Replenishment oiler

File:RFA Tiderace Dual RAS with HMS Lancaster and HMS Westminster.jpg frigates {{ship|HMS|Lancaster|F229|6}} and {{ship|HMS|Westminster|F237|6}}.]]

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 worldwide.File:Sirius refueling Juneau.jpgOne of the first generation of "blue-water" navy oiler support vessels was the British RFA Kharki, active 1911 in the run-up to the First World War. Such vessels heralded the transition from coal to oil as the fuel of warships and removed the need to rely on, and operate within range of coaling stations. During the Second World War, the United States Navy's dramatically enlarged fleets, especially those in the Pacific Theater, required massive quantities of black oil, diesel oil, avgas, and other fuels and lubricants to support American land, sea, and air operations against remote, widely dispersed Japanese forces. Those supply demands resulted in U.S. Navy personnel refining many established practices for oilers and creating new procedures for replenishing warships while underway and for transporting highly combustible materials with increased effectiveness through hostile waters and over vast ocean distances.[http://www.usmm.org/tankers.html "Tankers Built in U.S. During World War II"], American Merchant Marine at War (usmm.org). Retrieved June 9, 2017.Sawyer, L. A.; Mitchell, W. H. (1974). Victory ships and tankers; the history of the "Victory" type cargo ships and of the tankers built in the United States of America during World War II. Cornell Maritime Press, Cambridge, Maryland, 1974.

Modern examples of the fast combat support ship include the large British Fort class, displacing {{convert|31,066|LT}} and measuring {{convert|669|ft|m}} in length and the United States' {{sclass|Supply|fast combat support ship|0}} {{USNS|Arctic|T-AOE-8|6}}, which displaces {{convert|48,800|LT}} and has an overall length of {{convert|754|ft|m}}.

File:Wabash Refueling Midway 1974.jpg at work]]

For all but the largest navies, replenishment oilers are typically one of the largest ships in the fleet. 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. These ships, when operating in concert with surface groups, can act as an aviation maintenance platform where helicopters receive more extensive maintenance than can be provided by the smaller hangars of the escorting ships.

Their size, additional facilities, and ability to support the operation of other vessels, means that replenishment oilers have been used as command ships, with some ships, such as the French {{sclass|Durance|tanker|4}}, this capability being built into the vessels from the start.

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 for additional air defense capability.

• {{navy|Argentina}} operates one {{sclass|Durance|tanker|2}} purchased from France.
• {{navy|Australia}} operates two {{sclass|Supply|replenishment oiler|2}}s.
• {{navy|Brazil}} operates the Almirante Gastão Motta
• {{navy|Canada}} operates the {{MV|Asterix}}.
• {{navy|Chile}} operates a single {{sclass|Henry J. Kaiser|replenishment oiler|2}} purchased from the United States, and the Araucano.
• {{navy|China}} operates two Fuyu-class fast combat support ships, four Dayun-class general stores issue ships, nine Fuchi-class replenishment ships, and a single Fusu-class replenishment ship.
• {{navy|Taiwan}} operates the ROCS Wu Yi and ROCS Panshih
• {{navy|Colombia}} operates two {{sclass|Lüneburg|replenishment ship|2}}s, purchased from Germany.
• {{navy|Egypt}} operates a single {{sclass|Lüneburg|replenishment ship|2}}, purchased from Germany (being supplemented or replaced by two Fort Rosalie-class replenishment ships, purchased from the United Kingdom).
• {{navy|France}} operates one Jacques Chevallier-class and two {{sclass|Durance|tanker|2}}s
• {{navy|Germany}} operates six {{sclass|Elbe|replenishment ship|2}}s, two {{sclass|Rhön|tanker|2}}s, and three {{sclass|Berlin|replenishment ship|2}}s.
• {{navy|Greece}} operates a single {{sclass|Etna|replenishment oiler|2}} and two {{sclass|Lüneburg|replenishment ship|2}}s, purchased from Germany.
• {{navy|India}} operates two {{sclass|Deepak|fleet tanker|2}}s, one {{sclass|Aditya|auxiliary ship|2}}, and a single {{sclass|Komandarm Fedko|oiler|2}}.
• {{navy|Indonesia}} operates a single {{sclass2|Rover|tanker|2}} purchased from the United Kingdom, two Tarakan-class tankers and more on order.
• {{navy|Italy}} operates one Vulcano class logistic support ship, a single {{sclass|Etna|replenishment oiler|2}} and two {{sclass|Stromboli|replenishment oiler|2}}s.
• {{navy|Iran}} operates two {{sclass|Bandar Abbas|replenishment ship|2}}s.
• {{navy|Japan}} operates three {{sclass|Towada|replenishment ship|2}}s and two {{sclass|Mashū|replenishment ship|2}}s.
• {{navy|South Korea}} operates three {{sclass|Cheonji|fast combat support ship|2}}s, and the ROKS Soyang
• {{navy|Netherlands}} operates HNLMS Karel Doorman
• {{navy|New Zealand}} operates HMNZS Aotearoa.
• {{navy|Norway}} operates HNoMS Maud.
• {{navy|Pakistan}} operates a single Fuqing-class replenishment tanker and the PNS Moawin
• {{navy|Peru}} operates the BAP Tacna
• {{navy|Poland}} operates the ORP Bałtyk
• {{navy|Russia}} operates three {{sclass|Boris Chilikin|fleet oiler|2}}s, one Dora-class tanker, two Uda-class tankers, one Iman-class tanker, four Altay-class tankers, three Dubna-class tankers, two Kaliningradneft-class tankers, and a single Project 23130 replenishment oiler.
• {{navy|Saudi Arabia}} operates two {{sclass|Durance|tanker|2}}s.
• {{navy|South Africa}} operates the {{SAS|Drakensberg}}
• {{navy|Spain}} operates the {{ship|Spanish oiler|Patiño||2}} and {{ship|Spanish replenishment oiler|Cantabria||2}}.
• {{navy|Thailand}} operates the HTMS Similan
• {{navy|Turkey}} operates two {{sclass|Akar|replenishment oiler|2}}s and one Derya class.
• File:British-Royal-Fleet-Auxiliary-Ensign.svg British Royal Fleet Auxiliary operates one {{sclass|Fort Victoria|replenishment oiler|2}}, four {{sclass2|Tide|tanker|2}}s and two {{sclass2|Wave|tanker|2}}s (maintained in reserve).
• {{flagicon|USA}} United States Military Sealift Command operates two {{sclass|John Lewis|replenishment oiler|2}}s, fifteen {{sclass|Henry J. Kaiser|replenishment oiler|2}}s, fourteen {{sclass|Lewis and Clark|dry cargo ship|2}}s, and two {{sclass|Supply|fast combat support ship|2}}s.
• {{navy|Uruguay}} operates a single {{sclass|Lüneburg|replenishment ship|2}} purchased from Germany
• {{navy|Venezuela}} operates the RBNV Ciudad Bolívar

• {{navy|Philippines}} decommissioned BRP Lake Caliraya in 2020.
• {{navy|Portugal}} decommissioned NRP Bérrio in 2020. Two new Replenishment Oilers ordered in 2024.{{Cite web |date=2024-12-23 |title=Türkiye's STM in first with Portuguese support ship contract |url=https://www.janes.com/osint-insights/defence-news/sea/turkiyes-stm-in-first-with-portuguese-support-ship-contract |access-date=2024-12-24 |website=Default |language=en}}
• {{navy|Ukraine}} decommissioned its only {{sclass|Boris Chilikin|fleet oiler|2}} in 2001.

{{see|List of United States Navy oilers}}

File:USNS Big Horn.jpg an underway replenishment oiler.]]

File:Sailors prepare to receive fuel from the fleet replenishment oiler USNS Yukon (T-AO 202) during a replenishment-at-sea. (48947870241).jpg

In the United States Navy, an Oiler is a Combat Logistics ship that replenishes other ships with fuel and in some cases food, mail, ammunition and other necessities while at sea, in a process called Underway Replenishment or UNREP.{{cite web | title= UnRep| url= http://www.phdnswc.navy.mil/Pages/What_We_Do/TestAndEvaluation/UnRep/Default.aspx| archive-url= https://archive.today/20071222135342/http://www.phdnswc.navy.mil/Pages/What_We_Do/TestAndEvaluation/UnRep/Default.aspx| url-status= dead| archive-date= December 22, 2007| work= Naval Surface Warfare Center, Port Hueneme Division| publisher= US Navy| access-date=2009-04-10}} Up through the Second World War Navy oilers used commercial tanker hulls, with the addition of UNREP gear, defensive guns, and military electronic and damage-control equipment; since the 1950s however they have been built from the keel up as specialized naval auxiliaries. They were previously classified as Fleet Oilers{{cite web | title= Fleet Oilers| url=http://www.ibiblio.org/hyperwar/USN/ships/ships-ao.html | work= Hyperwar| publisher=Ibiblio | date=2002-09-01| access-date=2009-04-13}} in the 20th century; under the current MSC operation their full classification is listed as Fleet Replenishment Oilers.{{cite web | title= Fleet Replenishment Oilers| url= http://www.navy.mil/navydata/fact_display.asp?cid=4400&tid=600&ct=4| archive-url= https://web.archive.org/web/20051129161407/http://www.navy.mil/navydata/fact_display.asp?cid=4400&tid=600&ct=4| url-status= dead| archive-date= November 29, 2005| work= US Navy Fact File| publisher=US Navy | date=2007-08-22 | access-date=2009-04-10}} Since the 1960s the classification Transport Oiler (AOT) has applied to tankers which ship petroleum products to depots around the world, but do not engage in UNREP.

The first fleet oilers{{cite web | title= Fleet Oilers| url=http://www.ibiblio.org/hyperwar/USN/ships/ships-ao.html | work= HyperwarUS Navy Fact File| publisher=Ibiblio | date=2002-09-01| access-date=2009-04-13}} were identified by the hull designation AO, which is still in use. Large, fast multifunction oilers which also provide ammunition and dry stores are identified as Fast Combat Support Ships (AOE),{{cite web | title= Fast Combat Support Ships| url= http://www.navy.mil/navydata/fact_display.asp?cid=4400&tid=300&ct=4| archive-url= https://web.archive.org/web/20050527203857/http://www.navy.mil/navydata/fact_display.asp?cid=4400&tid=300&ct=4| url-status= dead| archive-date= May 27, 2005| work=US Navy Fact File | publisher= US Navy| date= 2007-08-22| access-date=2009-04-10}} and mid-size ones Replenishment Oilers (AOR). The AOR designation is no longer in use. All of these oilers provide the combined services of the AO, AE, AFS and AK.

The style "USNS" and prefix "T" identify a ship as being operated by a civilian crew under the Military Sealift Command (known as the Military Sea Transportation Service until 1970).

There are three classes of vessels currently in commissioned service:

• Henry J. Kaiser class, T-AO-187-T-AO-204, in service 1986
• Supply class, T-AOE, in service 1990
• John Lewis class, T-AO-205-T-AO-221, in service 2022

Both the Henry J. Kaiser-class and Supply class will be replaced by the John Lewis-class ships.

{{reflist}}

• [http://navysite.de/aor/aor6.htm DANFS USS KALAMAZOO (AOR-6) website]
• [https://web.archive.org/web/19981202072807/http://www.nvr.navy.mil/ US Naval Vessel Register]
• [http://www.german-navy.de/kriegsmarine/ships/auxships/dithmarschen/ KMS Dithmarschen]
• [http://www.naval-technology.com/projects/patino/ Spanish Navy Patino Class AOR]
• [http://www.navy.gov.au/hmas-success HMAS Success, AOR-304]

{{Commons category|Oilers}}

{{Warship types of the 19th & 20th centuries}}

{{MARCOMships}}

Category:Ship types

Category:Auxiliary ships