A contact type mine. Mines used in the NY harbor were tethered to the harbor floor.
Background:
In 1891, an experimental mine field was planted in the Potomac River
near Fort Washington, just south of Washington, D.C. The mine control
room was casemated and improved in 1899. In 1898, during the
Spanish-American War, the U.S. Engineers attempted to develop a
minefield for the New York harbor, but the attempt failed due to the
poor condition of the equipment and a complete lack of technical
knowledge concerning the matter.
This poor situation continued through World War I and the U.S. Army was
unable to plant any mines in the defense of the United States. The U.S.
Army Mine Planter Service was established within the Coast Artillery
Corps in July of 1918.
In 1931, the U.S. Army moved it's development and maintenance work from
Fort Totten, NY, to the Submarine Mine Depot at Fort Monroe, VA. In
1939, a reliable controlled submarine mine system had been developed,
but the U.S. had fallen far behind the British and Germans in mine
technology. In 1941, the Army finally had the material, adequate
facilities, and trained personnel in position at the local mine depots
along America's coasts.
On December 7, 1941, the U.S. Army had approximately 5,000 moored,
controlled mines in stock and 1,200 mines in defensive minefield
projects had already been planted. In early 1942, all defensive
minefields were completed in San Francisco, Portland, Boston,
Narragansett Bay, New York, Chesapeake Bay, Portsmouth, and Cristobal
and Balboa (located on each side of the Panama Canal).
The mission of these minefields was:
a) To effect the destruction or serious damage of hostile vessels which approach within effective range.
b) To supplement the offensive action of other weapons in repelling hostile naval attack.
c) To prevent the close approach or entry into a harbor of hostile
surface vessels under cover of night, fog, or smoke, when by reason of
invisibility of the ships from shore, other weapons of the army and Navy
are wholly or partially ineffective.
d) To limit or prevent the navigation by hostile submarines of specific
channels or water areas.
e) To restrict the freedom of maneuver of hostile naval forces in
formation.
f) By the moral effect of an unseen threat, to enforce a constant
element of caution and uncertainty in the planning and execution of all
hostile naval operations within the water areas known, or believed to be
protected by minefields.
g) To give warning of of hostile submarine activities or the presence of hostile surface vessels.
In the early part of World War II, these mines had an explosive charge
of 100 to 500 pounds of TNT, were anchored about 15 feet below the
surface, and required that the ship physically contact the mine in order
for the control station to be signalled that a ship was in the
minefield. The control station then had to determine if the ship was an
enemy or friendly craft. The control station could then electrically
fire the mines. In 1943, a newer generation of magnetic detection mines
were installed to replace the older "contact type" mines. These new
mines would signal the control station if a ship of over 1,000 tons
passed over any mine. The control station could likewise electrically
fire the mines.
Map of Mined Harbors during World War II
There is no record of any enemy ship being damaged or sunk, or even
detected, by any of these domestic minefields. After World War II, the
responsibilities of harbor defense mining was assumed by the US Navy.
Fort Tilden's Mine Casemate:
Fort Tilden was the control point for the minefield defenses on the east
side of the Ambrose Channel in New York Harbor, while Fort Hancock, at
Sandy Hook, NJ, was the control point for the minefield defenses on the
west side of the Ambrose Channel. Fort Wadsworth, at Staten Island, NY,
controlled the mines inside the submarine net at the Narrows.
The controlled submarine mines planted in the New York harbor were
connected by wires to their respective shore stations. From the mine
casemate bunker, these mines would indicate when a ship or submarine
contacted any mine and could then be fired individually or in groups.
What's left today?
The abandoned, overgrown, and empty mine casemate bunker still remains at Fort Tilden, but all equipment has long been removed.
M4 Emergency Mine Control (Special thanks to Pete Payette!)
The Mine Casemate Bunker at Fort Tilden
(Private Collection, 1999)
If you have any additional historic information concerning Fort Tilden's
mine casemate bunker and the controlled minefields of New York Harbor
(especially any maps showing the minefield locations), please contact
us.
Mines and Mine Casemate Equipment
References and further reading:
America's Use of Sea Mines, Robert C. Duncan, January 1962,
USGPO.
Controlled Submarine Mines. Field Manual 4-6, 1 May 1942.
