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 . Converted to s in 1942 : " " 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 , , and , for some then comprising the " Ashtabula " - class - sometimes with or without the " Mispillion " s . Adding to the confusion , some sources refer to the 18 war - construction repeat " Cimarrons " as the " Ashtabula " - class . 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 .