Cimarron-class oiler (1939)

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."

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 (CVE) in 1942; two others were sunk by enemy action.

Ships

 * USS Cimarron (AO-22); launched & commissioned 1939, decommissioned & struck 1968, sold for scrap 1969
 * USS Neosho (AO-23); launched & commissioned 1939, sunk during the Battle of the Coral Sea, 1942
 * USS Platte (AO-24); launched & commissioned 1939, decommissioned & struck 1970, scrapped 1971
 * USS Sabine (AO-25); ex-Esso Albany, launched & commissioned 1940, decommissioned 1970, struck 1971, sold 1983
 * USS Salamonie (AO-26); ex-Esso Columbia, launched 1940, commissioned 1941, struck 1969, scrapped 1970
 * USS Kaskaskia (AO-27); ex-Esso Richmond, launched 1939, commissioned 1940, decommissioned 1969, sold for scrap 1970
 * USS Sangamon (AO-28); ex-Esso Trenton, launched 1939, commissioned 1940, converted to CVE-26 1942
 * USS Santee (AO-29); ex-Seakay, launched 1939, commissioned 1940, converted to CVE-29 1942
 * USS Chemung (AO-30); ex-Esso Annapolis, launched 1939, commissioned 1941, decommissioned 1970, struck 1971, scrapped
 * USS Chenango (AO-31); ex-Esso New Orleans, launched 1939, commissioned 1941, converted to CVE-28 1942
 * USS Guadalupe (AO-32); ex-Esso Raleigh, launched 1940, commissioned 1941, decommissioned 1974, struck & scrapped 1975
 * USS Suwannee (AO-33); ex-Markay, launched 1939, commissioned 1941, converted to CVE-27 1942
 * USS Ashtabula (AO-51); launched & commissioned 1943, jumboized 1968, decommissioned 1982, struck 1991, partially scrapped 1995, expended as target 2000
 * USS Cacapon (AO-52); launched & commissioned 1943, decommissioned, struck and sold for scrap 1973
 * USS Caliente (AO-53); launched & commissioned 1943, decommissioned & struck 1973, sold for scrap 1974
 * USS Chikaskia (AO-54); launched 1942, commissioned 1943, decommissioned 1969, struck 1976, sold 1982
 * USS Elokomin (AO-55); launched & commissioned 1943, decommissioned, struck & scrapped 1970
 * USS Aucilla (AO-56); launched & commissioned 1943, decommissioned 1970, struck 1976, scrapped 1992
 * USS Marias (AO-57); launched 1943, commissioned 1944, transferred to MSC 1973, retired 1982, struck 1992, sold for scrapping 1995
 * USS Manatee (AO-58); launched & commissioned 1944, decommissioned, struck & sold for scrapping 1973
 * USS Mississinewa (AO-59); launched and commissioned 1944, torpedoed and sunk at Ulithi 1944
 * USS Nantahala (AO-60); launched & commissioned 1944, decommissioned & struck 1973, sold for scrapping 1975
 * USS Severn (AO-61); launched and commissioned 1944, decommissioned 1973, struck 1974, sold for scrapping 1975
 * USS Taluga (AO-62); launched and commissioned 1944, transferred to MSC 1972, struck 1992, to MARAD 1999, scrapped 2010
 * USS Chipola (AO-63); launched & commissioned 1944, struck 1973, sold 1974
 * USS Tolovana (AO-64); launched & commissioned 1945, decommissioned, struck & sold for scrapping 1975
 * USS Allagash (AO-97); launched & commissioned 1945, decommissioned 1970, struck 1973, sold for scrapping 1976
 * USS Caloosahatchee (AO-98); launched & commissioned 1945, jumboized 1966, decommissioned 1990, struck 1994, towed to Hartlepool UK 2003, scrapping complete March 2010
 * USS Canisteo (AO-99); launched & commissioned 1945, jumboized 1967, decommissioned 1989, struck 1992, towed to Hartlepool UK 2003, scrapping complete August 2010
 * USS Chukawan (AO-100); launched 1945, commissioned 1946, decommissioned & struck 1972, sold for scrapping 1973

Converted to Sangamon-class escort carriers in 1942:


 * USS Sangamon (CVE-26); ex-Esso Trenton, launched 1939, commissioned 1940 as AO-28, decommissioned 1945, sold for commercial service 1948
 * USS Suwannee (CVE-27); ex-Markay, launched 1939, commissioned 1941 as AO-33, decommissioned 1947, sold for scrap 1961
 * USS Chenango (CVE-28); ex-Esso New Orleans, launched 1939, commissioned 1941 as AO-31, decommissioned 1946, sold 1960
 * USS Santee (CVE-29); ex-Seakay, launched 1939, commissioned 1940 as AO-29, decommissioned 1946, struck 1959, scrapped 1960

"Mispillion" and "Ashtabula" classes
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 USS Ashtabula (AO-51), USS Caloosahatchee (AO-98), and USS Canisteo (AO-99), 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.


 * USS Mispillion (AO-105); launched & commissioned 1945, jumboized 1965, transferred to MSC 1974, retired 1990, struck 1995, NDRF, sold for scrapping Dec. 3, 2011
 * USS Navasota (AO-106); launched 1945, commissioned 1946, jumboized 1964, transferred to MSC 1975, retired 1991, struck 1992, sold for scrapping 1995
 * USS Passumpsic (AO-107); launched 1945, commissioned 1946, jumboized 1965, transferred to MSC 1973, retired, struck & sold for scrapping 1991
 * USS Pawcatuck (AO-108); launched 1945, commissioned 1946, jumboized 1965, transferred to MSC 1975, retired & struck 1991, sold for scrapping 2005
 * USS Waccamaw (AO-109); launched 1945, commissioned 1946, jumboized 1965, transferred to MSC 1975, retired 1989, struck 1991, sold for scrapping 2005

Jumboization
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. 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. 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.

Importance
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.