Auxiliary ship

Last updated
German Navy Berlin-class replenishment ship Navy supply vessel "Berlin".jpg
German Navy Berlin-class replenishment ship

An auxiliary ship is a naval ship designed to support combatant ships and other naval operations. [1] Auxiliary ships are not primary combatant vessels, though they may have some limited combat capacity, usually for purposes of self-defense. [2] [3]


Auxiliary ships are extremely important for navies of all sizes because if they were not present the primary fleet vessels would be unsupported. Thus, virtually every navy maintains an extensive fleet of auxiliary ships, however, the composition and size of these auxiliary fleets vary depending on the nature of each navy and its primary mission. Smaller coastal navies tend to have smaller auxiliary vessels focusing primarily on littoral and training support roles, while larger blue-water navies tend to have larger auxiliary fleets comprising longer-range fleet support vessels designed to provide support far beyond territorial waters. [4]


Royal Canadian Navy auxiliary oiler HMCS Preserver during New York fleet week, 2009 HMCS Preserver (AOR 510).jpg
Royal Canadian Navy auxiliary oiler HMCS Preserver during New York fleet week, 2009
Australian oiler HMAS Sirius refueling USS Essex, June 2007 US Navy 070615-N-4614W-035 Amphibious assault ship USS Essex (LHD 2) conducts a refueling at sea with Australian auxiliary oiler HMAS Sirius (AOR 266) as dock landing ship USS Tortuga (LSD 46) approaches during exercise Talisma.jpg
Australian oiler HMAS Sirius refueling USS Essex, June 2007
American cargo ship USNS Furman, 1981 USNS Furman (T-AK-280) underway off Guam 1981.JPEG
American cargo ship USNS Furman, 1981
American repair ship USS Vulcan, June 1992 USS Vulcan AR-5 Norfolk 1992.jpeg
American repair ship USS Vulcan, June 1992
German tugboat Wangerooge, 2005 Cuxhaven 2005 -Seeschlepper Wangerooge- by-RaBoe 001.jpg
German tugboat Wangerooge, 2005
Australian survey ship HMAS Leeuwin, December 2013 Leeuwin at Waterhen Dec2013.JPG
Australian survey ship HMAS Leeuwin, December 2013
US Navy barracks ship APL-61 in 2003 US Navy 031009-N-9693M-002 The U.S. Navy Barracks Craft Auxiliary Personnel Lighter Sixty One (APL-61) is moored alongside the U.S. Naval Academy's Dewey Seawall.jpg
US Navy barracks ship APL-61 in 2003


One of the most direct ways that auxiliary ships support the fleet is by providing underway replenishment (also known as "replenishment at sea") to major fleet units. This allows the fleet to remain in the same location, with the replenishment vessels bringing up fuel, ammunition, food, and supplies from shore to the fleet wherever it is operating.[ citation needed ]

Oilers ("replenishment tankers") are vessels specifically designed to bring fuel oil to the fleet, while the earlier Colliers supplied coal-burning steamships. Specific role replenishment vessels include combat stores ships, depot ships, general stores issue ships, and ammunition ships.[ citation needed ]

Tenders are specifically designed to support a type of smaller naval unit, like submarines, destroyers, and seaplanes, providing a mobile base of operations for these units: specifically destroyer tenders, submarine tenders, seaplane tenders, torpedo boat tenders. [5] [6]


Supporting front-line operating bases requires immense transportation capacity. Transport ships are often converted merchant ships simply commissioned (APA, APD, APH, APV)[ jargon ] into naval service. Tankers are transports specifically designed to ship fuel to forward locations. Transport ships are often employed not only carrying cargo for naval support but are in support of all forces of a nation's military (AK, AKA, AKN, AKR, AKS). In particular, troopships and attack transports are used to carry a large number of soldiers to operational theatres. Some transport ships are highly specialized, like the ammunition ships employed by the US Navy. [7] Large ocean tugs (AT, ATO, ATF, ATA, ATR)[ jargon ] are used to tow large auxiliary ships, like barges, floating repair docks, and floating cranes in the open sea, also disabled ships. [18]


Repairing ships at sea or in conflict areas is important as it allows these vessels to return to service more quickly, while also increasing the chance of survival for ships critically damaged in battle. Repair vessels (US Navy: AR, ARB, ARC, ARG, ARH, ARL, ARV)[ jargon ] range from small equipment ships known as Auxiliary repair docks, to the larger Auxiliary floating drydocks, there are also Aircraft repair ships that specialize in repair of naval aircraft. [19]


Harbor support is a critical support role, with various types of vessels including tugboats, barges, lighter barges, derrick-crane vessels, and others used to move ships and equipment around the port facilities, and depot ships and tends to service ships currently in the harbor. These vessels also help maintain the harbor by dredging channels, maintaining jetties and buoys, and even providing floating platforms for port defenses.[ citation needed ]

In US Navy, tugboats are type YT, YTB, YTM, YTL or a Type V ship. [20] and barges are classified as a Type B ship or YF, YFN, YFR, or YFRN. [21]


Radar picket to increase the radar detection range around a force. Communications Relay Ships (AGMR) are floating communications stations. Tracking ships or Range Instrumentation Ships (AGM) are equipped with antennas and electronics to support the launching and tracking of missiles and rockets. Command ship (AGF) are flagships of the commander of a fleet. Wind-class icebreaker (AGB WAGB) are support ships. Rescue and salvage ship and Submarine rescue ship (ASR) for surface support ship for ship and submarine rescue. Barracks ships or Auxiliary Personal Living ships, (APL) are vessels-barges for service men to live on.[ citation needed ]


A wide variety of vessels are employed as Technical Research Ships(AGTR), Tracking Ships(AGM), Environmental Research Ships (AGER), Hydrofoil Research Ships (AGEH), and Survey Vessels, primarily to provide a navy with a better understanding of its operating environment or to assist in testing new technologies for employment in other vessels. [22]


Hospital ships are able to provide medical care in remote locations to personnel. [23]

Unclassified auxiliary ship

The US Navy also used an unclassified miscellaneous auxiliary ship classification in which the unclassified miscellaneous auxiliary ship classification is IX. An unclassified miscellaneous auxiliary ship can be a new ship without a classified role or a ship that does not fit into a standard category or a ship that had been removed from its classification. [24] [25] [26]

See also

Related Research Articles

The United States Navy, United States Coast Guard, and United States National Oceanic and Atmospheric Administration (NOAA) use a hull classification symbol to identify their ships by type and by individual ship within a type. The system is analogous to the pennant number system that the Royal Navy and other European and Commonwealth navies use.

<span class="mw-page-title-main">Naval ship</span> Military ship used by a navy

A naval ship is a military ship used by a navy. Naval ships are differentiated from civilian ships by construction and purpose. Generally, naval ships are damage resilient and armed with weapon systems, though armament on troop transports is light or non-existent.

<span class="mw-page-title-main">Submarine tender</span> Type of ship that supplies and supports submarines

A submarine tender, in British English a submarine depot ship, is a type of depot ship that supplies and supports submarines.

USS <i>Proteus</i> (AS-19) US Navy submarine tender

The third USS Proteus (AS-19) was a Fulton-class submarine tender in the United States Navy.

<span class="mw-page-title-main">Service Squadron</span> Unit of the US Navy

A Service Squadron (ServRon) was a United States Navy squadron that supported fleet combat ships and US Navy Auxiliary ships. Service Squadrons were used by the US Navy from their inception in 1943 to as late as the early 1980s. At the time of their inception during the Second World War they allowed the US Navy to operate across the vast reaches of the Pacific Ocean for extended periods of time. Service Squadrons created temporary forward bases to allow the naval squadrons to spend less time in transit and more time in the area of combat. Ulithi, a small volcanic atoll in the central Pacific, is an example of a site converted for use as a forward base of supply. Service Squadrons essentially created a major naval base near the area of operation. With naval bases like, Naval Base Ulithi, to refit, repair and resupply, many ships were able to deploy and operate in the western Pacific for a year or more without returning to a major port facility. Among the vessels operating in service squadrons were tankers, Fleet oilers, refrigerator ships, ammunition ships, supply ships, floating docks and repair ships. They provided diesel, ordnance, aviation fuel, food stuffs and all other supplies. Equally important at places like Ulithi were the portable piers and floating dry docks which allowed many ships damaged by enemy action or Pacific storms to undergo repair without having to travel the thousands of miles back to a major US naval base. Ulithi was as far forward from the US naval base at San Francisco as the San Francisco base was from London, England. To have a fully functional major port in the middle of the Pacific was a significant aid to U.S. Navy operations.

<span class="mw-page-title-main">Barracks ship</span> Watercraft serving as floating personnel accommodation

A barracks ship or barracks barge or berthing barge, or in civilian use accommodation vessel or accommodation ship, is a ship or a non-self-propelled barge containing a superstructure of a type suitable for use as a temporary barracks for sailors or other military personnel. A barracks ship, a military form of a dormitory ship, may also be used as a receiving unit for sailors who need temporary residence prior to being assigned to their ship. The United States Navy used to call them Yard Repair Berthing and Messing with designations YRBM and YRBM(L) and now classes them as either Auxiliary Personnel Barracks (APB) or Auxiliary Personnel Lighter (aka barge) (APL).

USS <i>Ocelot</i> Cargo ship of the United States Navy

USS Ocelot (IX–110) was an unclassified miscellaneous vessel of the United States Navy, which served as the flagship of Service Squadron 10 in the Pacific War from late 1944, until she was wrecked in a typhoon in late 1945.

USS <i>Clifton</i> (IX-184)

USS Clifton (IX-184) was a storage tanker that served in the United States Navy from 1945 to 1946 as an unclassified miscellaneous vessel.

<span class="mw-page-title-main">Type B ship</span>

The Type B ship is a United States Maritime Administration (MARAD) designation for World War II barges. Barges are very low cost to build, operate and move. Barges were needed to move large bulky cargo. A tug boat, some classed as Type V ships, could move a barge, then depart and move on to the next task. That meant the barge did not have to be rushed to be unloaded or loaded. Toward the end of World War 2, some ships that had not been completed in time for the war were converted to barges. US Navy barges are given the prefix: YWN or YW. Due to shortage of steel during World War II, concrete ship constructors were given contracts to build concrete barges, with ferrocement and given the prefix YO, YOG, YOGN. Built in 1944 and 1945, some were named after elements.

USS <i>AFDM-2</i> Large auxiliary floating drydock of the US Navy

USS AFDM-2,, is an AFDM-3-class medium auxiliary floating drydock built in Mobile, Alabama by the Alabama Drydock and Shipbuilding Company for the U.S. Navy. Originally named USS YFD-4, Yard Floating Dock-4, she operated by Todd Shipyards at New Orleans, Louisiana for the repair of US ships during World War II. YFD-4 was renamed an Auxiliary Floating Dock Medium AFDM-2 in 1945 after the war.

USS <i>AFDB-2</i> Large auxiliary floating drydock of the US Navy

USS ABSD-2, later redesignated as AFDB-2, was a ten-section, non-self-propelled, large auxiliary floating drydock of the US Navy. Advance Base Sectional Dock-2 was constructed in sections during 1942 and 1943 by the Mare Island Naval Shipyard in Vallejo, California for World War II. Her official commissioning ceremony took place on 14 August 1943 with CDR. Joseph J. Rochefort in command. With all ten sections joined, she was 927 feet long, 28 feet tall, and with an inside clear width of 133 feet 7 inches. ABSD-2 had a traveling 15-ton capacity crane with an 85-foot radius and two or more support barges. The two side walls were folded down under tow to reduce wind resistance and lower the center of gravity. ABSD-2 had 6 capstans for pulling, each rated at 24,000 lbf (110,000 N) at 30 ft/min (0.15 m/s), 4 of the capstans were reversible. There were also 4 ballast compartments in each section.

Pollock-Stockton Shipbuilding Company was established in 1942 to build ships needed for World War II. As part of the Emergency Shipbuilding Program the US Navy provided some of the capital to start Pollock-Stockton Shipbuilding at Stockton, California. The shipyard was located at San Joaquin River and Stockton Channel, near Louis Park. After the war the shipyard closed down in February 1946.

This glossary defines the various types of ships and accessory watercraft that have been used in service of the United States. Such service is mainly defined as military vessels used in the United States Navy and United States Coast Guard, as well as the defunct, incorporated, or renamed institutions such as the United States Revenue Cutter Service. Service of the United States can also be defined in this context as special government missions in the form of expeditions, such as the Wilkes Expedition or the North Pacific Exploring and Surveying Expedition. The scope of the glossary encompasses both the "Old Navy" of the United States, from its beginnings as the "Continental Navy", through the "New Navy" and up to modern day. The watercraft included in the glossary are derived from United States ships with logbooks published by the National Archives and Records Administration.

APL-17-class barracks ship Class of United States Navy barrack ships

The APL-17-class barracks ship was a class of barracks ships of the United States Navy after the start of the Second World War, in the 1940s.

<span class="mw-page-title-main">Naval Base Eniwetok</span> Major US Navy Base in the Marshall Islands

Naval Base Eniwetok was a major United States Navy base located at Enewetak Atoll in the Marshall Islands, during World War II. The base was built to support the island-hopping strategy used by allied nations fighting the Empire of Japan in the Pacific War. During 1944-5 Eniwetok was one of the busiest naval bases in the world with over 488 ships.

<span class="mw-page-title-main">Naval Base Kossol Roads</span> Former major US Navy Base

Naval Base Kossol Roads also called Naval Base Kossol Passage was major United States Navy base at Kossol Roads in northern Palau in the western Caroline Islands in the western Pacific Ocean during World War II. Kossol Roads lagoon is surrounded by fringing coral reef. The base was built to support the island hopping Pacific war efforts of the allied nations fighting the Empire of Japan. In terms of the number of ships at one base, Naval Base Kossol Roads was one of the largest Naval Base in the world in 1944 and 1945. Naval Base Kossol Roads was unique, as it was the only large US Naval base to have no shore facilities. Kossol Roads was part of US Naval Base Carolines.



  1. Cutler and Cutler, p.16
  2. Morris, p.192
  3. Ship Abbreviations and Symbols
  4. Navy Ships: Turning Over Auxiliary Ship Operations to the Military Sealift Command Could Save Millions
  5. "Submarine Tenders (AS)". Retrieved 2019-01-23.
  6. "Other Auxiliaries(AGB, AGC, AGDS, AGEH, AGER, AGF, AGM, AGMR, AGP, AGR, AGTR)". Retrieved 2019-01-23.
  7. "Royal Fleet Auxiliary ship makes last Plymouth call". BBC News. 2011-02-01. Retrieved 2021-09-18.
  8. "Ocean Tugs (AT, ATO, ATF, ATA, ATR)". Retrieved 2019-01-23.
  9. "Oilers AO". Retrieved 2019-01-23.
  10. "Combat Logistics Resupply Ships AC AE AF AFS AKE AOE AOR". Retrieved 2019-01-23.
  11. "Cargo Ships AK AKA AKN AKS". Retrieved 2019-01-23.
  12. "Gasoline Tankers AOG". Retrieved 2019-01-23.
  13. "Destroyer Tenders AD". Retrieved 2019-01-23.
  14. "Aviation Support Ships AV AVP AVS". Retrieved 2019-01-23.
  15. "Miscellaneous Auxiliaries AG". Retrieved 2019-01-23.
  16. "Troop Transports (AP)". Retrieved 2019-01-23.
  17. "Attack and Other Transports (APA, APD, APH, APV)". Retrieved 2019-01-23.
  18. [8] [9] [10] [11] [12] [13] [14] [15] [16] [17]
  19. "Floating Dry-Docks (AFDB, AFDM, AFDL, ARD, ARDM, YFD)". 30 April 2015. Retrieved 8 January 2019.
  20. "Yard Tugs Wartime YT YTB YTM YTL". Retrieved 2019-01-23.
  21. "Freight Lighters Wartime YF YFN YFND YFR YFRN YFRT". Retrieved 2019-01-23.
  22. "Other Auxiliaries AGB, AGC, AGDS, AGF, AGM, AGMR, AGP, AGR". Retrieved 2019-01-23.
  23. Custodio, Jonathan. "U.S. transport ship and field hospitals heading to Haiti for quake relief". POLITICO. Retrieved 2021-09-18.
  25. Unclassified auxiliary ships
  26. Unclassified (IX): Special Types