United States Navy ships

The names of commissioned ships of the United States Navy all start with USS, for United States Ship. Non-commissioned, primarily civilian-manned vessels of the U.S. Navy under the Military Sealift Command have names that begin with USNS, standing for United States Naval Ship. A letter-based hull classification symbol is used to designate a vessel's type. The names of ships are selected by the Secretary of the Navy. The names are those of states, cities, towns, important persons, important locations, famous battles, fish, and ideals. Usually, different types of ships have names originated from different types of sources.
Modern aircraft carriers and submarines use nuclear reactors for power. See United States naval reactors for information on classification schemes and the history of nuclear-powered vessels.
Modern cruisers, destroyers and frigates are called surface combatants and act mainly as escorts for aircraft carriers, amphibious assault ships, auxiliaries and civilian craft, but the largest ones have gained a land attack role through the use of cruise missiles and a population defense role through missile defense.
Aircraft carriers.
Aircraft carriers (CVN) have the ability to put most nations within striking distance of U.S. air power which makes them the cornerstone of US forward deployment and deterrence strategy. Multiple carriers are deployed around the world to provide military presence, respond quickly to crises, and participate in joint exercises with allied forces; this has led the Navy to refer to their "Nimitz"-class carriers as "4.5 acres of sovereign and mobile American territory". "In accordance with customary international law as reflected in United Nations Convention on the Law of the Sea and as discussed in "The Commander's Handbook on the Law of Naval Operations" and The State Department Cable on the Status of Military Sealift Command Vessels, ships owned or operated by a State and used, for the time being, only on government non-commercial service are entitled to sovereign immunity. Whether in internal, territorial, or international waters, such ships are immune from arrest and search, and exempt from foreign taxation and any foreign regulation requiring flying the flag of that foreign state while in its ports or territorial sea." Former President Bill Clinton summed up the importance of the aircraft carrier by stating that "when word of crisis breaks out in Washington, it's no accident the first question that comes to everyone's lips is: where is the nearest carrier?" The power and operational flexibility of a carrier lie in the aircraft of its carrier air wing. Made up of both fixed-wing and rotary-wing aircraft, a carrier air wing is able to perform over 150 strike missions at once, hitting over 700 targets a day. Carrier air wings also protect friendly forces, conduct electronic warfare, assist in special operations, and carry out search and rescue missions. The carriers themselves, in addition to enabling airborne operations, serve as command platforms for large battle groups or multinational task forces. U.S. Navy aircraft carriers can also host aircraft from other nations' navies; the French Navy's Rafale has operated, during naval exercises, from U.S. Navy flight decks.
Amphibious warfare ships.
Amphibious assault ships.
Amphibious assault ships, sub-types known as landing, helicopter dock or LHD and landing, helicopter assault or LHA. (also referred to as a commando carrier or an amphibious assault carrier), are a type of amphibious warfare ship employed to land and support ground forces on enemy territory by an amphibious assault. The design evolved from aircraft carriers converted for use as helicopter carriers, but includes support for amphibious landing craft, with most designs including a well deck. Coming full circle, some amphibious assault ships now have a secondary role as aircraft carriers, supporting V/STOL fixed-wing aircraft.
The role of the amphibious assault ship is fundamentally different from a standard aircraft carrier: its aviation facilities have the primary role of hosting helicopters to support forces ashore rather than to support strike aircraft. However, some are capable of serving in the sea-control role, embarking aircraft like Harrier fighters for CAP and anti-submarine warfare helicopters or operating as a safe base for large numbers of STOVL fighters conducting air support for the Marine expeditionary unit once it has gone ashore. Most of these ships can also carry or support landing craft, such as air-cushioned landing craft (hovercraft) or LCUs.
Amphibious command ships.
Amphibious command ships (LCC) of the United States Navy are large, special purpose ships, originally designed to command large amphibious invasions. However, as amphibious invasions have become less likely, they are now used as general command ships, and serve as floating headquarters for two, forward deployed, numbered Fleet commands. Currently, they are assigned to the 6th and 7th fleets as flagships.
Amphibious transport docks.
Amphibious transport docks, also known as landing platform dock or LPD, is an amphibious warfare ship, a warship that embarks, transports, and lands elements of a landing force for expeditionary warfare missions. Several navies currently operate this kind of ship. The ships are generally designed to transport troops into a war zone by sea, primarily using landing craft, although invariably they also have the capability to operate transport, utility and attack helicopters and multi-mission tilt-rotor aircraft.
Dock landing ships.
Dock landing ships, also known as landing ship, dock or LSD, are amphibious warfare ships with well docks to transport and launch landing craft and amphibious vehicles. Some ships with well decks, such as the Soviet Ivan Rogov class, also have bow doors to enable them to deliver vehicles directly onto a beach (like a Landing Ship, Tank). Modern dock landing ships also operate helicopters.
A ship with a well deck (docking well) can transfer cargo to landing craft in rougher seas than a ship that has to use cranes or a stern ramp. The US Navy hull classification symbol for a ship with a well deck depends on its facilities for aircraft - a (modern) LSD has a helicopter deck, a LPD also has a hangar, and a LHD or LHA has a full-length flight deck.
Expeditionary sea base.
Expeditionary sea bases are semi-submersible, flexible, modular platforms providing that perform large-scale logistics movements such as the transfer of vehicles and equipment from sea to shore. These ships significantly reduce the dependency on foreign ports and provide support in the absence of port availability.
Cruisers.
Cruisers and guided missile cruisers CG are a type of warship. The term has been in use for several hundred years, and has had different meanings throughout this period. During the Age of Sail, the term "cruising" referred to certain kinds of missions – independent scouting, raiding or commerce protection – fulfilled by a frigate or sloop, which were the "cruising warships" of a fleet.
In the middle of the 19th century, "cruiser" came to be a classification for the ships intended for this kind of role, though cruisers came in a wide variety of sizes, from the small protected cruiser to armored cruisers that were as large (although not as powerful) as a battleship.
By the early 20th century, cruisers could be placed on a consistent scale of warship size, smaller than a battleship but larger than a destroyer. In 1922, the Washington Naval Treaty placed a formal limit on cruisers, which were defined as warships of up to 10,000 tons displacement carrying guns no larger than 8 inches in calibre. These limits shaped cruisers until the end of World War II. The very large battlecruisers of the World War I era were now classified, along with battleships, as capital ships.
In the later 20th century, the obsolescence of the battleship left the cruiser as the largest and most powerful surface combatant (excluding aircraft carriers). The role of the cruiser varied according to ship and navy, often including air defense, commerce raiding, and shore bombardment. The U.S. Navy in the Cold War period built guided-missile cruisers primarily designed to provide air defense, while the navy of the USSR built battlecruisers with heavy anti-ship missiles designed to sink NATO carrier task forces.
Destroyers.
Destroyers DDG are fast maneuverable long-endurance warships intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller powerful short-range attackers. They were originally developed in the late 19th century as a defence against torpedo boats, and by the time of the Russo-Japanese War in 1904, these "torpedo boat destroyers" (TBD) were "large, swift, and powerfully armed torpedo boats designed to destroy other torpedo boats."
Before World War II, destroyers were light vessels with little endurance for unattended ocean operations; typically a number of destroyers and a single destroyer tender operated together. After the war, the advent of the guided missile allowed destroyers to take on the surface combatant roles previously filled by battleships and cruisers. This resulted in larger and more powerful guided missile destroyers more capable of independent operation.
At the start of the 21st century, destroyers are the heaviest surface combatant ships in general use, with only two nations (United States and Russia) currently operating the heavier class cruisers, with no battleships or true battlecruisers remaining. Modern destroyers, also known as guided missile destroyers, are equivalent in tonnage but vastly superior in firepower to cruisers of the World War II era, capable of carrying nuclear tipped cruise missiles. Guided missile destroyers such as the "Arleigh Burke" class are actually larger and more heavily armed than most previous ships classified as guided missile cruisers, due to their massive size at long, displacement (9200 tons) and armament of over 90 missiles.
Guided-missile destroyers are destroyers designed to launch guided missiles. Many are also equipped to carry out anti-submarine, anti-air, and anti-surface operations. The NATO standard designation for these vessels is DDG. Nations vary in their use of destroyer D designation their hull pennant numbering, either prefixing, or dropping it altogether. The U.S. Navy has adopted the classification DDG in the American hull classification system.
In addition to the guns that destroyers have, a guided-missile destroyer is usually equipped with two large missile magazines, usually in vertical-launch cells. Some guided-missile destroyers contain powerful radar systems, such as the United States’ Aegis Combat System, and may be adopted for use in an anti-missile or ballistic-missile defense role. This is especially true of navies that no longer operate cruisers, as other vessels must be adopted to fill in the gap.
Frigates.
Frigates FF or FFG (according to the modern classification of U.S. navy warships) are smaller ships than destroyers. They are designed primarily to protect other ships (such as merchant convoys), and perform some Anti-Submarine Warfare duties. They are cheaper but of more limited capability than destroyers. The last active class of frigates in the US Navy was the , decommissioned in September 2015, leaving the navy no active frigates.
On January 15, 2015 U.S. Navy Secretary Ray Mabus announced that ships of the Littoral Combat Ship (LCS) classes built in the future would be re-classified as "frigates". This would apply only to the future variations of these ships. Current ships will retain the LCS classification unless and until they are upgraded to the standards of the newer ships.
On April 30, 2020, the US Navy awarded a contract to design and produce the next generation small surface combatant, the Guided Missile Frigate (FFG(X)). The contract for detail design and construction (DD&C) of up to 10 Guided Missile Frigates (consisting of one base ship and nine option ships) was awarded to Fincantieri Marinette Marine Corporation (MMC) of Marinette, Wisconsin. The FFG(X) will have multi-mission capability to conduct air warfare, anti-submarine warfare, surface warfare, electronic warfare, and information operations. Specifically FFG(X) will include an Enterprise Air Surveillance Radar (EASR) radar, Baseline Ten (BL10) AEGIS Combat System, a Mk 41 Vertical Launch System (VLS), communications systems, MK 57 Gun Weapon System (GWS) countermeasures and added capability in the EW/IO area with design flexibility for future growth.
Littoral combat ships.
Littoral combat ships LCS are a class of relatively small surface vessels intended for operations in the littoral zone (close to shore) by the United States Navy. It was "envisioned to be a networked, agile, stealthy surface combatant capable of defeating anti-access and asymmetric threats in the littorals."
The and the are the first two LCS variants. Both are slightly smaller than the U.S. Navy's guided missile frigates and have been likened to corvettes. They have the capabilities of a small assault transport, including a flight deck and hangar for housing two SH-60 or MH-60 Seahawk helicopters, a stern ramp for operating small boats, and the cargo volume and payload to deliver a small assault force with fighting vehicles to a roll-on/roll-off port facility. Standard armaments include Mk 110 57 mm guns and RIM-116 Rolling Airframe Missiles. They are also equipped with autonomous air, surface, and underwater vehicles. Possessing lower air defense and surface warfare capabilities than destroyers, the LCS concept emphasizes speed, flexible mission modules and a shallow draft.
The first littoral combat ship, , was commissioned on 8 November 2008 in Veteran's Park, Milwaukee, Wisconsin. The second ship, and first of the trimaran design, , was commissioned on 16 January 2010, in Mobile, Alabama. In 2012, CNO Jonathan W. Greenert stated that LCSs would be deployed to Africa in place of destroyers and cruisers. In late 2014, the Navy proceeded with a procurement plan for enhanced versions of the LCS and upgraded older ships to meet the program's 52-ship requirement; the modified LCS will be redesignated as FF. In December 2015, Secretary of Defense Ashton Carter ordered the Navy to reduce the planned LCS/FF procurement from 52 to 40, and downselect to one variant by FY 2019.
It was announced in January 2015 that future and retrofitted versions of these two classes will be re-classified as frigates. The navy has currently built and/or planned out to 24 of a total of 52 ships.
Mine countermeasures ships.
Mine countermeasures vessels or MCM are a type of naval ship designed for the location of and destruction of naval mines which combines the role of a minesweeper and minehunter in one hull. The term MCMV is also applied collectively to minehunters and minesweepers.
A "minesweeper" is a small naval warship designed to engage in minesweeping. Using various mechanisms intended to counter the threat posed by naval mines, waterways are maintained clear for safe shipping.
A "minehunter" is a naval vessel that actively detects and destroys individual naval mines.
Patrol ships.
Patrol ships PC are relatively small naval vessels generally designed for coastal defense duties. There have been many designs for patrol boats. They may be operated by a nation's navy, coast guard, police force or customs and may be intended for marine (blue water) and/or estuarine or river ("brown water") environments. They are commonly found engaged in various border protection roles, including anti-smuggling, anti-piracy, fisheries patrols, and immigration law enforcement. They are also often called upon to participate in rescue operations. Vessels of this type include the original yacht (from Dutch/Low German "jacht" meaning hunting or hunt), a light, fast-sailing vessel used by the Dutch navy to pursue pirates and other transgressors around and into shallow waters.
Submarines.
Submarines SSN, SSBN, SSGN are watercraft capable of independent operation underwater. There are currently two types; attack and ballistic. "Attack submarines" (SSN) have tactical missions, including controlling naval and shipping activity, serving as cruise missile-launching platforms, and intelligence-gathering. "Ballistic submarines" (SSBN) primarily have the single strategic mission of nuclear deterrence by being hidden launching-platforms for nuclear ICBMs. However, some of these boats have been converted to (SSGN) and launch standard cruise missiles.
Future requirements.
In a 2012 study called the "Force Structure Assessment", the Navy determined a post-2020 battle-force requirement of 306 ships. 
Historically significant vessels.
The U.S. Navy has operated a number of vessels important to both United States and world naval history: