I.

Introduction

Naval Vessels, ships designed for the various operations involved in modern naval warfare. The following survey identifies only the principal classes of United States naval vessels, except for submarines and aircraft carriers, described in separate articles. Most navies in the world today maintain only the smaller types of vessels discussed in this article.

II.

Battleship

The modern battleship traces its ancestry to the 74-gun ship-of-the-line of the sailing era. It is also the product of a series of modifications of the heavy steel ships that formed the backbone of the so-called New Navy of the 1880s, when the steel industry was introduced in the United States. The mission of the battleship was to conduct sustained combat operations at sea worldwide; to operate as an element of a carrier battle group or amphibious group; and in areas of lesser threat, to be capable of surface-action group operations with appropriate antisubmarine and antiair warfare escort ships.

The four battleships of the Iowa class were modernized and recommissioned in the 1980s. All were decommissioned in the 1990s. In addition to their nine 406-mm (16-in) guns in three turrets, used primarily for shore bombardment, each carries twelve 127-mm (5-in) twin batteries for antiaircraft protection, four Phalanx close-in weapons systems for defense against antiship missiles, and sixteen Tomahawk cruise missiles for surface warfare and land attack. Crew levels have dropped from 6,000 (during World War II) to 1,700 enlisted personnel and 100 officers. The sides, superstructure, and deck of the ship consist of steel plate armor varying in thickness from 13 to 41 cm (5 to 16 in). A battleship of the Iowa class measures 270 m (885 ft) in length and 33 m (108 ft) in beam; it displaces about 58,000 tons at full load and attains speeds of 33 knots.

III.

Cruiser

The cruiser replaced the fast frigate of the early U.S. Navy. During its evolution, it has served many roles; it has been used in commerce, raiding, communications control, screening, antiaircraft defense, escorting aircraft carriers, and supporting amphibious landings. Today, its mission is to destroy enemy surface ships, submarines, aircraft, and missiles. In addition to 5-in. guns, missiles such as Harpoon and Tomahawk, the Phalanx system, antisubmarine warfare helicopters, and torpedoes comprise some of the cruiser's firepower. Displacement ranges from 7,500 to 12,000 tons, length from 162 to 243 m (533 to 796 ft), and beam from 17 to 22 m (55 to 73 ft). Many cruisers now have the AEGIS surface-to-air missile system, a highly sophisticated and capable weapons system. Some cruisers are conventionally fueled and others are nuclear powered; their speed is about 30 knots. Crew members average about 550.

IV.

Destroyer

The destroyer is a light, fast, hard-hitting ship that serves a great variety of functions because of its speed, armament, and maneuver-ability. It replaced the sloop of war of the navy of the sailing era and evolved from the torpedo-boat destroyer designed to combat the torpedo boat. After the submarine was introduced into naval warfare, the destroyer, with acoustic and electronic underwater detection devices, was used for locating and destroying enemy submarines. Destroyers also served as protective screens against enemy submarines for larger ships, as smoke-screen layers, as airplane guards for carriers, as escort ships for convoys, and as support ships for amphibious landings. They now provide antiair, antisurface, and antisubmarine warfare capabilities. Armed with 5-in. guns, a variety of antiship missiles, the Phalanx system, antisubmarine helicopters, and torpedoes, destroyers are ready to execute their missions. They displace from 5,000 to 8,300 tons, measure from 133 to 172 m (437 to 563 ft) in length and from 14 to 18 m (47 to 59 ft) in beam, range in speed from 30 to 33 knots, and have crews of about 400.

V.

Frigate

The frigate and the guided-missile frigate differ from the standard destroyer in many respects. The frigate was designed as a special category of antisubmarine vessel. It serves as an ocean escort with amphibious-task groups, underway-replenishment groups, and convoys. The frigate is 126 to 135 m (414 to 445 ft) in length, has a beam of 12 to 14 m (40 to 47 ft), displaces about 3,600 tons, cruises at below 30 knots, and has a crew of about 200 to 300. Most are more lightly armed than destroyers, although some frigates carry missiles, antisubmarine rockets and helicopters, torpedoes, and the Phalanx system.

VI.

Amphibious Warfare Vessels

Amphibious warfare ships are uniquely designed to support assault from the sea against defended positions ashore. They include several types of vessels designed to execute specific missions during amphibious operations—many developed during during World War II for use in the island campaigns in the Pacific Ocean and the invasions in Europe.

The first amphibious ship, built in 1942, was the landing ship tank (LST), which was designed primarily for transporting tanks, bulldozers, road-building equipment, artillery, and general cargo. Although their mission remains the same, the current ships are larger and faster than earlier LSTs. They offload cargo by means of a ramp over their bows; a stern gate allows offloading amphibious vehicles directly into the water. Fully loaded, these ships displace 9,000 tons, measure 159 m (522 ft) in length and 21 m (69 ft) in beam, attain a speed of 20 knots, have a ship's crew of 290, and carry 400 troops.

Amphibious command ships were designed to provide control facilities to commanders during major amphibious operations. These ships displace 20,000 tons, are 189 m (620 ft) long, and are 25 m (82 ft) in beam. They have a speed of 23 knots and carry a crew of 740.

Amphibious assault ships transport elements of the landing force ashore using conventional landing craft, air-cushion landing craft, short-takeoff aircraft, and helicopters in support of amphibious landings. They displace 40,000 tons, are 257 m (844 ft) long and 32 m (106 ft) in the beam, have crews of 935, and carry 1,700 troops. Their speed is 20 knots.

Amphibious transport docks carry and land marines with their equipment by embarked landing craft or amphibious vehicles augmented by helicopters. They displace 18,000 tons, are 174 m (570 ft) long and 26 m (84 ft) wide, have a crew of 425, and carry 900 troops; they reach speeds of 21 knots. Dock landing ships transport and launch a variety of loaded amphibious craft and provide limited docking and repair services to small ships. They have a crew of 355 and they carry 800 troops.

Amphibious cargo ships carry heavy equipment and supplies in support of amphibious operations. They displace 21,000 tons, are 175 m (575 ft) long and 25 m (82 ft) wide, have a speed of 20 knots and a crew of 365, and carry 226 troops.

VII.

Mine Warfare Ships

Mine warfare vessels include oceangoing minesweepers and mine countermeasure ships. The former displace 800 tons, measure 57 m (188 ft) long and 11 m (36 ft) wide, and carry a crew of 45. Mine countermeasure ships displace 1,400 tons, measure 68 m (223 ft) in length and 12 m (39 ft) in beam; they have a crew of 74. Minelaying is now performed chiefly by submarines and aircraft. Helicopters also play an important role in minesweeping.

VIII.

Patrol Vessels

Designed to operate offensively against hostile surface craft and to conduct surveillance, screening, and special operations, the hydrofoil, missile-firing patrol combatant missile ships are the navy's fastest ships when foilborne and driven by their single gas turbine. They have good range on their diesel engines and excellent seakeeping qualities; they carry one rapid-firing gun and eight Harpoon missiles. Fully loaded, they displace 260 tons, measure 44 m (145 ft) in length and 9 m (28 ft) in the beam, and have a crew of 25. Patrol vessels play a major part in the national drug interdiction program.

IX.

Auxiliary Vessels

Auxiliary vessels—underway replenishment ships and material support ships—provide combatant ships with supplies and services essential to keep a fleet operating over a prolonged period of time.

Underway replenishment ships can transfer fuel, munitions, supplies, and personnel from one vessel to another while ships are under way. They include ammunition ships (which deliver missiles and ammunition to the fleet at sea) and fleet oilers (which provide ships with petroleum products), as well as replenishment oilers, fast combat-support ships, and combat-stores ships.

Material support ships include repair ships, tenders, salvage ships, submarine rescue ships, and fleet ocean tugs. Repair ships are floating shops carrying skilled mechanical and electrical workers; they provide full repair and logistics support and serve as repair facilities where shipyards are not available. Tenders perform some repair work, supply repair parts, and render medical, dental, and other services to ships as assigned; submarine tenders furnish mobile base facilities capable of providing maintenance and logistics support for nuclear-attack submarines. Salvage ships provide firefighting, battle-damage repair, and rescue towing assistance. Submarine rescue ships serve as surface support ships for deep submergence rescue during submarine rescue operations. Fleet ocean tugs can tow ships and conduct salvage operations.

X.

Military Sealift Command Vessels

The mission of the Military Sealift Command is to provide sea transportation needed to deploy and sustain U.S. forces worldwide. The command employs 6,000 civil service workers and has 1,000 military personnel assigned and 2,000 merchant mariners under contract. In peacetime this command contracts with private shipping companies to meet its requirements. It also operates three forces: the Naval Fleet Auxiliary Force, Special Mission Support Force, and Strategic Sealift Force. Each force has ships assigned to it that are crewed by civilian mariners—either civil servants or contract personnel. Most of these ships are merchant-type vessels used to support naval ships at sea and U.S. forces stationed overseas.

The Naval Fleet Auxiliary Force provides direct support to U.S. Navy combatant ships at sea so they can remain on station for extended periods. Ships in this force carry naval military detachments ranging from 4 to 67 persons. They provide communications, coordinate supply functions, conduct helicopter operations, and perform other duties in support of the mission. Oilers, used to transport bulk petroleum products from shore depots to combatant vessels and support ships, make up the biggest part of this force. Ammunition ships provide missiles and ammunition and can refuel ships at sea. Fleet-stores ships furnish provisions, technical parts, fleet freight, and personnel. Ocean surveillance ships tow sensor array systems for gathering submarine acoustical data and play a significant role in augmenting overall antisubmarine warfare capabilities. Fleet ocean tugs tow large ships damaged in battle or otherwise not operational and conduct salvage operations. Heavy lift ships carry damaged ships back to port for repair.

The Special Mission Support Force carries out highly specialized oceanographic research, missile tracking, oceanographic and hydrographic surveys, and cable laying and repair. Missile-range instrumentation ships monitor submarine launchings of missiles and collect data that scientists use to improve efficiency of missiles. They also formerly tracked missiles of the Soviet Union to ensure compliance with arms-limitation agreements, and they continue to track missiles launched by other nations. Oceanographic research and survey ships conduct tests to support technological advancement of undersea warfare and detection equipment. Cable-repair ships transport, deploy, retrieve, and repair submarine cables and conduct acoustic hydrographic and bathymetric surveys.

The Strategic Sealift Force deploys and sustains military forces, wherever needed, through delivery of materials, petroleum products, and other supplies. The Afloat Prepositioning Force is made up of 25 ships loaded with military equipment and prepositioned around the world, within five days' sailing time from potential trouble spots. The Maritime Prepositioning Force consists of 13 ships divided into 3 squadrons: one in the Atlantic, one in the western Pacific, and one in the Indian Ocean. Each squadron carries unit equipment and supplies required to support a U.S. Marine Corps expeditionary brigade for 30 days. For rapid, worldwide deployment of a mechanized army division, the U.S. Navy acquired eight Fast Sealift Ships—the fastest cargo ships in the world. They are nearly as large as aircraft carriers and can carry tanks, helicopters, and other military supplies. Large hospital ships, each with a 1,000-bed treatment facility, 12 operating rooms, and a medical staff of 820 persons provide a mobile, rapidly responsive medical capability to support amphibious and naval task forces.