SOME FUSES

Designed for Siege and Mountain ('S.M.') artillery, whose indirect (curved) shots needed variable propulsive charges, that fuse was built to be armed with the same security level either at high or low charge.

For that reason, the inertia load was heavier, and the arming system was composite : arming staple system for lower charges, arming grooves on the starter-bearer for the higher charges.

It mainly equipped the projectiles of the

• 120 mm and above heavy howitzers
• Crapouillots trench mortars (big caliber bombs)

Very sensitive, it needed very careful handling, since it could be armed only with the shock of a fall from a height of 3 to 4 meters !

Basic type of the French percussion fuses, its design was quite simple, and therefore robust.

The top cap contained the classic arming system (inertia block + spring + staple) . The classic percussion system was located at the centre, igniting the explosive charge of the bottom part, whose action could be multiplied by the addition of a detonator.

It equipped most of the explosive projectiles of the :

• 75, 80, 90, 95, 120, 155 mm guns and howitzers

That fuse included a 0.05 seconds delay. A further version (fuse 24/31 model 1899) had an identical design, but without any delay mechanism.

Evolution of the preceeding model, that fuse was equipped with a novative arming system, based on a security piece blocked with a tin pin, that could rotate and retire sliding on a helicoïdal slope also machined on the starter-bearer.

That mechanism insured a quicker functionning that the one of the model 1899 fuse, generally exploding when the the shell top penetrated the ground. The embarked explosive load was a 2 grammes fulminate detonator.

That fuse usually equipped the projectiles of the

• 75, 80, 90 and 95mm field guns
• 120mm guns
• 155mm howitzers

However, those fuses were not to be used with trench mortars, since the departure shock energy was not sufficient to arm the mechanism.

Les fusées à armement par force centrifuge présentaient souvent deux inconvénients : le risque était grand que la vitesse de rotation soit suffisante pour que l'armement se produise alors que l'obus était encore dans le canon, et il se pouvait aussi au contraire qu'au cours du vol, le système se désarme par ralentissement de cette même vitesse.

Cette fusée Schneider possédait un dispositif de sécurité basé sur des ensembles ressorts-masselottes qui maintenait serrés les segments d'armement à force centrifuge pendant la phase d'accélération, c'est à dire dans le canon, et les bloquait en position écartée en phase de vitesse constante.

Ce mécanisme était très précis, et ne fonctionnait qu'à des vitesses de rotation > 12000 tours/minute. Il était donc primordiales de ne les employer qu'avec le canon de 75.La charge explosive embarquée était encore un détonateur de 2 grammes de fulminate.

Cette fusée équipait principalement les projectiles des

• Canons de campagne de 75mm

The I.A. fuse was designed to induce maximum surface effects of the explosive shells, making them explode as soon as the top of this long fuse was hitting the objective.

Therefore, those ammunitions were practically making no shell hole, and their effects on infantrymen were devastating...

The fuse was armed by the means of the centrifugal force, ejecting during the flight two brass half-rings under the 'hat', those half-rings beeing blocked at rest by a tissue ribbon or a tin cover.

At the impact, the hat was actionning a rod, shearing a small safety pin, and made the percussion pin violently meet the starter, linked to the main charge by an explosive tube.
This fuse was generally equipping the shells of the

• 75 mm field guns (explosive shells)

Its use generally needed very careful handling, and its shape was modifying the shell maximum range, that had to be corrected by means of appropriate tables.

That model of instantaneous fuse was less sophisticated than the celeb 24/31 mod. P.R.1916. It however had the same function, a cylinder containing a stem preceding the projectile, so that the projectile exploded before the head of the shell hit the objective.

There was though both a non delayed AND a delayed model !

That fuse mainly equipped the bombs of the

• 58mm n°1 bis trench mortars (projectiles with rear rod, 16 kg)
• 240mm trench mortars (projectiles with rear rod, 87 kg)

That fuse used the typically french principle of the spiral tube time fuse. Graduated from 0 to 24 seconds for a time fuse function, initiated by a percussion concutor situated in the centre of the hat, the time before explosion was set by punching the time scale with the specific apparatus ('débouchoir').

Entirely made of brass, that fuse also had a classic percussion mechanism for an impact explosion.

It mainly equipped the projectiles of the

• 75 mm field gun (shrapnel shell mod 1897)

Since its role was to communicate the fire to the 'tulip' linked to the black powder room at the bottom of the shell, that fuse usually had no detonator.

Using the same principle than the 22/31 time fuse, since it also had a spiral fuzing tube ignited by a central percussion concutor, that fuse was designed for longer flight times, being graduated from 0 to 49 seconds.

It mainly equipped the projectiles of the

• 75, 120 et 150mm (shrapnel shells) field guns and howitzers

A specific model without impact percussion system was built, for the anti-aircraft use, so that the shell was not exploding back on friendly troops if it failed to explode in altitude.

Brass fuse, graduated from 0 to 55 hundreds of meter with 50 meters steps.

Designed and built at the Belgian Pyrotecnics School before 1914.

That fuse equipped the 77 mm Krupp guns.
A model entirely made of aluminium was also existing.

Double effect fuse, entirely made of brass, graduated from 0 to 22 seconds and with a roman cross sign for impact percussion function.

First dedicated to the shells of the :

• 13 pdr and 18 pdr field guns,

it was afterwards adapted on most of the existing calibers. This is the classical British fuse of WW1.

There is a strange but real story, feeding the thesis demonstrating that the war was intentionally created by the international of the weapons industrials : the design of this piece have been made by Krupp (Germany). after the end of the war, Vickers, the British society that manufactured those fuses, payed to Krupp royalties for an amount of 40.000 £...

Revolving discs time fuse quite impressive because of its size and its weight (made of brass).

Gradueted from 0 to 22 seconds, and with a roman cross sign for an impact percussion function.

A deep trapezoïdal groove is machined in the top of the fuse head for shell handling.

The British armies entered in war with the percussion fuse N°100, for explosive shells.

Because of big manufacturing difficulties, this model left its place to several succesive enhancements, named N°101, N° 102 et N°103, representing, with their different marks, more than 89 models !

The model shown on the picture, a N°101 mark II, equipped the explosive shells of the guns and howitzer of all calibers, from the 13 pdr guns to the 12 inches long range railway howitzers.

Brass fuse, with a steel mantle. This is a classical conception for a percussion fuse with optionnal delay, equipped with two different inertia percussion systems, with a pin for security handling.

A 100 grammes picric acid detonator was integrated at the bottom part of the fuse.

The optionnal delay was selected by a lever rotation, placed on the 'oV' position (Ohne Verzögerung - without delay) or on the 'mV' position (mit Verzögerung - with delay)

That fuse was dedicated to the explosive shells ('Gr' = Granate - Explosive shell) of heavy caliber. It mainly equipped the projectiles of the

• 150 mm heavy field howitzers (sFH02, sFH13)
• 150mm long tube guns
• 150mm bind tube guns
• 210mm howitzers

Those types of heavy shell needed quite a big detonator to explode (100 gr. picric acid)(

Brass or zinc alloy fuse, with steel cover.

The function with optionnal delay implied the presence of two different percussion systems, one having an integrated delay, and the other with no delay. Those systems were selected via a slight rotation of the upper rotating disc ('O/V').

Equipped with a 90 gr. acid picric detonator, it was used with the projectiles of

• 100, 130, 150, 150 (long) mm guns
• 150 mm heavy field howitzers sFH02, sFH13
• 6in & 8in Russian, and 150mm Belgian captured howitzers
• 210 mm mortars
• 210 mm Belgian captured howitzers

The mobile pieces of the percussion systems were blocked at rest condition with a security pin. Several marks were introduced before the war and during the war.

Brass fuse with a steel cover, and 45 mm diameter thread. Evolution of the Gr Z 04, the inertial percussion system was arm by a a concutor with security pin.

The modified version ('n/A' - neue Art) added another security pin on the main percussion system, t une goupille de sécurité sur le percuteur principal, remoced by the centrifugal force.

That fuse was equipped with a 63 gr. acid picric detonator.
It was mostly used with the shells of the

• 90, 100, 120, 150 mm guns
• 150 mm heavy field howitzers sFH02, sFH13
• 150mm Belgian captured guns
• 6in Russian captured howitzers

You will easily find that fuse in big quantities on the former battlefields. Unhopefully, most of these objects are very corroded now, because they were made in aluminium. Only some have a zinc alloy or brass body, and resisted far better.

Basic fuse of the explosive or gaz shell of the 77mm FK 96 n/A field gun, equipped with a 20 grammes acid picric detonator, it had a simple and economic design. Classic functionning of a German percussion system with black powder grain and stem arming.

It was usually used with the explosive and gaz shells of the

• 77 mm FK 96 n/A et FK 16 field guns

That fuse is often impressive because of its weight when found on the battlefields, because entirely made of brass.

The models that followed the first one (HZ 14, introduced in 1914) used a centrifugal force arming system (HZ14 Fb or HZ 14 Vorst. Fliehb.), as well as a safety pin (HZ 14 Vorst. Fliehb.).

Equipped with a 55 gr. acid picric detonator, it was used with the explosive or gaz shells of the

• 90 mm K73/88 guns
• 100 mm K97, K04, K14 guns
• 120 mm sK 12cm heavy guns
• 150 mm lFH 98/09 light howitzers
• 150 mm lFH 16 light howitzers
• lFH Kp Krupp light howitzers
• etc...

This is a classical German percussion fuse with arming by the combustion of a compacted powder grain ignited by a concutor, blocking a stem in contact with the inertia block.

This type of fuse is quite commonly found on the former battlefields. Its characteristic is in being of a very simple look, since te visible part of the shell is a steel cone. In fact, this part is a hat (that can be made of steel or of another grey alloy), that covers the brass percussion mechanism.

The fuse mechanism is composed by a double security system based on the centrifugal force :

• two security pieces, blocked by springs but allowed to move thanks to the shell spin are stopping the starter-bearer movements at rest condition,
• a lock that can slide horizontally under the effects of the same force is separating the percussion mechanism from the relay-charge.

, The delayed models have a little picric acid relay charge in this sliding lock ('L.K.Z.16 m.V.'). This relay charge is not present in the non-delayed models ('L.K.Z.16 o.V.').

Equipped with a 23 gr. picric acid charge, it was in use with the explosive projectiles of the

• 77 mm FK 96 n/A et FK 16 field guns
• 3 inches infantry guns (mountain russian guns model 1909)

Double effect fuse, this model had a classic percussion system in the tail and a rotating discs time system in the upper cone.

The lower disc, mobile, was engraved with graduations from 1 to 29 seconds, and a roman cross for the pure impact percussion function.

Entirely made of brass, it had a security pin blocking the concutor of the time system. The arming system of the percussion device was quite special, based on the movements of a tube sheltering the starter-bearer, blocked by a powder grain ignited by the concutor at the shooting time, and therefore without any stem, unlike most of the German fuses.

That fuse mostly equipped the projectiles of the :

• 90, 120, 130 and 150 mm (shrapnel) guns
• 150, 160 and 210 mm (shrapnel and explosive) howitzers

The inner mechanism of this Dopp Z92 nF fuse is strictly identical to the famous Dopp Z92 fuse (hera above), as this appears evidently on the scheme. The only differnec between the two fuses is the shape, more round, and the material (either all brass or aluminium plus brass).

The lower disc (that disappered on the showed item) was graduated from 2 to 41 seconds, and with a special mark for the pure percussion functionning.

This fuse was mostly equipping the projectiles of the :

• 90, 100 et 150 mm guns (shrapnel shells)
• 150 mm sFH 13 and sFH 02 howitzers (incendiary and explosive shells)

That revolving discs time fuse was also equipped with a percussion system, giving a sense to the name 'double effect' : 'Dopp' = Doppler (double). It was very common, since it was only used with the shells of the

• 77mm FK96 n/A and FK 16 field gun.

It is therefore often found on the former battlefields, or in the museums.

Used without modification on the shrapnel shells, or added with a detonator in the case of the explosive shells, its static disc was graduated from 0 to 65, for an ignition after a flight from 0 to 6500 meters (other types existed, with graduations up to 5350, 7150 or 7000 metres), and the mobile disc was engraved with the index.

The concutor (for the ignition of the time system) was located in the axis of the head, and the classical percussion system (for an occasionnal function at the impact time) in the tail. The most ancient models were equipped, at rest, with a safty pin.

The HZ05 existed through different marks, most of them being fuse-detonators. The item showned here does not have an attached detonator, and was therefore only dedicated to the shrapnel shells.

Composite (steel or zinc alloy cap, aluminium discs, steel and zinc alloy body), it was engraved with graduations from 3 to 70 hundred of meters and a roman cross for impact percussion function on its lower mobile rotating disc. The time system was ignited by a classical concutor, fixed at rest condition by a safety pin.

The classical percussion system, located in the tail, was armed by a slightly new 'gunpowder grain + blocking stem' German system.

That fuse was usually used on the shrapnel projectiles of the

• 105 mm light field howitzers lFH 98/09
• 105 mm light field howitzers lFH 16
• 105 mm light field howitzers lFH Kupp ('Kp')

In its successive marks, this fuse has been designed to equip the famous German 'universal shells', that was studied in the 'projectiles' webpage of this site.

This particuliar shell (with lead balls and back gunpowder room for the shrapnel function, thickened steel walls and TNT bedding of the balls for the explosive function) implied the use of specific fuses.

In addition to the classical percussion system and revolving disc time system (the upper rotating disc was engraved with graduations fron 2 to 50 hundred meters) and powder grain concutor, classical for a German 'double effect' fuse, the HZ 11 model was equipped with a lever the direction of the lower disc flame, either to the 23 gramms picric acid detonator (explosive function, position 'G' - 'Granate'), either to 8 lateral windows communicating with the back gunpowder room (shrapnel function, position 'S' - 'Shrapnel').

That fuse was mainly used with the projectiles of the

• 77 mm FK 96 n/A and FK 16 (universal shells)

That additionnal sophistication had a cost : this was one of the most complex fuses of the period, with more than 105 different brass parts !

The name of that fuse, 'I.W.M. Zdr.' - 'Leichte Wurf-Minen Zünder', specified its exclusive use with the bombs of the 77 mm light minenwerfers :

• 77 mm light trench mortars 'lWM', explosive or light gaz shells
• 77 mm light trench mortars mod 1916 lWM n/A, light gaz shells

Entirely built in brass, it was made of a classical revolving discs time system (with the lower mobile disc graduated from 7 to 24 seconds, and a central concutor blocked by a safety pin), and a classical gunpowder grain + stem arming system.

This fuse name, 'Z.s.u.m.W.M.' - 'Zünder für schwerer und mitteler Wurf-Minen', specifies its exclusive use with the bombs of the middle and heavy minenwerfers :

• 170 mm middle trench mortars mWM 13 or o/A, explosive, incendiary or gaz shells
• 170 mm middle trench mortars mWM 16 or n/A, explosive, incendiary or gaz shells
• Smooth 180 mm bomb-laucher (Projector), gaz or blue-crossed shells
• 250 mm heavy trench mortars sWM, explosive long shells, explosive or gaz half-bombs
• 250 mm heavy trench mortars sWM 16 or n/A, long explosive bombs.

made of brass, like the small IWMZ item of the 77 mm minenwerfer, this fuse is also composed of a classical time-delayed disc mechanism, where the mobile inferior disc is graduated from 7 to 21 seconds, with central concutor blocked by a safety pin. Some models have a centrifugal force security.

A symetrical percussion system with two opposite starters and percussion pins (to the front and to the rear) made sure the explosion occured whenever the shell felt on his back or on the nose (but theoritically not on the side !).

That fuse could be covered with an aluminium or thin steel cap for hiding the flames during night time use.