Construction
The Suamicos
Just before the war the United States Maritime Commission had developed a standardized tanker design, the T2, which could be mass-produced in time of war, and militarized as needed for naval auxiliaries. The T2 was given sufficient engine power to attain 16.5 knots (30.6 km/h), which the Navy considered the minimum required for a fleet oiler.
The T2 and its variants (see Kennebec-class oiler) however used conventional geared steam turbine propulsion, and with the massive expansion of US shipbuilding, a production bottleneck developed: the limited availability of the precision machinery needed to manufacture reduction gearing. [1] The Sun Shipbuilding and Drydock Company of Chester, Pennsylvania worked around this problem by designing a T2 variant which used turbo-electric propulsion; that is, the steam turbine ran a generator, which in turn powered electric drive motors without the need for gearing. [2] Compared to conventional geared turbines turbo-electric systems produced less power for the same size and weight, so Sun's T2-SE (steam-electric)-A1 design could only develop 6,000 shaft horsepower for 14 knots, but since commercial tankers typically only did 12–13 knots this was acceptable. Acknowledging the practicality of the design for merchant service, the Maritime Commission ordered 72 T2-SE-A1s from four shipyards in May 1941. Ultimately 536 T2-SEs would be built, the most-produced tanker design in history.
On 9 June 1942, Admiral Nimitz indicated an immediate need for four more fleet oilers. The War Shipping Board requisitioned the last remaining T2 and T2-A tankers still in commercial service, Catawba and Aekay, and, with reservations given their limited speed, two nearly-complete Sun T2-SE-A1s, Harlem Heights and Valley Forge. These were commissioned as USS Suamico (AO-49) and Tallulah (AO-50). In August, with the fourteen repeats of the big 18-knot (33 km/h) Cimarron class still a year from completion, the Navy took over the next two T2-SEs off Sun's ways, Oriskany and Stillwater, renamed Pecos (AO-65) and Cache (AO-67). On 7 August the Auxiliary Vessels Board recommended that the Navy add two oilers per month for a period of six months. While fifteen of the 15.3-knot T3-S-A1 type had been ordered by the Maritime Commission, only five (the Chiwawa class) would be completed in time, and so the Navy filled out the requirement with another seven T2-SE-A1s, AO-73 through 79, the first of which were acquired on the last day of 1942.
The Escambias
During the spring and summer of 1942, a period German U-boat captains called "the happy time," tankers were being sunk in the Atlantic faster than they could be built. In response, on 27 July the Maritime Commission decided that the new Marinship yard at Sausalito, California, created to produce Liberty ships, would construct T2-SE tankers instead, with an initial order of 22. However, there simply were not enough of the specified generator plants available. On the other hand, General Electric indicated its ability to provide the larger 10,000 hp (7,500 kW) turbo-electric plants designed for the P2-SE2-R1 Admiral-class fast transports, and Marinship's naval architects modified the original Sun design to make room for the larger installation. The Marin T2-SE-A2's engineering spaces were cramped, but it all fit; better yet, the new design was capable of speeds in excess of 15 knots (28 km/h). By the end of the year the Navy, unenthusiastic about the slower Suamicos, was eager to acquire the more powerful new version and requisitioned the first nine, which were launched starting in April 1943 and after conversion as fleet oilers started commissioning in October, as AO-80, USS Escambia, through AO-88.
The Maritime Commission followed its initial order of 22 T2-SE-A2s with another for 18 more; the Navy would acquire six of these as AO-91 through 96. By the time these started entering service in late 1944 the Navy was finding that fresh water was becoming more of a problem in the Pacific than fuel; accordingly Pasig and Abatan were converted to water-distilling ships (AW-3 and 4), and Soubarissen into a water tanker.
The A3s
On 16 October 1944 the Chief of Naval Operations recommended that the Maritime Commission building program for the last half of 1945 be modified to provide for the construction of nine additional oilers for the Navy. On 2 November 1944 the MC added to its program the construction of four ships at Marinship to the 10,000-horsepower T2-SE-A3 design together with five T3s at Bethlehem Steel. The T2-SE-A3 type was essentially an A2 built to Navy standards from the start rather than being modified later (converting a civilian tanker to a Navy fleet oiler represented an additional 4–6 months' work after delivery). The last three ships were completed without these features, after the Navy canceled them in the waning days of the war.
USS Ponaganset AO-86/AOG-86) was a Suamico-class fleet oiler, of the T2-SE-A2 tanker hull type, serving in the United States Navy during World War II. Laid down on 27 April 1942, she was named for the Ponaganset River located in Foster and Glocester, Rhode Island.
The T2 tanker, or T2, was a class of oil tanker constructed and produced in large numbers in the United States during World War II. Only the T3 tankers were larger "navy oilers" of the period. Some 533 T2s were built between 1940 and the end of 1945. They were used to transport fuel oil, diesel fuel, gasoline and sometimes black oil-crude oil. Post war many T2s remained in use; like other hastily built World War II ships pressed into peacetime service, there were safety concerns. As was found during the war, the United States Coast Guard Marine Board of Investigation in 1952 stated that in cold weather the ships were prone to metal fatigue cracking, so were "belted" with steel straps. This occurred after two T2s, Pendleton and Fort Mercer, split in two off Cape Cod within hours of each other. Pendleton's sinking is memorialized in the 2016 film The Finest Hours. Engineering inquiries into the problem suggested the cause was poor welding techniques. It was found the steel was not well suited for the new wartime welding construction. The high sulfur content made the steel brittle and prone to metal fatigue at lower temperatures.
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 evolved out of the bureau's (C&R) design for a fleet oiler."
SS Mission Capistrano was a Type T2-SE-A2 tanker built for the United States Maritime Commission during World War II. After the war she was acquired by the United States Navy as USS Mission Capistrano (AO-112). Later the tanker transferred to the Military Sea Transportation Service as USNS Mission Capistrano (T-AO-112). She was a Mission Buenaventura-class oiler and was named for San Juan Capistrano in San Juan Capistrano, California.
SS Mission Buenaventura was a Type T2-SE-A2 tanker built for the United States Maritime Commission during World War II. After the war she was acquired by the United States Navy as USS Mission Buenaventura (AO-111). Later the tanker transferred to the Military Sea Transportation Service as USNS Mission Buenaventura (T-AO-111). The lead ship in her class of fleet oilers, she was named for Mission San Buenaventura located in Ventura, California.
SS Mission Purisima was a Type T2-SE-A2 tanker built for the United States Maritime Commission during World War II. After the war, she was acquired by the United States Navy as USS Mission Purisima (AO-118). Later the tanker transferred to the Military Sea Transportation Service as USNS Mission Purisima (T-AO-118). She was a member of the Mission Buenaventura-class oiler and was named for Mission La Purísima Concepción near Lompoc, California.
USNS Redstone, designated T‑AGM‑20, was a tracking ship assigned to Apollo space mission support under the control of the Eastern Range. For a brief time during conversion the ship was named Johnstown with the designation AGM‑20.
USNS Mission Los Angeles (T-AO-117) was a Mission Buenaventura-class oiler that served in the United States Navy. The ship was originally intended as USS Conecuh (AO-103) for the U.S. Navy but her acquisition was canceled. The ship, a Type T2-SE-A3 tanker, was completed as SS Mission Los Angeles and delivered after the end of World War II. The tanker was acquired by the U.S. Navy in 1948 as USS Mission Los Angeles (AO-117), but was transferred to the Military Sea Transport Service upon its creation in 1949. The ship was named for Nuestra Señora Reina de los Angeles Asistencia, she was the only U.S. Naval Vessel to bear the name.
USNS Mission Santa Ana (T-AO-137) was a Mission Buenaventura-class oiler that served in the United States Navy. The ship was originally intended as USS Concho (AO-102) for the U.S. Navy but her acquisition was canceled. The ship, a Type T2-SE-A3 tanker, was completed as SS Mission Santa Ana and delivered after the end of World War II. The tanker was acquired by the U.S. Navy in 1948 as USS Mission Santa Ana (AO-137), but was transferred to the Military Sea Transport Service upon its creation in 1949. The ship was named for the Santa Ana Estancia, she was the only U.S. Naval Vessel to bear the name.
SS Mission Carmel was a Type T2-SE-A2 tanker built for the United States Maritime Commission during World War II. After the war she was acquired by the United States Navy as USS Mission Carmel (AO-113). Later the tanker transferred to the Military Sea Transportation Service as USNS Mission Carmel (T-AO-113). She was a member of the Mission Buenaventura-class oiler and was one of two named for Mission San Carlos Borroméo de Carmelo located in Carmel-by-the-Sea, California, the other being Mission San Carlos.
USS Kennebago (AO-81) was an Escambia-class replenishment oiler serving in the United States Navy during World War II. Laid down on 9 January 1943, she was named for the Kennebago River located in Rangeley, Maine.
USS Soubarissen (AO-93) was an Escambia-class fleet oiler converted to a water tanker, named for a chief of the "Neutral" Indian Nations which, although a part of the Iroquois confederation, were called "neutral" by the French because they took no part in the wars of the Iroquois and Hurons. The area he governed included the oil fields of northwestern Pennsylvania and western New York. The knowledge of the oil seepages there was well known among the Indians, and it was declared neutral ground so all Indians could obtain oil for medicinal and domestic purposes without danger or interference. In 1627, Joseph de La Roche Daillon heard of the oil springs and made an expedition to visit them. He was kindly received by Chief Soubarissen, shown the oil seepages, and duly reported his observations to his superiors. These observations contributed largely to the interest in the petroleum resources of the Pennsylvania region.
USS Escambia (AO-80) was the lead ship of her subclass of the Suamico class of fleet oilers acquired by the United States Navy for use during World War II. She had the dangerous, but necessary task of providing fuel to vessels in combat and non-combat areas primarily in the Pacific Ocean. For her valiant efforts, she received five battle stars during the war.
USS Cahaba (AO-82) was an Escambia-class replenishment oiler acquired by the United States Navy for use during World War II. She had the dangerous but necessary task of providing fuel to vessels in combat and non-combat areas primarily in the Pacific Ocean. For her brave efforts, she received eight battle stars during the war.
USS Oklawaha (AO-84) was a Escambia-class replenishment oiler acquired by the United States Navy for use during World War II. She had the dangerous but necessary task of providing water to smaller vessels not fitted with water-makers in combat and non-combat areas.
SS Mission Los Angeles may refer to one of two Type T2 tankers built for the United States Maritime Commission by Marinship Corporation:
SS Mission San Francisco may refer to one of two Type T2 tankers built for the United States Maritime Commission by Marinship Corporation:
SS Mission Santa Ana may refer to one of two Type T2 tankers built for the United States Maritime Commission by Marinship Corporation:
The T3 tanker, or T3, are a class of seaworthy large tanker ships produced in the United States and used to transport fuel oil, gasoline or diesel before and during World War II, the Korean War and the Vietnam War. The T3 tanker classification is still used today. The T3 tanker has a full load displacement of about 24,830 tons.
United States Navy