United States Navy oiler

File:USNS Mispillion CGLeahy FFSample 1980.JPEG

USNS Mispillion (AO-105) conducting an underway replenishment.

In the United States Navy, an Oiler is a Combat Logistics ship that replenishes other ships with fuel, food, mail, ammunition and other necessities while at sea, in a process called Underway Replenishment or UNREP. They were previously classified as Fleet Oilers in the 20th Century; under the current MSC operation their full classification is listed as Fleet Replenishment Oilers.

The first fleet oilers were identified by the hull name AO, which is still in use. Larger oilers are identified as Fast Combat Support Ship AOE, and a mid-size Replenishment Oiler AOR. The AOR name is no longer in use. All of these oilers provide the combined services of the AO, AE, AFS and AK.

A prefix "T" identifies the ships as being operated by Military Sealift Command.

A new class is now in service identified as T-AKE which provides the combined services of the AE and AFS replenishment ships.

US Navy oiler classes

Fleet Replenishment Oilers (AO)

Kanawha class

The Kanawha-class was a class of six ships commissioned between 1914 and 1921 which displaced 5,950 ts (AO-4 to AO-6 5,723 ts). Three ships were lost during World War II.

Patoka class

In 1919-1920 the U.S. Navy commissioned eight Patoka-class oilers of 5,422 ts displacement.

Cimarron class (1939)

The Cimarron-class was a class of 34 oil tankers which were first built in 1939. Four of the ships were converted into escort carriers in 1942, two were lost. These ships were of the United States Maritime Administration Type T3-S2-A1 (7,256 ts), the last five were of the T3-S2-A3 type (7,423 ts).

From 1964 through 1967, eight T3 type oilers were jumboized. Jumboization is done by cutting the ships in two with torches, the aft section is moved away, a new mid-body moved in and welded to the bow. After many other cutting and welding modifications a new long ship was created. The first ram tension rig was installed on USS Pawcatuck (AO-108).

Kennebec class

The second large oiler class built during World War II was the Kennebec-class of 5,958 ts displacement. These 16 ships were of the MARAD type T2-A and T3-S-A1 (AO-68 to AO-72).

Suamico class

The third large oiler class built during World War II was the Suamico-class of 5,730 ts displacement. These ships were of the MARAD Type T2-SE-A1 and -A3. 25 ships were commissioned, three were cancelled. Two further ships were converted into distilling ships (AW). One ship was lost in 1947.

Six further commercial tankers of various types were acquired by the U.S. Navy in 1942/43.

Neosho class

The Neosho-class oilers were the first streamlined oilers for the U.S. Navy. Six of these ships were constructed in the years 1954-55 time period, during the Cold War. "They were the first oilers designed specifically for underway replenishment. The final PROBE fueling device design was approved in 1965, consisting of a male fitting attached to the terminal end of a 7-inch hose".

Cimarron class (1979)

The second Cimarron-class was a class of five fleet oilers commissioned in the early 1980s to replace the WWII-built oilers. Due to budget restrictions these ships were smaller than needed and were jumboized in the late 1980s and early 1990s. However, to save costs these ships were decommissioned in the late 1990s in favour of MSC-operated ships.

Henry J. Kaiser class

The Henry J. Kaiser-class is a class of fleet replenishment oilers which began construction in August 1984. The class comprises eighteen underway replenishment oilers which are operated by Military Sealift Command to provide underway replenishment of fuel to United States Navy combat ships and jet fuel for aircraft aboard aircraft carriers at sea.

Transport Tanker (AOT)

The T-AOT Transport Tankers are part of the MSC Sealift Program, transporting fuel for the Department of Defense. The five Champion-class tankers, known as T5s, have double hulls and are ice-strengthened for protection against damage during missions in extreme climates. The MV Transpacific, a T-1 equivalent tanker, is smaller and has a shallow draft for coastal work.

Maumee class

The Maumee-class was a class of four fleet oilers in service from the mid-1950s until the mid-1980s. The ships were not designed for underway replenishment (refueling ships at sea). Rather they were intended to transport bulk petroleum products, such as fuel oil, gasoline, and aviation fuel, to American military forces overseas. At some time after the loss of USNS Potomac (T-AO-150) in 1961, the three survivors were reclassified as transport oilers (AOT).

Fast Combat Support Ships (AOE)

Sacramento class

The Sacramento-class fast combat support ships were a class of four supply ships used to refuel, rearm, and restock ships in the United States Navy in both the Atlantic and Pacific Oceans. These ships combined the capabilities of a fleet oiler (AO), ammunition ship (AE), and refrigerated stores ship (AF) and were in service between 1964 and 2005.

Supply class

The Sacramento-class was replaced by the four Supply-class ships commissioned between 1994 and 1998. All ships are now operated by the MSC.

Replenishment Fleet Oilers (AOR)

The Wichita-class replenishment oilers comprised a class of seven replenishment oilers used from the late 1960s to the mid-1990s. The ships were designed for rapid underway replenishment using both connected replenishment and vertical replenishment. The ships could carry 160,000 barrels of petroleum fuel, 600 tons of munitions, 200 tons of dry stores and 100 tons of refrigerated stores. With the reduction in the U.S. Navy fleet, these ships were all decommissioned and stricken from the Naval Vessel Register (NVR) in the 1990s.

The first ship to carry the AOR-designation was USS Conecuh (AOR-110), acquired as a war prize in 1946. She was the former German tanker Dithmarschen, which was placed in service from 1953 to 1956, and was used to test the AOE/AOR-concept.

Naming of Oilers

Oilers, large tankers fitted to refuel other ships at sea, are named for rivers (Monongahela, Patuxent) and for famous ship designers or builders (Andrew J. Higgins, Sacagawea). The newest class of these ships honors the names of honored supply ships of former years (Supply, Arctic). Each oiler that has a DANFS report has the source of its name displayed in that article.

Oiler museums

There are no US naval museums dedicated specifically to Oilers. There is one model of an Oiler that has been on display at the Defense Logistics Agency, in Fort Belvoir, VA. It is the USS Tamalpais AO-96, named after a little creek on a hill above Sausalito, California. In promoting the creation of an all 18 feet of the model can be seen.

United States Navy facts

The following is a list of tanker or cargo type hulls:

Naval Fleet Auxiliary Force (NFAF)

These perform Underway Replenishment. The first two are oilers; the others are dry cargo ships.

• Fleet Replenishment Oilers - T-AO (14)
• Fast Combat Support Ships] T-AOE (4)
• Ammunition Ships T-AE (5)
• Combat Stores Ships - T-AFS (2)
• Dry Cargo/Ammunition Ships - T-AKE (7)

Prepositioning ships

• OPDS Tanker (formerly T-AOT) (1)

Sealift ships

• Tankers - T-AOT (5)

Replenishment ships in other countries

The following countries also have replenishment ships:

• Argentina (1)
• Australia (1)
• Canada (2)
• Republic of China (Taiwan) (1)
• France (4)
• Germany (2)
• Netherlands (2)
• Peru (2)
• Portugal (1)
• Russia (15)
• Saudi Arabia (2)
• Spain (3)
• United Kingdom (10)
• India (10)

References

This article includes text from the public domain Dictionary of American Naval Fighting Ships.

See also

• Replenishment oiler
• List of auxiliaries of the United States Navy (oilers)
• Tanker (ship)

External links

• Dictionary of American Naval Fighting Ships - Neosho
• Frequently Asked Questions - Ship Naming section of the Navy Historical Center
• NavSource Online: Service Ship Photo AO-143
• United States Oiler History
• United States Oiler Naming History.