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USNS American Mariner (T-AGM 12) ca. 1965.

USNS American Mariner (T-AGM 12) ca. 1965.
Click on this photograph for links to larger images of this class.

Design: MC Z3-EC2-S-C1
Displacement (tons): 3,380 light, 14,245 full
Dimensions (feet): 442' oa, 427' wl, 416' pp, x 57' e/wl x 24.6'
Armament: none
Accommodations: 12 officers, 55 unlicensed, 50 RCA engineers
Speed (kts.): 11.5
Propulsion (HP): 2,500
Machinery: Steam triple expansion reciprocating, 2 boilers (220psi/450deg), 1 screw

12AMERICAN MARINER1 Jul 1964Bethlehem-Fairfield15 Aug 194130 Dec 19411 Jul 1964

AGMNameTDecomm/CustStrikeDisposalFateMA Sale/Depart
12AMERICAN MARINERT1 Jul 19661 Jul 1966Oct 1966Target--

Class Notes:
On 7 November 1941 the Director of the Division of Training of the War Shipping Administration recommended that an early Liberty ship (EC2-S-C1) then under construction be completely converted to a U.S. Maritime Service Training Ship (Z3-EC2-S-C1), joining the World War I-vintage AMERICAN SEAMAN and AMERICAN SAILOR. The recommendation was approved three days later by the Maritime Commission, and the GEORGE CALVERT (MCE 20) was selected. Her original name was transferred to MCE 29 and she was launched as AMERICAN MARINER on 30 December 1941 by the Bethlehem Fairfield Shipyard at Baltimore, delivered on 12 Feb 1942 when 65.4% complete, and towed to the nearby Bethlehem Key Harbor plant for completion as a training ship. Her conversion was completed 10 Mar 1943 and she was delivered to the WSA Division of Training for operation by the Coast Guard. When training ship activity in the New York port area was discontinued in the spring of 1946 she moved to the USMS training facility in St. Petersburg, Florida. This facility closed in March 1950 and it was decided that, instead of placing the ship in the Reserve Fleet, shw would be laid up in a ready reserve status at the U.S. Merchant Marine Academy at Kings Point, N.Y. This lasted until it became apparent that the Academy could not provide the maintenance needed by the ship in addition to the Academy's training duties, and on 9 December 1953 the ship was towed to the nearby MARAD Hudson River Reserve Fleet at Jones Point, N. Y. for full layup.

In 1958 a program called DAMP (Downrange Anti-Missile Measurement Program) was established jointly by the Army Rocket and Guided Missile Agency (ARGMA) at Redstone Arsenal, Alabama, and the Defense Department's Advanced Research Projects Agency (ARPA, now DARPA) as a part of Project Defender to investigate the physical characteristics of and phenomena associated with ballistic missiles and their nose cones as they reentered the earth's atmosphere. This information was needed to develop active defenses against ballistic missiles and, as a by-product, to aid in ballistic missile design. DAMP needed a mobile base with suitable equipment to measure re-entry phenomena of missile flights originating in Florida. A fixed base would not suffice as the location of these impact areas would change. On 14 May 1958 the Army asked that AMERICAN MARINER be reserved for its use, on 2 June 1958 it formally asked the Department of Commerce for the ship, and on 18 June 1958 the ship was withdrawn from the Hudson River Reserve Fleet and delivered to the Army. The prime contractor for the DAMP program was RCA, and the crew for the ship was provided by Mathiasen's Tanker Industries of Philadelphia as a sub-contractor. After an extensive conversion USAS AMERICAN MARINER sailed from Baltimore on 23 January 1959 to begin work on the Atlantic Missile Range (Eastern Test Range). The core of AMERICAN MARINER's data acquisition capability was two RCA AN/FPQ-4 C-band high precision narrow-beam (1 degree beam width) tracking radars similar to the AN/FPS-16. These were 16-foot dish antennas mounted one on each side facing aft on the boat deck. In early 1961 a new dual-frequency radar with a 30-foot diameter dish antenna operating in the UHF and L-bands was installed during a port layover at Capetown, South Africa. This unit, although large, was only a slave instrument tied into the smaller AN/FPQ-4 tracking radars. The AN/FPQ-4's received new radar dishes in a May-June 1961 refit. This equipment was far more advanced than that in the other range instrumentation ships then on the Eastern Range, and AMERICAN MARINER successfully collected data on many missile re-entries.

In April 1962 AMERICAN MARINER transited the Panama Canal to participate in Operation FISHBOWL. A treaty banning high-altitude nuclear testing was close to ratification, and the U.S. mounted a crash program at Johnston Island in the central Pacific to get before this happened the electromagnetic measurement data that would show whether or not an anti-ICBM system was workable. (The intent was to use a nuclear tipped NIKE-X as an area and point defense ABM system.) Because AMERICAN MARINER was the only ship with radars in the S, C, L, and UHF bands and because she had the highest precision trackers, she was selected to measure all of the high altitude nuclear tests in this program. After supporting FISHBOWL into December 1962 and observing five successful tests, she returned on 16 January 1963 to the Eastern Test Range.

In the meantime, a meeting between DOD and NASA representatives was held in June 1962 to discuss continuing and future instrumentation ship requirements. It was decided that beginning in the third quarter of CY 1963 the Atlantic Missile Range would probably take over the DAMP ship (AMERICAN MARINER) and operate her as a regular range ship. It was also decided that she would be further equipped to meet NASA requirements, one of which was covering the orbital insertion of the Gemini program in the area of Bermuda. However in January 1963 it was determined that land-based tracking stations could cover this event. Floating platforms remained important, but to be totally effective they had to have extensive amounts of "project peculiar" equipment on board identical to that of the ground network and they would have to be fully integrated into that network and operated by the same contractors. These requirements effectively precluded the use for NASA programs of general purpose range instrumentation ships. Instead funds were included in the FY 1964 and FY 1965 budgets to equip ships to support the Apollo program (see the T-AGM 19 class), and these ships could also support other NASA and DOD missions.

On 30 September 1963 the U.S. Army Advanced Research Projects Agency DAMP mission and contract expired. The Army Missile Command offered AMERICAN MARINER to the Air Force Missile Test Center as a missile range ship to track missiles launched from Cape Kennedy, and the Air Force Test Center accepted the offer and the transfer became effective on 1 July 1963. The ship became U.S. Air Force Ship AMERICAN MARINER, E-23-1932, call sign Kilo. AMERICAN MARINER was one of ten Air Force Atlantic Missile Range ships reassigned from the Air Force to MSTS by the Secretary of Defense on 16 November 1963 and directed on 1 May 1964 to be instated or reinstated in the Naval Vessel Register (NVR) as T-AGM 9 to T-AGM 18 effective the first day of the month following the date of their acceptance by the Navy. AMERICAN MARINER was instated on the NVR for the first time on 1 July 1964 as T-AGM 12. Late in December 1964 an instrumentation overhaul was conducted at West Palm Beach, Florida, but after maintenance work was completed on 15 February 1965 the ship was placed in wet storage (reserve) at Caven Point, New Jersey, near the Statue of Liberty. Six months later activity resumed and she returned to operations on the Eastern Test Range. Major modifications to eliminate deficiencies in her radar, telemetry, and data handling equipment were programmed for September 1965, but her functions had mostly been taken over by GENERAL H H ARNOLD and GENERAL HOYT S VANDENBERG (T-AGM 9 and 10) and these plans were cancelled, the Air Force deciding against continued operation of the vessel. The Air Force's National Range Division approved the status change in November 1965 and the ship returned to Port Canaveral in December 1965 for final deactivation. After removal of equipment she sailed in February 1966 to Caven Point for completion of the deactivation process. On 1 September 1966 she was released to MSTS as excess to Air Force Eastern Test Range requirements. Between 19 and 21 October 1966 she was scuttled by UDT swimmers using limpet mines at the site off Tangier Island in Chesapeake Bay previously occupied by USS HANNIBAL (AG 1) and has since been used as a target for guns, rockets and bombs by aircraft from the Naval Air Test Center at Patuxent River, MD. Her wreck, no longer intact, is still visible there.

Ship Notes:
12AMERICAN MARINER20(ex-GEORGE CALVERT). Liberty ship delivered 12 Feb 1942 when 65.4% complete for conversion to merchant marine training ship. To MA reserve 9 Dec 1953. To Army 18 Jun 1958 for an early ballistic missile defense program. To Air Force as AMERICAN MARINER, E-23-1932, 1 Jul 1963 as a missile range ship. On Navy list 1 Jul 1964 but with functions mostly taken over by T-AGM 9-10 was designated Nov 1965 by the Air Force for deactivation. Scuttled Oct 1966 for use as a target for naval aircraft in Chesapeake Bay, wreck still there 2022.

Page Notes:
Compiled: 18 Oct 2021
© Stephen S. Roberts, 2021
Sources: Herbert Hahn, American Mariner: A Documentary Biography of Her Role As Liberty Ship, Training Ship (1990). For the AGMs generally: https://afspacemuseum.org/facilities/support-ships-on-the-eastern-range/