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USNS American Explorer (T-AO 165).

USNS American Explorer (T-AO 165).
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Class: AMERICAN EXPLORER (T-AO 165)
Design: MA T5-S-RM2a
Displacement (tons): 8,402 light, 32,628 full
Dimensions (feet): 615' oa, 600' wl x 80' e/wl x 35' max nav/limit
Armament: none
Accommodations: 16 officers and 37 enlisted
Speed (kts.): 20
Propulsion (HP): 22,000
Machinery: Steam turbines, 2 boilers, 1 screw

Construction:
T-AONameAcqBuilderKeelLaunchSvc
165AMERICAN EXPLORER27 Oct 1959Ingalls SB, Pascagoula9 Jul 195711 Apr 195827 Oct 1959

Disposition:
T-AONameTInact/CustStrikeDisposalFateMA Sale/Depart
165AMERICAN EXPLORERT27 Jun 1984/CNone?1 Oct 1994MA/T8 Jul 2008

Class Notes:
This ship was ordered by MARAD on 12 Jul 1956 as part of a plan to build 15 large-capacity ("pipeline") T5 tankers to supplement the war-built T2s that then formed the bulk of the US tanker fleet. Petroleum usage had doubled in the decade after the war and a larger tanker capacity and greater transport speeds had become priorities. The new tankers were 100 feet longer than a standard T2 and carried 190,000 barrels of oil instead of the 141,000 barrels of the T2-SE-A1 and had a speed of 18 knots. The first four became AO 149-152, and Ingalls put in the lowest bid for a follow-on tanker in the series. Ingalls laid down the ship, which was to have 20,000 horsepower to produce 20 knots, on 8 July 1957.

As construction began MARAD decided that this tanker, appropriately named AMERICAN EXPLORER, should be nuclear powered. MARAD wanted to explore the advantages of nuclear power in commercial ships (also the motivation for the later SAVANNAH). Without having to carry fuel for steam boilers, the ship could carry another 30,000 barrels of oil cargo increasing her capacity to 210,000 barrels. Some initial funding had been approved, and General Electric was selected to design and build a reactor for the ship and George Sharp began preliminary drawings for an appropriately modern exterior design. At the same time MARAD had Ingalls store all of the steam machinery, boilers and associated auxiliary systems initially intended for the ship while awaiting the final decision on nuclear power. The tanker was launched before the keel of the nuclear freighter SAVANNAH was laid on 22 May 1958. A boiling water reactor was chosen for AMERICAN EXPLORER as a less-expensive alternative to the pressurized water reactor selected for SAVANNAH, although BWR reactors had some significant technical drawbacks. At the 11 Apr 1958 launching ceremony the nuclear option seemed a virtual certainty. She was launched with no structures above the main deck, the design of her upper works still being uncertain as the nuclear decision had not actually been finalized. The nuclear design and/or its reactor may have been designated T5-S-RMa.

However, while Congress had authorized SAVANNAH on 30 July 1956, it had not authorized a nuclear tanker. General Electric did not have a BWR reactor ready for installation, George Sharp had not finalized the streamlined superstructure, and the required funding for both needed confirmation. In the meantime Ingalls completed the hull which then languished at the far end of the shipyard without a power plant. Ultimately the Bureau of the Budget, influenced by massive cost overruns on SAVANNAH, found the anticipated costs too high, and in late July 1958 the decision was made to complete the ship with the original conventional boiler and turbine arrangement and a traditional three-island shape. Her horsepower rating still came to 22,000, and even without the nuclear plant she became the world's fastest commercial tanker. AMERICAN EXPLORER was delivered to MARAD and simultaneously to MSTS on 27 Oct 1959. She was placed in service and delivered to Mathiasen Tanker Industries for contract operation. Changing contract operators in 1972 and 1979, she spent most of her career moving petroleum products along the Atlantic coast and in the Caribbean and Gulf of Mexico. In 1978 the navy created the new classification symbol AOT, "Transport Oiler," for the MSC tankers that carried oil from point to point rather than delivering it to fleet units, and on 14 Sep 1978 effective 30 Sep 1978 CNO reclassified AO 165 to AOT 165. She was transferred from contract operation to MSC and MARAD on 27 June 1984 for layup in the Ready Reserve portion of the Beaumont Reserve Fleet.

Ship Notes:
T-AONameMANotes
165AMERICAN EXPLORER53FY 1960. Delivered by Ingalls 27 Oct 1959. To MA custody 27 Jun 1984 (RRF in BRF). Activated 28 Feb 1991 for Desert Storm, back to RRF Mar 1991. From RRF to NDRF (retention) Oct 1994. to non-retention Jan 2004. Departed NDRF for breakers (Southern Scrap Material Co, New Orleans) 13 Aug 2008.

Page Notes:
Compiled: 18 Sep 2021
© Stephen S. Roberts, 2021
Sources: "A Pipeline Pipe Dream, Tanker AMERICAN EXPLORER," by Captain Terry Tilton, USN, Ret., in PowerShips (the journal of the Steamship Historical Society of America) No. 308 (Winter 2019) pp. 38-41. This issue also has a detailed article on the contemporary nuclear-powered freighter SAVANNAH.