The Maginot Line - A misunderstood history

Canon de 25 AC

Light anti-tank gun

By the early 1920’s the French Army realized that the armour-piercing capability of their 37mm TRP (tire rapide, Puteaux = name of the arms manufacturer) infantry gun would be insufficient against modern tanks¹. The gun was originally designed to destroy machine gun nests and was first fielded during WW1.

Therefore, Hotchkiss proposed a 25mm design in 1926, the Canon de 25 antichar (AC = anti-tank) SA (semi-automatique) modèle 1934.

¹Nevertheless, the Canon de 37 TR Mle 1916 was commonly provided as an anti-tank/infantry gun for the casemates and blockhouses in e.g. the SF Maubeuge. One reason for it’s continued use was that it could fire both high-explosive(HE) and anti-tank rounds.

Hotchkiss Canon AC Mle1934 25mm
Total weight480 kg
Armour penetration40mm/0° at 500m
32mm/35° at 200m
Range 800m (heavy armored vehicles) 1000m (medium armored vehicles) 1500m (softskinned vehicles)
Rate of fire25 rpm against fixed targets, 15 rpm against moving target
Muzzle velocity918 m/sec

The 37 TRP was accepted for service in 1934 and eventually formed the basis for the Arme Mixte weapon. The shortened name of the weapon became Canon de 25.

This weapon was used in MOM and STG blockhouses (New Front fortifications and the CEZF line). Normally, no armament was installed in these blockhouses until French Army units set up defensive positions in the sector and emplaced its equipment. Only when taking up defensive positions, the French army installed it’s equipment. The Canon de 25 was not used in ouvrages or first line CORF interval casemates.