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The first artillery weapons, appeared well before the First World War and most often present on battlefields since the last periods of the middle-age, first launched solid cast iron or stone bullets, or various material grape-shot.
1273 a.d. records can be found of the use of a gunpowder cannon by the Arab Sultan Abou-Youssouf, shooting of the 'iron gravel' on the besieged soldiers of Sidjilmesa ! In the second part of the Middle Age, bombards of all calibers broke the walls of the most formidable fortresses with full cast iron or stone bullets, inducing a major reform of the principles of the fortifications and announcing the advent of systems of the 'Vauban' type with inclinated walls.
Hollow projectiles, named 'shells', still spherical and filled with inflammable material or gunpowder, appeared in the 17th century. The delayed ignition of the inner explosive charge induced the development of a new device, called 'fuze', that was only a wood cylinder inserted through the shell wall in an hole ('eye'), and filled by compacted slow-burning gunpowder that was ignited by the hot gasses inside the gun tube at the projectile discharge.
Another important evolution appeared in 1803 when the British officer Shrapnell invented a spherical hollow shell filled with gunpowder and steel bullets, whose explosion spread on the uncovered enemy soldiers a deadly cloud of balls.
The 19th century saw a rapid acceleration of the artillery techniques development, with guns progressively becoming more powerful, more accurate, with higher rate of fire and longer ranges. These weapons evolutions created the need of adapted ammunitions, that will evoluate from the initial spherical shape to the incomparably more sophisticated projectiles of the Great War.
The following highlights might serve as a tentative summary of this evolution :
At the end of the evolutions summarized above, the 1914 artillery projectiles were generally organized like this German 7.7cm shell :
Its 75mm French equivalent had the same structure :
The nature of the shells explosive fillings was also subject to a constant evolution. The initial times gun powder, that could easily be exploded by a blow or even friction was not poweful enough and used to braek shells into too big fragments that would not fly far and quick enough. It was still in use in WW1 but only with very old guns and ammunition, or in fuzes.
This material was then progressively replaced by derivated products of the Nitroglycerine, primal componebt of the well-jnown dynamite, and more particularly the Trinitrotoluene (TNT). This material acts by detonating rather than exploding. The detonation is a much more powerful reaction than the explosion, that is a surface reaction progressively progressing inside the explosive material layer by layer, while the detonation bursts the whole mass almost instantaneously. But if the breaking power of TNT was much higher, it was a difficult material to burst.
A 'miracle' material was then invented, alloying a great detonating power and ease. The picric acid, named 'Mélinite' in France, and 'Lyddite' in England, or 'Granatfüllung 88' in Germany, was used. However, this material manufacturing was hazardous, and it was so instable that it needed the shells inside walls to be varnished or tinned, since it was reacting with steel and formed highly unstable picrate salts that could burst the detonation only under the action of the shell acceleration in the gun barrel... !
This is how the armies came back to explosives giving a better compromise between power and stability, but needing to add to the fuzes a powerful exploder sometimes called gaine (for instance using powder picric acid), itself burst by a smaller fulminate of mercury detonator triggered directly by the fuze.
French typical pyrotechnic chain for detonation of high-explosive 75mm shells loaded with melinite, including (from the left to the right) a percussion fuze Nr 24/31, a thread adaptator, a 2-grams fulminate of mercury detonator, and an exploder (sometimes calles gaine) filled with powder picric acid.
Several explosives were used by the fighting nations during WW1, including :
German name |
French name |
British name |
Type of explosive |
Power |
Stability |
Remarks |
SchiessPulver |
Poudre noire |
Gunpowder |
Exploding |
Moderate |
Inflammable, explodes under a flame, a primer or a spark action. |
Used in artifices, fuzes pyrotechnics, and in old explosive shells. Different variants in granulometry and composition. |
Fulminate de mercure |
Fulminate of mercury |
Detonating |
Very high |
Highly unstable, detonates on shocks, friction or heat. |
Produces a violent flash but not hot and long enough to burst gunpowder or a stable explosive. Used as a primer or a detonator in shells, but usually in association with an unstable explosive filled exploder (or gaine). |
|
Nitroglycérine |
Nitroglycerine |
Detonating |
Very high |
Highly unstable, detonates on shocks, blows, heat or even by sun decomposition into even more unstable components. |
Used for manufacturing of more stable explosives and propellants. |
|
Granatfüllung 88 |
Acide Picrique or Mélinite |
Picric Acid or Lyddite (fondu) |
Detonating |
Very high |
Unstable. Detonates under the action of a blow, a primer or a spark. Forms an very unstable and self-detonating picrate salts when in contact with metals. |
Usual use in expolders ('gaines'), or in shells (molten condition) in association with an exploder. |
Füllpulver 02 |
Tolite or TNT |
Trinitrotoluene or Trotyl (TNT) |
Detonating |
High, slightly lower than picric acid |
Stable, cannot detonate under the action of a flame nor thye heat or a chemical reaction with metals. Needs a direct and powerful hit to detonate, or a detonator (f.i. fulminate of mercury) |
|
Füllpulver 60/40 |
60/40 Amatol |
Detonating |
High |
Stable, but less than TNT |
Mix of 60% TNT and 40% ammonium nitrate |
|
Tetryl |
Pyronite |
Tetryl or Composition Exploding |
Detonating |
Very high, higher than picric acid |
Unstable |
Used as a primer, a detonator, or relays in fuzes. |
German time and percussion fuze Dopp Z 92. The cut-through allows to observe the internals of the sophisticated mechanical and pyrotechnic system. |
The 'main types of artillery fuzes' in use during WW1 and the 'fuzes used by the different fighting nations' of WW1 are the topic of specific and detailed sections of this website, that can be easily accessed clicking on these links.
In August 1914, the shrapnel shells were the main ammunitions of the field artillery. Designed to burst right over the ennemy troops by the means of a specific time setting device (time fuze), they were spreading an deadly lead bullets and steel fragments rain while producing a smoke cloud that allowed the gunners to tune their aiming.
Two main types of shrapnel shells existed in 1914 ; the fragmentation shells and the more modern shrapnel shells.
Most of these ammunitions and their associated time fuzes had disappeared from the battlefields pby the end of the war. They were replaced by high explosive fuzes mounted with super-quick direct action fuzes, easier to manufacture, needing little to no settings by the less and less experimented gunners, and much more effective particularly against moderately entrenched troops.
Inner organisation of a French shrapnel shell |
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The high explosive and perforation shells have been designed in order to burst when hitting their target (but also in flight, for high explosive shells), under the action of a powerful and large quantity of inner explosive charge. Their thick steel walls were producing deadly fragments, and the charge burst a shock effect much larger than the fragmentation shells could ever do.
The early XXth century conflicts and war tactics demonstrated before 1914 what would be evident just some months after august 1914, that is an increasing need of fieldguns ammunitions more powerful than the usual shrapnel shells, that prooved just good enough in percussion mode when hitting light shelters (bricks, wood, earth, etc...). In order to improve the shells destruction behavior, better explosive properties were needed. This is how the German Army designed a 'Universal shell' ('Einheitsgeschoss') before the war, and used it in the early stages of the conflict. This shell was organized like a shrapnel shell but the resin mass usually surronding the bullets was replaced by TNT for a better explosive effect. Like many technical compromises, this projectile never gave full satisfaction neither as a shrapnel shell, nor as an explosive shelle, and was gradually abandoned. Moreover, it needed a very sophisticated time and percussion fuze ('KZ11' ou 'HZ05') able to order the multiple functions of the ammunition. |
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Wartime scheme of the German universal shell. | ||
France had a similar experience, equally short and disappointing, with their 'Robin shell' also named 'Mixed charge shrapnel shell', that did not have a bottom chamber for the rear burst charge. |
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Wartime scheme of the French Robin shell. | ||
The Austro-Hungarians adopted an even different concept of universal shell, called the 'SchrapnellGranate' or 'Obus Schrapnell'. It closely resembled a conventional bullet shell, with a powder chamber in the base and a propellant diaphragm and axial flame transmission tube.
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Wartime scheme of the Austrian SchrapnellGranate shell. | ||
Specialized projectiles were used during the conflict. Their exhaustive list would be pretty long, but some of them will stay forever sadly famous.
The gaz, suffocating or tear shells, were based on the same kind of design as the incendiary shells, but diepersed toxic or irritating material when hitting the ground. These shells were often made of a double envelope system : the inner envelope containing the agressive liquid could be made of glass or thin steel plate. In other designs, the toxic material was contained inside a glass bottle that was broken by the shock of landing, simultaneously with the shell casing dismantling. These shells were most often used with 'superquick' fuzes, so that the shell burst occurs over the ground. See this excellent website for an extensive presentation of the WW1 gaz war history and material : 'La Guerre des Gaz' |
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Wartime scheme of the German 7.7cm 'Yellow cross' shell. Toxic material directly in contact with the shell walls. | Wartime scheme of the German 7.7cm 'Yellow cross' shell, with the toxic liquid contained into a glass bottle. | |