initially they were little more than enhanced versions of proximity fuzes, typically offering a choice proximity heights or impact options. A choice of burst heights could also be used to get optimum burst heights in terrain with different reflectivity. However, they were cheaper than older proximity fuzes and the cost of adding electronic functions was marginal, this meant they were much more widely issued. In some countries all their war stock HE was fitted with them, instead of only 5 – 10% with proximity fuzes.

The most modern multi-option artillery fuzes offer a comprehensive choice of functions. For example, Junghans DM84U provides delay, super quick, time (up to 199 seconds), two proximity heights of burst and five depths of foliage penetration.

Sensor and course correcting fuzes

Sensor fuzes can be considered smart proximity fuzes. Initial developments were the United States ‘Seek and Destroy Armour’ (SADARM) in the 1980s using sub-munitions ejected from 203mm carrier shell. Subsequent European developments, BONUS and SMArt 155, are 155 mm calibre due to advances in electronics. These sensor fuzes typically use millimetric radar to recognise a tank and then aim the sub-munition at it and fire an explosively formed penetrator from above.

The main fuze development activities in the early 21st century are course-correcting fuzes. These add guidance and control functions to the standard multi-option nose fuze package. However, they are not the same as precision guided artillery munitions and are not designed to be precise or unaffordable for widespread use. An example would be the M1156 Precision Guidance Kit which allows 155mm shells to have a 5x better accuracy at max range (267m CEP vs 50m CEP)

Fuze setting

Many fuzes have to be set before being loaded into the breech, although in the case of impact fuzes it may be very simple matter of selecting the delay option if required, 'instantaneous' being the factory set default. However, airburst fuzes have to have the required fuze length set. Modern fuzes invariably use a fuze length in seconds (with at least tenths) that reflect the required time of flight. However, some earlier time fuzes used arbitrary units of time.

The fuze length reflects the range between the gun and its target, before digital computers this range was manually calculated in the command post or fire direction center. Some armies converted the range to an elevation and fuze length and ordered it to the guns. Others set the range on the sights and each gun had a fuze indicator that converted the range to a fuze length (with allowance for muzzle velocity and local conditions). In World War I German fuzes were graduated with ranges in metres.

With digital computers fuze lengths are usually computed in the command post or fire direction center, unless the gun itself does the full ballistic calculations.

Naval and anti-aircraft artillery started using analogue computers before World War 2, these were connected to the guns to automatically aim them. They also had automatic fuze setters. This was particularly important for anti-aircraft guns that were aiming ahead of their target and so needed a very regular and predictable rate of fire.

Field artillery used manual time fuze setting, at its simplest this uses a hand ‘key’ or wrench to turn the fuze nose to the required setting. Manual fuze setters are set at the fuze length and then used to set the fuze, this has the advantage of ensuring that every fuze is correctly and identically set. Electronic fuzes are designed use electronic setters to transfer data electronically, early ones required an electrical contact between the fuze and the setter. These have been superseded by induction fuze setters that do not require physical contact with the fuze. Electronic setters may also check fuze functioning in a ‘Go/No Go’ test.

Fuze Packaging

Fuzes may be delivered fitted to shells or in separate containers, in the latter case the shell itself has a plug that has to be removed before fitting the fuze. Historically, fuzed HE shells were provided with a standard impact fuze that had to be removed and replaced by a time fuze when airburst was required.

Whether or not shells are delivered fuzed depends on whether or not the shells are in sealed packaging. Historically smaller calibres, e.g. 105mm and less, usually were while larger calibre shells were without packaging and plugged. However, in many armies it is now normal for 155mm shells to be delivered in sealed packaging with fuzes fitted.

Image gallery

M107 Shells.JPEG

Fuzes fitted to M107 155mm artillery shells, circa 2000

White Phosphorous mortar round

Fuzed 81mm white phosphorus mortar shell in 1980. Note spelling of "fuze" on adjacent boxes

Multiple fuzes

An assortment of fuzes for artillery and mortar shells

No63FuzeMkIC

British No. 63 Mk I Time and Percussion fuze, circa 1915 - used in shrapnel shells

No100FuzeDiagram

British No. 100 Graze Fuze for high-explosive shell, World War I.

No110MkIIIPercussionFuzeDiagram

British Percussion Fuze No. 110 Mk III, World War I, used in trench mortars

No131DAImpactFuzeMkVIDiagram

British No. 131 D.A. (Direct Action) Impact Fuze, Mk VI, World War I, used in anti-aircraft artillery

No16DMkIVNBasePercussionFuzeLarge

British No. 16 D Mk IV N Base percussion fuze, circa 1936

No45PDAImpactFuzeDiagram

British No. 45 P Direct Action Impact Fuze, World War I, used in howitzer shells

Fze Perc No 106E Mk 4

British No 106E Mk 4 Direct Action percussion fuze introduced in the middle of World War 1 and used with HE and Smoke showing the safety and arming sequence. The Original No 106 did not have a shutters or magazine. Fuze No 115E was the same as No 106E but with a streamlined body to match streamlined shells.

Fze T & P No 80 Mk XI

British No 80 Mk XI Time & Percussion showing the safety and arming sequence

See also

Notes

  1. ^ Hogg pg 164, 184 – 186, 202
  2. ^ Hogg pg 185 - 186
  3. ^ Hogg pg 203 - 203
  4. ^ Hogg pg 185 - 187
  5. ^ Hogg pg 202 - 205
  6. ^ Hogg pg 188 - 189
  7. ^ Hogg pg 190
  8. ^ Hogg pg 205
  9. ^ Hogg & Thurston 1972, page 220
  10. ^ Bethel pg 96
  11. ^ Hogg pg 201
  12. ^ Canadian Army. B-GL-306-006/FP-001, 1992-06-01
  13. ^ Hogg pg 255
  14. ^ http://www.pyetelecomhistory.org/prodhist/military/military.html
  15. ^ Hogg pg 201
  16. ^ Bethell pg 95
  17. ^ Hogg & Thurston 1972, page 220

References

External links

2-inch medium mortar

The 2 inch medium trench mortar, also known as the 2-inch howitzer, and nicknamed the "toffee apple" or "plum pudding" mortar, was a British smooth bore muzzle loading (SBML) medium trench mortar in use in World War I from mid-1915 to mid-1917. The designation "2-inch" refers to the mortar barrel, into which only the 22-inch bomb shaft but not the bomb itself was inserted; the spherical bomb itself was actually 9 inches (230 mm) in diameter and weighed 42 lb (19 kg), hence this weapon is more comparable to a standard mortar of approximately 5-6 inch bore.

Artillery

Artillery is a class of heavy military weapons built to fire munitions far beyond the range and power of infantry's small arms. Early artillery development focused on the ability to breach defensive walls, and fortifications during sieges, and led to heavy, fairly immobile siege engines. As technology improved, lighter, more mobile field artillery cannons developed for battlefield use. This development continues today; modern self-propelled artillery vehicles are highly mobile weapons of great versatility providing the large share of an army's total firepower.

In its earliest sense, the word artillery referred to any group of soldiers primarily armed with some form of manufactured weapon or armour. Since the introduction of gunpowder and cannon, the word "artillery" has largely meant cannon, and in contemporary usage, it usually refers to shell-firing guns, howitzers, mortars, and rocket artillery. In common speech, the word artillery is often used to refer to individual devices, along with their accessories and fittings, although these assemblages are more properly called "equipments". However, there is no generally recognised generic term for a gun, howitzer, mortar, and so forth: the United States uses "artillery piece", but most English-speaking armies use "gun" and "mortar". The projectiles fired are typically either "shot" (if solid) or "shell" (if not). "Shell" is a widely used generic term for a projectile, which is a component of munitions.

By association, artillery may also refer to the arm of service that customarily operates such engines. In some armies one arm has operated field, coastal, anti-aircraft artillery and anti-tank artillery, in others these have been separate arms and in some nations coastal has been a naval or marine responsibility. In the 20th century technology based target acquisition devices, such as radar, and systems, such as sound ranging and flash spotting, emerged to acquire targets, primarily for artillery. These are usually operated by one or more of the artillery arms. The widespread adoption of indirect fire in the early 20th century introduced the need for specialist data for field artillery, notably survey and meteorological, in some armies provision of these are the responsibility of the artillery arm.

Artillery originated for use against ground targets—against infantry, cavalry and other artillery. An early specialist development was coastal artillery for use against enemy ships. The early 20th century saw the development of a new class of artillery for use against aircraft: anti-aircraft guns.

Artillery is arguably the most lethal form of land-based armament currently employed, and has been since at least the early Industrial Revolution. The majority of combat deaths in the Napoleonic Wars, World War I, and World War II were caused by artillery. In 1944, Joseph Stalin said in a speech that artillery was "the God of War".

Contact fuze

A contact fuze, impact fuze, percussion fuze or direct-action (D.A.) fuze (UK) is the fuze that is placed in the nose of a bomb or shell so that it will detonate on contact with a hard surface.

Many impacts are unpredictable: they may involve a soft surface, or an off-axis grazing impact. The pure contact fuze is often unreliable in such cases and so a more sensitive graze fuze or inertia fuze is used instead. The two types are often combined in the same mechanism.

Electric battery

A battery is a device consisting of one or more electrochemical cells with external connections provided to power electrical devices such as flashlights, smartphones, and electric cars. When a battery is supplying electric power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells, however the usage has evolved to include devices composed of a single cell.Primary (single-use or "disposable") batteries are used once and discarded; the electrode materials are irreversibly changed during discharge. Common examples are the alkaline battery used for flashlights and a multitude of portable electronic devices. Secondary (rechargeable) batteries can be discharged and recharged multiple times using an applied electric current; the original composition of the electrodes can be restored by reverse current. Examples include the lead-acid batteries used in vehicles and lithium-ion batteries used for portable electronics such as laptops and smartphones.

Batteries come in many shapes and sizes, from miniature cells used to power hearing aids and wristwatches to small, thin cells used in smartphones, to large lead acid batteries or lithium-ion batteries in vehicles, and at the largest extreme, huge battery banks the size of rooms that provide standby or emergency power for telephone exchanges and computer data centers.

According to a 2005 estimate, the worldwide battery industry generates US$48 billion in sales each year, with 6% annual growth.

Batteries have much lower specific energy (energy per unit mass) than common fuels such as gasoline. In automobiles, this is somewhat offset by the higher efficiency of electric motors in converting chemical energy to mechanical work, compared to combustion engines.

Elna (Swiss company)

Elna is a Swiss brand and former manufacturer of textile machines, including fabric presses and sewing, overlock and coverstitch machines. Elna sewing machines are included in the collections of the Museum of Design, Zürich and the Museum of Modern Art.

FH-2000

The FH-2000 or Field Howitzer 2000 was developed by Singapore Technologies for the Singapore Army. It is a 155 mm/52-calibre towed howitzer gun. It fires projectiles to a maximum range of 42 kilometers using special extended range ammunition, that was field tested in New Zealand. It has a crew of eight and uses a 75 hp diesel auxiliary power unit to give it a self-propelled speed of 16 kilometers an hour movement without towing.

Fuse (explosives)

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 describes a simple pyrotechnic initiating device, like the cord on a firecracker whereas the term fuze is sometimes 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, pencil detonator, or anti-handling device.

Fuze

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. The relative complexity of even the earliest fuze designs can be seen in cutaway diagrams.

Killer Junior

Killer Junior and Killer Senior are techniques of employing artillery direct fire air bursts, first developed during the Vietnam War. The technique involves a howitzer or gun firing a high explosive (HE) shell fuzed with a mechanical time-super quick (MTSQ) artillery fuze set to cause an airburst over a target in very close proximity to the gun's position. Set properly, the shell would detonate approximately 10 meters (33 feet) above the ground at ranges of 200 to 1,000 meters.

The term Killer Junior was applied to this technique when used with 105 mm or 155 mm howitzers, and the term Killer Senior applied to its use with the M115 203 mm (8-inch) howitzer. The term "Killer" came from the call-sign of the battery which developed the technique. The technique was later perfected by Lieutenant Colonel Robert Dean, commander of the 1st Battalion, 8th Field Artillery Regiment, of the 25th Infantry Division Artillery.

Killers Junior and Senior were developed as alternatives to the Beehive flechette rounds previously used against nearby enemy troops. The advantage of Killer Junior over beehive is that the airburst projects fragments in all directions, and is able to wound enemies crawling or lying in defilade, whereas the flechettes of a Beehive round would simply fly harmlessly over a low target.

M777 howitzer

The M777 howitzer is a towed 155 mm artillery piece. It succeeded the M198 howitzer in the United States Marine Corps and United States Army in 2005. The M777 is also used by the ground forces of Australia, Canada, India and Saudi Arabia. It made its combat debut in the War in Afghanistan.

The M777 is manufactured by BAE Systems' Global Combat Systems division. Prime contract management is based in Barrow-in-Furness in the United Kingdom as well as manufacture and assembly of the titanium structures and associated recoil components. Final integration and testing of the weapon is undertaken at BAE's facility in Hattiesburg, Mississippi.

No. 106 fuze

The number 106 fuze was the first British instantaneous percussion artillery fuze, first tested in action in late 1916 and deployed in volume in early 1917.

Proximity fuze

A proximity fuze is a fuze that detonates an explosive device automatically when the distance to the target becomes smaller than a predetermined value. Proximity fuzes are designed for targets such as planes, missiles, ships at sea, and ground forces. They provide a more sophisticated trigger mechanism than the common contact fuze or timed fuze. It is estimated that it increases the lethality by 5 to 10 times, compared to these other fuzes.British military researchers Sir Samuel Curran and W. A. S. Butement invented a proximity fuze in the early stages of World War II under the name VT, an initialism of "Variable Time fuze". The system was a small, short range, Doppler radar. However, Britain lacked the capacity to develop the fuze, so the design was shown to the United States during the Tizard Mission in late 1940. The fuze needed to be miniaturized, survive the high acceleration of cannon launch, and be reliable.The National Defense Research Committee pulled in researchers from the National Bureau of Standards (this research unit of NBS later became part of the Army Research Laboratory) to work on proximity fuzes for US Army ordnance, with focus on non-rotating projectiles such as bombs, mortars, and rockets. In 1942, the US Army developed its own version of the proximity fuze in an effort spearheaded by Harry Diamond while serving as Chief of the Ordnance Development Division. Much of the basic technology implemented in the proximity fuze used in World War II was inspired by the version created by Diamond’s group. Development was completed under the direction of physicist Merle A. Tuve at The Johns Hopkins University Applied Physics Lab (APL). Over 2,000 American companies were mobilized to build some 20 million shell fuzes.

The proximity fuze was one of the most important technological innovations of World War II. It was so important that it was a secret guarded to a similar level as the atom bomb project or D-Day invasion. Adm. Lewis L. Strauss wrote that, "One of the most original and effective military developments in World War II was the proximity, or 'VT', fuze. It found use in both the Army and the Navy, and was employed in the defence of London. While no one invention won the war, the proximity fuze must be listed among the very small group of developments, such as radar, upon which victory very largely depended." The fuze was later found to be able to detonate artillery shells in air bursts, greatly increasing their anti-personnel effects.The Germans were supposedly also working on proximity fuzes in the 1930s, based on capacitive effects rather than radar. Research and prototype work at Rheinmetall were halted in 1940 to devote available resources to projects deemed more necessary. In the post-World War II era, a number of new proximity fuze systems were developed, including radio, optical, and other means. A common form used in modern air-to-air weapons uses a laser as an optical source and time-of-flight for ranging.

Spin lock

Spin lock may refer to:

Spin lock, a part of artillery fuze mechanism which arms the munition upon firing

Spinlock, a concept in multithread programming

Thermalite

Thermalite 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.

An expedient formerly used to ignite bickford style safety fuses was to split the end of a safety fuse, place a match head into the split and tie the split back together, holding the match head against the powder core. This technique was slower, cumbersome and more failure prone than piercing and cross matching. Also, a single length of igniter cord could pass through and serially ignite multiple pieces of safety fuse attached to various charges in more complex, multiple charge blasting schemes. This technique and the several burn rate types of igniter cord manufactured by ICI could be used to implement quite complex ignition sequences.

This fuse is used in high-power model rocketry as a means of simultaneously igniting multiple "clustered" rocket motors. A single flashbulb or flash pan is used to ignite pieces of Thermalite leading to each motor.Thermalite comes in three burn rates identifiable by the colour of the fuse wrapping:

Pink: slow (20 sec/foot)

Green: medium (10 sec/foot)

White: fast (5 sec/foot)Thermalite igniter cords and connectors were manufactured in Quebec by ICA Canada Inc., however in November 1995 they ceased manufacturing igniter cord. Sources for thermalite are increasingly hard to come by and purchasing it by mail will usually require permits and licenses. As a result, those who want to use thermalite fuses will sometimes make their own.

Timex Group USA

Timex Group USA, Inc. (formerly known as Timex Corporation) is an American manufacturing company founded in 1854. The company is now a wholly owned subsidiary of the Dutch conglomerate Timex Group B.V..

In 1854, the company was founded as the Waterbury Clock Company in Waterbury, Connecticut. In 1944, the company was thought to have become insolvent, but it was reformed into Timex Corporation. In 2008, the company was acquired by Timex Group B.V, and was renamed into Timex Group USA.

Shortly after purchasing the Waterbury Clock Company in 1941, founder Thomas Olsen had renamed the company Timex, as a portmanteau of Time (referring to Time magazine) and Kleenex.

Type 4 70 mm AT Rocket Launcher

The Type 4 70 mm AT Rocket Launcher was a Japanese rocket launcher used during the last year of World War II. It was to be used in the Japanese mainland in case of an invasion by the Allies.

It is comparable to the German Panzerschreck and the American Bazooka.

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