Developed at the end of the 19th century, the 75 mm field gun model 1897, better known as the "75mm gun," is one of the most iconic weapons in French military history. A true technological feat for its time, it profoundly transformed modern artillery and left its mark on the First World War with its effectiveness and exceptional rate of fire.
Designed by engineers from the Atelier de Puteaux firm and the French Artillery Service, the 75 mm gun introduced a decisive innovation: the hydro-pneumatic recoil system.
This mechanism absorbed the recoil of each shot without moving the gun carriage, allowing crews to reload and fire at an unprecedented rate of up to 15 rounds per minute. Thanks to this stability, the 75 mm gun could maintain rapid and accurate fire, whereas older guns required repositioning after each shot.
Designed to support infantry, the 75mm gun was light, maneuverable, and quick to deploy. Firing high-explosive, shrapnel, or gas shells, it proved formidable on the battlefield. At the start of the 1914 conflict, it embodied the offensive spirit of the French army: a precision weapon intended to support the rapid advance of troops.
The 75mm shells
True marvels of engineering, the shells of the 75 mm Model 1897 gun embody the technical advancements of French artillery on the eve of the First World War. Designed to adapt to numerous combat situations, they reflect the rapid evolution of tactical needs between 1914 and 1918.
Each 75mm shell consists of several essential components:
The warhead, the front part of the projectile, which determines its effect (high-explosive, shrapnel, illuminating, etc.)
The body, containing the main charge
The fuse, the firing mechanism, often adjustable to determine the timing of the detonation (on impact or in flight)
The forcing ring, a copper ring ensuring a seal and engaging the rifling of the barrel to stabilize the shot
This design allowed for highly accurate firing, even at ranges exceeding 8 km, and compatibility with different types of ammunition depending on battlefield needs, of which the following four main types are:
The shrapnel (bullet) shell
This is one of the most iconic shells from the early part of the war. Filled with hundreds of steel balls and a small explosive charge, it detonated in flight thanks to a time fuse, hurling a deadly cloud of projectiles at exposed enemy troops. This type of shell was designed to neutralize infantry before an assault.
The explosive shell (common shell)
Containing a powerful explosive charge such as melinite, it was used to destroy shelters, light fortifications, and trench networks. Its use became dominant as the war dragged on and enemy positions became more fortified.
The gas shell
Introduced in 1916, it contained irritating or lethal chemical agents, such as phosgene. Used in saturation fire, it aimed to disrupt enemy lines before an offensive.
Special shells
Less common, they included illuminating, smoke-producing or training models, suitable for signaling or training missions.
Fuzes (detonators)
The fuzes (or firing mechanisms) of 75 mm ammunition play a crucial role: they control when and how the projectile explodes (in flight, on impact, or after a short delay). During the period 1897–1918, several standardized series were used on 75 mm gun shells: the DE 22/31 double-effect fuze (typical for shrapnel shells), the 24/31 double-effect fuze, and the 24/31 series impact fuzes (used primarily on high-explosive shells). Each of these devices exists in several variants: instantaneous (without delay), short-delay, and adjustable-delay, depending on the desired tactical application.
Here are some detailed examples:
DE 22/31 Double-Effect fuze
The DE 22/31 is the typical fuze for 75mm shrapnel shells. Its principle is dual-effect: a time-delay fuze (ignited by a timer to detonate above the troops) or an explosion on contact if the impact occurs before the timer expires.
Adjustable timing: a fuze or combustion train mechanism allows adjustment of the time before detonation (adjustment is made using equipment on the casing).
Double safety: if the timer has not expired, the impact triggers the explosion (prevents misfires in direct fire).
Primary use: ejecting shrapnel in flight to neutralize enemy infantry.
Double-action detonating 24/31 fuze
The 24/31 (double-effect) is an evolution adapted for high-explosive shells: it combines the possibility of impact detonation (percussion) and delayed detonation (for destroying shelters/false vaults).
Double-effect : instantaneous/percussion detonation upon impact (mechanical action on the firing pin), or delayed detonation if the fuse is set to delay (for example, to produce a burst after penetration or to maximize the effect on structures).
Compatibility: This series was widely used and adapted to different models (1899, 1914, 1916 versions, etc.), sometimes with thread adapter rings for other calibers.
Tactical use: strikes against shelters, light fortifications, and for achieving optimized internal fragmentation.
Impact detonating 24/31 fuze
These fuzes represent the "percussion" family, designed to ensure ignition by impact upon contact (integrated detonator). The 24/31 Mle 1899 is one of the best-documented versions (Robin-Lejay system) and was fitted to numerous calibers, including the 75mm.
Integrated detonator: no need for a relay detonator; the fuse and detonator form a compact unit.
Variants: "instantaneous", "short delay," and "delay" models, each variant has different internal mechanisms (firing pins, weights, safety stop system, etc.).
Distribution: used extensively on high-explosive shells from 1899 onward and subsequently improved during the war.
Some illustrative images used may be subject to copyright. My work is also subject to terms of use and copyright. For more information, please refer to the terms of use on the page About.
