Quick Links Menu.

USNS <I>Yukon</I> (T-AO 152).

USNS Yukon (T-AO 152).
Click on this photograph for links to larger images of this class.

Class: MAUMEE (T-AO 149)
Design: MA T5-S-12a
Displacement (tons): 7,814 light, 34,757 full
Dimensions (feet): 620' oa, 600' wl x 84' e/wl x 34' max nav, 32' limit
Armament: none
Accommodations: 17 officers, 35 unlicensed
Speed (kts.): 18 sustained
Propulsion (HP): 18,600 normal, 20,460 maximum continuous
Machinery: Geared steam turbines, 2 boilers (600psi/850deg), 1 screw

149MAUMEE19 Nov 1954Sun SB & DD8 Mar 195515 Nov 195517 Dec 1956
150POTOMAC19 Nov 1954Sun SB & DD9 Jun 19558 Oct 195630 Jan 1957
151SHOSHONE19 Nov 1954Sun SB & DD15 Aug 195517 Jan 195715 Apr 1957
152YUKON22 Nov 1954Ingalls SB, Pascagoula16 May 195516 Mar 195617 May 1957

T-AONameTInact/CustStrikeDisposalFateMA Sale/Depart
149MAUMEET2 Oct 1985/C13 Apr 199223 Dec 1994MA/T23 Jan 2007/D
150POTOMACT--26 Sep 196127 Sep 1961Lost--
151SHOSHONET10 Feb 1984None?1 Oct 1994MA/T15 Jan 2014
152YUKONT20 Oct 198513 Apr 199218 Sep 1995Navy sale--

Class Notes:
Increased demand for oil for international postwar reconstruction and domestic U.S. economic growth produced an acute worldwide tanker shortage in the winter of 1947-48. Nearly all of the war-built T2 tankers were transferred to commercial service, but the oil industry also wanted larger tankers to more efficiently fill the capacity gap. A program was developed to build 64 tankers for American operators by the end of 1950. Of the 64 tankers actually delivered between 1949 and 1952, 56 were “supertankers” that fell into the Maritime Commission's T5 category (waterline length between 600 and 650 feet). Most were in the 27,000-28,000 dwt class, carried around 230,000 barrels of oil (about 70% more than a T2), and had a designed service speed of 16 knots. During 1948 the Maritime Commission canvassed oil companies to find how many would be interested in building some of these ships with national defense features paid for by the Government, the main feature being a higher speed of 18.5 knots. The MC developed the T5-S-DU1 design for these national defense tankers and offered funding for the increased speed for five privately built ships in FY 1949 and ten in FY 1950, but there were no takers. (The characteristics of the T5-S-DU1 design were 630’ waterline length x 83’ beam, 20,000 shp for 18.5 knots, 24,000 deadweight tons, 217,500 barrels of cargo, and a crew of 56.) At the same type construction was authorized of one prototype 18.5 knot cargo ship (design C3-S-DX1). For more on this ship, the only one of this type built, see SCHUYLER OTIS BLAND (AK 277).

During the Korean War there was again a severe tanker shortage, and on 15 May 1951 MARAD Administrator Vice Admiral Cochrane (formerly the wartime Chief of BUSHIPS) wrote to SECNAV asking the opinion of the Navy regarding a proposed Government-sponsored building program to provide tankers of relatively higher speeds to respond to expected requirements in an emergency. The National Security Council, concerned that the U.S. lacked the tankers needed to meet its mobilization requirements, undertook a large scale petroleum study and directed the Navy to suggest how it could help improve the position of the privately owned U.S. flag tanker fleet. A MSTS study concluded that the Navy could charter 20 new privately owned and operated tankers for a 10-year period and lay up and maintain in reserve 37 of its present T2 tankers for almost exactly the same amount of money that it would cost the Navy to continue to operate its existing T2 tanker fleet. Because the new ships might have to serve secondary harbors with shallow drafts and limited storage capacity, the Navy limited them to a capacity of 25,000 deadweight tons, a beam not exceeding 84 feet, and a draft fully loaded not to exceed 32 feet (characteristics matching the T5 type). For survivability against submarines a high sustained sea speed fully loaded of at least 18 knots was specified. Because of these military requirements the Navy opposed larger ships that might better fit commercial requirements.

On 24 May 1954 the Senate passed a Long Range Tanker Bill (S.3458) by Senator Saltonstall that essentially authorized this program but increased the size of the ships to between 25,000 and 32,000 dwt. The bill specified that the ships were to be built by private industry in the U.S. with private funds under a ten year charter to the Government, renewable for ten more years. The private charter operator would pay insurance, overhead, repair and maintenance, wages, and other expenses, and in return would be paid by the Government up to $5 a deadweight ton a month. (It was later specified that this rate was not to result in the recovery of more than 2/3 of the construction cost of each tanker.) The House Armed Services Committee preferred an arrangement under which the government instead of private interests would own the ships and, overriding the calculation by MSTS that this would cost an extra $95,000 per ship per year, it replaced the Senate bill with one that authorized the President to build the 20 ships and appropriated $150 million for them. It also restored the tonnage limit to the Navy's preferred 25,000 dwt. The law that emerged on 10 August 1954 after a House-Senate conference authorized the Secretary of the Navy to contract for the time charter to the Navy of 15 tankers that were to be privately built and authorized the President to build 5 tankers.

On 9 July 1954 MSTS informed the BUSHIPS Ship Design Division (Code 410) that the House version of S.3458, adopted the previous day, authorized the construction of 20 tankers to be owned by the Government and operated by MSTS. MSTS also passed to BUSHIPS preliminary characteristics for the ships: 25,000 dwt, 18 kts, 600-650’ oa x 84’ x 32’ draft max, and 17,000 HP. As the earlier Senate version of S.3458 had called for the construction of the 20 tankers by private interests with provision for long term charter by the Government, the five major U.S. tanker designers already had designs under development to meet specifications issued in May 1954. BUSHIPS set a target date of 1 October 1955 for awarding the shipbuilding contracts. As the contract plans and specifications developed by the Sun Shipbuilding & Dry Dock Co. of Chester, Pa., contained the required characteristics and were essentially complete while the designs of the other four firms required considerable time to complete, the Sun design was selected by BUSHIPS on 23 July 1954 and Sun was made design agent under contract NObs-3617. The Sun design was designated by MARAD as T5-S-10a. On 23 July 1954 BUSHIPS also learned from MARAD that S.3458 had been modified in a House-Senate conference to provide for the construction of five 25,000 dwt, 18-knot tankers by the Navy and the charter by the Navy of fifteen of the same type to be built by private capital with not more than three ships to be constructed in one yard. This version became law (PL 575) on 10 August 1954 and included an appropriation of $37.5 million for the five government-owned ships.

On 20 Aug 1954 MSTS invited offers from industry for the time charter under PL 575 of from 1 to 15 American flag tankers not now in being, built in U.S. shipyards, of 25,000 dwt and a draft of 32 feet both at the summer load line, for a period of 10 years from tender. On 27 August 1954 MARAD mailed out to shipyards invitations to bid on the five Navy ships. However on 3 September 1954 the chiefs of BUSHIPS and MSTS and DCNO (Logistics) met to consider concerns that the T5-S-10a design did not follow the intent of the authorizing law. The program presented to and approved by the Congress was predicated on the acquisition of tankers to be 1.87 T2 equivalents. New calculations showed that the maximum draft of the T5-S-10a design at the summer load line (scantling draft) was 35 feet instead of the expected 32 feet and its tonnage at this draft was 28,340 dwt instead of the specified 25,000 dwt. The meeting concluded that a redesign was necessary, and on the same day BUSHIPS asked MARAD to recall its invitations to bid. Contract NObs-3617 was amended to permit Sun to redesign the tanker, the redesign commenced on 27 September 1954, and on the same date BUSHIPS forwarded a revised preliminary design, soon designated T5-S-12a, to MSTS for approval. In the redesign the cargo capacity fell from 231,825 to 190,000 barrels, the displacement fell from 37,340 to 32,950 tons, and the length fell from 640' oa and 615' pp to 620' oa and 590' pp. MSTS approved the new design on 1 October 1954 and on 7 October 1954 BUSHIPS reported to MARAD that contract plans and specifications had been revised to delineate a smaller capacity tanker to conform to the most recent concept of these ships (to bring them in line with the interpretation of PL 575) and that Sun would deliver the revised plans and specifications to MARAD on 11 October 1954. MARAD sent out new bid invitations on or before 2 November 1954 with bids to be opened on 15 November 1954. BUSHIPS furnished funds in the amount of $30 million to MARAD to build four of the tankers and contracts were awarded on 19 November 1954 for three ships to Sun and on 22 November 1954 to Ingalls for one. Technical control for AO 149-152 within BUSHIPS was transferred from the Ship Design Division (Code 410) to the Ship Technical Division (Code 500) on 21 December 1954 following the completion of design work.

On 21 October 1954 MARAD complained that the final tanker design involved fairly severe sacrifices in commercial operating efficiency, particularly in short haul commercial coastwise operation, due to curtailment of hull dimensions. The design revisions directed in September 1954 had made the ships less attractive than the earlier ones from the commercial operator’s viewpoint. In the event, the five government-owned ships (T-AO 149-152 for MSTS and the later experimental T-AO 165 for MARAD) were built but the charter ships were not. A Senate investigation in 1955 found that bureaucratic obstacles had prevented bidders from getting adequate mortgage insurance before the bids for the charter ships became due on 19 November 1954. The Navy's four ships, T-AO 149-152, emerged as T5 class (600-650 foot wl) pipeline (point-to-point) tankers capable of 18 knots with a 190,000 barrel capacity. The first of the four ships, MAUMEE (T-AO 149), was accepted by MARAD at Chester following acceptance trials scheduled for 10 November 1956, placed in service on 17 December 1956, and put under contract operation by Marine Transport Lines, Inc. MAUMEE was the first ship to be constructed from the keel up as a USNS (MSTS) ship. Acceptance trials for the second ship, POTOMAC (T-AO 150), were scheduled for 22-24 January 1957.

Late in the afternoon of 26 September 1961 at the Radio Island fuel terminal across from the port of Morehead City, N.C., crews had begun the process of pumping cargo aviation fuel from the just-arrived POTOMAC into large holding tanks on shore when the midsection of the tanker suddenly burst into flames. After fighting the blaze for more than 12 hours, the decision was made to let the fire burn itself out, and six days later the fire was considered extinguished. The conflagration destroyed all but the stern of the ship. Official reports said that it appeared that a seal leak during the discharge of the fuel through a suction valve allowed some fuel to spill down the side of the tanker and into the Newport River, and that a lantern used by fishermen at a nearby train trestle that fell overboard or a cigarette butt tossed into the water lit the trail of fuel taking it back to the tanker. The stern with its intact propulsion plant was salvaged and joined to a new bow/midsection to became SS SHENANDOAH, later USNS POTOMAC (T-AO 181, q.v.).

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. On 14 September 1978 effective 30 September 1978 CNO reclassified AO 149, 181, 151, and 152 to AOT 149, 181, 151, and 152.

Ship Notes:
149MAUMEE38FY 1955 (MSTS). To MA custody 2 Oct 1985 (RRF in JRRF, to BRF Sep 1986 after yard period, to NDRF retention Apr 1987). Held as a spare parts source for T-AO 181 until to non-retention Jan 2004. Departed BRF 23 Jan 2007 for breakers (ESCO Marine, Brownsville). BU completed 22 Jun 2007.
150POTOMAC39FY 1955 (MSTS). Lost by fire and explosion pierside at the Aviation Fuel Annex, Radio Island, Moorehead NC, 26 Sep 1961 (reported 270253Z). Assignment to MSTS terminated 28 Sep 1961. Ravaged bow section offered for sale 24 Sep 1962 with bids to be opened 18 Oct 1962, sold Mar 1963. Stern sold 7 Oct 1963 to Keystone Shipping Co. under a contract that required rebuilding the ship and bareboat chartering her to MSC. New midbody and bow completed by Newport News, ship renamed SHENANDOAH and bareboat chartered to MSC 11 Dec 1964. See T-AO 181 (AOT 181).
151SHOSHONE40FY 1955 (MSTS). To MA custody 10 Feb 1984 (RRF in SBRF). Activated 24 Feb 1991 for Operation Desert Storm, back to RRF Mar 1991 and to NDRF (retention) 1 Oct 1994. To non-retention 1 Oct 2004. Scrapping contract with ESCO Marine effective 15 Jan 2014 (signed by company 27 Jan.) BU completed 18 Aug 2014.
152YUKON41FY 1955 (MSTS). To MA custody Oct 1985 (RRF in JRRF, to BRF Jan 1986, to NDRF retention Apr 1987). Name cancelled 9 May 1989 for reassignment to T-AO 202 though still used by MA for T-AO 152. Sold by Navy to Rig Ventures, Brownsville, withdrawn from NDRF (Navy non-retention) 21 Nov 1995 to BU.

Page Notes:
Compiled: 18 Sep 2021
© Stephen S. Roberts, 2021
Special sources: NARA: RG 19 Entry P62 box 27; RG 428 (Dept of the Navy) File FS/A1-1; Congressional documents including House hearings on the Independent Offices Appropriations Bill for 1950, part 2, 1 March 1949, pp. 539-548; New York Times 14 January 1949 p. 46 and 15 January 1949 p. 29.