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Wartime Requisition and Conversion of Merchant Tankers

Although the War Plans Division anticipated the need to convert large numbers of merchantmen in the event of war, arrangements for the timely requisition of merchant vessels were not instituted until 1939. In August of that year, Congress amended Section 902 of the Merchant Marine Act allowing the maritime commission to requisition or acquire any vessel or watercraft owned by a citizen of the United States for use in a national emergency. The navy promptly worked out a procedural agreement with the commission under which requisitioned vessels could be transferred to the navy.1

Other changes followed. By the beginning of 1941, it had become apparent within the department that the rapid expansion of the fleet would require a corresponding increase in auxiliaries. The Auxiliary Vessels Board was established in January to advise the secretary of the navy on the number and types of auxiliaries needed and to coordinate the requisition and conversion of all merchant ships that were acquired for use as naval auxiliaries.2 In practice, the board reviewed requests submitted by the various operational commands for additional auxiliaries and made recommendations as to what specific merchant ships should be acquired according to need and availability. Acquisitions approved by the Auxiliary Vessels Board were routinely endorsed by the chief of naval operations, then passed on to the secretary of the navy who usually did the same.

The pace of acquiring merchant ships for use as auxiliaries increased dramatically after the Japanese attack on Pearl Harbor. On the day after the attack, President Roosevelt "concerned with the necessity of securing the most effective use of the Merchant Marine to carry out the war," decided to form the Strategic Shipping Board.3 Under his supervision it would establish policies for the wartime employment and allocation of merchant shipping. The strategic board was to be composed of the chairman of the maritime commission, the chief of staff, the chief of naval operations, and presidential advisor Harry


Hopkins. The strategic board was short lived, however, having immediately recommended the formation of an office of shipping coordination with Admiral Land appointed "coordinator."4

This proposal led to the creation of the War Shipping Administration (WSA) created by executive order of 7 February 1942. On that date all of the functions, duties, and powers formally conferred upon the maritime commission with respect to the operation, purchase, charter, insurance, repair, maintenance, and requisition of vessels were transferred to the WSA. Vessels under the control of the WSA were to constitute a pool to be allocated to the army, navy, other federal departments, and the Allies. The administrator of this new organization was given extraordinary powers and responsibilities with the admonition that he "keep the President informed with regard to the progress made in carrying out this order and perform such related duties as the President shall from time to time assign or delegate to him."5 It was no surprise when Roosevelt appointed Admiral Land as chief administrator three days later.

Still chairman of the maritime commission, Land retained control over the huge shipbuilding program already instituted. With his appointment as administrator of the War Shipping Administration, moreover, he emerged as undisputed wartime "czar" of merchant shipping. His first official act after being anointed head of the WSA was to make Commissioner Howard L. Vickery the deputy administrator for ship construction.6 This served to tie the two organizations together. Henceforth, all oilers acquired by the U.S. Navy in World War II would be obtained from one or the other of these two agencies. In the case of merchant vessels already in commission, procurement would proceed via the WSA, while those being built by the maritime commission would be acquired directly from that agency.

Chicopee Class AO-34 and AO-35

The first oilers to be acquired under emergency war regulations were the Standard Oil tankers Esso Trenton and Esso Albany. Ironically, both vessels had been ordered as replacements for their T3 namesakes, which had already been taken over by the navy. First to be completed was the Esso Albany (II). Trials were held on 15 November 1991, and although she was only designed for 151/2 knots, she easily achieved a speed in excess of 17 knots, making her one of the fastest tankers in the United States Merchant Marine.7 The high speed of the Esso Albany and her sister ship the Esso Trenton made them ideal candidates for use as fleet oilers. They were immediately acquired by the maritime commission and transferred to the navy. The Esso Trenton was the first taken over, having been acquired on 3 January, and thus became lead ship of the class even though she had been completed one month after the Esso Albany.8


The Esso Trenton was renamed the Chicopee (AO-34) and quickly commissioned (on 9 February 1942). After a short period as station tanker at Casco Bay, Maine, she was pressed into service as a coastal tanker making runs between the oil ports on the Gulf of Mexico and the East Coast. This was during the height of the tanker sinkings along the East Coast at a time when the shortage of escorts along the Atlantic seaboard and the lack of a convoy system forced ships carrying cargoes critical to the war effort to proceed alone "through waters infested with German submarines."9 It is likely that the Chicopee was chosen for this duty because of her high speed. Earlier studies had shown that ships steaming at speeds of 15 knots or more would be relatively safe from attack by submarine. Steaming at high speed shortened the transit time within a potential attack zone, reducing the likelihood of being detected by an enemy submarine in the area. Even if sighted by an enemy submarine, high-speed steaming greatly complicated the targeting problem for the U-boat making it extremely difficult for the enemy to get into position for the required torpedo solution. Unless the target vessel's track passed directly in front of a lurking submarine, it was very unlikely to be attacked.

The Chicopee's sister ship, the Esso Albany, became the Housatonic (AO-35) when commissioned on 19 February 1942. After a short shakedown cruise, she too was engaged in transporting fuel oil and aviation gasoline from the gulf until July, when she performed her first refueling at sea, servicing the Ranger (CV-4), Augusta (CA-31), and six destroyers that were engaged in ferrying aircraft to North Africa.10

Kennebec Class (AO-37 through 40 and 48) and Mattaponi Class (AO-41 through 44 and 47)

In addition to the Esso Albany and the Esso Trenton, the navy also decided to acquire the Socony tankers Corsicana, Caddo, and Calusa. The first two had been launched in April and October respectively, with Calusa nearing completion. All three had been constructed by Bethlehem Steel Sparrows Point under the maritime commission's second contract for national defense tankers. The increased speed of these vessels (161/2 knots) made them ideally suited for conversion to fleet oilers--as intended when they were laid down. The Corsicana was renamed the Kennebec (AO-37), becoming the lead ship of her class when commissioned on 4 February 1942.

Further steps to acquire additional oilers were taken in March when the Auxiliary Vessels Board advised that "steps be taken to acquire and man at least six [more] tankers" from those nearing completion.11 Recommended for immediate acquisition were two more national defense tankers being built by Bethlehem: the Colina and Conestoga, as well as Kalkay, Ellkay, Jorkay, and Emmkay, four others ordered by Keystone Shipping that were nearing completion at the Sun yard in Chester. First of the Keystone ships to be acquired was the Kalkay.


Housatonic (AO-35) wears an early war camouflage scheme at Norfolk Navy Yard, 26 May 1942. (National Archives)
Housatonic (AO-35) wears an early war camouflage scheme at Norfolk Navy Yard, 26 May 1942. Built by Sun, the Housatonic and her sister the Chicopee (AO-34) were less-powerful versions of the national defense tankers built for the Keystone Transportation Company. (National Archives)

She was renamed the Mattaponi (AO-41), becoming the lead ship of her class.

For some unexplained reason two other national defense tankers, Keystone's Aekay and Socony's Catawba, were not immediately acquired by the navy. They would be acquired in the near future, however, and renamed the Neches and the Neosho upon commissioning. In the meantime the expediencies of war dictated the assignment of additional hull numbers for two more tankers that were suddenly taken into the navy.

Big Horn (AO-45) and Victoria (AO-46)

Hull numbers AO-36 through AO-44 were assigned to the national defense tankers described in the last section. The Aekay and the Catawba should have been included in this group for consistency, but the next unassigned hull number was given the Big Horn. Originally built by Sun Shipbuilding and Dry Dock Company as the SS Gulf Dawn for the Gulf Oil Company, Big Horn was taken into the navy on 31 March 1942 and placed into commission on 16 April at Bethlehem Steel's Shipbuilding Division Pier #4 in Brooklyn, New York. She departed New York on 22 April for the Boston Navy Yard for conversion into a Q-ship under the navy's "Project LQ."12

Q-ships were supposed to act as decoys inviting a close-in torpedo attack. In theory, an exploding torpedo would have little effect on a Q-ship since it would be filled with empty oil drums or some other buoyant cargo designed to keep the vessel afloat in the event of a hit. The strategy was to get the U-boat to surface to finish off the stricken tanker. When this occurred, the Q-ship would open fire from guns


The former Gulf Oil tanker Gulf Dawn, Big Horn (AO-45) masqueraded as a Q-ship for more than a year without once engaging an enemy submarine. (National Archives)
The former Gulf Oil tanker Gulf Dawn, Big Horn (AO-45) masqueraded as a Q-ship for more than a year without once engaging an enemy submarine. (National Archives)

concealed behind false structures or tarpaulins. Adm. Adolphus Andrews, chief of the Eastern Sea Frontier, thought that the best decoy would be a tanker since the enemy had been concentrating on this type of vessel.13 Thus, Big Horn was first deployed operationally as a Q-ship on 27 September 1942. Masquerading under her original identity as Gulf Dawn, she sailed for Guantanamo Bay to join convoy GAT-11 bound for Trinidad. Disguised as a merchant oiler, the Big Horn spent the next twelve months plying the trade routes of the Caribbean and the East Coast without once engaging the enemy. In January 1944, she was transferred to the U.S. Coast Guard and redesignated as a weather ship, WAO-124.

Victoria (AO-46)

By a coincidence of history, the George G. Henry was destined to serve once again with the U.S. Navy as she had in the First World War, albeit with a different name. Still owned by the Standard Oil Company of New Jersey in 1941, she was time chartered in the early months of 1941 to the Standard-Vacuum Oil Company for use in the Far East. Over the next six months, the old ship carried oil from Balikpapan and Palembang in the Dutch East Indies; Tarakan, Borneo; and Miri, Sarawak, to ports in the Philippines, Shanghai, and Hong Kong. Oblivious to the war clouds darkening the skies in the Far East, the George G. Henry steamed toward Manila in the first few days of December 1941 with a cargo of oil.


The venerable tanker had already discharged that part of her cargo consigned for delivery at Manila and was preparing to depart for Cebu in the southern Philippines when Pearl Harbor was attacked on 8 December (7 December, east of the International Date Line). As she stood out of the harbor, the ship received a signal from the army signal station on the island of Corregidor that "No ships are allowed to leave port." By 10 December she had exchanged her civilian colors for a coat of "war gray" paint and lay anchored in Manila Bay when Japanese planes leisurely bombed the Cavite Navy Yard. Several bombs landed near the tanker causing the old girl "to roll and vibrate as if she were breaking up on the rocks." Emerging unscathed, she discharged her remaining cargo and departed under cover of darkness on 15 December with orders from the navy to proceed to Balikpapan, Borneo.14

Steaming southward, the George G. Henry reached Balikpapan on 20 December having made the passage from Manila in four days, eight hours, and three minutes--a record run according to her engineer's log. There she loaded 75,000 barrels of fuel oil--the last cargo of oil to be taken from the Royal Dutch Shell refinery before its capture by the Japanese--and headed for Surabaya on the southeast tip of Java. The George G. Henry reached Surabaya on 26 December and anchored offshore the next day to await further instructions. Under way again on New Years Eve, the heavily laden ship sailed with a heavily guarded convoy bound for Darwin, Australia, making port on 6 January 1942.

During the next three months, the George G. Henry was the only privately owned American-built ship to fuel the warships of the Asiatic Fleet in company with the navy oilers Trinity (AO-13) and ill-fated Pecos (AO-6), the latter bombed and sunk on 1 March 1942.15 Though the George G. Henry fueled the four American survivors of the Battle of the Java Sea soon after they arrived in Australian waters, the demise of the Asiatic Fleet eliminated the need for a tanker in the waters she served, so in the last week in March, the old girl steamed to Melbourne, arriving 8 April.

When her time charter to Standard-Vacuum ran out on 15 April, the ship was taken over by the navy and her master, Capt. Jens G. Olsen--a member of the Naval Reserve--called to active duty as a lieutenant commander and given command of the ship. Captain Olsen knew the ship well for he had sailed in the George G. Henry as a boatswain in 1917 and was said to have been the last civilian crewman to leave the ship when she was taken over by the navy in World War I. Erroneously named the Victor, she was taken to Sydney where her correct name the Victoria was received. Classified as AO-46, the Victoria was fitted out for service at Mort's Dock under the supervision


of the Royal Australian Navy and manned by a navy crew made up from survivors of the Langley, Peary, and Pecos--three casualties of the running fight in the Java Sea.

The Victoria served with distinction throughout the Pacific issuing 2,136,228 barrels of navy special oil. She was decommissioned on 14 December 1945 and struck from the Naval Vessel Register on 8 January 1946.

T2-SE-A1 Tankers Suamico (AO-49) and Tallulah (AO-50)

By June 1942, the navy was desperately short of the tankers needed to support the far-ranging ships that the department was beginning to deploy around the world. Although nine additional tankers had been acquired since the start of war, the total number of oilers in commission had only increased by three. Two, the Neosho and the Pecos, had already been lost to enemy action. In addition, four of the Cimarron class had been taken out of service and were being converted into escort carriers.

On 9 June, the commander in chief, Pacific Fleet, indicated an immediate need for four more fleet oilers.16 The Auxiliary Vessels Board met on 18 June and recommended the acquisition of the Aekay and the Catawba, then operating in the Pacific, and two of the new T2-SE-A1 type, which were just coming down the ways.17 By this point, auxiliaries board recommendations for the acquisition of specific merchant vessels had developed a standard procedure that included final endorsement by the vice chief of naval operations, now responsible for shipbuilding. Once endorsed, the recommendation was passed to the secretary of the navy for action. The auxiliaries board usually consulted with both the War Shipping Administration and the Bureau of Ships before a report was issued. Members of both agencies were usually present at board meetings as was a representative of the commander in chief.

The first T2-SE-A1 tankers acquired by the navy were the Harlem Heights (MC hull number 319) and the Valley Forge (MC hull number 321). Both were built at the Sun yard in Chester, Pennsylvania. The Harlem Heights was delivered to the navy on 27 June 1942, immediately converted to a fleet oiler at the Brooklyn Navy Yard, and renamed the Suamico (AO-49) when commissioned on 10 August 1942. The Valley Forge followed, becoming the Tallulah (AO-50) when commissioned on 5 September 1942. Both vessels were immediately sent to the South Pacific with urgently needed cargoes of fuel oil.

The Ashtabula Class AO-51 through AO-64

Earlier in the war, Emory S. Land, chairman of the maritime commission and former chief constructor, recognized that the navy would need to build additional fleet oilers. Since the navy was already overloaded with combatant construction, Land proposed that the maritime commission build fourteen additional oilers of the Cimarron class directly for the


navy.18 This action was approved by the secretary of the navy on 28 January 1942.19 As a result, funding for fourteen AOs was included in the Large Auxiliaries Section of the Maximum War Effort Building Program passed by Congress on 20 March 1942.20 Two days later, the maritime commission awarded a contract to Bethlehem Steel's Sparrows Point Yard for the construction of fourteen Cimarron-type tankers.21 Sparrows Point was a logical choice for constructing these vessels since it was one of the few prewar yards that had specialized in tanker construction. Sparrows Point had also participated in the earlier Cimarron program having built the Platte, Sabine, and Chemung. As the lead yard in the original T3-S2-A1 program, Sun Shipbuilding probably would have been the preferred yard, but its building ways were already committed to the construction of T2-SE-A1 tankers.

Hull numbers and names for the new tankers were assigned that summer, even though the keel for the lead ship, the Ashtabula, would not be laid until October. At about this time, the Bureau of Ships arranged with the maritime commission to convert the ships to fleet oilers while under construction so that they would be immediately ready for duty when delivered. Fitting out after completion was scheduled to be accomplished at the Norfolk Navy Yard.22

Except for their main armament, which now consisted of one 5-inch, .38 caliber, dual-purpose and four 3-inch, 50-caliber, dual-purpose guns, the Ashtabula and her sister ships were nearly identical to the earlier Cimarron class. The change in armament had been necessitated by a shortage of 5-inch, 38-caliber guns. The huge expansion program initiated in late 1940 had created a tremendous demand for this weapon, which formed the main antiaircraft battery for almost all combatants then under construction or refit. In March 1941, the Antiaircraft Defense Board advised the chief of naval operations that no 5-inch, 38-caliber guns or directors would be available for auxiliaries during the next two years.23 To avoid delays in the conversion of acquired auxiliaries, the board recommended the adoption of the 3-inch, 50-caliber gun with a follow-the-pointer director system as the main antiaircraft battery for auxiliary vessels.24 All auxiliaries (including fleet oilers) converted after this date were armed with four 3-inch guns plus one 5-inch, 38-caliber gun for surface engagement.25A secondary battery of four twin 40 mm antiaircraft guns plus as many 20 mm mounts as could be fitted was later adopted to further strengthen antiaircraft defenses.

Pecos (AO-65), Atascosa (AO-66), and Cache (AO-67)

The Ashtabula would not be commissioned until 7 August 1943, and in the meantime, the continued shortage of fleet oilers forced the navy to acquire and convert additional commercial tankers. The shortage became critical in the late summer and early fall of 1942. In desperation, the navy requisitioned the next two T2-SE-A1 tankers off the


ways as well as the Esso Columbia, one of nine 18,000-ton deadweight tankers ordered from Sun Shipbuilding and Dry Dock Company by the Standard Oil Company of New Jersey in February 1940.26 Built for its Panama Transport Company subsidiary, the contracts issued by Standard Oil called for the construction of five diesel and four steam-powered ships. The Esso Columbia was one of the four ships built with steam-driven geared turbines. This feature plus a design speed of 151/2 knots made her ideally suited for the navy and she was acquired on 12 October 1942. Renamed the Atascosa (AO-66) and commissioned on 9 November 1942, she was the largest oiler (by cargo capacity) operated by the U.S. Navy in World War II. The Atascosa was a single-ship class since no other vessels of her type were acquired by the navy. Her characteristics are listed in table 14.

The Chiwawa Class AO-68 through AO-72

The next five oilers acquired by the navy had been laid down under the expanded emergency shipbuilding program initiated by the "unlimited state of emergency" declared by President Roosevelt on 21 May 1941.27 Appropriations for an additional 50 percent increase in construction funding for merchant tonnage was submitted to Congress in July of that year. The maritime commission's stated goal was to "load the shipbuilding industry with all the ships it [could] absorb as fast as it [could] absorb them."28 After additional funds were approved on 25 August, the commission immediately placed orders for as many vessels as could be scheduled in those yards not committed to naval construction.

Among the new orders placed by the commission was a contract with Bethlehem Steel's Sparrows Point Yard for thirteen tankers (MC hull numbers 516 through 528).29 The ships ordered under this contract were classified as T3-S-A1 tankers in accordance with the commission's standard terminology for designating various types of vessels being built by the commission. They were apparently intended to be duplicates of the Mobilfuel, a Bethlehem-built vessel that had already

Principal Dimensions of Atascosa (AO-66)

Length, overall 547' 3"
Length, between perpendiculars 521' 0"
Beam, molded   70' 0"
Depth, molded to upper deck at side   40' 0"
Draft, molded, summer freeboard   30' 31/2"
Total displacement 23,976 tons
Total deadweight capacity 18,450 tons
Tank capacity, barrels 156,840
Shaft horsepower, max. continuous 9,020
Speed on trials 15.70 knots
Nominal sea speed (trial speed at 80% s.h.p.) 14.80 knots


Atascosa (AO-66), the former Esso Columbia II, was the only ship of her class to be taken over by the navy during the tanker shortage of 1942. (National Archives)
Atascosa (AO-66), the former Esso Columbia II, was the only ship of her class to be taken over by the navy during the tanker shortage of 1942. (National Archives)

demonstrated its value in commercial operation. The maritime commission was not very concerned about their lack of speed, since the record suggests that they were ordered with the same size power plants used on the earlier Mobilfuel and its sister ships.30 These were rated at 4,000 s.h.p.--enough power for a normal speed of 13 knots. A decision to enlarge the size of the engines must have been made sometime after January 1942, however, as all T3-S-A1 types were subsequently delivered with engines rated at 7,000 s.h.p. raising their speed of 15 knots.31 This change probably occurred before the keel for the first vessel was laid and was certainly influenced by wartime needs. The first five to be completed were quickly taken over by the navy for conversion into fleet oilers. The first of these, the Chiwawa (AO-68), was acquired and commissioned on Christmas Eve 1942. The next four were completed in monthly intervals and commissioned as the Enoree (AO-69), Escalante (AO-70), Neshanic (AO-71), and Niobrara (AO-72).


AO-73 through AO-79

On 7 August 1942 the Auxiliary Vessels Board had recommended that the navy acquire and convert twelve additional oilers "now building" at the rate of two per month starting that month.32 Even though the board recognized the advantage of a single standard type, it realized that the navy would have to accept a number of different ships in order to obtain the required number in the time allotted. The navy would have preferred to have obtained as many of the Chiwawa class as possible since the greater speed of these vessels (15 knots) was "in accordance with the expressed desires of the commander-in-chief."33Although Bethlehem had orders for fifteen of this type, only five could be completed in time to meet the navy's timetable for delivery. To make up the difference, a decision was made to procure seven additional T2-SE-A1 tankers from those under construction for the maritime commission at the Sun yard even though these vessels were half a knot slower

Chiwawa (AO-68), taken 20 June 1943. The first of the Bethlehem-built T3-S-Als, she carried an extensive AA suite of four 3-inch 50s, two twin 40 mms, twelve 20 mms, and a single 5-inch 38 gun at the stern. (National Archives)
Chiwawa (AO-68), taken 20 June 1943. The first of the Bethlehem-built T3-S-Als, she carried an extensive AA suite of four 3-inch 50s, two twin 40 mms, twelve 20 mms, and a single 5-inch 38 gun at the stern. (National Archives)


than the Chiwawa. Hull numbers for all seven of these Suamico-class vessels were assigned at one time. The first two, the Saranac (AO-74) and the Saugatuck (AO-75), were acquired on the last day of 1942. Both were subsequently commissioned in February 1943. They were followed by the Millicoma (AO-73), Schuylkill (AO-76), Cossatot (AO-77), Chepachet (AO-78), and Cowanesque (AO-79).

Escambia Class AO-80 through AO-86

By the early summer of 1942, commercial-tanker sinkings in the Atlantic were exceeding the rate of new tanker construction. Even though the number of shipways committed to the construction of tankers had been greatly increased during the prior year, the number scheduled for delivery was still below demand. Both of the older yards that had specialized in tankers prior to the war--the Sun yard at Chester and the Bethlehem yard at Sparrows Point--had already expanded beyond their original capacity. Two new yards, the Kaiser Swan Island yard in Oregon and the Alabama Dry Dock and Shipbuilding yard in Mobile, had also been committed solely to the construction of the T2-SE-A1 design. To meet the need for even more tanker hulls, the maritime commission decided to shift the production in the new Marinship yard (recently established at Sausalito, California) from Liberty Ships, as originally intended, to tankers.

On 27 July 1942, Commissioner Vickery visited the new yard for the first time and announced that it would be converted to tanker construction.34 The first order for tankers was not received until 26 October.35 On that date the maritime commission issued Marinship a contract to build twenty-two T2 tankers. Nine of these would eventually be converted to navy oilers, although this was not known at the time the orders were placed.

While the commission's staff was planning the conversion of the Marinship yard to tanker construction, the shortage of main propulsion equipment became critical. Only two companies had facilities for manufacturing the 6,600-horsepower, turboelectric propulsion units utilized in the T2-SE-A1 design, and both were already producing at peak capacity. It was determined, however, that the General Electric Company would be able to furnish 10,000-horsepower units in time to meet the launching schedules desired by the commission. These had been developed for the ten P2-SE2-R1 "Admiral Class" transports that the maritime commission had ordered from the Bethlehem yard in Alameda in February.36 To meet the urgent need for more tankers, it was decided to incorporate these larger units in the tankers to be built by Marinship. Thus the development of the 10,000-horsepower, T2-SE-A2 design was awarded to Marinship.

In awarding the contract for these ships, the maritime commission emphasized that Marinship was to incorporate as much of the Sun


Shipbuilding and Dry Dock Company T2-SE-A1 design as possible.37Sun tracings of the T2-SE-A1 design had been received in Sausalito by late October.38 They were immediately reviewed by Marinship's Engineering Department in order to determine what changes would be needed to incorporate the 10,000-horsepower power plant. Steel requirements for the hull were almost identical to the original version and required little change. Redesigning the machinery arrangement to allow for the larger power plant presented considerable difficulty, however, due to the limited space available within the engine room and a decision by the maritime commission to add an extra bulkhead at Frame 19. This latter requirement necessitated the elimination of the original shaft-alley arrangement wherein the aft bilge and fire pumps, salt-water service pumps, main feed pumps, and main thrust bearing were located in a single convenient and readily accessible location immediately aft of the lower engine room space. In lieu of the original arrangement, the aforementioned pumps had to be crowded into the space between Frame 19 and Frame 25 on both sides of the shaft, and the thrust bearing had to be moved to the forward end of the main propulsion motor, thus making the lower machinery space more crowded. Other changes were made in the design of the plant and in the heat balance of the power plant itself, which required changes to the basic design. The most important of these were (1) changing the boilers from transverse drum-section header type with air heaters to fore and aft drum-bent tube-type with economizers; (2) elimination of the second-stage heater because of the addition of the economizer; (3) addition of a drain cooler; (4) turbine-driven, in lieu of motor-driven, forced draft fans; (5) installation of a contaminated evaporator to provide heating steam for all contaminated (oil) heating exclusive of cargo oil heating; (6) installing the main turbogenerator set with the turbine forward instead of aft; and (7) supporting the main condenser on an independent foundation instead of suspending it from the main turbine.39 All were major design changes departing from the basic T2-SE-A1 design.

Toward the end of 1942, the navy decided to acquire the first nine T2-SE-A2 tankers completed by Marinship. The Escambia was the first of these. Launched on 24 April 1943, she was delivered to the maritime commission on 30 June and immediately transferred to the navy on the same day. Plans for converting the Escambia and eight other Marinship tankers still to be delivered were drawn under separate contract by the Matson Company in San Francisco.40Because of the considerable amount of work that was required for conversion, the Escambia (AO-80) was not commissioned until 28 October.

Fleet oilers required a significant amount of special equipment not carried by commercial oilers in addition to more accommodations for


the much larger crew needed for a navy ship. Conversion of the T2-SE-A2s required few alterations within the machinery spaces, although the fire-fighting systems were completely revised and certain damage-control precautions added. Changes outside the machinery spaces included modification of the cargo system so fuel oil, gasoline, and diesel oil could be handled separately, an enlarged distilling plant, addition of an emergency diesel fire pump, and installation of fueling-at-sea gear. Considerable changes and additions were also made to the electrical system.

The last of the nine Escambia-class tankers completed by Marinship was the Tomahawk (AO-88). Launched on 10 August 1943, she was delivered on 24 October 1943, but was not commissioned until 16 April 1944. By then Marinship had begun to complete its second group of eighteen T2-SE-A2s.41

Pasig (AO-89) and Shikellamy (AO-90)

The next two oilers acquired by the U.S. Navy were each one of a kind. The Pasig (AO-89), built in 1917 as the J. C. Donnell, was acquired on 22 January 1943. She was intended to serve as a station tanker, but was replaced by concrete barges. The Shikellamy (AO-90) was the former merchant tanker Daniel Pierce, owned and operated by the Sinclair Refining Company. She was acquired by the navy through the War Shipping Administration on 26 March 1943 on a bare-boat basis. She was converted for naval use by the Tampa Shipbuilding Company and placed into commission on 14 April. Her classification was changed from AO-90 to AOG-47 in July while in dry dock at Balboa, Canal Zone. The Shikellamy operated in the Southwest Pacific throughout the war and was returned to her owners in January 1946.

AO-91 through AO-90

Of the eighteen vessels in the second group of T2-SE-A2 tankers awarded to Marinship, the last six were assigned to the navy as AOs. Marinship was awarded a separate contract to convert them to fleet oilers based on the Matson plans used to convert the first group of Marinship-built AOs. Except for some minor design changes, these ships were identical to the Escambia class completed earlier. The Pasig, launched as the Mission San Xavier, was the first to be completed. She was redesignated as a water tanker and commissioned as AW-3. The Ataban (AO-92), the next to be launched, was also redesignated as a water tanker and commissioned as AW-4. Both vessels were modified to distill and carry fresh water and were designed to supply boiler feed and drinking water to ships and shore stations without other source of supply. The need for this type of vessel evolved out of the large-scale amphibious operations then being conducted in the Pacific. The lack of natural sources on the islands being invaded, the large number of troops involved, and the presence of a large number


of small ships having minimal distilling capabilities created a shortage of water for both ships and men.

The first navy oiler actually commissioned at Marinship was the Soubarissen (AO-93) on 5 January 1945. The Tamalpais (AO-96) was the final member of this group of tankers to be launched and the last oiler acquired before the war officially ended.


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