Replenishment oiler

HMCS Protecteur

A replenishment oiler or fleet tanker is a naval auxiliary ship with fuel tanks and dry cargo holds, which can replenish other ships while underway in the high seas. Such ships are used by several countries around the world.

The US Navy hull classification symbol for this type of ship was AOR before the classification was discontinued. The lead ship in the class was the Wichita. In the Soviet/Russian Navy it has been the Boris Chilikin type, and in the Canadian Navy, the Protecteur class. AORs are slower and carry fewer dry stores than Fast Combat Support Ship (AOE) ships (lead ship USS Sacramento). The word Replenishment is now included in the hull identification of the Fleet Replenishment Oiler - AO.

History of design

The development of the oiler paralleled the change from coal to oil fired boilers in warships. Prior to the adoption of oil fired machinery, navies could extend the range of their ships either by maintaining coaling stations or for warships to raft together with colliers and for coal to be manhandled aboard. Though arguments related to fuel security were made against such a change, the ease with which liquid fuel could be transferred led in part to its adoption by navies world wide.

The forerunner of the modern replenishment oiler was a Kriegsmarine (German Navy) ship, the Dithmarschen, which was built in 1938. The Dithmarschen was designed to provide fuel and stores (including munitions) in a "One Stop Shopping At Sea" context to the German fleet. After World War II she was claimed by the United States as a war prize and commissioned into the United States Navy as the USS Conecuh (AOR-110). The ship proved the feasibility and flexibility of this sort of vessel in supporting task forces at sea. The USS Conecuh was decommissioned in 1956.

The AOE class was developed first by the United States Navy as a logistics support vessel for aircraft carrier task forces, but the resulting vessel, while capable of high speed and of maintaining station as a component in the task force, was at the time the most expensive auxiliary ship ever procured by the United States Navy. For other applications not requiring high speed, such as anti-submarine groups, a smaller, less capable but much less expensive variant was desirable. This variant was the Wichita class AOR.

Characteristics of an AOR

A replenishment oiler at work

For smaller navies, such as the Canadian Navy, the AOR are typically one of the largest ships in the navy. Such ships are designed to carry large amounts of fuel and dry stores for the support of naval operations far away from port. Replenishment oilers are also equipped with more extensive medical and dental facilities than smaller ships can provide.

Such ships are equipped with multiple refueling gantries to refuel and resupply multiple ships at a time. The process of refueling and supplying ships at sea is called underway replenishment. Furthermore, such ships often are designed with helicopter decks and hangars. This allows the operation of rotary-wing aircraft, which allows the resupply of ships by helicopter. This process is called vertical replenishment. Furthermore, such ships, when operating in concert with surface groups, can act as the aviation maintenance platform where helicopters receive more extensive maintenance than can be provided by the smaller hangars of the escorting ships.

USS Willamette (AO-180) (center) refuels USS Duncan (FFG-10) (left), while the USS Gray (FF-1054) (back right) follows behind.

Armament

Because the replenishment oiler is not a combat unit, but rather a support vessel, such ships are often lightly armed, usually with self-defense systems (such as the Phalanx CIWS close-in weapons systems), small arms, machine guns and/or light automatic cannons. They may also carry man-portable air-defense systems, or MANPADS, for additional air defence capability.

Smaller class oilers in other navies

HMAS Sirius (right) is a converted commercial oil tanker.

Navies of other countries are actively designing and building replenishment oilers similar to the Wichita-class replenishment oiler of the USN. These navies such as the Canadian Navy Joint Support Ship Project and the Spanish Navy^[1] who have requirements that do not include high speed and high capacity; thus a smaller design meets the logistics needs of these navies better than a larger AOE design would.

See also

• Collier (ship type)
• United States Navy oiler
• Cimarron class oiler
• Protecteur class auxiliary vessel
• Provider class auxiliary vessel
• Joint Support Ship Project
• Supply class fast combat support ship
• Sacramento class fast combat support ship
• Wichita class replenishment oiler

References

1. ^ "Petrolero de Flota 'Marqués de la Ensenada' - Surface Ships". armada.mde.es. Armada Española. 2011. http://www.armada.mde.es/ArmadaPortal/page/Portal/ArmadaEspannola/buques_superficie/05_Petrolero_Flota. Retrieved May 4, 2011. 

• DANFS USS KALAMAZOO (AOR-6) website
• US Naval Vessel Register
• KMS Dithmarschen
• Spanish Navy Patino Class AOR
• HMAS Success, AOR-304

External links