French Breaching Drills

Written by Jacob Sullivan Edited by Zach Batson

The Char Sapeur Modèle 1938 has revolutionized French warfare, allowing them to infiltrate strategic targets on the battlefield. The design of the Char Sapeur was originally based on the Aulnoye II mining drill manufactured by Compagnie des Forges et Aciéries de la Marine et d'Homécourt at their home factory in Saint-Chamond in 1928. The design for the Aulnoye I was created by Eugène Brillié, who came up with the idea for the drill after observing the behavior of a Concordian drill wasp tunneling into a stone slab at the 1918 World’s Fair in Paris. The insect achieved this feat by secreting a red milky liquid onto the stone before hitting it with its elongated corkscrew head. This inspired Brille to seek the help of Arthur James Arnot and William Blanch Brain to create a drill that could easily penetrate stone, hoping to make mining easier for French workers. Brille worked out the general design of the drill as well as the mechanical components, while Arnot and Blanch worked out the laser and the drill bit. They began work on a prototype in 1924, but their progress stalled when they accidentally lost control of a drill bit, causing it to fly through the factory melting and damaging much of the equipment on the work floor. Luckily no one was injured in the incident, but this event pushed production back another few years.

By 1926, the first Aulnoye came off the factory floor, and was put into use to mine in the Le Bourneix Mines in search of gold. The designers of the Aulnoye I found some immediate flaws in the design of the drill after first putting it into service. The main issue was that there was no place for the debris of the drill to go as it tunneled into the earth. As a result, workers would have to tirelessly shovel dirt and debris from the front of the drill to avoid clogging. The other major flaw was the high potential for cave-ins due to the vibrations and heat put off by the drill. Both of these issues were taken into account in the design of the Aulnoye II which was released in 1928. The new and improved drill featured a conveyor belt that deposits waste behind the drill while operating to reduce the likelihood of clogging. The Aulnoye II also featured small Balfour engines to help mitigate the danger of cave-ins. Although these issues were solved, the drill still required a dedicated team of miners to maintain the structural integrity of the tunnels as the drill cleared a path. Despite this, the new design revolutionized the mining industry and has served the revolutionary military well.