3-inch/50-caliber gun

USS Rambler (SP-211) was a steam yacht acquired by the United States Navy during World War I for patrol duty.

USS Pivot (AM-276), an Admirable-class minesweeper, and the first ship of the United States Navy named Pivot. She was built at the Gulf Shipbuilding Corporation, Chickasaw, Alabama and christened on 11 November 1943 by Mrs Clara L Prouty. Trials started on 12 July 1944 in the Gulf of Mexico and she worked up in Chesapeake Bay.

The Bainbridge-class destroyers were a class of United States Navy Torpedo Boat Destroyers (TBDs) built between 1899 and 1903. The first class so designated, they comprised the first 13 of 16 TBDs authorized by Congress in 1898 following the Spanish–American War. One ship of the class was lost at sea during service in World War I: Chauncey, which collided with the British merchant ship SS Rose in 1917. The balance were decommissioned in 1919 and sold postwar in 1920, eleven to Joseph G. Hitner of Philadelphia, and the Hopkins to the Denton Shore Lumber Company in Tampa, Florida.

The Connecticut class of pre-dreadnought battleships were the penultimate class of the type built for the United States Navy. The class comprised six ships: Connecticut, Louisiana, Vermont, Kansas, Minnesota, and New Hampshire, which were built between 1903 and 1908. The ships were armed with a mixed offensive battery of 12-inch (305 mm), 8-inch (203 mm), and 7-inch (178 mm) guns. This arrangement was rendered obsolete by the advent of all-big-gun battleships like the British HMS Dreadnought, which was completed before most of the Connecticuts entered service.

World War II or the Second World War, often abbreviated as WWII or WW2, was a global conflict that lasted from 1939 to 1945. The vast majority of the world's countries, including all of the great powers, fought as part of two opposing military alliances: the Allies and the Axis. Many participants threw their economic, industrial, and scientific capabilities behind this total war, blurring the distinction between civilian and military resources. Aircraft played a major role, enabling the strategic bombing of population centres and the delivery of the only two nuclear weapons ever used in war.

A built-up gun is artillery with a specially reinforced barrel. An inner tube of metal stretches within its elastic limit under the pressure of confined powder gases to transmit stress to outer cylinders that are under tension. Concentric metal cylinders or wire windings are assembled to minimize the weight required to resist the pressure of powder gases pushing a projectile out of the barrel. Built-up construction was the norm for guns mounted aboard 20th century dreadnoughts and contemporary railway guns, coastal artillery, and siege guns through World War II.

In artillery, caliber or calibre is the internal diameter of a gun barrel, or, by extension, a relative measure of the barrel length.

USS Texas (BB-35) is a museum ship and former United States Navy New York-class battleship. She was launched on 18 May 1912 and commissioned on 12 March 1914.

Destroyer escort (DE) was the United States Navy mid-20th-century classification for a 20-knot warship designed with the endurance necessary to escort mid-ocean convoys of merchant marine ships.

A submarine chaser or subchaser is a small naval vessel that is specifically intended for anti-submarine warfare. Many of the American submarine chasers used in World War I found their way to Allied nations by way of Lend-Lease in World War II.

A submarine is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. Submarines are referred to as boats rather than ships irrespective of their size.

The Clemson class was a series of 156 destroyers which served with the United States Navy from after World War I through World War II.

A seaplane tender is a boat or ship that supports the operation of seaplanes. Some of these vessels, known as seaplane carriers, could not only carry seaplanes but also provided all the facilities needed for their operation; these ships are regarded by some as the first aircraft carriers and appeared just before the First World War.

High-speed transports were converted destroyers and destroyer escorts used in US Navy amphibious operations in World War II and afterward. They received the US Hull classification symbol APD; "AP" for transport and "D" for destroyer. In 1969, the remaining ships were reclassified as "Fast Amphibious Transports", hull symbol LPR.

A minelayer is any warship, submarine or military aircraft deploying explosive mines. Since World War I the term "minelayer" refers specifically to a naval ship used for deploying naval mines. "Mine planting" was the term for installing controlled mines at predetermined positions in connection with coastal fortifications or harbor approaches that would be detonated by shore control when a ship was fixed as being within the mine's effective range.

A shell, in a military context, is a projectile whose payload contains an explosive, incendiary, or other chemical filling. Originally it was called a bombshell, but "shell" has come to be unambiguous in a military context. Modern usage sometimes includes large solid kinetic projectiles, which are more properly termed shot. Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used.

A deck gun is a type of naval artillery mounted on the deck of a submarine. Most submarine deck guns were open, with or without a shield; however, a few larger submarines placed these guns in a turret.

The R-class submarines were a class of United States Navy submarines active from 1918 until 1945. With the first of the class laid down following the American entry into World War I, they were built rapidly. Although R-15 through R-20 were completed July–October 1918, they did not serve overseas, and the bulk of the class were not completed until after the Armistice.

The Porpoise class were submarines built for the United States Navy in the late 1930s, and incorporated a number of modern features that would make them the basis for subsequent Salmon, Sargo, Tambor, Gato, Balao, and Tench classes. In some references, the Porpoises are called the "P" class.

The Gato class of submarines were built for the United States Navy and launched in 1941–1943. Named after the lead ship of the class, USS Gato, they were the first mass-production U.S. submarine class of World War II.

A conning tower is a raised platform on a ship or submarine, often armoured, from which an officer in charge can conn the vessel, controlling movements of the ship by giving orders to those responsible for the ship's engine, rudder, lines, and ground tackle. It is usually located as high on the ship as practical, to give the conning team good visibility of the entirety of the ship, ocean conditions, and other vessels.

The United States' S-class submarines, often simply called S-boats, were the first class of submarines with a significant number built to United States Navy designs. They made up the bulk of the USN submarine service in the interwar years and could be found in every theater of operations. While not considered "Fleet Submarines" in the traditional sense of that term, they were the first submarines in the USN designed for open ocean, blue water operations. All previous submarines had been intended for harbor or coastal defense. These boats were intended to have greater speed and range than previous classes, with improved habitability and greater armament.

The attack on Pearl Harbor was a surprise military strike by the Imperial Japanese Navy Air Service upon the United States against the U.S. naval base at Pearl Harbor in Honolulu, Territory of Hawaii, just before 8:00 a.m. on Sunday, December 7, 1941. The United States was a neutral country at the time; the attack led to its formal entry into World War II the next day. The Japanese military leadership referred to the attack as the Hawaii Operation and Operation AI, and as Operation Z during its planning.

Aalborg Søfarts- og Marinemuseum is a marine museum located on the wharf of Aalborg, Denmark. Inaugurated on 24 May 1992, by Margrethe II of Denmark, the museum's collections have been expanded considerably since opening. They now include an extensive collection of ship radios and navigation instruments, showing the development of such tools.

The Oerlikon 20 mm cannon is a series of autocannons, based on an original German Becker Type M2 20 mm cannon design that appeared very early in World War I. It was widely produced by Oerlikon Contraves and others, with various models employed by both Allied and Axis forces during World War II. Many versions of the cannon are still used today.

Kamikaze , officially Shinpū Tokubetsu Kōgekitai , were a part of the Japanese Special Attack Units of military aviators who flew suicide attacks for the Empire of Japan against Allied naval vessels in the closing stages of the Pacific campaign of World War II, intending to destroy warships more effectively than with conventional air attacks. About 3,800 kamikaze pilots died during the war, and more than 7,000 naval personnel were killed by kamikaze attacks.

The Essex class was a class of aircraft carriers of the United States Navy. The 20th century's most numerous class of capital ship, the class consisted of 24 vessels, which came in "short-hull" and "long-hull" versions. Thirty-two ships were ordered, but as World War II wound down, six were canceled before construction, and two were canceled after construction had begun. Fourteen saw combat during World War II. None were lost to enemy action, though several sustained crippling damage. Essex-class carriers were the backbone of the U.S. Navy from mid-1943 and, with the three Midway-class carriers added just after the war, continued to be the heart of U.S. naval strength until supercarriers joined the fleet in the 1950s, 1960s and 1970s. Several of the carriers were rebuilt to handle heavier and faster aircraft of the early jet age, and some served until well after the Vietnam War.

The Allen M. Sumner class was a group of 58 destroyers built by the United States during World War II. Another twelve ships were completed as destroyer minelayers. The class was named for Allen Melancthon Sumner, an officer in the United States Marine Corps. Often referred to as simply the Sumner, this class was distinguished from the previous Fletcher class by their twin 5-inch/38 caliber gun mounts, dual rudders, additional anti-aircraft weapons, and many other advancements. The Allen M. Sumner design was extended 14 feet (4.3 m) amidships to become the Gearing class, which was produced in larger numbers but did not see significant service in World War II.

The Gearing class was a series of 98 destroyers built for the U.S. Navy during and shortly after World War II. The Gearing design was a minor modification of the Allen M. Sumner class, whereby the hull was lengthened by 14 ft (4.3 m) at amidships, which resulted in more fuel storage space and increased the operating range.

A proximity fuze is a fuze that detonates an explosive device automatically when the distance to the target becomes smaller than a predetermined value. Proximity fuzes are designed for targets such as planes, missiles, ships at sea, and ground forces. They provide a more sophisticated trigger mechanism than the common contact fuze or timed fuze. It is estimated that it increases the lethality by 5 to 10 times, compared to these other fuzes.

A fire-control radar (FCR) is a radar that is designed specifically to provide information to a fire-control system in order to direct weapons such that they hit a target. They are sometimes known as narrow beam radars, targeting radars, or in the UK, gun-laying radars. If the radar is used to guide a missile, it is often known as a target illuminator or illuminator radar.

The Fleet Rehabilitation and Modernization (FRAM) program of the United States Navy extended the lives of World War II-era destroyers by shifting their mission from a surface attack role to that of a submarine hunter. The FRAM program also covered cruisers, aircraft carriers, submarines, amphibious ships, and auxiliaries. The United States Coast Guard also used this term in the 1980s for the modernization of its Hamilton-class cutters.

The 3"/70 Mark 26 Gun was developed to protect United States warships from Japanese kamikaze attacks in World War II, based on the 3"/50 caliber gun. The name indicates in US Navy terminology that this piece of naval artillery fires a projectile 3 in (76 mm) in diameter and has a barrel length of 70 calibers [barrel length = 3" × 70 = 210 in ].

A surface-to-air missile (SAM), also known as a ground-to-air missile (GTAM) or surface-to-air guided weapon (SAGW), is a missile designed to be launched from the ground to destroy aircraft or other missiles. It is one type of anti-aircraft system; in modern armed forces, missiles have replaced most other forms of dedicated anti-aircraft weapons, with anti-aircraft guns pushed into specialized roles.

The Mark 42 5"/54 caliber gun (127mm) is a naval gun mount used by the United States Navy and other countries. It consisted of the Mark 18 gun and Mark 42 gun mount. United States naval gun terminology indicates the gun fires a projectile 5 inches (127.0 mm) in diameter, and the barrel is 54 calibers long In the 1950s a gun with more range and a faster rate of fire than the 5"/38 caliber gun used in World War II was needed, therefore, the gun was created concurrently with the 3"/70 Mark 26 gun for different usages. The 5"/54 Mk 42 is an automatic, dual-purpose gun mount. It is usually controlled remotely from the Mk 68 Gun Fire Control System, or locally from the mount at the One Man Control (OMC) station.

The Bainbridge-class destroyers were a class of United States Navy Torpedo Boat Destroyers (TBDs) built between 1899 and 1903. The first class so designated, they comprised the first 13 of 16 TBDs authorized by Congress in 1898 following the Spanish–American War. One ship of the class was lost at sea during service in World War I: Chauncey, which collided with the British merchant ship SS Rose in 1917. The balance were decommissioned in 1919 and sold postwar in 1920, eleven to Joseph G. Hitner of Philadelphia, and the Hopkins to the Denton Shore Lumber Company in Tampa, Florida.

The three Chester-class cruisers were the first United States Navy vessels to be designed and designated as fast "scout cruisers" for fleet reconnaissance. They had high speed but little armor or armament. They were authorized in January 1904, ordered in fiscal year 1905, and completed in 1908. In 1920 all scout cruisers were redesignated as "light cruisers" (CL).

The Connecticut class of pre-dreadnought battleships were the penultimate class of the type built for the United States Navy. The class comprised six ships: Connecticut, Louisiana, Vermont, Kansas, Minnesota, and New Hampshire, which were built between 1903 and 1908. The ships were armed with a mixed offensive battery of 12-inch (305 mm), 8-inch (203 mm), and 7-inch (178 mm) guns. This arrangement was rendered obsolete by the advent of all-big-gun battleships like the British HMS Dreadnought, which was completed before most of the Connecticuts entered service.

The Indiana class was a class of three pre-dreadnought battleships launched in 1893. These were the first battleships built by the United States Navy comparable to contemporary European ships, such as the British HMS Hood. Authorized in 1890 and commissioned between November 1895 and April 1896, these were relatively small battleships with heavy armor and ordnance that pioneered the use of an intermediate battery. Specifically intended for coastal defense, their freeboard was insufficient to deal well with the waves of the open ocean. The turrets lacked counterweights, and the main belt armor was placed too low to be effective under most conditions.

The Mississippi class of battleships comprised two ships which were authorized in the 1903 naval budget: Mississippi and Idaho; these were named for the 20th and 43rd states, respectively. These were the last pre-dreadnought battleships to be designed for the United States Navy, but not the last to be built, because one more ship of a prior design was completed later under the 1904 naval budget. While the quality and technology of the weaponry and armor were first-rate, these ships included a variety of main, intermediate, secondary, and tertiary gun sizes in a predreadnought configuration which became obsolete before the ships were completed.

The Nevada class comprised two dreadnought battleships—Nevada and Oklahoma—built for the United States Navy in the 1910s. They were significant developments in battleship design, being the first in the world to adopt "all or nothing" armor, a major step forward in armor protection because it emphasized protection optimized for long-range engagements before the Battle of Jutland demonstrated the need for such a layout. They also introduced three-gun turrets and oil-fired water-tube boilers to the US fleet. The two Nevadas were the progenitors of the standard-type battleship, a group that included the next four classes of broadly similar battleships that were intended to be tactically homogeneous.

The New York class was a pair of super-dreadnought battleships built for the United States Navy between 1911 and 1914. The two ships of the class, New York and Texas, saw extensive service beginning in the occupation of Veracruz, World War I, and World War II.

The Paulding-class destroyers were a series of United States Navy destroyers derived from the Smith class with the torpedo tubes increased from three to six via twin mounts. They were the first destroyers in the US Navy with oil-fired boilers. The 21 Pauldings doubled the number of destroyers in the US Navy. The Paulding class derived its name from the class's lead ship, Paulding, named for Rear Admiral Hiram Paulding (1797–1878). Like the Smiths, they were nicknamed "flivvers" after the small and shaky Model T Ford once the larger "thousand tonner" destroyers entered service.

The Pennsylvania class consisted of two super-dreadnought battleships built for the United States Navy just before the First World War. The ships were named Pennsylvania and Arizona, after the American states of the same names. They constituted the United States' second battleship design to adhere to the "all or nothing" armor scheme, and were the newest American capital ships when the United States entered the First World War.

The Pennsylvania class of six armored cruisers served in the United States Navy from 1905 to 1927. All six were renamed for cities 1912–1920, to make the state names available for the new battleships beginning with the Pennsylvania-class battleships. All of these served during World War I, with California being the only ship of the class to be lost. The remaining five armored cruisers were scrapped between 1930 and 1931 in accordance with the London Naval Treaty.

The Smith-class destroyers were the first ocean-going destroyers in the United States Navy, and the first to be driven by steam turbines instead of the reciprocating engines fitted in the sixteen earlier and much smaller torpedo boat destroyers ordered in 1898. Flusser and Reid are sometimes considered to be Flusser-class ships. Also, since Flusser was completed first, some period documentation refers to the entire class as Flussers.

The London Naval Treaty, officially the Treaty for the Limitation and Reduction of Naval Armament, was an agreement between the United Kingdom, Japan, France, Italy, and the United States that was signed on 22 April 1930. Seeking to address issues not covered in the 1922 Washington Naval Treaty, which had created tonnage limits for each nation's surface warships, the new agreement regulated submarine warfare, further controlled cruisers and destroyers, and limited naval shipbuilding.