The Army Mine Planter Service was formally established by act of Congress on 7 July 1918 as a part of the
Coast Artillery Corps. By the same act the grade of Army
Warrant Officer was established to provide officers as masters, mates, chief engineers, and assistant engineers for the larger mine planting vessels, the Army Mine Planter (AMP). Mine Planter Service ship's officers wore distinctive sleeve insignia stripes similar to maritime and naval ships' officers, with deck officers indicated by an anchor and engineering officers by a propeller. With the formal establishment of the AMPS and the Warrant Officer grades to provide officers for the ships the service became an entirely military operation. The larger vessels, designated
U.S. Army Mine Planter (USAMP), were supported by a variety of smaller craft comprising a submarine mine flotilla to plant and maintain the mine fields associated with Army
coast defense commands and their subordinate
coastal fortifications of the United States. The smaller vessels included slightly smaller Junior Mine Planters, Distribution Box Boats, mine yawls and assorted other small craft. The mine fields were composed of both contact mines, similar to conventional naval mines exploded by contact with a vessel, and
controlled mines such as the M4 Ground Mine with a 3,000 pound TNT charge. The contact mines were placed in areas vessels were not to enter, and the controlled mines were placed in designated ship channels. Those mines were planted in planned groups at predetermined locations, connected to shore by electrical cables for firing when a target was observed within their effective range. The mines could be fired individually or as a group. The Distribution Box Boats were specially equipped to maintain the distribution boxes that joined the individual mines within a mine group to the main cable connecting the group to the mine casemate. Early mine planters of the AMPS were capable of planting the mines, but did not have specific cable-laying or maintenance capability. Two
Signal Corps vessels with that capability were used and eventually taken into service for that function. Studies of those capabilities led to an increased cable capability in a ship constructed in 1917 and the later ships constructed in 1919. At least one of those vessels went on to further cable work after disposal by Army. Full mine and cable capability was integrated in the single new ship built in 1937, the
Lt. Col. Ellery W. Niles. At the entry of the United States into World War II sixteen new Army Mine Planter vessels were either under construction or planned. All had dual capability and several, including the
Niles, went on to operate as small cable ships after Army service. On 16 May 1921 SGT Benjamin Lee Woodhouse (1893-1921) died of wounds received in an explosion on Junior Mine Planter 46 in the New York Harbor area. He was married two days prior to the explosion. He was a cousin of
Carol Ryrie Brink, author of
Caddie Woodlawn and numerous other works. World War II quickly demonstrated the obsolete nature of the static coastal defenses of which the mine fields were considered part of the principal armament. By the end of the war the forts were standing down and the Navy had been given responsibility for all mine operations. Many of the 1942 and 1943 construction vessels were transferred to the Navy to be converted to Auxiliary Minelayers (ACM), where they were armed and modified for mine operations more in the nature of the naval mine warfare model. The ships' mine planting capability was similar to
buoy tender capability, and that was included in the naval mission and later
U.S. Coast Guard service. The Mine Planter Service faced major change during and at the end of the war, with its ships and role in mining transferred to the Navy. The
Coast Artillery Journal for March–April 1948 noted joint training with Navy and how USAMP
Spurgin was serving as a "floating laboratory" with "as many Navy hands as soldiers aboard the
Spurgin as she works in the San Francisco harbor entrance". The Army Mine Planter Service was officially terminated by the 1954 Warrant Officer Personnel Act. ==Insignia==