"The subterranean self-propelled torpedo" Topic

Old but still interesting.

"At the end of 1916, Mr Henri and René Breton (whose possible relationship with the Député du Cher Jules Louis Breton, -who, during that very year promoted various devices to break through barbed wire obstacles- is unknown) offered this little machine powered by an electric motor (P1 on the drawing) fed from an outside source (range was estimated at 1000m). This is how the inventors thought to use their « subterranean self-propelled torpedo » :
« the length of the feed line being set according to the target distance, the machine is lowered is lowered into a pre-dug hole and orientated straight toward the target. The hole is then filled up with earth especially on the sides and at the rear. Then power is sent to the electric engine which activates […] the drill bits which will lead earth removed from the front of the machine to the rear. The feed lines are laid into the earth moved by the machine while the machine moves forward. When the end of the shorter line is reached it breaks at a predeterminated point , the power is cut and the amperemeter signals this fact to the crew. The other , longer, feedline is still connected to the electric fuze, ready to explode the torpedo"…

From here
link

Amicalement
Armand