US Navy Auxiliary Ships: Mispillion (AO-105) Class

USS Mispillion (AO-105) in the late 1950s or early 1960s
Click on this photograph for links to larger images of this class.

Class:        MISPILLION (AO-105)
Design        MC T3-S2-A3
Displacement (tons):        7423 light, 25,400 lim.
Dimensions (feet):        553.0' oa, 525.0' wl x 75.0' e x 32.3' lim.
Original Armament:        1-5"/38 4-3"/50 4-40mmT 4-20mmT
Later armaments:
1-5"/38 4-3"/50 2-40mmQ 2-40mmT 4-20mmT (1947-49: all);
4-3"/50 (1958-61: all)
none (1973-75: all, in MSTS)
Complement        --
Speed (kts.):        18.3
Propulsion (HP):        13,500
Machinery:        2 screws, Westinghouse turbines

Construction:

AO	Name	Acq.	Builder	Keel	Launch	Commiss.
105	MISPILLION	29 Dec 45	Sun SB & DD	14 Feb 45	10 Aug 45	29 Dec 45
106	NAVASOTA	27 Feb 46	Sun SB & DD	22 Feb 45	30 Aug 45	27 Feb 46
107	PASSUMPSIC	1 Apr 46	Sun SB & DD	8 Mar 45	31 Oct 45	1 Apr 46
108	PAWCATUCK	10 May 46	Sun SB & DD	22 Mar 45	19 Feb 46	10 May 46
109	WACCAMAW	25 Jun 46	Sun SB & DD	28 Apr 45	30 Mar 46	25 Jun 46

Disposition:

AO	Name	Decomm.	Strike	Disposal	Fate	MA Sale
105	MISPILLION	1990	15 Feb 95	1 May 99	MA/T	--
106	NAVASOTA	1991	2 Jan 92	25 Oct 95	Sold	--
107	PASSUMPSIC	1991	17 Dec 91	18 Dec 91	MA/S	19 Dec 91
108	PAWCATUCK	1991	21 Sep 91	1 May 99	MA/T	26 Aug 05
109	WACCAMAW	1989	11 Oct 91	1 May 99	MA/T	26 Aug 05

Class Notes:
FY 1944. On 6 Jun 1944 the JCS asked the MC to modify its building program for the first half of 1945 to include the construction of 56 merchant type vessels as Naval auxiliaries including 12 oilers. The MC informed the JCS on 22 Jun 44 that it was able to provide for all of the requested 56 ships except for two of the 12 oilers. The deficit in this tanker program increased to four when two T2's were converted to distilling ships during construction (AW 3-4). On 16 Oct 44 the Navy representative of the Joint Chiefs of Staff recommended that, to make up this deficit and to provide sufficient fast oilers to support fleet operations by the fourth quarter of 1945, the Maritime Commission building program for the last half of 1945 be modified to provide for the construction of nine merchant type AO's for the Navy. On 2 Nov 44 the MC added to its program the construction of four ships at Marinship to the T2-SE-A3 design and ordered under its Military Program five ships at Sun Shipbuilding and Drydock Co, Chester, Pa. to the fast T3-S2-A3 design. On 11 Nov 44 the Auxiliary Vessels Board recommended that these ships be acquired. The T3-S2-A3 design incorporated some minor changes that the Navy wanted made to the T3-S2-A1 design of the AO-51 class, but the two may be regarded as essentially identical.

AOR-109: The idea of building or converting a combined tanker and supply ship had been around since 1946, when the Navy acquired the ex-German DITHMARSCHEN (IX-301), which already had some of these attributes, and redesignated her CONECUH (AO-110) in hopes of making her a prototype. The idea was dropped in late 1946 because of cost, but on 6 May 1949 SecNav approved a shipbuilding and construction request for FY-1951 that included the conversion of one AO to a replenishment oiler (AOR) according to specifications for conversion of an AO-105 class ship being developed by the Ships Characteristics Board as SCB Project 50. The basic concept was that in the future replenishments would have to be carried out in less time than had been available during World War II because of advances in both aircraft and submarines and that a single replenishment ship had to be capable of transferring various categories of fuel, ammunition, and stores during one alongside period. On 27 Jul 50 the project was included in a supplemental portion of the FY 1951 Shipbuilding and Conversion Program. AO-109 was selected for the conversion and was reclassified AOR-109 on 11 Dec 50. The Navy's tanker force was fully occupied by the demands of the Korean War, however, and on 29 Oct 51 CNO informed the Bureaus that "in view of the non-availability of a regular fleet oiler for the subject conversion, the USS CONECUH (AO-110) is tentatively designated for the AOR conversion provided for in the FY 1951 1st Supplemental Appropriations." The designation of AOR-109 had already been changed back to AO-109 on 7 May 51. CONECUH was reclassified AOR-110 on 4 Sep 52 and was activated at NSY Philadelphia as a prototype replenishment oiler between June 1952 and May 1953.

"Jumbo" conversions: On 24 Feb 61 ComServLant submitted to CNO an analysis done jointly with ComServPac of the construction and conversion of fleet oilers that would be required in Fiscal Years 1963-1968. The study showed that the total force could be maintained at 33 ships by jumboizing 9 AO-22 class ships and building new ships of the AO, AOR, and AOE types to offset the loss of the remaining AO-22 class ships, all of which would be phased out by 1972. The 9 jumboized tankers would have their tank sections replaced and would be thoroughly rehabilitated for extended service life. At the same time, BuShips in February 1961 contracted with the Maryland Shipbuilding and Drydock Co. to assist in developing plans for a jumboized AO-22 based on their extensive experience with jumboizing commercial tankers. By 15 Nov 61 Navy and OSD plans called for 2 AO Jumbo conversions in FY 1963, three in FY 1964, and three in FY 1965.

The newest AO-22 type ships, AO 105-109, were selected for the FY 1963 and 164 conversions. In these ships the bow, stern, and amidships deckhouse were separated from the old mid-section and attached to a new 394-foot one that increased the ships' length by 91 feet. Other improvements included a new large counterbalanced rudder, new shorter propeller shafts, and updated fueling and replenishment at sea equipment that used electro hydraulic instead of steam winches. A new auxiliary diesel generator plant with a tall exhaust forward of the aft superstructure was installed to power the new winches, and with the winch load taken off of the steam plant the replenishment speed of the ships rose from about 12-13 to 15-16 knots. Initially only a helo VERTREP pickup spot forward was fitted, but later in their careers many of these ships had the refueling station ahead of the bridge deleted clearing more deck space for full helicopter ops. The full load displacement of the new design as of August 1962 was 34,600 tons and the corresponding hull dimensions were 644' oa, 616' pp x 75' x 35.4'. The contracts for the two FY 1963 ships (AO-106 and 109) were awarded on 7 Mar 63 to the Lockheed Aircraft Corp. for its subsidiary, the Puget Sound Bridge and Dry Dock Co., Harbor Island, Seattle, Wash., and the contracts for the three FY 1964 ships were awarded on 26 Nov 63 to the American Shipbuilding Co., Lorain, Ohio., with preparatory and post-conversion work being done at NSY Boston. For the three FY 1965 ships see AO-51, 98, and 99 in the AO-51 class, which were converted to a different design.

Ship Notes:

AO	Name	MC	Notes
105	MISPILLION	2701	Received "jumbo" conversion at American SB, Lorain, Ohio. New mid-section begun at Lorain 30 Mar 64. Ship placed in commission in reserve at Lorain on 16 April 1965 shortly after arrival. Conversion completed at NSY Boston 1 Jun 66. Decomm. and to MSTS 26 Jul 74. To NDRF 8 Feb 90. In Suisun Bay reserve fleet as of 31 May 10.
106	NAVASOTA	2702	Received "jumbo" conversion at the Puget Sound Bridge and Dry Dock Co., Seattle, Wash. New mid-section laid down 27 May 63 and launched 11 Aug 63 by the Kawasaki Dockyard Co., Kobe, Japan. Ship departed Long Beach 14 Nov 63 for NSY Bremerton, then entered Puget Sound Bridge and Drydock Co. (Lockheed), Harbor Island, Seattle for the conversion. Her amidships deckhouse was transferred to the new bow/mid-section by heavy lift crane 9 January 1964. Conversion completed 28 December 1964. Decomm. and to MSC 13 Aug 75. Out of service 2 Oct 91, to NDRF 19 Nov 91. Withdrawn from NDRF 14 Nov 95 for delivery to Navy buyer.
107	PASSUMPSIC	2703	Received "jumbo" conversion at American SB, Lorain, Ohio. New mid-section begun at Lorain 2 Mar 64. Ship departed Long Beach 12 Oct 64 for the Great Lakes with a stop at the Boston Navy Yard for preliminary work. Placed “in commission, in reserve” 26 November at Lorain with a nucleus crew of 28 men and 4 officers. Departed Lorain 22 November 1965 with a merchant marine master and civilian crew and arrived at Boston 1 December. Conversion completed at NSY Boston 15 Dec 65. Decomm. and to MSTS 24 Jul 73. At Subic Bay during eruption of Mt. Pinatubo 15 Jun 91 and underway replenishment gear rendered unusable by corrosive ash. To NDRF 18 Dec 91 for immediate sale at Yokohama, Japan.
108	PAWCATUCK	2704	Received "jumbo" conversion at American SB, Lorain, Ohio. New mid-section begun at Lorain 1 Jun 64. After preliminary work at Boston, the ship arrived at Lorain on 14 Sep 65. Conversion completed at NSY Boston 16 Dec 66. Decomm. and to MSTS 15 Jul 75. To NDRF 19 Sep 91. Withdrawn 19 Oct 05, scrapping completed 7 Oct 06.
109	WACCAMAW	2705	To AOR-109 11 Dec 50, conversion cancelled, to AO-109 7 May 51. Received "jumbo" conversion at the Puget Sound Bridge and Dry Dock Co., Seattle, Wash. New mid-section laid down 10 Jun 63 and launched 28 Sep 63 by the Kawasaki Dockyard Co., Kobe, Japan. Ship arrived at Seattle on 21 Feb 64 and was scheduled to enter the conversion yard on 29 Feb 64. Conversion completed and ship moved to NSY Puget Sound, Bremerton, Wash., 26 Feb 65, at which time, her status was changed from "in commission, in reserve" to "in commission, active." Decomm. and to MSC 24 Feb 75. To NDRF 11 Oct 89. Withdrawn 11 Oct 05, scrapping completed 20 Jun 06.