WW1 BRITISH FUZES GALLERY

Introduced in 1913, the percussion fuze N°44 was designed on the simpliest of the percussion systems, named 'système à refoulement' in France and 'direct action fuzes' in Great Britain. It was composed of a small threaded brass truncated cone, with a Tetryl explosive load in its tail side, and closed at its upper side by a 'percussion disk' made in copper and shaped like an upside down dish plate with a percussion pin in its center.

At impact, the percussion disc was deformed by the shock, pressing the percussion pin against a detonator cap whose spark was communicated to the detonating charge through a Tetryl-filled channel.

The same principle was in use in the British fuzes N°1, N°3 and N°17, all obsolete in 1914.

Concerning the N°44 fuze, and for the very first time in the British fuzes history, a safety system was added by means of a centrifugal action shutter that was closing the flame communication channel at rest, and was opened in flight under the action of the shell spin just after it left the gun tube.

A brass cap that had to be removed before use was protecting the percussion disk from accidental triggering by handlings. It was including a safety pin that was also keeping the centrifugal shutter in 'closed' position.

There was a variant, the percussion fuze N°44-B, whose more sensitive centrifugal shutter was designed for the lower spins of the shells of the heavy artillery.

More surprising variants, the precussion fuzes N°44/80 and N°44/83 were not not equipped with a top cap nor safety pin, but included a stronger centrifugal shutter spring, and were designed to be used in series with a time fuze N°80/44 or N°83/44 that didn't have a percussion system or a detonator. In this configuration, the percussion disk of the N°44 fuze was pressed down by the small explosion of time fuze primer charge, so that the percussion fuze was rather a secured detonator.

The N°44 fuze was used with the explosive shells of the :

• QF 3 in guns (3 inches - 76.2 mm),
• BL 6 in siege howitzers (6 inches - 152 mm),
• BL 9.2 in siege howitzers (9.2 inches - 234 mm),
• BL 12 in howitzers (12 inches - 305 mm),

and with the smoke shells of the :

• QF 4.5 in field howitzers (4.5 inches - 114 mm)

Numerous marks were produced during WW1, from Mark I to Mark IX, the very first ones being known for their bad reliability. Some of these fuzes were still in use during WW2. A total of 32 variants and marks have been produced.

More sophisticated than the 'direct action fuzes', 'Graze fuzes' are the most usual percussion fuzes in WW1. The N°100 percussion fuze is the root of a rich family of numerous British percussion fuzes including the famous N°101, N°102, N°103, N°104, N°108, N°109, etc....

Designed in the emergency of the end of 1914, this model went from the engineering table to the production in 10 days only ! This unbelievable performance was a real success, but obviously didn't leave enough time for optimizing its manufacturing and the fuze properties. Despite its imperfections, the fuze N°100 was continuously used from 1915 to 1917.

It was a classical graze action percussion system, working on the momentum action, although including a pretty specific design : the detonator cap / percussion pin was placed within a transversal cylinder machined at the fuze base. The detonator cap was static, and the mobile percussion pin could be projected against it by the action of a rear spring, just like a rifle striker. This movement was blocked by an axial stem linked to a mobile pellet located in the fuze axis and compressed by a spring. At impact time, this pellet was propulsed forward pressing on its spring, and provoked the freed the movement of the percussion pin striker towards the detonator cap.

A centrifugal safety system was integrated that blocked the mobile pellet at rest. This lock was itself secured by a vertical rod compressed by a spring, retracred by the shock of discharge momentum.

This ingenious system was allowing an identical detonator cap percussion force whatever was the angle of the shell impact on the target (as far as the axial stem worked)

This fuze equipped the explosive shells of the :

• QF 18 pdr field guns (3.3 inches - 84 mm),
• BL 60 pdr field guns (5 inches - 127 mm),
• QF 4.5 in field howitzers (4.5 inches - 114 mm),
• BL 6 in siege howitzers (6 inches - 152 mm),
• BL 9.2 in siege howitzers (9.2 inches - 234 mm),
• BL 8 in howitzers (8 inches - 203 mm),
• BL 12 in howitzers (12 inches - 305 mm),
• BL 15 in howitzers (15 inches - 381 mm),

As most of the British fuzes, the N°100 needed an additional detonator.

The British Armies standard percussion N°100 fuze, introduced in emergency in 1915, gave its place to successive improved models named Percussion fuze N°101, N°102, N°103, N°104, N°108, N°109, that altother include more than 89 different fuzes when adding their different models and versions !

The N°101 percussion fuze is the first evolution introduced in 1916 with the replacement of the unusual transversal percussion system by a more conventional percussion system where the detonator cap is mounted on an axial graze pellet and the percussion pin (needle) fixed under the fuze head cap, both being separated from eachother at rest by a safety creep spring. The fuze centrifugal safety system (transversal bolt restraining the pellet movement) remained unchanged. A gunpowder relay charge was included under the pellet, and the pyrotechnic chain could be added with a small delay charge.

The fuze body was still in brass (sometimes with a steel cap) with a similar shape to the N°100, the only visible difference being machined circular grooves on the cone face, and a deeper groove at its base used for blocking the fuze on the shell after mounting, by crimping this zone with a hammer and a stamp.

In addition to the different marks (I to IV) several variations of this fuze were introduced during WW1, including :

• the N°101 E percussion fuze (1916), equipped with an additional safety design by a centrifugal shutter closing the flame communication channel (triggered at a spin of 2000 to 3000 rpm)
  


• the N°101 B percussion fuze (1916), dedicated to the heavy howitzers shells and therefore equipped with weaker safety springs (shutter and bolt) to compensate slower spin.
  


• the N°101 EX percussion fuze (1917), equipped with a stronger creep spring for use with 6 in. gun.

In its different versions, this N°101 fuze equipped the high explosive shells of all calibers guns and mortars, from 18 pdr fieldguns to railway 15 in. heavy mortars.

This fuze was therefore used mainly with the high explosive shells of the :

• QF 18 pdr fieldguns (3.3 inches - 84 mm),
• BL 60 pdr fieldguns (5 inches - 127 mm),
• QF 4.5 in field howitzers (4.5 inches - 114 mm),
• BL 6 in siege howitzers (6 inches - 152 mm),
• BL 9.2 in siege howitzers (9.2 inches - 234 mm),
• 8 in heavy howitzers (8 inches - 203 mm),
• 12 in heavy howitzers (12 inches - 305 mm),
• 15 in heavy howitzers (15 inches - 381 mm)

The N°101 graze percussion fuze gave birth to several variants during WW1 :

• the N°102 percussion fuze were N°100 fuzes transformed into N°101 fuzes by removing the transversal percussion mechanism and replacement of the axial pellet by a conventional detonator cap pellet. A crimping groove was machined at the cone base.
  


• the N°103 percussion fuze were similar to the N°101 fuzes, dedicated to the high explosive shells of the 18 Pdr (84 mm) shells, but with a shortened base thread. The detonators (often equipped with a specific centrifugal safety) associated with this fuze had to be mounted on the adaptor, and not on the fuze itself,
  


• the N°108 percussion fuze were N°100 fuzes not associated with a detonator, for use with gunpowder filled shells,
  


• the N°109 percussion fuze were N°101 fuzes or N°102 fuzes not associated with a detonator, for use with gunpowder filled shells or chemical shells,
  


• the N°109 E percussion fuze were N°109 fuzes with a centrifugal shutter similar to the one of the N°101 fuzes (closing the flame communication channel at rest), designed for the 60 pdr gun chemical shells with a gunpowder bursting charge.

The lessons learned during the war years led the fighting countries armies to continuously develop new equipments. In particuliar, the percussion fuzes sometimes failed in the muddy grounds battlefields of Flanders where the British Armies were engaged. In these conditions, the landing impact energy could be so much absorbed by the mud that the fuze deceleration was not quick enough to trigger the usual mechanisms of the existing graze percussion fuzes, or the ground not hard enough to deform the head of the 'direct action fuzes'.

Moreover, the classical projectiles and their fuzes were not really efficient for barbed wires destruction, that were too weak a target to trigger the percussion fuzes of high explosive shells, and a too small one to be aimed by shrapnell shells.

The N°106 super-quick percussion fuze is the British answer to these new requests. Inspired by a French 1915 concept (the 'fusée IAL'), it was designed to be very sensitive to landing impacts, even in soft grounds or on non resisting targets. It was therefore a 'super quick' direct action fuze. It was tested at the end of the summer of 1916, and distributed to the batteries in the early 1917.

The basic principle was very simple, asa direct action fuze can be : a mobile percussion head, composed with a steel hammer covered by a hemispheric aluminium hat was mounted on an axial steel rod acting as a percussion pin able to hit a detonator cap that would burst a flame via a central communication channel to the rear explosive load. On the contrary, the safety devices of this ultra-sensitive system were very complex, avoiding any kind of safety springs that would have given some mechanical unwanted delay, but including :

• a steel plate hard hat protecting the percussion mechanism, that the gunner had to remove before use,
• a copper tape rolled around the percussion hammer rod and preventing it from going down. This tape was unrolled under the spin action during flight, only when the shell had left the gun tube and was not submitted to acceleration,
• a shearing wire of very little resistance but preventing the wind pressure on the head to push it backwards during the flight,
• a centifugal shutter closing the flame communication channel (on models N°106 E appearing from January 1918 only), and triggered at 1300 - 1700 rpm.

This fuze was used with the high explosive shells of the :

• QF 18 pdr field guns (3.3 inches - 84 mm),
• BL 3.7 in mountain pack howitzers (3.7 inches - 94 mm),
• BL 60 pdr field guns(5 inches - 127 mm),
• BL 6 in field guns (6 inches - 152 mm),
• BL 12 in guns (12 inches - 305 mm),
• QF 4.5 in field howitzers (4.5 inches - 114 mm),
• BL 6 in siege howitzers (6 inches - 152 mm),
• BL 8 in howitzers (8 inches - 203 mm),
• BL 12 in howitzers (12 inches - 305 mm),
• BL 15 in howitzers (15 inches - 381 mm),

as well as the chemical or smoke shells of the :

• QF 18 pdr field guns (3.3 inches - 84 mm),
• QF 4.5 in field howitzers (4.5 inches - 114 mm),
• BL 6 in siege howitzers (6 inches - 152 mm),

An impressive quantity of 'marks' were created, as well as some derivated models. Amongst them, the N°115 E fuze that was a N°106 E with an elongated more aerodynamic shape for use with an improved shape shell was only delivered in December 1918, but remained in service until WW2.

In the fourth quarter of the XIXth century, a new kind of time fuze appeared in Great Britain with the Fuze Nr24. This kind of equipment gave way to a rich series of time, then time and percussion that will survive long and participate to WW1, all reckognizable with their cylindric or hemi-spherical shape and presence of a top hexagonal locking bolt. One of the first time and percussion fuzees of that family was the Middle Time and Percussion Fuze Nr54 designed in 1887.

The N°54 was organized on a time system and a percussion system, both separated and selectionable by a safety pin marked with a 'T' and a 'P' respectively allowing the activation of the movements of the time system pellet firing the time ring powder track, or the percussion pellet that would enable the inertia block movements at arrival, under the action of the shell departure shock.

The time behaviour was limited to 16 seconds (graduations from 0 to 30) on this single time ring model, whose setting was secured by tightening the top bolt.

The N°54 fuze was used mainly with the shrapnell shells of the :

• BL 5-in howitzer,
• BL 5.4-in howitzer,
• BLC 6-in,
• BL 6-in,
• BL 6-in 25-cwt howitzer,
• BL 6-in 30-cwt howitzer,
• BL 9.2-in,
• BL 10-in,
• QF 4.7-in
• QF 6-in

Officially service until 1921, the N°54 was though quickly replaced by its son-models Nr 62 and N°64 with compatible threads but longer combustion times.

Evolution of a family of fuzes based on the same principles and including the fuzes N°56 (1894), N°57 (1900), N°60 (1901) and N°63 (1904), the original time and percussion fuze N°65 (1910) was only a conversion of these latters. Its properties were however considered so interesting that a new design was introduced in 1914 : the time and percussion fuze N°65A. All these fuzes had a similar profile, easily recognizable by its cylindrical shape, a graduated ring and a top hexagonal locking bolt.

The new fuze N°65A was organized on two separate systems : a time system and a percussion system, each secured by a safety pin.

• In order to select a percussion behaviour, the gunner had to remove the safety pin marked 'P' (Percussion), freeing the movements of a percussion pellet only blocked by a weak shearing safety pin. On shock of discharge, this pellet went backwards, liberating the movements of a small bronze ball pushed laterally by the centrifugal force and finally unlocking the movements of the classical graze percussion system located in the fuze tail.
• If the time behaviour only had to be selected, the combustion time had to be set by rotationg the graduated disk (0 to 44). In order to do that, the gunner had to loosen first the locking head hexagonal bolt, set the time, then tighten it again to prevent the graduated disk rotation in flight due to the shell spin. The safety pin marked 'T' (Time) had to be removed. This action liberated the movements of a time percussion pin pellet blocked by a small shearing pin, whose backwards move induced by the shell departure shock ignited time cap putting fire to the time composition contained in two superposed rings. At the end of the combustion of the preset length, a small powder pellet bursted and projected the mobile pellet of the tail graze percussion system one on each other.
• A time and percussion behaviour could be obtained by removing both the pins marked T and P.

The N°65A fuze was used mainly with the shrapnell shells of the :

• BL 4-in gun,
• BL 30-pdr gun,
• BL 15-pdr gun,
• BL 12-pdr 6 cwt gun,
• BL 10-pdr gun,
• QF 15-pdr gun,
• QF 12-pdr 12 cwt gun,
• QF 2.95-in mountain pack howitzer

In service until 1932, the N°65A gave way to a more sensitive N°65C fuze (1916) (weaker shearing safety pin) for the nay service, and a AA dedicated N°66 fuze (1916) that was never bring to service.

The time and percussion fuze N°80 was the fuze usually used with the British shrapnell shells of the famous 18 pounders fieldguns in WW1. Designed by the German company Krupp in 1905 and manufactured under license in England before the war and during it, its peculiar story will feed the arguments of the believers of a war wanted by the weapons international industry since once the war over, the British company Vickers Armament Industries, who manufactured these fuzes between 1914 and 1918, kindly accepted to pay to Krupp 40 000 £ royalties...

Although the initial models were made in aluminium, this fuse was entirely made in brass. The time system is a classical rotating disk system, with a ring graduated from de 0 to 22 secones, a departure ignition caused by an axial time pellet caused by the discharge shock momentum. The percussion system, selectable by choosing the rotating disk graduation marked with a roman cross was a very classical one as well, of graze type, with a staple safety device actionned by the shell departure shock. A gunpowder load was placed at the base of the fuze to ignite the shell (with an additional detonator if needed).

Living through 16 different marks, it will remain in service until the middle of WW2.

Known variants are :

• the time and percussion fuzes N°80B only differed by a small difference in shape, one lip having been suppressed so that the fuze could be adapted to certain shell types.
• the time fuzes N°80/44 et N°80B/44, with no percussion mechanism, were dedicated to the explosive shells that had to detonate in flight (for instance for anti-aircraft), and needed the serial mounting with a direct action percussion fuze N°44/85 acting as a detonator. The 0 to 2 graduations of these fuzes were masked, and a blue 'T' mark was painted on the fuze body,
• the time fuzes N°180 and N°180B, with no percussion mechanism, were used with incendiary and shrapnel shells in anti-aircraft action. A blue 'T' was painted on their body.

In addition to these conversions, the N°80 fuze is at the basis of the design of N°83 and N°88 fuzes described individually later in this section.

Initially dedicated to the shrapnell shells of the famous :

• QF 13 pdr field guns (3 inches - 76 mm),
• QF 18 pdr field guns (3.3 inches - 84 mm),

it was afterwards adapted for other weapons of similar power, that is shrapnell shells of the :

• 10 pdr and 2.7-in mountain guns (2.75 inches - 70 mm),
• QF 2.95-in mountain pack howitzer (75mm),
• BL 15 pdr field guns (3 inches - 76 mm),

The time system of the Time and percussion fuze N°83 introduced in 1911 is very similar to the one of the famous fuze N°80, at the exception of the excentric pyrotechnic arming system. The time ring was graduated from 0 to 22 time units, for a maximum combustion time of 30 seconds.

The differences are much bigger for the percussion system, where the graze staple arming system of the fuze N°80 was replaced by a bronze ball centrifugal system, more adapted to the firing conditions of heavy caliber shells.

Several variants are listed :

• the time and percussion fuzes N°83R, with a modified time pellet creep spring for use with low muzzle speed howitzer shells.
• the time fuzes N°83/44, without percussion mechanism, were dedicated to the high explosive shells supposed to detonate in flight -for instance for an anti-aircraft role), and needing the serial mounting with a percussion fuze N°44/85 acting as a detonator. The 0 to 2 graduations of these fuzes were masked, and a blue 'T' sign was painted on the fuze body,
• the time fuzes N°94, without percussion mechanism, were used with the shrapnel and incendiary shells in anti-aircraft combat. A blue 'T' sign was painted on the fuze body.

Dedicated mainly to the shrapnell shells of the :

• BL 60 pdr field guns long range (5 inches - 127 mm),

Before joining the war in 1917, the USA allowed its industry to sell weapons and ammunitions to their fighting friend countries. It is worth remembering that this is the reasons why the Kaiser's submarines torpedoed the US civil ship 'Lusitania' that was transporting thousands of civilians, but also tons of war ordnance. This tragedy has been one of the elements that triggered the decision of USA joining the war against Germany.

Perhaps some N°85 fuzes are still lying within the Lusitania remains in the North sea : the 'time and percussion fuze N°85' is indeed the name given by the British army to designate fuzes made by US metallurgist to UK thread standards on the base of an existing US fuze model 1907 and imported in huge quantities as an alternative to the N°80 fuze.

The characteristics of these two fuzes were similar, but it was far from being identical items. For instance the N°85 fuze had a nose exhaust for combustion gazes escape, protected by a hat. It was also equipped with a percussion system safety mechanism composed with two centrifugal bolts activated between 1850 and 2150 rpm. The maximum combustion time was 23 secondes, corresponding to the graduations on the mobile disc.

This fuze was mainly used with the shrapnell shells of the :

• QF 13 pdr field guns (3 inches - 76 mm),
• QF 18 pdr field guns (3.3 inches - 84 mm),

At least two important variants are reported :

• the time fuzes N°85/44, without percussion mechanism, were dedicated to high explosive shells that were to explode in flight (anti-aircraft role), and had to be associated with a percussion fuze N°44/85 acting as a detonator. The graduations 0 to 2 were hidden, and a blue 'T' letter was painted on the fuze body,
• the time fuzes N°185, without percussion mechanism, were used with shrapnel and incendiary shells for anti-aircraft missions. A blue 'T' sign was painted on the fuze body.

The time and percussion fuze N°88 was a variant of the fuze N°83, with a slow burning time composition path, allowing the system to reach a maximum burning time of 45 seconds instead of 30 seconds for longer ranges. Entirely made of brass and graduated from 0 to 22 time units plus a roman cross for percussion behaviour.

The time and percussion fuzes N°88R, was a variant with a modified time pellet creep spring for use with low muzzle speed howitzer shells.

This fuze was dedicated to the shrapnell shells of the :

• BL 60 pdr long range field guns (5 inches - 127 mm),
• BL 6 in field guns and siege howitzer (6 in - 152 mm),
• BL 9,2 in guns on railway mounting (9.2 inches - 234 mm),
• BL 12 in guns on railway mounting (12 inches - 305 mm),

Initially developped in 1917 for BL 4.7in and BL 60pr field guns in anti-aircraft role, the time and percussion fuze N°89 was the longer range fuze that was used by the British army in WW1, with a maximum combustion time of 60 seconds, 15 seconds longer than the long range fuze N°88.

Designed to reach that long delay, the N°89 was another evolution of the fuze N°83, keeping the same graze percussion system with a centrifugal ball safety system and the eccentric time pellet system, but with 3 time combustion rings instead of 2 as in every other British T & P fuze. The lower disk was graduated from 0 to 22 time units as usual, but even set to '0', the to ring composition had to burn completely before the burst.

Its long range properties later made this fuze the conventionnal one for shrapnell shells of the heavy guns up to 12 inches. It stayed in service until 1934.

This fuze was dedicated to the shrapnell shells of the :

• BL 4.7 in long range field guns 4.7 inches - 120 mm),
• BL 60 pdr long range field guns (5 inches - 127 mm),
• BL 6 in field guns (6 in - 152 mm),
• BL 9,2 in guns on railway mounting (9.2 inches - 234 mm),
• BL 12 in guns on railway mounting (12 inches - 305 mm),