It is often said about WW1 that the catastrophic casualties were due to the fast pace of battlefield technology far out-stripping the development of tactics. The fifty years leading up to 1914 saw steel gun tubes, rifling, cordite, TNT and its precursors, time fuses, self-contained ammunition, brass casings, breech loading, rapid fire systems (everything from machine guns to rifle magazines down to stripper clips), railroad transport, armored ships and the list can go on.
As the first rapid-firing artillery piece, the French 75mm was, along with the machine gun, among the first manifestations of 20th century warfare. However, clearly the biggest game-changer was – not the machine gun – but the quick-firer field gun. It is estimated that up to seventy per cent of battlefield casualties in WW1 were inflicted by artillery. In a macabre one-on-one comparison, machine guns had an effective range of around 2,000 yards while quick-firers could hit targets over 7,000 yards away.
By the 1890s, breech-loaders had replaced muzzle loaders, but the barrel was affixed to the carriage and so the recoil of firing drove the whole gun several feet backward. The gun crew then had to man-handle it back into position and re-aim it. The rate of fire was thus limited to the time it took to stand clear of the recoil, reposition the gun, and re-lay it. Moreover, the repositioning effort wore out the gun crew.
In 1896 two French artillery captains named Etienne Sainte-Claire Deville and Emile Rimailho invented a hydraulic shock absorber that took up the recoil of the barrel and returned the gun to the firing position, eliminating the movement of the carriage. With the addition of self-contained ammunition – smokeless propellant and a projectile within a single brass casing. Improved devices for aiming and fuse-setting were also developed. These features became the basis for the Matériel de 75mm Mle 1897. Gunners could now fire as fast as they could load – over twenty rounds per minute was possible – because there was no need to re-lay the gun once the shells were hitting the target area.
A 75-mm gun crew in action was a wonder to observe. The gun’s controls had been carefully arranged for ease and speed of use. A rotating breech mechanism could be closed and opened with the throw of a single lever; this replaced the usual door-like hatch that had to be shut and then latched down. The shell weighed only 12 pounds and, because it combined the charge and projectile in a single package, could easily be loaded by one man. The natural frequency of the gun’s firing cycle exactly matched the loading and firing cadence of the crew, achieving a near-perfect integration of man and machine; neither had to stop to wait for the other at any point in the operation. No wonder that the French fired about 300 million 75 mm shells during the war.
The quick-firer had drawbacks – it fired a flat trajectory, so it could not reach into trenches or dugouts, and its shells were too light to penetrate fortifications or deep shelters. But against troops in the open it was super-deadly. With time-fused shrapnel shells a 4-gun battery could deliver 17,000 ball projectiles over an area 100 meters wide by 400 meters long in a single minute, and could stop either an infantry or a cavalry charge in its tracks. Later in the war quick-firers also delivered gas shells with equally devastating effect.
The 75 gets major credit for stopping the German offensive in 1914.
The French kept their 75 secret until 1901, when it was employed in the Boxer Rebellion. The ‘Dreyfus Affair’ espionage scandal involved the alleged sale of quick-firer technology to the Germans. Nevertheless, other countries quickly copied the French 75. The Russian ‘three-incher’ (76.2 mm) was introduced in 1902, the British “13-pounder” (also 76.2 mm) in 1904, followed by the “18-pounder” (84 mm), which became their standard. A year later, Germany retro-fitted recoil absorption and other improvements to its now-obsolete 77 mm field gun, but the resulting upgraded 77 could achieve a rate of fire of only about 10 rounds per minute, as its recoil mechanism was inferior to that of the French. The US hadn’t developed a practical gun in time for World War I, so it obtained all of its field guns from the French at a considerable cost.
The 75 was widely used all the way throughout the inter-war years and into WW2. In 1939, the French Army had over 4,500 75’s and the Polish Army over 1,300. Many of these were later adapted by Germans as anti-tank weapons and fortress guns. In 1941 the US Army had over 1,000 substantially modified 75’s, most of which saw service in the Pacific Theater mounted on half-tracks.
The 75 is still used by the French Army for ceremonial duties.