Glossary

Ammonal	Ammonium nitrate-based commercial blasting explosive, safer and more powerful than gunpowder, adopted in 1915 as the British standard mining explosive.
Camouflet	Explosive charge intended to destroy an enemy tunnel, which is not of sufficient power to cause a crater.
Cheddite	A blasting explosive adopted by the French for mining.
Chevaux-de-frise	Crossed pointed iron stakes generally used with barbed wire for defensive purposes.
Clay-kicking	Method of digging small tunnels quickly and silently through clay, imported into the British Army by sewer tunnellers.
Common mine	Explosive charge which has just sufficient charge to form a crater on the surface.
Cordeau detonant	Detonating cord used for simultaneous firing of large charges.
Countermine	Tunnels dug to defend against enemy mines.
Demi-galerie	Standard French mine gallery, dimensions 1.30 to 1.50m high by 1m wide
Firestep	Raised step on the trench wall facing the enemy, which enables the defender to fire out of the trench.
Gaize	Sandstone which comprises the Vauquois ridge.
Geophone	Instrument used to magnify underground vibrations as sound waves.
Grafting tool	Type of spade used for clay-kicking.
Guncotton	Nitro-cellulose explosive used by the British Army for demolitions.
Gunpowder	Traditional explosive comprising saltpetre, sulphur and charcoal, used for military mining until 1915.
Incline	Sloped entrance to a tunnel used as an alternative to a vertical shaft.
Line of least resistance	The distance of a mine to the surface, used to calculate whether it would form a crater.
Mine	Explosive charge laid underground, or the tunnel in which that charge is laid.
Overcharged mine	Explosive charge which has more than sufficient charge to form a crater on the surface and which forms in addition lips of debris.
Proto	British self-contained breathing apparatus capable of lasting 45 minutes.
Push pick	Tool used for working in clay.
Radius of rupture	The globe around an explosive charge in which damage will be caused to mine workings.
Rameaux de combat	French attack branch gallery measuring 0.80m by 0.65m.
Russian sap	A shallow underground gallery which could be converted into a trench by breaking down the top cover.
Salvus	British self-contained breathing apparatus capable of lasting 30 minutes.
Sap	A trench dug towards a point to be attacked (sometimes used for a mine gallery).
Sapper	Generic term for a military engineer, also the basic rank of a member of the Royal Engineers.
Seismomicrophone	Electrical version of the geophone.
Spiling	Sheet piling technique used for working in sandy ground.
Stollen	German term for mine gallery or tunnel, also sometimes used for a tunnelled dugout.
Tamping	The backfilling of a mine tunnel to prevent the force of the explosion being directed back down the tunnel in which it was laid.
Tramming	Use of wheeled trolleys to remove spoil and carry forward explosives.
Transversal	Defensive tunnel dug parallel to the front line trench, used for listening and as a starting point for listening and attack galleries, also called a lateral.
Tubbing	Steel cylindrical sections used for sinking shafts in wet ground.
Westfalit	Ammonium nitrate-based commercial blasting explosive and one of several brands adopted by the Germans.