U. S. Naval Mines- A History

Early History

Possibly the first water mine in the world with a target-fired trigger (as opposed to earlier ones which had simple, slow-burning fuzes) was invented by David Bushnell, the man who is most famous for inventing a one-man submersible, the Turtle. Like the Turtle, these sea mines were unsuccessful when they were used against the British fleet in Philadelphia during January 1778, although the resulting "Battle of the Kegs" did cause a few casualties and inspired a well-known Revolutionary War poem.

Bushnell's mine was a simple watertight wooden keg, loaded with gunpowder, which hung from a float. At that time, it was called a torpedo. Late in1777, under orders from General George Washington, a number of these “torpedoes” were set adrift by Bushnell in an attempt to destroy a fleet of British warships anchored in the Delaware River near the city of Philadelphia. That early attempt failed to achieve its goal, but the naval mine has since gained a well‑deserved reputation as one of the Navy's least costly, yet most effective offensive and defensive weapons.

For most of the 19th century the US Army was responsible for the development and use of mines, as mines were considered to be defensive weapons that were useful for protecting harbors and coastal waters. The Confederate Navy used mines, or torpedoes, as they were then called, quite extensively during the American Civil War, and sank approximately 27 Federal vessels and damaged many more. By comparison, only nine Federal vessels were sunk by gunfire. Many different kinds of mines were used by the Confederates, with one of the most effective being the frame torpedo, which was a large nose-fuzed artillery shell that was mounted on a wooden frame and located where a ship might strike it.

Not until late in the 19th century did the Navy start to take any interest in these weapons, but none were used during the Spanish-American War of 1898 and it was not until the Russo-Japanese War of 1905 that this interest became serious. During that war, both Imperial Russia and Japan had some success with their naval mines, which prompted the US Navy to ask Congress for funds for a mine depot ship. The old cruiser USS San Francisco (C-5) was converted in 1912 and she became the first mine warfare ship in the US Navy.
The first mines procured by the Navy were originally called "Naval Defense Mines" and were either purchased from European powers or were copies of European designs. Progress on mines was considered satisfactory prior to the start of World War I, but with the US entry into the war it was discovered that British mines of the same general types had proved unreliable. Bureau of Ordnance reports of 1917 declared that the status of mining in the USN with these Naval Defense Mines was "very unsatisfactory" and recommended development of new types, which led to the Mark 5 contact mine and the Mark 6 antenna mine.

These Naval Defense Mines were all declared obsolete in 1930 and removed from inventory. None of these designs were very successful, so perhaps it is surprising that it took so long to take them out of service.

Triggering and Fuzes

The first USA designed mine, the Mark 5, was of the "Horned" type. Horns were made of soft metal such as lead and held a glass ampoule containing battery acid, usually potassium-bichromate. The lower end of the horn contained an electric battery minus the electrolyte. Contact with the horn broke open the acid container, energizing the battery which then heated a platinum wire in a mercury fulminate detonator, thus exploding the mine. By definition, this was a weapon with limited range and fields needed to be densely packed in order for it to be effective against shipping. However, such close-laid fields ran the risk of one mine setting off adjacent mines as fraternal kills.

An interesting source that discusses Aerial Mine Warfare is provided here.
Entitled, "MINES AWAY! it discusses WWII aerial mine warfare.



Mine Warfare from Other Countries






This history of naval mines is provided exclusively from unclassified sources, including:
US Naval Weapons and Guide to World Naval Weapons Systems, 1991/92,  both by Norman Friedman and are used by permission of the The U.S. Naval

Other data has been provided from:

Naval Weapons of World War Two by John Campbell
America's Use of Sea Mines by Robert C. Duncan, Ph.D.
US Warships of World War II by Paul Silverstone

Other on-line sources:
US Navy Fact File
US Navy Mine Warfare Programs
US Navy Mobile Mine Group
Current U.S. Naval Mine Inventory
COMOMAG Mine Familiarization
FAS Military Analysis Network



Derick S. Hartshorn - 2009-present
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