Hull classification symbol - wikipedia Hull classification symbol Wikimedia list article This article is about the U.S. Navy, U.S. Coast Guard, and NOAA systems. For the similar system used by Canadian Forces, see Hull classification symbol ( Canada ). This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. ( September 2017 ) The United States Navy, United States Coast Guard, and United States National Oceanic and Atmospheric Administration ( NOAA ) use a hull classification symbol ( sometimes called hull code or hull number ) 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. Contents 1 History 1.1 United States Navy 1.2 United States Revenue Cutter Service and United States Coast Guard 1.3 United States Coast and Geodetic Survey 2 The modern hull classification system 2.1 United States Navy 2.1. 1 Military Sealift Command 2.2 United States Coast Guard 2.3 National Oceanic and Atmospheric Administration 3 United States Navy hull classification codes 3.1 Warships 3.1. 1 Aircraft carrier type 3.1. 2 Surface combatant type 3.1. 3 Submarine type 3.1. 4 Patrol combatant type 3.1. 5 Amphibious warfare type 3.1. 6 Expeditionary Support 3.1. 7 Combat Logistics Type 3.1. 8 Mine warfare type 3.1. 9 Coastal defense type 3.1. 10 Mobile logistics type 3.2 Auxiliary type 3.2. 1 Airships 3.3 Support ships 3.3. 1 Support type 3.3. 2 Service type craft 3.4 United States Coast Guard craft 3.5 Temporary designations 4 National Oceanic and Atmospheric Administration hull codes 5 See also 6 Notes 6.1 Footnotes 6.2 Citations 7 References 8 Further reading 9 External links History United States Navy The U.S. Navy began to assign unique Naval Registry Identification Numbers to its ships in the 1890s. The system was a simple one in which each ship received a number which was appended to its ship type, fully spelled out, and added parenthetically after the ship 's name when deemed necessary to avoid confusion between ships. Under this system, for example, the battleship Indiana was USS Indiana ( Battleship No. 1 ), the cruiser Olympia was USS Olympia ( Cruiser No. 6 ), and so on. Beginning in 1907, some ships also were referred to alternatively by single - letter or three - letter codes -- for example, USS Indiana ( Battleship No. 1 ) could be referred to as USS Indiana ( B - 1 ) and USS Olympia ( Cruiser No. 6 ) could also be referred to as USS Olympia ( C - 6 ), while USS Pennsylvania ( Armored Cruiser No. 4 ) could be referred to as USS Pennsylvania ( ACR - 4 ). However, rather than replacing it, these codes coexisted and were used interchangeably with the older system until the modern system was instituted on 17 July 1920. During World War I, the U.S. Navy acquired large numbers of privately owned and commercial ships and craft for use as patrol vessels, mine warfare vessels, and various types of naval auxiliary ships, some of them with identical names. To keep track of them all, the Navy assigned unique identifying numbers to them. Those deemed appropriate for patrol work received section patrol numbers ( SP ), while those intended for other purposes received `` identification numbers '', generally abbreviated `` Id. No. '' or `` ID ; '' some ships and craft changed from an SP to an ID number or vice versa during their careers, without their unique numbers themselves changing, and some ships and craft assigned numbers in anticipation of naval service never were acquired by the Navy. The SP / ID numbering sequence was unified and continuous, with no SP number repeated in the ID series or vice versa so that there could not be, for example, both an `` SP - 435 '' and an `` Id. No 435 ''. The SP and ID numbers were used parenthetically after each boat 's or ship 's name to identify it ; although this system pre-dated the modern hull classification system and its numbers were not referred to at the time as `` hull codes '' or `` hull numbers, '' it was used in a similar manner to today 's system and can be considered its precursor. United States Revenue cutter service and United States Coast Guard The United States Revenue Cutter Service, which merged with the United States Lifesaving Service in January 1915 to form the modern United States Coast Guard, began following the Navy 's lead in the 1890s, with its cutters having parenthetical numbers called Naval Registry Identification Numbers following their names, such as ( Cutter No. 1 ), etc. This persisted until the Navy 's modern hull classification system 's introduction in 1920, which included Coast Guard ships and craft. United States Coast and Geodetic survey Like the U.S. Navy, the United States Coast and Geodetic Survey -- a uniformed seagoing service of the United States Government and a predecessor of the National Oceanic and Atmospheric Administration ( NOAA ) -- adopted a hull number system for its fleet in the 20th century. Its largest vessels, `` Category I '' oceanographic survey ships, were classified as `` ocean survey ships '' and given the designation `` OSS ''. Intermediate - sized `` Category II '' oceanographic survey ships received the designation `` MSS '' for `` medium survey ship, '' and smaller `` Category III '' oceanographic survey ships were given the classification `` CSS '' for `` coastal survey ship. '' A fourth designation, `` ASV '' for `` auxiliary survey vessel, '' included even smaller vessels. In each case, a particular ship received a unique designation based on its classification and a unique hull number separated by a space rather than a hyphen ; for example, the third Coast and Geodetic Survey ship named Pioneer was an ocean survey ship officially known as USC&GS Pioneer ( OSS 31 ). The Coast and Geodetic Survey 's system persisted after the creation of NOAA in 1970, when NOAA took control of the Survey 's fleet, but NOAA later changed to its modern hull classification system. The modern hull classification system United States Navy The U.S. Navy instituted its modern hull classification system on 17 July 1920, doing away with section patrol numbers, `` identification numbers '', and the other numbering systems described above. In the new system, all hull classification symbols are at least two letters ; for basic types the symbol is the first letter of the type name, doubled, except for aircraft carriers. The combination of symbol and hull number identifies a modern Navy ship uniquely. A heavily modified or re-purposed ship may receive a new symbol, and either retain the hull number or receive a new one. For example, the heavy gun cruiser USS Boston ( CA - 69 ) was converted to a gun / missile cruiser, changing the hull number to CAG - 1. Also, the system of symbols has changed a number of times both since it was introduced in 1907 and since the modern system was instituted in 1920, so ships ' symbols sometimes change without anything being done to the physical ship. Hull numbers are assigned by classification. Duplication between, but not within, classifications is permitted. Hence, CV - 1 was the aircraft carrier USS Langley and BB - 1 was the battleship USS Indiana. Ship types and classifications have come and gone over the years, and many of the symbols listed below are not presently in use. The Naval Vessel Register maintains an online database of U.S. Navy ships showing which symbols are presently in use. After World War II until 1975, the U.S. Navy defined a `` frigate '' as a type of surface warship larger than a destroyer and smaller than a cruiser. In other navies, such a ship generally was referred to as a `` flotilla leader '', or `` destroyer leader ''. Hence the U.S. Navy 's use of `` DL '' for `` frigate '' prior to 1975, while `` frigates '' in other navies were smaller than destroyers and more like what the U.S. Navy termed a `` destroyer escort '', `` ocean escort '', or `` DE ''. The United States Navy 1975 ship reclassification of cruisers, frigates, and ocean escorts brought U.S. Navy classifications into line with other nations ' classifications, at least cosmetically in terms of terminology, and eliminated the perceived `` cruiser gap '' with the Soviet Navy by redesignating the former `` frigates '' as `` cruisers ''. Military Sealift Command If a U.S. Navy ship 's hull classification symbol begins with `` T - '', it is part of the Military Sealift Command, has a primarily civilian crew, and is a United States Naval Ship ( USNS ) in non-commissioned service -- as opposed to a commissioned United States Ship ( USS ) with an all - military crew. United States Coast Guard If a ship 's hull classification symbol begins with `` W '', it is a ship of the United States Coast Guard. Until 1965, the Coast Guard used U.S. Navy hull classification codes, prepending a `` W '' to their beginning. In 1965, it retired some of the less mission - appropriate Navy - based classifications and developed new ones of its own, most notably WHEC for `` high endurance cutter '' and WMEC for `` medium endurance cutter ''. National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration ( NOAA ), a component of the United States Department of Commerce, includes the National Oceanic and Atmospheric Administration Commissioned Officer Corps ( or `` NOAA Corps '' ), one of the seven uniformed services of the United States, and operates a fleet of seagoing research and survey ships. The NOAA fleet also uses a hull classification symbol system, which it also calls `` hull numbers, '' for its ships. After NOAA took over the former Coast and Geodetic Survey fleet in 1970 along with research vessels of other government agencies, it adopted a new system of ship classification. In its system, the NOAA fleet is divided into two broad categories, research ships and survey ships. The research ships, which include oceanographic and fisheries research vessels, are given hull numbers beginning with `` R '', while the survey ships, generally hydrographic survey vessels, receive hull numbers beginning with `` S ''. The letter is followed by a three - digit number ; the first digit indicates the NOAA `` class '' ( i.e., size ) of the vessel, which NOAA assigns based on the ship 's gross tonnage and horsepower, while the next two digits combine with the first digit to create a unique three - digit identifying number for the ship. Generally, each NOAA hull number is written with a space between the letter and the three - digit number, as in, for example, NOAAS Nancy Foster ( R 352 ) or NOAAS Thomas Jefferson ( S 222 ). Unlike the Navy, once an older NOAA ship leaves service, a newer one can be given the same hull number ; for example, `` S 222 '' was assigned to NOAAS Mount Mitchell ( S 222 ), then assigned to NOAAS Thomas Jefferson ( S 222 ), which entered NOAA service after Mount Mitchell was stricken. United States Navy hull classification codes The U.S. Navy 's system of alpha - numeric ship designators, and its associated hull numbers, have been for several decades a unique method of categorizing ships of all types : combatants, auxiliaries and district craft. Though considerably changed in detail and expanded over the years, this system remains essentially the same as when formally implemented in 1920. It is a very useful tool for organizing and keeping track of naval vessels, and also provides the basis for the identification numbers painted on the bows ( and frequently the sterns ) of most U.S. Navy ships. The ship designator and hull number system 's roots extend back to the late 1880s, when ship type serial numbers were assigned to most of the new - construction warships of the emerging `` Steel Navy ''. During the course of the next thirty years, these same numbers were combined with filing codes used by the Navy 's clerks to create an informal version of the system that was put in place in 1920. Limited usage of ship numbers goes back even earlier, most notably to the `` Jeffersonian Gunboats '' of the early 1800s and the `` Tinclad '' river gunboats of the Civil War Mississippi Squadron. It is important to understand that hull number letter prefixes are not acronyms, and should not be carelessly treated as abbreviations of ship type classifications. Thus, `` DD '' does not stand for anything more than `` Destroyer ''. `` SS '' simply means `` Submarine ''. And `` FF '' is the post-1975 type code for `` Frigate. '' The hull classification codes for ships in active duty in the United States Navy are governed under Secretary of the Navy Instruction 5030.8 B ( SECNAVINST 5030.8 B ). Warships Warships are designed to participate in combat operations. The origin of the 2 letter code derives from the need to distinguish various cruiser subtypes. Cruiser armored ( 1921 -- 1931 ) heavy ( 1931 -- ) CA large CB battle ( prior to 1961 ) command CC light CL aviation or voler CV Destroyer ship DD escort DE Aircraft carrier type Aircraft carriers are ships designed primarily for the purpose of conducting combat operations by aircraft which engage in attacks against airborne, surface, sub-surface and shore targets. Contrary to popular belief, the `` CV '' hull classification symbol does not stand for `` carrier vessel ''. `` CV '' derives from the cruiser designation, with the v for French voler, `` to fly ''. Aircraft carriers are designated in two sequences : the first sequence runs from CV - 1 USS Langley to the very latest ships, and the second sequence, `` CVE '' for escort carriers, ran from CVE - 1 Long Island to CVE - 127 Okinawa before being discontinued. AV : Seaplane Tender ( retired ) AVG : Auxiliary Aircraft Ferry ( Escort carrier ) ( 1941 -- 42 ) AVD : Seaplane Tender Destroyer ( retired ) AVP : Seaplane Tender, Small ( retired ) AVT ( i ) Auxiliary Aircraft Transport ( retired ) AVT ( ii ) Auxiliary Training Carrier ( retired ) ACV : Auxiliary Aircraft Carrier ( Escort carrier ) ( 1942 ) CV : Fleet aircraft carrier ( 1921 -- 1975 ), multi-purpose aircraft carrier ( 1975 -- present ) CVA : Aircraft Carrier, Attack ( category merged into CV, 30 June 1975 ) CV ( N ) : Aircraft Carrier, Night ( Deck equipped with lighting and pilots trained and for nighttime fights ) ( 1944 ) ( retired ) CVAN : Aircraft Carrier, Attack, Nuclear - powered ( category merged into CVN, 30 June 1975 ) CVB : Aircraft Carrier, Large ( Original USS Midway class, category merged into CVA, 1952 ) CVE : Escort aircraft carrier ( retired ) ( 1943 -- retirement of type ) CVHA : Aircraft Carrier, Helicopter Assault ( retired in favor of several LH - series amphibious assault ship hull codes ) CVHE : Aircraft Carrier, Helicopter, Escort ( retired ) CVL : Light aircraft carrier or Aircraft Carrier, Small ( retired ) CVN : Aircraft Carrier, Nuclear - powered CVS : Antisubmarine Aircraft Carrier ( retired ) CVT : Aircraft Carrier, Training ( changed to AVT ( Auxiliary ) ) CVU : Aircraft Carrier, Utility ( retired ) CVG : Aircraft Carrier, Guided Missile ( retired ) CVV : Aircraft Carrier, Vari - Purpose, Medium ( retired unused ) Surface combatant type Surface combatants are ships which are designed primarily to engage enemy forces on the high seas. The primary surface combatants are battleships, cruisers and destroyers. Battleships are very heavily armed and armored ; cruisers moderately so ; destroyers and smaller warships, less so. Before 1920, ships were called `` < type > no. X '', with the type fully pronounced. The types were commonly abbreviated in ship lists to `` B-X '', `` C-X '', `` D-X '' et cetera -- for example, before 1920, USS Minnesota ( BB - 22 ) would have been called `` USS Minnesota, Battleship number 22 '' orally and `` USS Minnesota, B - 22 '' in writing. After 1920, the ship 's name would have been both written and pronounced `` USS Minnesota ( BB - 22 ) ''. In generally decreasing size, the types are : ACR : Armored Cruiser ( pre-1920 ) AFSB : Afloat Forward Staging Base ( also AFSB ( I ) for `` interim '', changed to ESB for Expeditionary Mobile Dock ) B : Battleship ( pre-1920 ) BB : Battleship BBG : Battleship, Guided Missile or Arsenal Ship ( theoretical only, never assigned ) BM : Monitor ( 1920 -- retirement ) C : Cruiser ( pre-1920 Protected Cruisers and Peace Cruisers ) CA : ( first series ) Cruiser, Armored ( retired, comprised all surviving pre-1920 Armored and Protected Cruisers ) CA : ( second series ) Heavy Cruiser, category later renamed Gun Cruiser ( retired ) CAG : Cruiser, Guided Missile ( retired ) CB : Large cruiser ( retired ) CBC : Large Command Cruiser ( retired, never used operationally ) CC : Battlecruiser ( retired, never used operationally ) CC : ( second usage ) Command Ship ( retired ) CLC : Command Cruiser CG : Cruiser, Guided Missile CGN : Cruiser, Guided Missile, Nuclear - powered CL : Light Cruiser Cruiser Light ( retired ) CLAA : Cruiser, Light, Anti-aircraft ( retired ) CLG : Cruiser, Light, Guided Missile ( retired ) CLGN : Cruiser, Light, Guided Missile, Nuclear - powered ( retired ) CLK : Cruiser, Hunter - Killer ( abolished 1951 ) CM : Cruiser - minelayer ( retired ) CS : Scout Cruiser ( retired ) CSGN : Strike Cruiser Cruiser, Strike, Guided Missile, Nuclear - powered D: Destroyer ( pre-1920 ) DD : Destroyer DDC : Corvette ( briefly proposed in the mid-1950s ) DDE : Escort Destroyer, a Destroyer ( DD ) converted for antisubmarine warfare -- category abolished 1962. ( not to be confused with Destroyer Escort DE ) DDG : Destroyer, Guided Missile DDK : Hunter - Killer Destroyer ( category merged into DDE, 4 March 1950 ) DDR : Destroyer, Radar Picket ( retired ) DE : Destroyer Escort ( World War II, later became Ocean escort ) DE : Ocean escort ( abolished 30 June 1975 ) DEG : Guided Missile Ocean Escort ( abolished 30 June 1975 ) DER : Radar Picket Destroyer Escort ( abolished 30 June 1975 ) There were two distinct breeds of DE, the World War II Destroyer Escorts ( some of which were converted to DERs ) and the postwar DE / DEG classes, which were known as Ocean Escorts despite carrying the same type symbol as the World War II Destroyer Escorts. All DEs, DEGs, and DERs were reclassified as FFs, FFGs, or FFRs, 30 June 1975. DL : Destroyer Leader ( later Frigate ) ( retired ) DLG : Frigate, Guided Missile ( abolished 30 June 1975 ) DLGN : Frigate, Guided Missile, Nuclear - Propulsion ( abolished 30 June 1975 ) The DL category was established in 1951 with the abolition of the CLK category. CLK 1 became DL 1 and DD 927 -- 930 became DL 2 -- 5. By the mid-1950s the term Destroyer Leader had been dropped in favor of Frigate. Most DLGs and DLGNs were reclassified as CGs and CGNs, 30 June 1975. However, DLG 6 -- 15 became DDG 37 -- 46. The old DLs were already gone by that time. DM : Destroyer, Minelayer ( retired ) DMS : Destroyer, Minesweeper ( retired ) FF : Frigate PF : Patrol Frigate ( retired ) FFG : Frigate, Guided Missile FFH : Frigate with assigned Helicopter FFL : Frigate, Light FFR : Frigate, Radar Picket ( retired ) FFT : Frigate ( Reserve Training ) ( retired ) The FF, FFG, and FFR designations were established 30 June 1975 as new type symbols for ex-DEs, DEGs, and DERs. The first new - built ships to carry the FF / FFG designation were the Oliver Hazard Perry - class frigates. In January 2015, it was announced that the LCS ship types would be redesignated as FF. PG : Patrol Gunboat ( retired ) PCH : Patrol Craft. Hydrofoil ( retired ) PHM : Patrol, Hydrofoil, Missile ( retired ) K : Corvette ( retired ) LCS : Littoral Combat Ship In January 2015, the Navy announced that the up - gunned LCS will be reclassified as a frigate, since the requirements of the SSC Task Force was to upgrade the ships with frigate - like capabilities. Hull designations will be changed from LCS to FF ; existing LCSs back - fitted with modifications may also earn the FF label. The Navy is hoping to start retrofitting technological upgrades onto existing and under construction LCSs before 2019. M : Monitor ( 1880s -- 1920 ) TB : Torpedo boat Submarine type Submarines are all self - propelled submersible types ( usually started with SS ) regardless of whether employed as combatant, auxiliary, or research and development vehicles which have at least a residual combat capability. While some classes, including all diesel - electric submarines, are retired from USN service, non-U.S. navies continue to employ SS, SSA, SSAN, SSB, SSC, SSG, SSM, and SST types. With the advent of new Air Independent Propulsion / Power ( AIP ) systems, both SSI and SSP are used to distinguish the types within the USN, but SSP has been declared the preferred term. SSK, retired by the USN, continues to be used colloquially and interchangeably with SS for diesel - electric attack / patrol submarines within the USN, and, more formally, by the Royal Navy and British firms such as Jane 's Information Group. SC : Cruiser Submarine ( retired ) SF : Fleet Submarine ( retired ) SM : Submarine Minelayer ( retired ) SS : Submarine, Attack Submarine SSA : Submarine Auxiliary, Auxiliary / Cargo Submarine SSAN : Submarine Auxiliary Nuclear, Auxiliary / Cargo Submarine, Nuclear - powered SSB : Submarine Ballistic, Ballistic Missile Submarine SSBN : Submarine Ballistic Nuclear, Ballistic Missile Submarine, Nuclear - powered SSC : Coastal Submarine, over 150 tons SSG : Guided Missile Submarine SSGN : Guided Missile Submarine, Nuclear - powered SSI : Attack Submarine ( Diesel Air - Independent Propulsion ) SSK : Hunter - Killer / ASW Submarine ( retired ) SSM : Midget Submarine, under 150 tons SSN : Attack Submarine, Nuclear - powered SSNR : Special Attack Submarine SSO : Submarine Oiler ( retired ) SSP : Attack Submarine ( Diesel Air - Independent Power ) ( alternate use ), formerly Submarine Transport SSQ : Auxiliary Submarine, Communications ( retired ) SSQN : Auxiliary Submarine, Communications, Nuclear - powered ( retired ) SSR : Radar Picket Submarine ( retired ) SSRN : Radar Picket Submarine, Nuclear - powered ( retired ) SST : Training Submarine AGSS : Auxiliary Submarine AOSS : Submarine Oiler ( retired ) ASSP : Transport Submarine ( retired ) APSS : Transport Submarine ( retired ) LPSS : Amphibious Transport Submarine ( retired ) SSLP : Transport Submarine ( retired ) SSP, ASSP, APSS, and LPSS were all the same type, redesignated over the years. IXSS : Unclassified Miscellaneous Submarine MTS : Moored Training Ship ( Naval Nuclear Power School Training Platform ; Reconditioned SSBNs ) Patrol combatant type Patrol combatants are ships whose mission may extend beyond coastal duties and whose characteristics include adequate endurance and sea keeping, providing a capability for operations exceeding 48 hours on the high seas without support. This notably included Brown Water Navy / Riverine Forces during the Vietnam War. Few of these ships are in service today. PBR : Patrol Boat, River, Brown Water Navy ( Pibber or PBR - Vietnam ) PC : Coastal Patrol, originally Sub Chaser PCF : Patrol Craft, Fast ; Swift Boat, Brown Water Navy ( Vietnam ) PE : Eagle Boat of World War I PF : World War II Frigate, based on British River class. PFG : Original designation of USS Oliver Hazard Perry ( FFG - 7 ) PG : Gunboat, later Patrol combatant PGH : Patrol Combatant, Hydrofoil PHM : Patrol, Hydrofoil Missile PR : Patrol, River, such as the USS Panay ( PR - 5 ) PT : Motor Torpedo Boat ( World War II ) PTF : Patrol Torpedo Fast, Brown Water Navy ( Vietnam ) PTG : Patrol Torpedo Gunboat Monitor : Heavily gunned riverine boat, Brown Water Navy ( Vietnam ) ASPB : Assault Support Patrol Boat, `` Alpha Boat '', Brown Water Navy ; also used as riverine minesweeper ( Vietnam ) PACV : Patrol, Air Cushion Craft, Brown Water Navy ( Vietnam ) SP : Section Patrol, used indiscriminately for patrol vessels, mine warfare vessels, and some other types ( World War I ; retired 1920 ) Amphibious warfare type Amphibious warfare vessels include all ships having organic capability for amphibious warfare and which have characteristics enabling long duration operations on the high seas. There are two classifications of craft : amphibious warfare ships which are built to cross oceans, and landing craft, which are designed to take troops from ship to shore in an invasion. Ships AKA : Attack Cargo Ship ( To LKA, 1969 ) APA : Attack Transport ( To LPA, 1969 ) APD : High speed transport ( Converted Destroyer or Destroyer Escort ) ( To LPR, 1969 ) AGC : Amphibious Force Flagship ( To LCC, 1969 ) LCC : Amphibious Command Ship LHA : General - Purpose Amphibious Assault Ship also known as Landing Helicopter Assault LHD : Multi-Purpose Amphibious Assault Ship also known as Landing Helicopter Dock LKA : Amphibious Cargo Ship ( out of commission ) LPA : Amphibious Transport LPD : Amphibious transport dock LPH : Landing Platform Helicopter LPR : High speed transport LSD : Landing Ship, Dock LSH : Landing Ship, Heavy LSIL : Landing Ship, Infantry ( Large ) ( formerly LCIL ) LSL : Landing Ship, Logistics LSM : Landing Ship, Medium LSM ( R ) : Landing Ship, Medium ( Rocket ) LSSL : Landing Ship, Support ( Large ) ( formerly LCSL ) LST : Landing Ship, Tank LST ( H ) : Landing Ship, Tank ( Hospital ) LSV : Landing Ship, Vehicle Landing Craft LCA : Landing Craft, Assault LCAC : Landing Craft Air Cushion LCFF : ( Flotilla Flagship ) LCH : Landing Craft, Heavy LCI : Landing Craft, Infantry, World War II era classification further modified by ( G ) -- Gunboat ( L ) -- Large ( M ) -- Mortar ( R ) -- Rocket LCL : Landing Craft, Logistics ( UK ) LCM : Landing Craft, Mechanized LCP : Landing Craft, Personnel LCP ( L ) : Landing Craft, Personnel, Large LCP ( R ) : Landing Craft, Personnel, Ramped LCPA : Landing Craft, Personnel, Air - Cushioned LCS ( L ) : Landing Craft, Support ( Large ) changed to LSSL in 1949 LCT : Landing Craft, Tank ( World War II era ) LCU : Landing Craft, Utility LCVP : Landing Craft, Vehicle and Personnel LSH : Landing Ship Heavy ( Royal Australian Navy ) Expeditionary support Operated by Military Sealift Command, have ship prefix `` USNS '', hull code begins with `` T - ''. ESD : Expeditionary Transfer Dock ESB : Expeditionary Mobile Base ( a variant of ESD, formerly AFSB ) EPF : Expeditionary Fast Transport MLP : Mobile Landing Platform ( changed to ESD ) JHSV : Joint High Speed Vessel ( changed to EPF ) HST : High Speed Transport ( similar to JHSV, not to be confused with WWII - era High speed transport ( APD ) ) HSV : High Speed Vessel Combat logistics type Ships which have the capability to provide underway replenishment to fleet units. AC : Collier ( retired ) AE : Ammunition Ship AF : Stores Ship ( retired ) AFS : Combat Stores Ship AKE : Advanced Dry Cargo Ship AKS : General Stores Ship AO : Fleet Oiler AOE : Fast Combat Support Ship AOR : Replenishment Oiler AW : Distilling Ship ( retired ) Mine warfare type Mine warfare ships are those ships whose primary function is mine warfare on the high seas. ADG : Degaussing Ship AM : Minesweeper AMb : Harbor Minesweeper AMc : Coastal Minesweeper AMCU : Underwater Mine Locater AMS : Motor Minesweeper CM : Cruiser ( i.e., Large ) Minelayer CMc : Coastal Minelayer DM : High Speed Minelayer ( Converted Destroyer ) DMS : High Speed Minesweeper ( Converted Destroyer ) MCM : Mine Countermeasures Ship MCS : Mine Countermeasures Support Ship MH ( C ) ( I ) ( O ) ( S ) : Minehunter, ( Coastal ) ( Inshore ) ( Ocean ) ( Hunter and Sweeper, General ) MLC : Coastal Minelayer MSC : Minesweeper, Coastal MSO : Minesweeper, Ocean PCS : Submarine Chasers ( wooden ) fitted for minesweeping YDG : District Degaussing Vessel Coastal defense type Coastal defense ships are those whose primary function is coastal patrol and interdiction. FS : Corvette PB : Patrol boat PBR : Patrol Boat, River PC : Patrol, Coastal PCE : Patrol Craft, Escort PCF : Patrol Craft, Fast, ( Swift Boat ) PF : Frigate, in a role similar to World War II Commonwealth corvette PG : Patrol Gunboat PGM : Motor Gunboat ( To PG, 1967 ) PR : Patrol, River SP : Section Patrol Mobile logistics type Mobile logistics ships have the capability to provide direct material support to other deployed units operating far from home ports. AD : Destroyer Tender AGP : Patrol Craft Tender AR : repair ship AS : Submarine tender AV : Seaplane Tender Auxiliary type An auxiliary ship is designed to operate in any number of roles supporting combatant ships and other naval operations. AN : Net Laying Ship ARL : Auxiliary Repair Light -- light craft or landing craft repair ship ( World War II - era, out of commission ) ATF : Fleet Ocean Tug AGHS : Patrol Combatant Support Ship -- Ocean or Inshore Airships Although technically an aircraft, pre-World War II rigid airships ( e.g., zeppelins ) were treated like commissioned surface warships and submarines, flew the U.S. ensign from their stern and carried a United States Ship ( USS ) designation. Non-rigid airships ( e.g., blimps ) continued to fly the U.S. ensign from their stern, but were always considered to be primarily aircraft. ZMC : Airship Metal Clad ZNN - G : G - Class Blimp ZNN - J : J - Class Blimp ZNN - L : L - Class Blimp ZNP - K : K - Class Blimp ZNP - M : M - Class Blimp ZNP - N : N - Class Blimp ZPG - 3W : surveillance patrol blimp ZR : Rigid Airship ZRS : Rigid Airship Scout Support ships Support ships are not designed to participate in combat, and are generally not armed. For ships with civilian crews ( owned by and / or operated for Military Sealift Command and the Maritime Administration ), the prefix T - is placed at the front of the hull classification. Support type Support ships are designed to operate in the open ocean in a variety of sea states to provide general support to either combatant forces or shore based establishments. They include smaller auxiliaries which, by the nature of their duties, leave inshore waters. AC : Collier ( retired ) ACS : Auxiliary Crane Ship AG : Miscellaneous Auxiliary AGDE : Testing Ocean Escort AGDS : Deep Submergence Support Ship AGER ( i ) : Miscellaneous Auxiliary, Electronic Reconnaissance AGER ( ii ) : Environmental Research Ship AGF : Miscellaneous Command Ship AGFF : Testing Frigate AGL : Auxiliary vessel, lighthouse tender AGM : Missile Range Instrumentation Ship AGOR : Oceanographic Research Ship AGOS : Ocean Surveillance Ship AGP : Motor Torpedo Boat Tender AGS : Surveying Ship AGSE : Submarine and Special Warfare Support AGSS : Auxiliary Research Submarine AGTR : Technical research ship AH : Hospital ship AK : Cargo Ship AKR : Vehicle Cargo Ship AKS : Store Issue Ship AO : Oiler AOE : Fast Combat Support Ship AOR : Replenishment oiler ( retired ) AOG : Gasoline Tanker AOT : Transport Oiler AP : Transport ARC : Cable Repair Ship ( see also Cable layer ) ARG : Internal Combustion Engine repair ship APB : Self - propelled Barracks Ship APL : Barracks Craft ARB : Battle Damage Repair Ship ARL : Small Repair Ship ARS : Salvage Ship AS : Submarine tender ASR : Submarine Rescue Ship AT : Ocean - Going Tug ATA : Auxiliary Ocean Tug ATF : Fleet Ocean Tug ATLS Drone Launch Ship ATS : Salvage and Rescue Ship AVB ( i ) : Aviation Logistics Support Ship AVB ( ii ) : Advance Aviation Base Ship AVS : Aviation Stores Issue Ship AVT ( i ) : Auxiliary Aircraft Transport AVT ( ii ) : Auxiliary Aircraft Landing Training Ship EPCER : Experimental -- Patrol Craft Escort -- Rescue ID or Id. No. : Civilian ship taken into service for auxiliary duties, used indiscriminately for large ocean - going ships of all kinds and coastal and yard craft ( World War I ; retired 1920 ) PCER : Patrol Craft Escort -- Rescue SBX : Sea - based X-band Radar -- a mobile active electronically scanned array early - warning radar station. Service type craft Service craft are navy - subordinated craft ( including non-self - propelled ) designed to provide general support to either combatant forces or shore - based establishments. The suffix `` N '' refers to non-self - propelled variants. AB : Crane Ship AFDB : Large Auxiliary Floating Dry Dock AFD / AFDL : Small Auxiliary Floating Dry Dock AFDM : Medium Auxiliary Floating Dry Dock APB : Self - Propelled Barracks Ship APL : Barracks Craft ARD : Auxiliary Repair Dry Dock ARDM : Medium Auxiliary Repair Dry Dock USS Oak Ridge ( ARDM - 1 ) ATA : Auxiliary Ocean Tug DSRV : Deep Submergence Rescue Vehicle DSV : Deep Submergence Vehicle JUB / JB : Jack Up Barge NR : Submersible Research Vehicle YC : Open Lighter YCF : Car Float YCV : Aircraft Transportation Lighter YD : Floating Crane YDT : Diving Tender YF : Covered Lighter YFB : Ferry Boat or Launch YFD : Yard Floating Dry Dock YFN : Covered Lighter ( non-self propelled ) YFNB : Large Covered Lighter ( non-self propelled ) YFND : Dry Dock Companion Craft ( non-self propelled ) YFNX : Lighter ( Special purpose ) ( non-self propelled ) YFP : Floating Power Barge YFR : Refrigerated Cover Lighter YFRN : Refrigerated Covered Lighter ( non-self propelled ) YFRT : Range Tender YFU : Harbor Utility Craft YG : Garbage Lighter YGN : Garbage Lighter ( non-self propelled ) YH : Ambulance boat / small medical support vessel YLC : Salvage Lift Craft YM : Dredge YMN : Dredge ( non-self propelled ) YNG : Gate Craft YNT : Net Tender YO : Fuel Oil Barge YOG : Gasoline Barge YOGN : Gasoline Barge ( non-self propelled ) YON : Fuel Oil Barge ( non-self propelled ) YOS : Oil Storage Barge YP : Patrol Craft, Training YPD : Floating Pile Driver YR : Floating Workshop YRB : Repair and Berthing Barge YRBM : Repair, Berthing and Messing Barge YRDH : Floating Dry Dock Workshop ( Hull ) YRDM : Floating Dry Dock Workshop ( Machine ) YRR : Radiological Repair Barge YRST : Salvage Craft Tender YSD : Seaplane Wrecking Derrick YSR : Sludge Removal Barge YT : Harbor Tug ( craft later assigned YTB, YTL, or YTM classifications ) YTB : Large Harbor Tug YTL : Small Harbor Tug YTM : Medium Harbor Tug YTT : Torpedo Trials Craft YW : Water Barge YWN : Water Barge ( non-self propelled ) ID or Id. No. : Civilian ship taken into service for auxiliary duties, used indiscriminately for large ocean - going ships of all kinds and coastal and yard craft ( World War I ; retired 1920 ) IX : Unclassified Miscellaneous Unit X : Submersible Craft `` none '' : To honor her unique historical status, USS Constitution, formerly IX 21, was reclassified to `` none '', effective 1 September 1975. United States Coast Guard craft Prior to 1965, U.S. Coast Guard ships used the same designation as naval ships, but preceded by a `` W '' to indicate Coast Guard subordination. CG : all Coast Guard Ships in the 1920s ( retired ) WAGB : Coast Guard Polar - class icebreaker WAGL : Auxiliary vessel, lighthouse tender ( retired 1960 's ) WAVP : seagoing Coast Guard seaplane tenders ( retired 1960s ) WDE : seagoing Coast Guard destroyer escorts ( retired 1960s ) WHEC : Coast Guard High Endurance Cutters WIX : Coast Guard Barque Eagle WLB : Coast Guard buoy tenders WLBB : Coast Guard seagoing buoy tenders / ice breaker WLM : Coast Guard coastal buoy tenders WLI : Coast Guard inland buoy tenders WLIC : Coast Guard inland construction tenders WLR : Coast Guard river buoy tenders WMEC : Coast Guard Medium Endurance Cutters WMSL : Coast Guard Maritime Security Cutter, Large ( referred to as National Security Cutters ) WPC : Coast Guard patrol craft -- later reclassed under WHEC WPB : Coast Guard Patrol Boats WPG : seagoing Coast Guard gunboats ( retired 1960s ) WTGB : Coast Guard Tug Boat ( 140 ' icebreakers ) WYTL : Small harbor Tug Temporary Designations United States Navy Designations ( Temporary ) are a form of U.S. Navy ship designation, intended for temporary identification use. Such designations usually occur during periods of sudden mobilization, such as that which occurred prior to, and during, World War II or the Korean War, when it was determined that a sudden temporary need arose for a ship for which there was no official Navy designation. During World War II, for example, a number of commercial vessels were requisitioned, or acquired, by the U.S. Navy to meet the sudden requirements of war. A yacht acquired by the U.S. Navy during the start of World War II might seem desirable to the Navy whose use for the vessel might not be fully developed or explored at the time of acquisition. On the other hand, a U.S. Navy vessel, such as the yacht in the example above, already in commission or service, might be desired, or found useful, for another need or purpose for which there is no official designation. IX : Unclassified Miscellaneous Auxiliary Ship, for example yacht Chanco acquired by the U.S. Navy on 1 October 1940. It was classified as a minesweeper AMc - 5, but instead, mainly used as a patrol craft along the New England coast. When another assignment came, and it could not be determined how to classify the vessel, it was redesignated IX - 175 on 10 July 1944. IXSS : Unclassified Miscellaneous Submarines, such as the USS Cod ( IXSS - 224 ), the USS Angler ( IXSS - 240 ) and the USS Croaker ( IXSS - 246 ). YAG : Miscellaneous Auxiliary Service Craft, such as the USS George Eastman ( YAG - 39 ), USS Butternut ( YAG - 60 ) and USS Christiana ( YAG - 32 ) which, curiously, was earlier known as IX - 80. Numerous other U.S. Navy vessels were launched with a temporary, or nominal, designation, such as YMS or PC, since it could not be determined, at time of construction, what they should be used for. Many of these were vessels in the 150 to 200 feet length class with powerful engines, whose function could be that of a minesweeper, patrol craft, submarine chaser, seaplane tender, tugboat, or other. Once their destiny, or capability, was found or determined, such vessels were reclassified with their actual designation. National Oceanic and Atmospheric Administration hull codes R : Research ships, including oceanographic and fisheries research ships S : Survey ships, including hydrographic survey ships The letter is paired with a three - digit number. The first digit of the number is determined by the ship 's `` power tonnage, '' defined as the sum of its shaft horsepower and gross international tonnage, as follows : If the power tonnage is 5,501 through 9,000, the first digit is `` 1 ''. If the power tonnage 3,501 through 5,500, the first digit is `` 2. '' If the power tonnage is 2,001 through 3,500, the first digit is `` 3. '' If the power tonnage is 1,001 through 2,000, the first digit is `` 4. '' If the power tonnage is 501 through 1,000, the first digit is `` 5. '' If the power tonnage is 500 or less and the ship is at least 65 feet ( 19.8 meters ) long, the first digit is `` 6. '' The second and third digits are assigned to create a unique three - digit hull number. See also United States Navy 1975 ship reclassification List of hull classifications Ship prefix Hull classification symbol ( Canada ) Pennant number for the British Commonwealth equivalent Notes Jump up ^ This odd entry is not recognised by the U.S. Naval Vessel Register, and appears only in MIL - STD - 2525A : Common Warfighting Symbology ( 15 December 1996 ) and later editions ( MIL - STD - 2525B : Common Warfighting Symbology ( 30 January 1999 ) and MIL - STD - 2525C : Common Warfighting Symbology ( 17 November 2008 ) ). It seems to refer to some kind of nuclear - powered submarine used by Special Operations Forces. Footnotes Jump up ^ See USS Kentucky ( BB - 66 ). Jump up ^ See USS Hawaii ( CB - 3 ). Jump up ^ See Lexington - class battlecruiser. ^ Jump up to : See USS Northampton ( CLC - 1 ). ^ Jump up to : see USS Norfolk ( DL - 1 ). Citations Jump up ^ Naval History and heritage Command Online Library of Selected Images ( at http://www.history.navy.mil/photos/shusn-no/spid-no.htm ). Jump up ^ United States Department of State, United States Treaties and Other International Obligations, Volume 23, Part Four, Washington, D.C. : U.S. Government Printing Office, 1972, p. 3612. Jump up ^ United States Department of Commerce, Annual Report of the Director of the Coast and Geodetic Survey for the Fiscal Year Ending June 30, 1964, U.S. Government Printing Office, Washington, D.C. : 1964, pp. 3 -- 5. Jump up ^ Derdall and DiGiulian, ( section : Nomenclature history ) Jump up ^ Wertheim, The Naval Institute Guide to Combat Fleets of the World, 15th Edition : Their Ships, Aircraft, and Systems, p. 1005. Jump up ^ `` U.S. Navy Ships -- Listed by Hull Number ''. Naval History and Heritage Command. Jump up ^ Derdall and DiGiulian, ( section : Cruisers ) Jump up ^ Bureau of Aeronautics, Navy Department. `` New Carrier Designations ''. BuAER News ( title later changed to Naval Aviation News ). Washington, D.C. No. 198 ( 1 Aug 1943 ) p. 9. Jump up ^ United States. Office of Naval History. Glossary of U.S. Naval Abbreviations. 3d ed. Washington : U.S. Govt. Print. Off., 1947. p. 20. Jump up ^ United States. Office of Naval Records and History. Glossary of US Naval Abbreviations. 5th ed. Washington : U.S. Govt. Print. Off., 1949. Naval History and Heritage Command. accessed 6 May 2017. Jump up ^ http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=AD0757047 Jump up ^ Friedman, Norman ( 2003 ). U.S. Destroyers : An Illustrated Design History ( Revised ed. ). Annapolis, MD : U.S. Naval Institute Press. pp. 266 -- 267. ISBN 978 - 1 - 55750 - 442 - 5. Retrieved 2010 - 05 - 24... a gutted Benson - class destroyer. This `` corvette '' ( DDC ) `` can be readily obtained... '' Jump up ^ DiGiulian, Tony. `` History and Technology -- USN Ship Designations ''. www.navweaps.com. Jump up ^ SNA : Modified Littoral Combat Ships to be Designated Frigates -- News.USNI.org, 15 January 2015 Jump up ^ Navy Plans to Expand, Speed - Up LCS Modifications -- Military.com, 4 March 2015 Jump up ^ Russia still employs several SSA and SSAN class submarines like the Delta Stretch as well as one SST, China has older SSB and SSG types such as the Golf and Mod Romeo classes, and North Korea has built many SSCs and SSMs. See 2007 -- 2008 Jane 's Fighting Ships. Jump up ^ U.S. Navy Ship And Service Craft Classifications Archived 16 October 2004 at the Wayback Machine. Jump up ^ Buff, Joe ( June 2007 ). `` Subs in the Littoral : Diesels Just Blowing Smoke ? ''. Proceedings of the Naval Institute. 133 ( 6 ) : 40 -- 43. ISSN 0041 - 798X. Retrieved 2007 - 06 - 13. Diesel AIP boats are known as SSIs, differentiating them from purely diesel - electric - powered hunter - killer subs, or SSKs. Jump up ^ Inactive Classification Symbols Archived 18 January 2012 at the Wayback Machine. Jump up ^ 28034_cov. fh Archived 27 September 2007 at the Wayback Machine. Jump up ^ `` Hull Classification Symbol ''. militarypower.wikidot.com. Retrieved 17 January 2018. Jump up ^ `` PCER - 848 ''. navsource. Retrieved 21 December 2017. Jump up ^ Abunassar, US Department of Commerce, NOAA Office of the Chief Administrative Officer ( OCAO ). Elias. `` National Oceanic and Atmospheric Administration ( NOAA ) Home Page ''. www.corporateservices.noaa.gov. References Derdall, Guy ; DiGiulian, Tony ( 12 November 2016 ). `` USN Ship Designations ''. navweaps.com. Retrieved 8 March 2017. United States Naval Aviation 1910 -- 1995, Appendix 16 : U.S. Navy and Marine Corps Squadron Designations and Abbreviations. U.S. Navy, c. 1995. Quoted in Derdall and DiGiulian, op cit. `` ACP 113 ( AF ) Call Sign Book for Ships '' ( PDF ). NATO. September 2004. Archived from the original ( PDF ) on 27 February 2009. Retrieved 2 July 2008. USCG Designations Naval History and Heritage Command Online Library of Selected Images : U.S. Navy Ships -- Listed by Hull Number : `` SP '' # s and `` ID '' # s -- World War I Era Patrol Vessels and other Acquired Ships and Craft Wertheim, Eric. The Naval Institute Guide to Combat Fleets of the World, 15th Edition : Their Ships, Aircraft, and Systems. Annapolis, Maryland : Naval Institute Press, 2007. ISBN 978 - 1 - 59114 - 955 - 2. ISSN 1057 - 4581. Further reading Friedman, Norman. U.S. Small Combatants, Including PT - Boats, Subchasers, and the Brown - Water Navy : An Illustrated Design History. Annapolis, Md : Naval Institute Press, 1987. ISBN 0 - 87021 - 713 - 5. 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Question: what does dd stand for in the navy
Answer: Destroyer