As the conflict shifted to
trench warfare in the autumn of 1914, a development contemporaries likened to an extended siege, French artillery adjusted its equipment, organization, and tactics to meet new demands.
More Cannons Pending the development and production of newer artillery models, the French military employed existing resources in late 1914. This included deploying older guns to the front, repurposing naval and coastal artillery, producing improvised trench mortars, and requisitioning export-bound cannons from manufacturers, such as the 75 mm modèle 1914 (originally the Schneider PD07, designed for the Russian Army). Subsequent programs expanded artillery inventories through phased initiatives: a ministerial decision on October 24, 1914, known as the "De Bange barrier," allocated older De Bange guns; a reorganization of heavy artillery was ordered on July 27, 1915; and a plan on May 30, 1916, increased the number of 155 mm short guns threefold.
First Makeshift Solutions open
breech for loading the shell (the
powder canister will follow). The SP carriage (which weighs 3.2 t) is completed by
cingolis and return wedges in battery; the installation of such a gun takes an hour, not to mention the pit, the wooden platform and the
camouflage. On September 22, 1914, the
Grand Quartier Général (GQG) requested artillery pieces from fortified positions from the Ministry of War. From February 1916, 120 modèle 1877 155 mm long guns were refitted with a Schneider-designed carriage, incorporating a recoil brake, shield, and 42° elevation, achieving a firing rate of up to three rounds per minute. Designated the 155 mm L modèle 1877-1914 (contracted in 1913 but paused in August 1914), these upgrades improved performance. Some 120 mm and 155 mm guns also received tracked mobility. These guns were supported by horse-drawn transport (horses, limbers, caissons) and personnel drawn from fortifications, coastal batteries, and depots, including rear forts (
Langres,
Besançon,
Dijon,
Lyon,
Grenoble,
Toulon, and
Brest) and frontline positions (the forts of
Paris,
Verdun,
Toul,
Épinal, and
Belfort).
New field guns The 75 mm gun continued to serve as a primary artillery piece for French forces. To address losses—447 guns were abandoned or captured between August 1914 and February 1915—and to equip additional batteries, production resumed in the autumn of 1914. On September 25, 1914, 240 75 mm guns were ordered withdrawn from
Algeria. In February 1915, field batteries were reduced from four to three guns to stretch existing stocks. Despite this output, the 75 mm guns had limited range and explosive power for trench destruction or counter-battery fire, necessitating heavier artillery. Schneider had developed models originally intended for export, particularly to Russia, some ordered by the French Army before 1914. Production of the 105 mm L modèle 1913 gun (initially the Russian 42-line, 106.7 mm) began in August 1914; twelve guns from an order of 220 were delivered at mobilization and assigned to the 6th Army on September 16, 1914 (IV/2nd RAL). In November 1913, Schneider received an order for 18
280 mm TR Model 1914 mortars (a 279.4 mm
breech-loading howitzer, originally the Russian 11-inch), with deliveries planned for 1915. Additionally, eleven 120 mm howitzer batteries, intended for
Bulgaria, were requisitioned from the Creusot factory and deployed with the
French Army in the East. was developed to disrupt entrenchments with its curved shot (
initial velocity of 450 m/s) and its powerful projectile (FA model 1915 shell weighing 43.55 kg, including 4.8 kg of explosive). In June 1915, General Joseph Joffre requested short-barreled 155 mm howitzers to target enemy fortifications. In October 1915, 512 of these guns were ordered: Schneider supplied the
155 mm C 1915 and 1917 S models (derived from its 6-inch howitzer for Russia), while Saint-Chamond provided the
155 mm C 1915 CH (originally developed for Mexico). Deliveries began in summer 1916 at a rate of 60 guns per month. Additionally, 40 220 mm TR modèle 1915 mortars, adapted from Schneider's 9-inch Russian design, were ordered in October 1915, with deliveries starting in winter 1916-1917. Two long-barreled 155 mm designs were adopted in 1916: the 155 mm L modèle 1917 S (using the modèle 1877-1914 carriage) and the
155 mm Model 1917 GPF (with a biface carriage allowing 60° traverse), both reaching the front in summer 1917).
Heavy High-Powered Artillery , in 1918. We can clearly see the concrete location and the fixed mount which allows 360° firing. In September 1914, the potential for a siege of the Paris fortified camp, recalling the 1870-1871 precedent, prompted the deployment of naval artillery for long-range support. Starting in October, naval guns with their crews were sent to the Verdun arsenal (for the northern fortified region) and the Toul arsenal (for the
Grand Couronné of
Nancy). These included modèle 1910 14 cm (138.6 mm) guns, originally for the
Bretagne class battleships, and modèle 1887, 1891, and 1893 16 cm (164.7 mm) guns from the
République,
Suffren, and
Iéna classes. Mounted on their ship's gun platforms, they were placed in fixed positions, some in semi-buried casemates; several were captured in February 1916 in the
Fays and
Vauche woods. On October 14, 1914, the Grand Quartier Général (GQG) requested artillery from naval, coastal, and industrial sources (
Schneider and
Saint-Chamond) for mounting on concrete platforms or locomotive chassis. In December 1914, four modèle 1870-1887 24 cm guns from the
Couplets battery near
Cherbourg were transferred to the front, despite objections from the regional admiral-prefect. On October 25, 1914, the GQG listed desired large-caliber guns, approved by the Minister of War on October 31: one 305 mm naval gun, two 274 mm naval guns, eight 240 mm coastal guns, and twelve 19 cm coastal guns. Orders were issued to arsenals and manufacturers, with naval guns requiring rifling and all mounted on railway trucks or fixed wooden platforms. Deliveries began in early 1915, forming batteries within foot artillery regiments or independent groups, assigned by GQG to armies, supplemented by four gunboats in November 1914 and sixteen 240 mm guns in February 1915. new program on March 9, 1915, targeted 201 guns, including eight 400 mm pieces, with expansions on June 22, 1915, May 30, 1916, June 22, 1916, and February 24, 1917 (the latter adding 318 guns). Industrial production delays extended deliveries over one to two years. On June 28, 1915, the heavy high-powered artillery command (ALGP) was established under General Vincent-Duportal, overseeing ALVF, gunboats, and other large-caliber guns, focusing on training and operational protocols. This force joined the general reserve of heavy artillery on February 14, 1917, and was reorganized into six, later eight, RALGP regiments (nos. 70-78). File:ECPAD SPA-60-L-2971.jpg|Presentation of a 320 mm model 1870/84 cannon on a railway track to a
Chinese military mission, in August 1917 in
Thierville-sur-Meuse. The gunners operate the
jacks lowering the six support
crosspieces. File:ECPAD SPA-46-T-1924.jpg|
240 mm model 1884 cannon near
Dannemarie in August 1916, dismantled into two bundles (
carriage +
tube) to be placed on a narrow track. File:Train blindé de canons de 190.jpg|Marine gunners and their
armoured train, armed with 19 cm model 1870-1893 guns on Schneider all-round truck mounts (TAZ). For ALVF (heavy railway artillery) equipment, mounting configurations varied by gun weight. Guns up to 240 mm caliber were fitted on all-around swiveling mounts (TAZ, tout-azimut), stabilized by jacks anchored to the ground. Heavier guns used beam mounts, aligned with the railway track, with a curved section called an "épi" enabling directional adjustment. Sliding models managed recoil with oak timbers rubbing against beams parallel to the rails, while cradle models allowed the barrel to slide within a cradle before returning to position. The ALGP (heavy high-powered artillery) primarily utilized 190 mm, 240 mm, and 320 mm calibers, adapted from coastal guns (designated 19 cm, 24 cm, and 32 cm, reflecting cast-iron bands around steel tubes). Additionally, eight modèle 1915 370 mm howitzers and twelve modèle 1915 and 1916
400 mm howitzers—re-bored from (
305 mm and
340 mm—were deployed. These weapons engaged targets such as
Fort de Douaumont in October 1916, the Mont Cornillet tunnels in May 1917, and Mort-Homme in August 1917.
Trench Mortars In late September 1914, French infantry positioned in the
Argonne region faced intense short-range fire from German trenches. This bombardment came from
minenwerfers ("mine throwers"), heavy mortars originally sourced from the
Metz fortress arsenals and operated by German pioneers of the
16th Corps under
General von Mudra. These weapons proved effective in the Argonne's dense, uneven terrain, where limited visibility hindered traditional artillery observation and direct cannon fire. The
2nd French Corps experienced increasing casualties, prompting urgent requests for comparable equipment to counter the German advantage. The French military initially responded by retrieving approximately 100 bronze 15 cm Model 1838
mortars from storage. These antiquated weapons, nicknamed "crapouillots" for their squat appearance, fired spherical black-powder bombs. As demand grew, frontline units began improvising mortars using salvaged materials—such as shell casings or obsolete cannon barrels—while factories produced additional designs to meet immediate needs. Examples included the
Cellerier bomb launcher, the Gatard mine thrower, and the Imphy Type A launcher. By the winter of 1914–1915, development of purpose-built trench mortars accelerated. In January 1915, the first 70 units of the 58 mm T mortar, which fired finned projectiles, were deployed to the
Artois front. Subsequent models, such as the 58 mm T No. 1 bis and the larger No. 2, were produced in large quantities at the
Saint-Étienne arsenal, including the Leflaive factories in La Chaléassière. Starting in February 1915, the French military reorganized trench mortar units. High-powered mortars were assigned to artillery batteries, typically organized in groups of twelve, while lower-powered models—such as 37 mm guns and later 81 mm Stokes mortars—remained with infantry units, often operated by specialized bomber platoons. That year, the Trench Artillery Training Center (Centre d'instruction de l'artillerie de tranchée, CIAT) was established in Bourges to train personnel. Early trench artillery crews included a mix of soldiers, some of whom were reassigned from disciplinary units across various military branches, supervised by reserve officers who took on these roles voluntarily. Trench mortars had a short range but compensated with low muzzle velocities—approximately 70 m/s for the 58 mm T No. 1 bis—enabling the use of thin-walled projectiles with substantial explosive payloads. For comparison, a standard 75 mm artillery shell weighed about 5.4 kg, including 0.775 kg of explosives, whereas an LS-type bomb for the 58 mm T No. 2 mortar weighed 18 kg, carrying 5 kg of explosives. Additionally, starting in October 1915, around 1.5 million defective 75 mm shells, produced during the winter of 1914–1915, were repurposed as low-pressure projectiles for the 75 mm Schneider mortar, enhancing resource efficiency.
More ammunition The shift from
maneuver warfare to trench warfare during World War I transformed artillery tactics and ammunition use. In the earlier phase, light, mobile artillery delivered rapid but sporadic strikes. However, trench warfare introduced prolonged bombardments, often lasting hours or days, executed by heavier, less mobile batteries. This change dramatically increased shell consumption, with historical accounts noting intense and sustained barrages that overwhelmed defensive positions. A vivid description of this escalation comes from the artillery preparation for the Champagne offensive in autumn 1915: New
fuses were introduced, notably dual-effect fuses that allowed for either timed airburst fire (with graduated drums to adjust detonation time) or impact detonation using the same shell. Examples include the DE 24/31 mm model 1915 fuse, which replaced the DE 22/31 model 1897 and allowed adjustments from 0 to 24 seconds. During the war of movement in August and September 1914,
shrapnel shells were primarily used. However, as the war bogged down into trench warfare, explosive shells proved more useful. Consequently, the
ammunition batches delivered to parks were modified. Initially composed of 2,952 explosive shells and 3,384 shrapnel shells per batch (each batch containing 5,976 75 mm rounds, typically packed in 664 crates of nine rounds each), by November 1914, the composition shifted to 5,688 explosive shells and 288 shrapnel shells. By June 1915, the ratio further evolved to 5,391 explosive shells and 585 shrapnel shells. Artillery fired millions of explosive shells, supplemented by shrapnel shells, but also
smoke shells (loaded with
phosphorus), incendiary shells (containing tarred fuses and
magnesium),
tear gas, and
toxic gas shells (with a small charge that ruptured the shell to release the gas). Other specialized shells included armor-piercing shells (type AL, with thick walls and base fuses), illuminating shells (ejecting a cylinder with a parachute that retained a flare cartridge), tracers, and even propaganda shells carrying leaflets.
Chemical Shells The development of chemical weapons during World War I (1914–1918) spurred rapid innovation among belligerent nations, each adapting to the other's advancements. In October 1914, French infantry employed tear gas grenades loaded with ethyl bromoacetate to clear trenches and shelters. On October 27, 1914, German artillery fired 3,000 7.7 cm shells containing bromoacetone, a tear gas, at
Neuve-Chapelle. The first large-scale toxic gas attack on the Western Front occurred on April 22, 1915, during the
Second Battle of Ypres, when German troops released
chlorine gas from cylinders, forming a yellow-green cloud that breached a three-kilometer stretch of trenches between Steenstrate and
Langemark. French artillery losses included 29 90 mm cannons, 16 75 mm cannons, six 95 mm cannons, and four 120 mm L cannons, though the latter were recaptured on April 25. Following the Ypres attack, French General Headquarters requested gas-capable equipment and projectiles by late April 1915. The first French chlorine gas attack occurred in July 1915. To improve precision and reduce reliance on wind-dependent gas clouds, all belligerents developed chemical artillery shells. The French introduced "Shell No. 1" in June 1915, a 75 mm explosive shell with an insulated interior filled with carbon tetrachloride, a suffocating agent. These were first fired on July 14, 1915, near Fricourt and in larger quantities during the
Battle of Champagne in September 1915. Prisoner interrogations indicated limited effectiveness, with symptoms restricted to eye irritation and mild respiratory discomfort due to insufficient toxic concentration. Subsequent French designs included Shell No. 2 (phosphorus and carbon disulfide, incendiary-suffocating) and Shell No. 3 (phosphorus, incendiary-smoke), both based on the 75 mm shell. In May 1916, Germany countered with diphosgene ("green cross") shells around Verdun. France responded with Shell No. 4 ("Vincennite"—hydrocyanic acid, arsenic chloride, chloroform, and tin chloride) and Shell No. 5 ("Collongite"—phosgene and arsenic chloride), developed in 1915 but deployed in 1916 at Verdun (February) and the Somme (July), respectively. From 1917 to 1918, chemical shell use intensified. In July 1917, Germany introduced cyanodiphenyl arsine ("blue cross"), inducing vomiting, and ethyl dichloride sulfide ("yellow cross"), a vesicant known as mustard gas or yperite after its use near
Ypres. German forces recorded 200,000 gas-related casualties, with 9,000 deaths, while French forces reported 190,000 cases, including 8,000 fatalities. Pre-war reliance on German suppliers further strained resources, though some German-owned factories in France were seized. As stockpiles dwindled, steel was substituted with cast steel, notably in FA shells made from "gray cast iron" with lower carbon content, which was less costly and easier to
mold. Explosive formulations shifted in October 1914 from cresylite (
trinitrocresol) to alternatives like Schneidrite (ammonium nitrate and
dinitronaphthalene), tolite (
trinitrotoluene), melinite (
trinitrophenol), xylite (trinitrometaxylene), and
cheddite.
Powder B, a propellant, was partially sourced from the United States, while phenol was derived from coal gas. Industrial production of ether, nitrocellulose, and sulfuric acid began, though the chemical industry, partly relocated to southwestern cities like
Angoulême,
Bassens,
Toulouse,
Saint-Médard, and
Bergerac, depended on Chilean sodium nitrate and Norwegian
ammonium nitrate. The armaments workforce included military personnel reassigned to production ("special assignees," totaling 500,000 by 1918), women (430,000 "
munitionettes" by war's end, often former textile workers), and civilian laborers. Additional labor came from adolescents, foreign workers (including Chinese recruits), colonial workers (primarily Algerians, Indochinese, Moroccans, and Tunisians), voluntary prisoners of war, and individuals with disabilities.
Logistical Challenges near the
Quesnel station in August 1916. The high demand for artillery ammunition during World War I necessitated a robust logistical system. By 1915, the responsibility for maintaining sufficient ammunition reserves shifted from rear command to the 1st Bureau of the
General Headquarters (GQG) to support sustained offensives. Factories shipped cartridges and components to general reserve (GR) depots in rear cities such as
Besançon,
Lyon,
Clermont,
Bourges,
Angers,
Rennes, and
Nevers. In August and September 1915, these depots were expanded with additional warehouses and railway lines, and new facilities were established at
Héricy (for 75 mm and 105 mm ammunition),
Cosne (for trench artillery), and
Vincennes (for "special" shells). Each depot was linked to an army by at least one railway line, with a minimum of four trains operating daily. Ammunition trains typically comprised 30 to 35 wagons, with a capacity of 300 to 350 tons. Armies maintained reserves in "mobile stockpiles"—fully loaded trains stationed on sidings. By August 1915, rail parks at
Vaivre (under the GR of
Gray),
Brienne (GR of
Troyes),
Noisy-le-Sec,
Le Bourget,
Creil, and
Dunkirk collectively held 3,440 wagons. Additional reserves were drawn from fortresses, partially utilized by nearby armies. During preparations for the
Champagne offensive (September–October 1915), rear services expanded railway and road networks and stockpiled supplies throughout August. In the event of a breakthrough, automobile convoys were organized to transport ammunition from rail terminals to horse-drawn units supporting corps and armies. The rail park northeast of Brienne, on the Jessains-Éclaron line, featured a yard with twenty sidings for mobile stockpiles (initially 800 wagons, later increased to 1,000) and six warehouses (each 200 meters by 16 meters, rail-connected, storing approximately 700,000 75 mm rounds and 200,000 heavy shells). Security included earthwork barriers, hand pumps, and motorized pumps, with handling by two Grand Park detachments and protection from a territorial company and cavalry squadron; anti-aircraft guns and searchlights were added by mid-1916. Further forward, stations at
Saint-Dizier,
Résigny, and
Châlons served as sidings for additional mobile stockpiles (100–200 wagons each). Near the front, the Suippes-Sainte-Menehould line was upgraded to double-track, and a new 33.8 km line was built six kilometers south between
Cuperly and
Dampierre to enhance supply flow.
New Organizations During World War I, the French artillery expanded significantly, growing from 434,000 personnel in August 1914 (16% of the total army) to 771,000 by 1918 (26% of the total), excluding logistical units tasked with ammunition transport. Recruitment for artillery units encountered fewer difficulties than for infantry, due to lower attrition rates. Personnel needs were met through foot artillery regiments, depots, and conscription of the 1914–1919 classes, with early call-ups for the latter beginning in April 1918. Recruits were drawn from all social classes, with urban individuals valued for technical skills (e.g., workers, mechanics, drivers) and rural recruits for horse-related roles (e.g., drivers, cart handlers, blacksmiths) to manage the thousands of horses required. Starting in January 1915, Army command addressed officer losses and the demand for trained leaders in newly established heavy and field artillery regiments. Between January 1915 and December 1917, the commanding general directly appointed 6,000 officers. Non-commissioned officers (NCOs) with at least ten months of rank and twelve months of active service were selected by superiors for advanced training at the Fontainebleau school, yielding 4,000 sub-lieutenants and 800 trench artillery specialists across 14 cohorts during this period. Separately, NCOs with less than eight months of seniority, chosen by the High Command, attended candidate courses without entry exams, alongside conscripts from new classes who scored at least 12 on a general knowledge test. This process produced 3,500 NCOs and 5,000 conscripts who attained the rank of aspirant cadet.
Creation of Units To support the formation of new divisions (up to the 170th Infantry Division by December 1916) and army corps (up to the 40th Corps in the same period), French artillery resources were reorganized. This involved regrouping the fourth groups from existing corps artillery regiments, transferring 75 mm batteries from colonial territories, and forming batteries from stockpiles of older
80 mm and
90 mm Model 1877 guns (Bange system). By April 1, 1917, these groups were consolidated into new Field Artillery Regiments (RAC), numbered 201 to 276. The field heavy artillery expanded during the winter of 1914–1915 and was restructured on October 1, 1915, into 20 Horse-Drawn Heavy Artillery Regiments (RALH, nos. 101 to 121) and five Motorized Heavy Artillery Regiments (RALT, nos. 81 to 85), increased to ten (nos. 81 to 90) by November 1, 1915. These regiments served administrative purposes rather than tactical roles. RALH regiments, with 20 batteries each, supplied corps and army heavy artillery groups (two batteries per group), while RALT regiments, planned for 24 batteries each but limited by production delays, functioned as a mobile reserve, initially assigned to armies and later to the General Artillery Reserve. On May 30, 1916, RALH regiments expanded to 36 batteries each to equip divisional heavy artillery groups with the 155 mm C gun, introduced gradually through summer 1918. An order on October 1, 1917, doubled RALT regiments from 10 to 20 (nos. 281 to 290, with 289 and 290 formed in early 1918) without increasing artillery groups. Similarly, on December 28, 1917, RALH regiments grew from 20 to 32 (nos. 130 to 145, with some numbers skipped) to provide each corps with an organic artillery regiment. In February 1918, four groups were detached from each RALH regiment for the General Reserve, forming 30 new RALH regiments (nos. 301 to 456, calculated by adding 200 to the original regiment number). In 1917, infantry divisions were reorganized: brigades were eliminated, infantry regiments reduced from four to three per division, and divisional artillery was strengthened. A Horse-Drawn Heavy Artillery Group with 155 mm C guns, standardized by a July 12, 1917 decision and fully implemented by summer 1918, was added, along with a trench battery to the divisional Field Artillery Regiment (equipped with 75 mm guns). At the corps level, units included a Mounted Field Artillery Regiment (progressively motorized as RAC regiments with truck-mounted 75 mm guns) and മtwo artillery groups (each with two batteries) from a Heavy Artillery Regiment, armed with 105 mm and 155 mm L guns, often supplemented by older
120 mm L guns.
General Reserve of Artillery On June 28, 1915, the "high-power artillery" (ALGP) was established, consolidating units equipped with large-caliber naval and coastal guns, including
heavy artillery on railway tracks (ALVF). Following the battles of 1915 and 1916, General Buat, an artillery officer, proposed a reserve to enable concentrated firepower, termed an "artillery maneuver." Supported by
General Nivelle, the new commander-in-chief and fellow artillery officer, the "General Reserve of Heavy Artillery" was formed in January 1917 and formalized by a note on February 14, 1917. This reserve, under direct control of the
General Headquarters (GQG), included a
staff (initially led by Buat, succeeded by General Herr in 1918), groups with the largest-caliber guns, a maintenance and training center at Mailly, aviation squadrons for observation and targeting, and transport services (e.g., standard track constructor groups, material depots, a driver and mechanic school in Langres, and an automotive service). It was structured into three divisions: • The first division brought together the ALGP (including ALVF). • The second division included tractor-drawn artillery. • The third division consisted of units manned by naval gunners. On January 26, 1918, the reserve was renamed the "General Reserve of Artillery" (RGA), encompassing all artillery units outside the organic structure of larger formations. It included 3,200 towed field artillery pieces, 4,480 towed or horse-drawn heavy artillery pieces, and 200 ALGP pieces. With the addition of foot and trench artillery groups, a fourth division was created, resulting in the following organization: • The 1st Division, under Colonel (later General,
Maurin), included ALGP and ALVF, with regiments numbered 70 to 80. • The 2nd Division consisted of tractor regiments (nos. 81–90 for long guns, nos. 281–290 for short guns), reinforced by caterpillar groups and, in 1918, horse-drawn regiments (nos. 101–118, 120, 121, 130–138, 141, 142). • The 3rd Division, led by a rear admiral, comprised naval gunners operating tractor-drawn batteries and an armed flotilla (gunboats and barges on river networks). • The 4th Division included foot artillery regiments (1st, 3rd, 5th–11th), foot batteries from the 1st, 2nd, and 3rd colonial artillery regiments, and trench artillery regiments (nos. 175–178). Equipment replacement was managed by armies for the 2nd and 4th divisions and by the RGA for the 1st and 3rd divisions. In January 1918, a general inspection of artillery was established, led by a division general, to oversee training across armies and direct the RGA. Distinctive artillery features persisted: scarlet red collar insignia and trouser piping, with the helmet displaying two crossed cannons on the front. For practical use, artillerymen, tasked with prolonged harassment or preparatory fire and handling heavier ammunition and equipment, often wore fatigue dress instead of combat uniforms. This consisted of a canvas work shirt and linen drill pants. Early in the war, due to shortages of horizon blue fabric, non-regulation items such as brown, beige, or blue-gray corduroy clothing were incorporated, supplemented by civilian winter gear like scarves, sweaters, gloves, and hats.
New roles Following challenges in breaching German lines during 1915, the French General Staff increased artillery and munitions stockpiles to support major offensives: the Second Battle of Champagne (fall 1915), the Battle of the Somme (summer 1916), and the
Second Battle of the Aisne (spring 1917). This involved expanding artillery resources and adjusting their tactical employment. The adaptation process was incremental, informed by lessons from each offensive, though implementation faced delays due to resistance from some General Staff members, including certain artillery officers.
In 1915 The French artillery doctrine evolved from practices tested in large units starting in fall 1914. Reports from these units were relayed up the chain of command, leading the General Staff to issue the
Instruction on the Employment of Artillery on November 9, 1914, and the
Note on the Role of Artillery in Attacks on February 14, 1915. The latter outlined four primary missions: • Preparation: Neutralize
barbed wire and enemy trenches, with a planned density of one artillery piece per ten meters of front; •
Barrages: Deliver fire 100–200 meters ahead and on the flanks of an attack to block
counterattacks and reinforcements; • Destruction of flanking
machine guns: Target machine guns over a 700–800-meter width on the attack's flanks; •
Counter-battery fire: Suppress or destroy enemy artillery, aided by airplane or balloon observation. From 1915, each corps and army established an artillery intelligence service (SRA) to collect data from land observation sections (SROT), sound ranging sections (SRS), captive balloons, and aviation squadrons (one per corps) for observation and targeting. Liaison officers coordinated with infantry, and each artillery regiment's colonel advised their general. Divisional and corps artillery were managed by a small staff, supported at the army level by a fire planning group from the Army Geographic Service (SGA) for mapping. Telephone networks linked batteries, staffs, airfields, and observation posts, while radio (TSF) or signals facilitated targeting communication. Artillery plans were developed prior to attacks, as demonstrated in two cases. On February 15, 1915, the
5th Corps attacked
Vauquois,
Boureuilles, and Hill 263 with a two-hour preparation, including two ten-minute pauses to disrupt German infantry. Orders directed that, upon infantry advance, artillery would shift to barrages, extending fire to the second line and reserves to hinder counterattacks. The Champagne offensive of September 22–27, 1915, employed 872 heavy artillery pieces across a 35 km front (one per 40 meters) and one 75 mm gun per 33 meters, expending 300,000 heavy shells and 1.3 million 75 mm shells. This preparation captured the first German line but faltered before the intact second line, halting due to ammunition shortages. These findings informed two instructions: one on November 20, 1915, addressing heavy artillery use, and another on January 16, 1916, defining the purpose and conditions for a general offensive. On February 21, 1916, the first day of the
Battle of Verdun, German artillery employed a new tactic: a nine-hour preparation, shorter than the French three-day barrage at Champagne in 1915, despite greater intensity. This brevity surprised French command, whose older heavy artillery fired more slowly. Lessons from Verdun's initial phase were codified in the
Instruction on the Use of Artillery in Defense on May 27, 1916, introducing the "counter-preparation offensive" (CPO). This involved firing on enemy trenches during their preparation phase, just before an attack, when starting positions were occupied. An enemy artillery increase could escalate into a duel, targeting opposing lines in a war of attrition. During the Battle of the Somme, the
6th Army, under
General Fayolle (an artillery officer), attacked along a 15 km front starting July 1, 1916, after a week-long preparation. Artillery reinforcement included 444 field guns, 360 trench mortars, 228 short cannons, 300 long heavy artillery pieces, and 56 mortars and 61 long guns from the ALGP. The new
French 400 mm howitzers obliterated the fortified villages of
Herbécourt,
Estrées, and
Belloy-en-Santerre. This enabled the infantry to capture the first German line, with reports from the
21st RIC noting effective destruction of defenses and trenches near
Dompierre. However, the second German line, largely unaffected and beyond trench artillery range, stopped further advance. Ammunition expenditure from June 24 to July 10 totaled two million 75 mm shells and 500,000 heavy shells. The offensive proceeded with planned attacks on July 14, July 30, and September 3, requiring time between phases to reposition artillery over damaged terrain. German defenses in depth prevented a breakthrough.
In 1917 The development of an interarms employment doctrine was assigned to the Artillery Studies Center (CEA), established on June 27, 1916, in
Châlons-sur-Marne, while the Artillery School of
Fontainebleau adjusted its training to prepare new officers. Lessons from the Somme informed the
Instruction of December 16, 1916, which guided the Second Battle of the Aisne (
Chemin des Dames) in April 1917. This offensive spanned a 40 km front, employing four million 75 mm shells and 1.2 million heavy shells from April 7 to April 17, with one 75 mm gun and one heavy gun per 20 meters of front. The operation faced challenges due to adverse weather, complicating fire adjustment, and rugged terrain, which hindered the 1,650 trench artillery pieces from supporting infantry advances. in August 1917: four gunners carry a shell (100 kg) to the open
breech, while another primes a
fuse. In summer 1917, the 2nd Army conducted a limited offensive north of Verdun, on both sides of the Meuse, using concentrated artillery support. Approximately 600 batteries, totaling 2,256 pieces and manned by 60,000 artillerymen, supported 50,000 infantrymen (eight divisions) across an 18 km front, averaging one piece per eight meters. The deployment included: 1,195 75 mm guns for tactical support (one group per battalion); 1,016 trench mortars, 435 short 155 mm guns (160 Bange, 140 S, 135 CH), 122 220 mm mortars, and eight 270 mm mortars for fortification destruction; 16 100/105 mm guns, 50 105 mm guns, 140 120 mm Bange long guns, 24 145 mm guns, 250 155 mm Bange long guns, 55 155 mm long S guns, and eight 155 mm GPF guns for counter-battery fire; and approximately 100 ALGP guns (17 240 mm, 28 270 mm, 16 32 cm, four 370 mm, and four 400 mm) targeting railway stations, ammunition depots, and tunnels like Mort-Homme and Bois des Corbeaux. This setup, representing about one-third of French heavy artillery, required five weeks to prepare. Bombardment began on August 13, intensified on August 19–20, and continued until August 23, expending 3.5 million rounds (including 311,000 chemical shells) and 82,400 tons of ammunition over eleven days.
Use of gas French doctrine on gas shells evolved with the introduction of new chemical agents, serving two primary purposes: destructive fire to eliminate occupants of targeted areas or neutralization fire to disrupt zones. Effectiveness depended on weather conditions, particularly wind speed, with temperature, humidity, and solar radiation as secondary factors. Winds exceeding 3 m/s dispersed gases too quickly for lethal concentrations, limiting use to neutralization. Initial destructive fire, aimed at clearing trenches, occurred in July 1915 in Champagne using early gas shells. Low toxicity prevented lethal outcomes. Phosgene, introduced in May 1916, enabled destructive fire against small targets like batteries, trench sections, shelters, or supply points. This involved rapid barrages—200–500 75 mm rounds, 50–100 155 mm rounds, or 20–50 58 mm mortar rounds—delivered in two to five minutes, the time required for a trained soldier to don a gas mask. used fewer rounds to restrict movement and disrupt operations. Neutralizing a 100-meter front required approximately 500 75 mm shells, 250 120 mm shells, or 200 155 mm shells, often alternated with explosive shell barrages for enhanced effect. Tear gas shells, used in 1916 for area coverage, had persistent effects, with a 75 mm shell affecting 5 m² and a 155 mm shell covering 50 m².
Protection during the summer of 1916. The adoption of
powder B, a smokeless propellant invented in the late 19th century, reduced the visibility of artillery compared to
black powder. At the war's outset, older equipment was painted matte
olive green to minimize reflection, while newer pieces were coated in pearl gray, termed "artillery gray," per a December 21, 1896 decision initially aimed at reducing heat absorption in ammunition boxes exposed to sunlight. With the shift to trench warfare, camouflage techniques emerged. In October 1914, gunners from the 6th Heavy Artillery Regiment began individually concealing their pieces. On February 12, 1915, the Ministry of War established a camouflage unit led by
Guirand de Scevola, a mobilized artist in the foot artillery, staffed by non-mobilized painters and decorators. To counter aerial observation, artillery was painted with irregular patches in colors like yellow ochre, rust brown, sienna red, dark green, and black to blend with the environment and disrupt outlines. Factory-produced equipment reverted to olive green, with additional camouflage applied by army painters. Alternative methods included multicolored cloths, netting, or branches. To withstand enemy artillery fire, positions were modified. Shelters or trenches were dug beside firing platforms, guns were partially buried in pits (sometimes with shelter traverses), or placed in casemates with roofs of logs or railway tracks. In fortified areas like Dunkirk and Verdun, concrete reinforcement was used. Dummy wooden cannons were also deployed to draw counter-battery fire or simulate heavy artillery presence along the front. == The peak ==