US Navy Auxiliary Ships: Mattaponi (AO-41) Class

USS Patuxent (AO-44) on 9 November 1942
Click on this photograph for links to larger images of this class.

Class:        MATTAPONI (AO-41)
Design        MC Tanker (Sun)
Displacement (tons):        5,882 light, 22,325 lim.
Dimensions (feet):        520.0' oa, 500.0' wl x 68.0' e x 30.75 lim.
Original Armament:        1-4"/50 4-3"/50 (1942: AO-41, 43)
Later armaments:        1-4"/50 4-3"/50 12-20mm (1942: AO-41, 44); 1-4"/50 4-3"/50 2-40mmT 12- 20mm (1943: AO-41);
1-5"/51 4-3"/50 12-20mm (1942-43: AO 42-44); 1-5"/51 4-3"/50 2-40mmT 12- 20mm (1943: AO-44);
1-5"/38 4-3"/50 12-20mm (1942: AO-47); 1-5"/38 4-3"/50 2-40mmT 12-20mm (1943-44: all 5 ships); 1-5"/38 4-3"/50 4-40mmT 8-20mmS or 4-20mmT (1944- 45: AO41-43); 1-5"/38 4-3"/50 2-40mmT 4-20mmT (1949: AO-47);
no large, 2-20mmT (1951: AO41-43, 47); no large, 4-40mmT 2-20mmT (1952: AO 41-43); no large, 2-40mmT 2-20mmT (1952: AO-47);
5-3"/50 4-40mmT 2-20mmT (1955: AO-41); 5-3"/50 4-40mmT (1955-57: AO 41- 43);
2-3"/50 2-40mmQ 4-20mmT (1955: AO-47);
4-3"/50 (1961-68: AO-41, 43, 47)
Complement        217 (1944)
Speed (kts.):        17.5
Propulsion (HP):        12,800
Machinery:        1 screw, Westhinghouse or G.E. turbine

Construction:

AO	Name	Acq.	Builder	Keel	Launch	Commiss.
41	MATTAPONI	31 Mar 42	Sun SB & DD	9 Sep 41	17 Jan 42	11 May 42
42	MONONGAHELA	31 Jul 42	Sun SB & DD	3 Jan 42	30 May 42	11 Sep 42
43	TAPPAHANNOCK	29 May 42	Sun SB & DD	24 Dec 41	18 Apr 42	22 Jun 42
44	PATUXENT	28 Sep 42	Sun SB & DD	5 Mar 42	25 Jul 42	22 Oct 42
47	NECHES	20 Jul 42	Sun SB & DD	12 Jun 41	11 Oct 41	16 Sep 42

Disposition:

AO	Name	Decomm.	Strike	Disposal	Fate	MA Sale
41	MATTAPONI	30 Sep 70	15 Oct 70	1 Sep 71	MA/D	15 Dec 71
42	MONONGAHELA	22 Aug 57	1 Feb 59	10 Dec 58	MA/R	19 Mar 82
43	TAPPAHANNOCK	6 Mar 70	15 Jul 76	1 Sep 71	MA/R	2 Feb 87
44	PATUXENT	21 Feb 46	12 Mar 46	1 Jul 46	MC/D	23 Dec 47
47	NECHES	1 Oct 70	1 Oct 70	1 Sep 71	MA/D	15 Dec 71

Class Notes:
FY 1942. With the orders for the 12 large ships of the Standard Oil type (later AO-22 class) and the six smaller ships of the Socony-Vacuum type (later AO-36 class), eighteen of the twenty-four high speed tankers that the Navy wanted to have available had been provided for. After signing the contracts for the six Socony-Vacuum ships the Maritime Commission announced that it was requesting bids for six more ships of the same type, the bids to include both 16.5 knot and 13.5 knot variants to allow computation of the government's subsidy. The lowest bid for the 16.5 knot variant was submitted by the Sun Shipbuilding and Dry Dock Co., but even lower was an alternative bid that Sun submitted to provide the requested ships to its own design. This design was the highly successful one to which it built ESSO ALBANY, ESSO TRENTON (later AO 34-35) and nine later ships (including these five) during 1941 and 1942. For the high speed ships Sun modified its basic design, which was 12.5 feet longer on the waterline than the Socony-Vacuum ships, by replacing the original 9,900 hp, 15.5 knot plant with a 12,800 hp plant that would produce the 16.5 knots desired by the Navy. On this basis, Sun received orders for five national defense tankers for the Keystone Tankship Corp., the first two (AEKAY and KALKAY) on 20 Apr 40 and three more in June. As with the other national defense feature tankers, the MC paid only for the national defense features and Keystone owned the ships. These were initially carried in MC records as simply "Tankers", sometimes followed by the name of their builder (the designations "T2 Tankers" and "T2-A" appear later and may not have been official).

On 28 Feb 42 CominCh recommended to CNO that steps be taken to acquire and man at least six tankers completing subsequent to March 1942. On 4 Mar 42 the Board recommended that they be acquired, and four of them, SS KALKAY, ELLKAY, JORKAY, and EMMKAY became AO 41-44. On 9 Jun 42 CinCPac stated that he had an immediate need for four more fleet oilers. A representative of CinCUS recommended to the Auxiliary Vessels Board the acquisition of two ships already in operation in the Pacific and two under construction on the East Coast. A representative of the War Shipping Administration stated that there would be no objection to the transaction, and on 19 Jun 42 the Board recommended acquiring the ships. One of the two ships in the Pacific, AEKAY, became AO-47.

AO-47 had 1-4"/50 as a merchant vessel. Except for one ship (AO-44) returned to the Maritime Commission because of the "unsatisfactory condition of main turbine and reduction gears," the Navy retained the entire class for postwar service. It may have been influenced by the fact that their engine rooms were less crowded than those of the AO-36 class because of their extra 12 feet of waterline hull length. Three of them remained in use until 1970.

Ship Notes:

AO	Name	MC	Notes
41	MATTAPONI	149	Ex merc. KALKAY (completed 30 Mar 42). Conversion completed 23 May 42. From NTS to MSTS as "Commissioned Naval Vessel" 1 Oct 49. In USN reserve 1949-50 (decomm. 17 Apr 50). To MSTS 28 Nov 50, recomm. 28 Dec 50. In USN reserve 1954-56 (decomm. 12 Oct 54). To MSTS 15 Nov 56, recomm. 12 Dec 56. Decomm. 12 Nov 57, to NDRF 3 Dec 57, to MA 10 Dec 58, stk. 1 Feb 59. From MA 4 Aug 61, on list 1 Sep 61, recomm. 30 Nov 61. Final strike date officially changed from 1 Oct 70. Sale to Venezuela fell through, to NDRF 22 Jan 71. To buyer 22 Dec 72.
42	MONONGAHELA	158	Ex merc. ELLKAY (completed 31 Jul 42). Conversion completed 19 Sep 42 by Maryland DD, Baltimore, Md. From NTS to MSTS as "Commissioned Naval Vessel" 1 Oct 49. In USN reserve 1949- 50 (decomm. 9 Jun 50). To MSTS 28 Nov 50, recomm. 9 Jan 51. In USN reserve 1955-56 (decomm. 10 Jun 55). To MSTS 9 Nov 56, recomm. 28 Dec 56. Decomm. 22 Aug 57, to NDRF 13 Sep 57 (stricken in error on same day and reinstated). To buyer 25 Mar 82.
43	TAPPAHANNOCK	157	Ex merc. JORKAY (completed 29 May 42). Conversion completed 28 Jun 42 by the Philadelphia Navy Yard. From NTS to MSTS as "Commissioned Naval Vessel" 1 Oct 49. In USN reserve 1949-50 (decomm. 1 Jun 50). To MSTS 28 Nov 50, recomm. 4 Jan 51. In USN reserve 1955-56 (decomm. 23 Dec 54). To MSTS 26 Nov 56, recomm. 12 Dec 56. Decomm. 18 Nov 57, to NDRF 3 Dec 57, to MA 10 Dec 58, stk. 1 Feb 59. From MA 20 Aug 65, recomm. 31 May 66. To NDRF 16 Oct 70.
44	PATUXENT	159	Ex merc. EMMKAY (completed 28 Sep 42). Converted 28 Sep 42 to 10 Nov 42 by Maryland DD, Baltimore, Md. Relinquished by Navy because of unsatisfactory condition of main turbine and reduction gears. Merc. EMMKAY (MC) 1946, DAVID D. IRWIN 1947. Lengthened and widened 1961. Scrapped 1985 as FAIRWIND.
47	NECHES	148	Ex merc. AEKAY (completed 24 Feb 42). Conversion completed 18 Sep 42 by Bethlehem Steel, San Francisco. From NTS to MSTS as "Commissioned Naval Vessel" 1 Oct 49. Decomm. 10 Jul 50 and in USN reserve. To MSTS 28 Nov 50, recomm 3 Jan 51. Decomm. 5 Mar 56 and in USN reserve. To MSTS 23 Nov 56, recomm. 11 Dec 56. Decomm. 24 Sep 57, to NDRF 10 Oct 57, to MA 10 Dec 58, stk. 1 Feb 59. From MA 9 Aug 61, on list 1 Sep 61, recomm. 24 Nov 61. To NDRF 13 Jan 71. To buyer 3 Jan 73.