MAIN TYPES OF ARTILLERY AMMUNITION IN 1914-1918

The hollow projectiles, filled with inflammable material or powder, appeared afterwards. And, in 1803, the English officer Shrapnel invented the shell bearing his name, whose explosion in the middle of its flight dispersed a rain of lead balls on the uncovered enemies.

Another evolution concerned the propelling charge.. In the past, it used to be poured in the tube of the gun by the muzzle, then compacted before the introduction of the ball. The gunpowder was conditioned inside of cloth bags ("cartridge-bags") or in brass or copper casings. In these last types, a primer with mercury fulminate was sealed at the base of the casing, struck (or electrically fired) by the gun's fire setting mechanism, mounted on the breech. The charges that were not not conditioned in casings required the use of a friction, percussion or electric quick-match, passing through the breech mechanism.

All the propelling charges of 1914 used cordite or smokeless powder, more recommended for the furtivity of the batteries. Certain propelling mixtures, flammable with more difficulty (e.g. powder 'B'), required a charge relay (e.g. blasting powder) put on fire by the primer.

Several techniques existed for the assembly of the shell and the propelling load :

• fixed : the shell is sealed onto the soft metal casing (brass, and sometimes iron, aluminium...) which contains an invariable load of propelling mixture, and the whole piece is handled in only one part, allowing high fire rates.









• semi-fixed : the shell and the casing are transported separately, but are assembled at the time of the shooting. The capacity of propelling charge of the casing can thus be decreased before the shooting accordingly to calculations of the battery officer, which can be useful for the indirect curved trajectories of the mortars and howitzers.






• separated : the propelling charge is introduced into the behind the shell, in cloth bags, and the last load (on the side of the breech or the gun bottom) is contained in a small soft metall casing including the starter for the fire setting. Here the propelling charge quantity can be even more easily modified.

The stability of the shell flight was ensured by the rotational movement (spin) that was conferred by the grooves of the gun tube (gyroscopic effect). For this intention, the base of the shell was girdled with one or more soft metal or copper bands, of diameter equal to the diameter of the tube in the bottom of grooves. Thus, at the time of the shooting, this band was embedded in the spiral grooves of the gun, and gave to the shell a screw-type movement, a spin. Innumerable fragments of these bands, as deadly than the steel glares of the shells, can still be found on the old battle fields.

Finally, the nature of the explosives was also subject to an evolution. The black powder of the beginnings, easy to explode but not very powerful and breaking the shells in much too large fragments, left its place, little by little, to the TNT. But if the explosive power of this latter was far better, its detonation was often difficult.

A 'miracle' substance was found, which combined great explosive power and good detonation facility. Picric acid, called ' Mélinite' in France, and ' Lyddite' in England, or ' Granatfüllung 88 ' in Germany was used. On the other hand, this substance was delicate to produce and required to varnish or to galvanize the interior of the shells because it reacted with steel to form unstable picrates that were willing to explode easily under the acceleration of the departure. It should be noted that in its molten or compressed form, the mélinite was also rather difficult to detonate !

Thus everybody returned little by little to the TNT, but associating to the fuses a separate detonator with high explosiveness (for example with pulverulent mélinite), to detonate the principal charge.

All these types of explosives were in use in 1914.

• The grape-shot shells still equipped the old "de Bange" French guns of 80, 90, 95, 120 and 155 mm in 1916. Composed of a thick steel base in which balls housings were machined, on which were stacked alveolated cast iron wafers, weakened for a better fragmentation, and lead balls, then at the top a hollow warhead including the explosive load connected to the detonator, the whole assembly was packaged in a steel envelope of small thickness.

  The shock of the departure broke the cast iron plates, and the explosion of the warhead charge during the flight dislocated the thin envelope, dispersing the tiny cast iron pieces and the lead bullets in every directions, but in quite a small quantity, with a relatively low speed and not a very visible burst cloud. Only the good compactness of the unit was an advantage and made also this projectile an effective weapon by its simple inertia for the destruction of shelters.

• The back load shells acted just like flying guns. The same general organization had been adopted by all the belligerents. For example, in the particular case of the balls shell of the French 75 mm gun (7.240 kg), the shell body was a cylinder made with stamped steel. Its base had thicker walls to constitute the back powder back load room (100 gr. of blast powder).

  This back room was closed by a lower diaphragm, at the top of which were placed the 250 lead bullets hardened with antimony, glued in a special resin ('collophane') for a good steadiness. A higher diaphragm closed the cylinder, on which the warhead was screwed, carrying the fuse at its top. A mild steel tube crossed the shell right through along its main axis, putting in communication the tail of the rocket (via some kind of a funnel called ' Tulipe') and the powder back room at the base.

  When the fuse commanded, at a given point of the flight trajectory, the explosion of the shell, the central tube communicated the flame to the back charge which, exploding, ejected the warhead, and violently pushed on the back diaphragm, propelling the balls forwards, with a speed higher than that of the shell. The balls shower was thus ellipsoidal, sprinkling a zone of almost 300 m in length and 25 m in width

The crushing performances of the balls shells were considered to be sufficiently effective against light shelters (small masonry, wooden shelters...). The Germans even increased those performances by using, at the beginning of the conflict, a 'universal shell' ('Einheitsgeschoss')in which the resin surrounding the balls was replaced by TNT. But quite usually with the compromises, this projectile never gave complete satisfaction neither as a balls shell, nor as a high-explosive shell, and was thus gradually abandoned. The French made the same experiment, equally disappointing, with their ' Robin' Shells.

To be complete, let us mention as well the grape-shot boxes (or 'cannister'), designed for a closer defense. It was generally made with a cylindrical zinc box, provided with a zinc lid and a wooden base.

This projectile, filled with lead bullets more massive than the balls shells ones, tore in the tube of the gun under the shooting effect, point-blank sending its balls shower. The guns shooting ball shells could easily obtain the same results without this kind of device, since their conventional time fuses could be set in a position to start the 'shogun shooting' right at the gun's muzzle.

The German grape-shot boxes were a little different, longer, and with a spherical warhead.

Traditionally reserved for the large caliber guns, whose mission was the destruction of the strengthened obstacles rather than the elimination of the troops, the 'rupture' shells, or high-explosive shells were quickly adopted by field artillery, taking a role in the ramming of the position war.

The general organization of such a shell was also rather traditional. Let us take again as an example the high-explosive shell of the French 75 mm gun. It was made of a single-piece forged steel shell, from the base to the warhead. The walls were a little thicker, and it was a threaded hole was machined at its higher end for screwing the fuse. The shell weighed 5.300 kg, and was filled of 850 gr. mélinite. This explosive being corrosive for the steel, the interior of the shell was varnished or galvanized (products of corrosion being likely to start spontaneously an explosion !).

It should be noted that with the difference of the French shells, the German high-explosive shells were never produced in one steel part. In the case of the shells of large caliber, a separate base was screwed at the back of the shell. In the shells having low or middle calibers, the separate warhead was screwed to the body of the shell. The effects of these projectiles were frightening. The glares they projected ranged from tiny sizes able to penetrate deeply in the human body up to large fragments able to tear off a member or to literally chop a man... The underground explosions (obtained with delayed fuses) turned the ground over and created this lunar landscape so characteristic in this period the photographs, and still so visible 90 years after..

The shells of the heavy artillery, designed for the destruction of heavily armoured targets, were equipped with a solid, full and resistant warhead, in order to enable them to penetrate deeply in the concrete solid masses before exploding, thus causing more considerable effects (the mine effect adding to the shock effect).

The steel walls being much thicker, their explosive charge was proportionally less important than in smaller caliber shells (10 to 12 % of weight of explosive relative to the weight of the shell, compared to 16 to 30 % for calibers 75 to 220 mm). The fuse (ignition system) was located at the bottom, and not at the head of warhead. The German heavy projectiles had a separate base, screwed to the main body of the shell.

Lastly, a more important attention was given to their aerodynamic shaping, because of their heavy weight and of the long ranges, sometimes equipping them for that reason with a false warhead made out of thin steel sheet.

Specialized projectiles were used throughout all the conflict. It is practically impossible to be exhaustive in their enumeration. Let us only note the followings :

• the incendiary projectiles, filled with tarred canvas and gun powder dust, burning for nearly 2 minutes. It should be noted that all the shells having a blasting powder load had incendiary properties.

• lighting shells, simple envelope containing fireworks 'stars', pushed out towards the back of the shell by the explosion of a small powder load, and slowly falling, often slowed down by a parachute, lighting the night landscape.

• tracer shells, filled with a fusing material (having a regular combustion) and whose warhead included bored holes to let the flames escape during the projectile flight. These shells left a smoke stream indicating their trajectory, useful for example for the adjustment of the shooting on aerials target. These shells also have incendiary properties.

• shells with gases, lachrymatory or suffocating, based on the same kind of principle as the incendiary bombs, but releasing toxic or irritating gas materials. These shells were often composed of a system with a double envelope, the inner one, made of glass or thin steel, containing the aggressive product.

The trench mortars, ' Crapouillots' for the French army, 'Mortars' for the English one, and ' Minenwerfers' for German soldiers, sent projectiles at a low initial speed therefore on which was applied quite a low pressure.

Therefore less solicited mechanically than the common shells, these bombs could be satisfied with thin steel walls, and be devoted to the transport of considerable quantities of powerful explosive, which represented up to 50 to 60 % of the total bomb weight !

One understands better that such charges were able to level tens of meters of trenches, and to terrorize their unhappy occuppants.

The trench artillery gun tubes had no internal spiral grooves. This means that the stability of the projectile in flight was generally ensured by wings, whose effect was sufficient thanks to the low speeds.

Depending on the mortar type, a steel tail was welded at the bottom of the bomb in order to be inserted in the mortar tube (case of the French 58 mm mortars, with a wide variety of projectiles), or the whole rear section of the projectile was engaged in the large caliber gun (case of the German minenwerfers, the English mortars, and the French crapouillots).