The Cimarron-class oilers were an underway replenishment class of oil tankers which were first built in 1939 as "National Defense Tankers," United States Maritime Commission Type T3-S2-A1, designed "to conform to the approved characteristics for naval auxiliaries in speed, radius and structural strength", anticipating their militarization in the event of war. "Tentative plans had been reached with the Standard Oil Company of New Jersey to build ten high-speed tankers with the government paying the cost of the larger engines needed for increased speed. By the first week in December [1937], Standard Oil had solicited and received bids from a number of yards providing for the construction of a number of 16,300-ton (deadweight) capacity tankers. Bids were requested for two versions: a single-screw design of 13 knots and a twin-screw design of 18 knots. The price difference between the two would be used to establish the government's cost subsidy for greater speed. Plans and specifications for both designs were prepared for Standard Oil by naval architect E. L. Stewart. It seems certain that the design for the 18-knot tanker (Standard Oil Co. of New Jersey Design No. 652 NDF) evolved out of the bureau's (C&R) design for a fleet oiler."[1]
Three of the original twelve ships were commissioned directly into the Navy at launch in 1939; the remainder entered merchant service with Standard Oil of New Jersey and Keystone Tankships before being acquired under the Two-Ocean Navy Act of July 1940. A further eighteen were built for the Navy between 1943 and 1946, with five additional units, sometimes called the Mispillion class, built to the slightly larger Type T3-S2-A3 design.
Four of the Cimarrons were converted to escort carriers in 1942; two others were sunk by enemy action.
| +Ships in class[2] | |||||||
| Name | Hull Number | Builder | Laid down | Launched | Commissioned | Decommissioned | Fate |
|---|---|---|---|---|---|---|---|
| AO-22 | Sun Shipbuilding & Drydock Co. | 18 April 1938 | 7 January 1939 | 20 March 1939 | 1 October 1968 | Struck 10 October 1968, Sold for scrap 1969 | |
| AO-23 | Federal Shipbuilding and Drydock Company, Kearny, New Jersey | 22 June 1938 | 29 April 1939 | 7 August 1939 | Scuttled, Battle of the Coral Sea, 11 May 1942 | ||
| AO-24 | Bethlehem Shipbuilding Corporation, Sparrow Point Shipyard | 14 September 1938 | 8 July 1939 | 1 December 1939 | 19 September 1970 | Struck 25 September 1970, Sold for scrap 14 May 1971 | |
| AO-25 | 18 September 1939 | 27 April 1940 | 5 December 1940 | 20 February 1969 | Struck 1 December 1976, Sold for scrap 1 August 1983 | ||
| AO-26 | Newport News Shipbuilding | 5 February 1940 | 18 September 1940 | 28 April 1941 | 20 December 1968 | Struck 2 September 1969, Sold for scrap 24 July 1970 | |
| AO-27 | 16 January 1939 | 29 September 1939 | 29 October 1940 | 19 December 1969 | Struck 19 December 1969, Sold for scrap 3 August 1970 | ||
| AO-28 | Federal Shipbuilding and Drydock Company, Kearny, New Jersey | 13 March 1939 | 4 November 1939 | Converted to Sangamon-class escort carrier | |||
| AO-29 | Sun Shipbuilding & Dry Dock Co. | 31 May 1938 | 4 March 1939 | Converted to Sangamon-class escort carrier | |||
| AO-30 | Bethlehem Shipbuilding Corporation, Sparrow Point Shipyard | 20 December 1938 | 9 September 1939 | 3 July 1941 | 18 September 1970 | Struck 18 December 1970, Sold for scrap 14 May 1971 | |
| AO-31 | Sun Shipbuilding & Dry Dock Co. | 10 July 1938 | 1 April 1939 | Converted to Sangamon-class escort carrier | |||
| AO-32 | Newport News Shipbuilding | 8 May 1939 | 26 January 1940 | 19 June 1941 | 15 May 1975 | Struck 15 May 1975, Sold for scrap 16 October 1975 | |
| AO-33 | Federal Shipbuilding and Dry Dock Company, Kearny, New Jersey | 3 June 1938 | 4 March 1939 | Converted to Sangamon-class escort carrier | |||
| AO-51 | Bethlehem Shipbuilding Corporation, Sparrow Point Shipyard | 1 October 1942 | 22 May 1943 | 7 August 1943 | 30 September 1982 | Struck 6 September 1991, Partially scrapped 1995, expended as SINKEX target ship, 15 October 2000 | |
| AO-52 | 16 November 1942 | 12 June 1943 | 21 September 1943 | 14 August 1973 | Struck 14 August 1973, Sold for scrap 10 December 1973 | ||
| AO-53 | 2 January 1943 | 25 August 1943 | 12 October 1943 | 15 December 1973 | Struck 15 December 1973, Sold for scrap 5 April 1974 | ||
| AO-54 | 3 February 1943 | 2 October 1943 | 10 November 1943 | 18 December 1969 | 1 December 1976, Sold for scrap 26 May 1982 | ||
| AO-55 | 9 March 1943 | 19 October 1943 | 30 November 1943 | 17 March 1970 | Struck 17 March 1970, Sold for scrap 2 November 1970 | ||
| AO-56 | 25 May 1943 | 20 November 1943 | 22 December 1943 | 18 December 1970 | Struck 1 December 1976, Sold for scrap, 25 October 1992 | ||
| AO-57 | 15 June 1943 | 21 December 1943 | 12 February 1944 | 22 November 1982 | Struck 12 December 1992, Sold for scrap 18 September 1995 | ||
| AO-58 | 28 August 1943 | 18 February 1944 | 6 April 1944 | 14 August 1973 | Struck 14 August 1973, Sold for scrap 10 December 1973 | ||
| AO-59 | 5 October 1943 | 28 March 1944 | 19 May 1944 | Sunk on 20 November 1944 | |||
| AO-60 | 31 October 1943 | 29 April 1944 | 19 June 1944 | 2 July 1973 | Struck 1 July 1973, Sold for scrap 5 March 1975 | ||
| AO-61 | 24 November 1943 | 31 May 1944 | 19 July 1944 | 1 July 1973 | Struck 1 July 1974, Sold for scrap 22 January 1975 | ||
| AO-62 | 23 December 1943 | 10 July 1944 | 25 August 1944 | 4 May 1972 | Struck 21 February 1992, Sold for scrap 1 July, 2010 | ||
| AO-63 | 3 May 1944 | 21 October 1944 | 30 November 1944 | 14 August 1973 | Struck 14 August 1973, Sold for scrap 15 July 1974 | ||
| AO-64 | 5 June 1944 | 6 January 1945 | 24 February 1945 | 15 April 1975 | Struck 15 April 1975, Sold for scrap 16 October 1975 | ||
| AO-97 | 26 October 1944 | 14 April 1945 | 21 August 1945 | 21 December 1970 | Struck 1 June 1973, Sold for scrap 22 March 1976 | ||
| AO-98 | 30 November 1944 | 2 June 1945 | 10 October 1945 | 28 February 1990 | Struck 18 July 1994, Sold for scrap to Able UK and towed to Hartlepool UK, 2003. Scrapping complete, April 2010. | ||
| AO-99 | 11 January 1945 | 6 July 1945 | 3 December 1945 | 2 October 1989 | Struck 31 August 1992, Sold for scrap to Able UK and towed to Hartlepool UK, 2003. Scrapping complete, August 2010. | ||
| AO-100 | 25 January 1945 | 28 August 1945 | 22 January 1946 | 13 June 1972 | Struck 1 July 1972, Sold for scrap 1 March 1973 |
There is some controversy about the MARAD Type T3-S2-A3 oilers being a class of their own, the Mispillion class. This is further complicated by the fact that these ships were jumboized in the 1960s, together with,, and, for some then comprising the Ashtabula class – sometimes with or without the Mispillions. Adding to the confusion, some sources refer to the 18 war-construction repeat Cimarrons as the Ashtabula class.
The argument for separation of Ashtabula, Caloosahatchee, and Canisteo as a separate class from Mispillion, Navasota, Passumpsic, Pawcatuck, and Waccamaw can be made by comparing the actual design and equipment of the two groups. The Ashtabulas and Mispillions are quite different in appearance and UNREP equipment. The three Ashtabulas have a fully enclosed well deck, no exterior deck walkways on the forward superstructure, a tunnel through the forward superstructure to allow the movement of cargo to the forward deck, two sets of STREAM gear, the second being forward of the forward superstructure, and no helo deck on the bow. The Mispillions have none of these features.
| +Ships in class[3] | ||||||||
| Name | Hull Number | Builder | Laid down | Launched | Commissioned | Jumboized | Decommissioned | Fate |
|---|---|---|---|---|---|---|---|---|
| AO-105 | Sun Shipbuilding & Drydock Co. | 14 February 1945 | 10 August 1945 | 29 December 1945 | 1965-66 | 1990 | Struck 15 February 1995, Sold for scrap December 2011 | |
| AO-106 | 22 February 1945 | 30 August 1945 | 27 February 1946 | 1963-64 | 1991 | Struck 2 January 1992, Sold for scrap 25 October 1995 | ||
| AO-107 | 8 March 1945 | 31 October 1945 | 1 April 1946 | 1964-65 | 1991 | Struck 17 December 1991 or 18 December 1991, Sold for scrap 19 December 1991 | ||
| AO-108 | 22 March 1945 | 19 February 1946 | 10 May 1946 | 1965-66 | 1991 | Struck 21 September 1991, Sold for scrap 21 September 2005 | ||
| AO-109 | 28 April 1945 | 30 March 1946 | 25 June 1946 | 1964-65 | 1989 | Struck 11 October 1991, Sold for scrap and towed to Brownsville, TX, 11 October 2005. |
From 1964 through 1967, eight of the T3 type oilers were "jumboized" in order to increase their capacity to 180,000 barrels, which the Navy considered the amount necessary to support a supercarrier and its jet air wing's fuel needs. The conversion of the Mispillion sub-class was designed under project SCB 223, while that of the Ashtabula sub-class was designed under SCB 706.[4] This jumboization was done by cutting the ships in two with cutting torches, then the aft section was pulled away, and new mid-body moved in and welded to the bows and sterns. After many other cutting and welding modifications a new long ship was created; a helipad was also fitted forward on the five Mispillions. Ashtabula, Caloosahatchee and Canisteo were jumboized after the five Mispillions and were given a limited capacity for ammunition and dry stores as well as a new midships superstructure and full scantlings, whereas AO-105 through 109 retained their shelter-deck configuration.
The US Navy's mastery of underway replenishment and its ability to refuel the fleet at sea without returning to port was a major factor in its successful operations against the Japanese during the Second World War. As the largest and fastest of the Navy's oilers, the Cimarrons were the principal class employed in direct support of the task forces. Many of the Cimarron class continued to sustain this function through the Korean and Vietnam wars as well, with the "jumbos" serving right up to the Persian Gulf War.
US Navy captains who had flight status ("wings") were eligible to command aircraft carriers, but it was a prerequisite that the officer in question first have a "deep-draft" command; accordingly the Navy assigned these officers to oilers which had a similar draft.