Last week we discussed mines, with some focus on command detonated mines. Use of those sort of mines dated back to the invention of gunpowder. The action of the mine was timed by the defender to effect. If triggered correctly, the mine could disrupt an attack. Even rumors of mines might even dissuade an attack on a particular sector. But as we saw there were drawbacks to the use of mine. (One I neglected to mention was maintenance of the powder charge, which by necessity was often in a place apt to be damp.) Thus mines were rated as an elaborate, though sometimes worthwhile, obstacle.
It should come as no surprise the Civil War saw the major debut of the automatic mine (we might argue that the “first” were used in the Seminole Wars, though). Usually called torpedoes in contemporary reports, these differed from the earlier mines by using a trip or trigger acted upon by the attacker. The torpedoes were set in a manner that an attacker’s footfall or passage would trigger the explosion. The leader in this field of weaponry was Confederate Brigadier-General Gabriel J. Rains. There were several different fusing mechanisms employed. I’ll save the technical details for another time (however, for those with an appetite, there is an examination of Confederate torpedoes used on Morris Island in 1863).
Writing for the edification of cadets in the 1880s, Junius B. Wheeler discussed the use of Rains’ “infernal machiens”, …er… torpedoes in the defense:
Torpedoes – Loaded shells buried in the earth just deep enough to be concealed, and arranged so they can be exploded automatically, or at the will of the defense, have been used as obstacles. Arrangements of this kind are known as torpedoes.
The case enclosing the charge may be either of wood or iron. Condemned shells are especially suitable for the purpose.
The explosive compound used to charge them may be powder, gun-cotton, nitro-glycerine, or any material which, upon being fired, will burst the case containing the charge and scatter the fragments in every direction.
The automatic – sometimes known as the “sensitive” torpedo – is fired by contact. It has the advantage of being exploded at the right time, but has the disadvantages of making the ground, in which it is buried, dangerous to the defense, and of subjecting the men when handling it to the danger of accidental explosions.
The torpedo which is fired “at will” has the disadvantage of being fired oftentimes prematurely, or when it is too late.
Circumstances can only decide as to which of the two is to be preferred as an obstacle.
Wheeler made clear distinction between the command detonated and automatic, or sensitive, mines/torpedoes. We see a familiar method of employment, being concealed in the earth.
What is not discussed in detail is arrangement of the obstacle. Wheeler did not discuss seeding roadways or footpaths with these torpedoes. Instead, at other points in the lesson Wheeler suggests use of torpedoes in the ditch or the ground in front of the works, integrated with other obstacles. “Torpedoes, military pits, entanglements, etc., may all be combined.”
Wheeler cited a couple of disadvantages to the use of torpedoes. To that we should add the aforementioned need to protect the powder from dampness. As the technology evolved through the 19th and 20th centuries, better handling configurations, powder, and triggering mechanisms reduced those disadvantages. Yet the automatic mine remains an indiscriminate killer on the battlefield to be feared by attacker, defender, and non-combatant alike.
What I do find most interesting is the tone of Wheeler’s instruction. Gone were mention of “infernal machines” or violations of civilized warfare. Indeed, the only restraints offered are those practical for the defender. Fifteen years removed from the Civil War, military leaders accepted the torpedo as a weapon and gone forward to embrace its use.
It would be another century before the Convention on Conventional Weapons, in 1980, would offer limits to the use of anti-personnel mines. Seventeen years later, the Ottawa Treaty directly banned the use of most types of anti-personnel mines (anti-vehicle and command detonated still being allowed under the treaty). You see, while the technical evolution of the mine has progressed in a linear form, the acceptance of the weapon has seen rises and falls.
(Citations from Junius B. Wheeler, The Elements of Field Fortifications, New York: D. Van Nostrand, 1882, pages 178-9, 183.)