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USS Helena (CL-50)
USS ''Helena'' was a light cruiser built for the United States Navy in the late 1930s, the ninth and final member of the class. The ''Brooklyn''s were the first modern light cruisers built by the US Navy under the limitations of the London Naval Treaty, and they were intended to counter the Japanese ; as such, they carried a battery of fifteen guns, the same gun armament carried by the ''Mogami''s. ''Helena'' and her sister were built to a slightly modified design with a unit system of machinery and an improved anti-aircraft battery. Completed in 1939, ''Helena'' spent the first two years of her career in peacetime training that accelerated as tensions between the United States and Japan increased through 1941. She was torpedoed at the attack on Pearl Harbor in December 1941 and was repaired and modernized in early 1942. After returning to service, ''Helena'' was assigned to the forces participating in the Guadalcanal campaign in the south Pacific. There, she took part in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helena, Montana
Helena (; ) is the List of capitals in the United States, capital city of the U.S. state of Montana and the county seat, seat of Lewis and Clark County, Montana, Lewis and Clark County. Helena was founded as a gold camp during the Montana gold rush, and established on October 30, 1864. Due to the gold rush, Helena became a wealthy city, with approximately 50 millionaires inhabiting the area by 1888. The concentration of wealth contributed to the city's prominent, elaborate Victorian architecture. At the 2020 United States census, 2020 census Helena's population was 32,091, making it the 5th least populous state capital in the United States and the List of cities and towns in Montana, 6th most populous city in Montana. It is the principal city of the Helena, Montana metropolitan area, Helena Metropolitan Statistical Area, which includes all of Lewis and Clark, and Jefferson County, Montana, Jefferson counties; the MSA's population being 83,058 according to the 2020 census. The l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbette
Barbettes are several types of gun emplacement in terrestrial fortifications or on naval ships. In recent naval usage, a barbette is a protective circular armour support for a heavy gun turret. This evolved from earlier forms of gun protection that eventually led to the pre-dreadnought. The name ''barbette'' ultimately comes from fortification: it originally meant a raised platform or mound, as in the French phrase ''en barbette'', which refers to the practice of firing a cannon over a parapet rather than through an embrasure in a fortification's casemate. The former gives better angles of fire but less protection than the latter. The disappearing gun was a variation on the barbette gun; it consisted of a heavy gun on a carriage that would retract behind a parapet or into a gunpit for reloading. Barbettes were primarily used in coastal defences, but saw some use in a handful of warships, and some inland fortifications. The term is also used for certain aircraft gun mounts. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ship Class
A ship class is a group of ships of a similar design. This is distinct from a ship type, which might reflect a similarity of tonnage or intended use. For example, is a nuclear aircraft carrier (ship type) of the (ship class). In the course of building a class of ships, design changes might be implemented. In such a case, the ships of different design might not be considered of the same class; each variation would either be its own class, or a subclass of the original class (see for an example). If ships are built of a class whose production had been discontinued, a similar distinction might be made. Ships in a class often have names linked by a common factor: e.g. s' names all begin with T (, , ); and s are named after American battles (, , , ). Ships of the same class may be referred to as sister ships. Naval ship class naming conventions Overview The name of a naval ship class is most commonly the name of the lead ship: the first ship commissioned or built of its design. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Navy
The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 million tons in 2021. It has the world's largest aircraft carrier fleet, with List of aircraft carriers in service, eleven in service, one undergoing trials, two new carriers under construction, and six other carriers planned as of 2024. With 336,978 personnel on active duty and 101,583 in the Ready Reserve, the U.S. Navy is the third largest of the United States military service branches in terms of personnel. It has 299 deployable combat vessels and about 4,012 operational aircraft as of 18 July 2023. The U.S. Navy is one of six United States Armed Forces, armed forces of the United States and one of eight uniformed services of the United States. The United States Navy traces its origins to the Continental Navy, which was established during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire-control Radar
A fire-control radar (FCR) is a radar that is designed specifically to provide information (mainly target azimuth, elevation, range and range rate) 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, tracking 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. A typical fire-control radar emits a narrow, intense beam of radio waves to ensure accurate tracking information and to minimize the chance of losing track of the target. This makes them less suitable for initial detection of the target, and FCRs are often partnered with a medium-range search radar to fill this role. In British terminology, these medium-range systems were known as tactical control radars. Most modern radars have a track-while-scan capability, enabling them to function simultaneously as both fire-control radar and se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Search Radar
Radar is a system that uses radio waves to determine the distance (''ranging''), direction (azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track aircraft, ships, spacecraft, guided missiles, motor vehicles, map weather formations, and terrain. The term ''RADAR'' was coined in 1940 by the United States Navy as an acronym for "radio detection and ranging". The term ''radar'' has since entered English and other languages as an anacronym, a common noun, losing all capitalization. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwave domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Search Radar
A surface-search radar, sometimes more accurately known as a sea-surface-search radar or naval surveillance radar, is a type of military radar intended primarily to locate objects on the surface of lakes and oceans. Part of almost every modern naval ship, they are also widely used on maritime patrol aircraft and naval helicopters. When mounted on an aircraft, they are sometimes known, in British terminology, as air-to-surface-vessel radar — ASV for short. Similar radars are also widely used on civilian ships and even small pleasure craft, in which case they are more commonly known as marine radar. As with conventional surveillance radars, these systems detect objects from the reflections of radio signals off target objects, especially metal. The range of a surface-search radar is greatly increased compared to other roles due to several aspects of the sea surfaces and the objects in it. In low sea states, water makes an excellent reflector for radio signals, which helps maximize th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oerlikon 20 Mm Cannon
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. Blowback-operated models History Origins During World War I, the German industrialist Reinhold Becker developed a 20 mm caliber cannon, known now as the 20 mm Becker using the advanced primer ignition blowback (API blowback) method of operation. This used a 20×70mmRB cartridge and had a cyclic rate of fire of 300 rpm. It was used on a limited scale as an aircraft gun on ''Luftstreitkräfte'' warplanes, and an anti-aircraft gun towards the end of that war. Because the Treaty of Versailles banned further production of such weapons in Germany, the patents and design works were transferred in 1919 to the Swiss firm SEMAG (''Seebach M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bofors 40 Mm Automatic Gun L/60
The Bofors 40 mm Automatic Gun L/60 (often referred to simply as the "Bofors 40 mm gun", the "Bofors gun" and the like, see #Name, name) is an Anti-aircraft warfare, anti-aircraft autocannon, designed in the 1930s by the Swedish arms manufacturer AB Bofors. The gun was designed as an intermediate anti-aircraft gun, filling the gap between fast firing close-range small calibre anti-aircraft guns and slower firing long-range high calibre anti-aircraft guns. For its time, the Bofors 40 mm L/60 was perfectly suited for this role and outperformed competing designs in the years leading up to World War II in both effectiveness and reliability. It entered the export market around 1932 and was in service with 18 countries by 1939. Throughout World War II it became one of the most popular and widespread medium-weight anti-aircraft guns. It was used by the majority of the western Allies of World War II, Allies and some Axis powers such as Nazi Germany and Hungary. In the po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft Catapult
An aircraft catapult is a device used to help fixed-wing aircraft gain enough airspeed and lift for takeoff from a limited distance, typically from the deck of a ship. They are usually used on aircraft carrier flight decks as a form of assisted takeoff, but can also be installed on land-based runways, although this is rare. The catapult used on aircraft carriers consists of a track or slot built into the flight deck, below which is a large piston or ''shuttle'' that is attached through the track to the nose gear of the aircraft, or in some cases a wire rope, called a catapult bridle, is attached to the aircraft and the catapult shuttle. Other forms have been used historically, such as mounting a launching cart holding a seaplane on a long girder-built structure mounted on the deck of a warship or merchant ship, but most catapults share a similar sliding track concept. Different means have been used to propel the catapult, such as weight and derrick, gunpowder, flywheel, co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stern
The stern is the back or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite the bow, the foremost part of a ship. Originally, the term only referred to the aft port section of the ship, but eventually came to refer to the entire back of a vessel. The stern end of a ship is indicated with a white navigation light at night. Sterns on European and American wooden sailing ships began with two principal forms: the ''square'' or ''transom'' stern and the ''elliptical'', ''fantail'', or ''merchant'' stern, and were developed in that order. The hull sections of a sailing ship located before the stern were composed of a series of U-shaped rib-like frames set in a sloped or "cant" arrangement, with the last frame before the stern being called the ''fashion timber(s)'' or ''fashion piece(s)'', so called for "fashioning" the after part of the ship. This frame i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floatplane
A floatplane is a type of seaplane with one or more slender floats mounted under the fuselage to provide buoyancy. By contrast, a flying boat uses its fuselage for buoyancy. Either type of seaplane may also have landing gear suitable for land, making the vehicle an amphibious aircraft. British usage is to call floatplanes "seaplanes" rather than use the term "seaplane" to refer to both floatplanes and flying boats. Use Since World War II and the advent of helicopters, advanced aircraft carriers and land-based aircraft, military seaplanes have stopped being used. This, coupled with the increased availability of civilian airstrips, has greatly reduced the number of flying boats being built. However, many modern civilian aircraft have floatplane variants, most offered as third-party modifications under a supplemental type certificate (STC), although there are several aircraft manufacturers that build floatplanes from scratch. These floatplanes have found their niche as one type ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
