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Cimarron Class, U.S. Fleet Oilers


Photograph of
                  Cimarron-class fleet oiler

National Archives #19-N-30121

Schematic diagram of Cimarron class fleet oiler

ONI 222


Specifications:


Tonnage 24,830 tons fully loaded
Dimensions 553' by 75' by 32'
168.6m by 22.9m by 9.8m
Maximum speed       18 knots
Complement 315
Armament 4 5"/38 dual purpose guns
4 0.50 machine guns
Protection
STS splinter protection only around guns, handling rooms, and bridge
Machinery
2-shaft geared turbine (12,000 shp)
4 Babcock and Wilcox boilers
Capacity 147,150 barrels
Modifications
Late 1942: Light antiaircraft upgraded to 1x2 1.1" AA guns, 6x1 20mm Oerlikon AA guns.

1944: Light antiaircraft upgraded to 8x1 20mm guns and 4x2 40mm Bofors AA guns.


The Cimarrons were completed from 1939-1942 as Maritime Commission standard T3-S2-A1 tankers. The first twelve T3-S2-A1 tankers were built for Standard Oil with subsidies and technical assistance from the Navy to ensure that the ships would be usable as fleet oilers in the event of war. This required more powerful machinery and a better hull form to permit a higher sustained speed than was the norm for civilian tankers. As it turned out, the Navy was so anxious to obtain modern fleet oilers that it took over the contracts for the first few T3-S2s that were completed. These became the Cimarron class fleet oilers.

At the time of completion, they were the fastest tankers ever built in U.S. yards and among the largest in the world. Their hull form was developed in Navy test basins and included a bulbous clipper bow to reduce wave resistance. Cimarron's trial performance actually exceeded the design specification, at 16,9000 shp and 19.28 knots. They were armed and equipped with underway replenishment gear at their first refits. One Cimarron could simultaneously refuel two warships, one on each beam, while underway at reduced speed in calm to moderate seas.

Navalization of the ships involved greatly increasing the berthing space for the much larger Navy crews, installing underway replenishment gear and armament, and adding ship's boats and Navy communications gear. The ships were also modified to carry lubricating oil, diesel oil, and gasoline in addition to fuel oil.

A typical loadout for a Cimarron supporting 5 Fleet in late 1943 was 80,000 barrels (12,700,000 liters) fuel oil, 18,000 barrels (2,860,000 liters) aviation gasoline and 6782 barrels (1,080,000 liters) diesel oil.

A second group of oilers were completed in 1943-45 on the basic Cimarron plan. Some authors list these separately as the Ashtabula class. Their chief distinction from their earlier sister ships is that the shortage of 5"/38 guns led to their being armed with just one 5"/38 and four 3"/50 guns with inferior fire control ("follow the pointer" system).


Units in the Pacific:

Kaskaskia Mare Island 
Neosho Pearl Harbor  Crippled by aircraft 1942-5-7 in the Coral Sea; scuttled
Platte San Diego
Sabine Mare Island
Guadalupe arrived 1942-1
Cimarron arrived 1942-3
Ashtabula arrived 1943-9-1
Cacapon arrived 1943-11
Caliente arrived 1943-12
Chikaskia arrived 1943-12
Marias arrived 1944-3-28
Manatee arrived 1944-5-1
Mississinewa       arrived 1944-6-30 Sunk by kaiten on 1944-11-20 at Ulithi
Salamonie arrived 1944-7-15
Severn arrived 1944-8 Assigned to use as water tanker
Nantahala arrived 1944-8-1
Aucilla arrived 1944-10-11      
Taluga arrived 1944-10-14
Chipola arrived 1945-2
Tolovana arrived 1945-4-6

Photo Gallery


Forward view of Cimmaron

U.S. Navy

Aerial view of Cimmaron-class oiler refueling
                destroyer

U.S. Navy

Cimmaron-class oiler training out its refueling
                hose

U.S. Navy

References

DANFS

Morison (1951)
Wildenberg (1996)



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