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Boom Defence Vessel
A net laying ship, also known as a net layer, net tender, gate ship or boom defence vessel was a type of naval auxiliary ship. A net layer's primary function was to lay and maintain steel anti-torpedo or anti-submarine nets. Nets could be laid around an individual ship at anchor, or around harbors or other anchorages. Net laying was potentially dangerous work, and net laying seamen were experts at dealing with blocks, tackles, knots and splicing. As World War II progressed, net layers were pressed into a variety of additional roles including salvage, troop and cargo transport, buoy maintenance, and service as tugboats. US Navy 1930s War Plan Orange, the pre-WW2 US plan for war with Japan, anticipated that Pearl Harbor would be too small for the US Navy fleet that would be amassed in Hawaii. Orange anticipated the construction of a large anchorage in Lahaina Roads between the islands of Maui, Lānaʻi, and Molokaʻi. Construction would consist of massive nets and minefields ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boom (navigational Barrier)
A boom or a chain (also boom defence, harbour chain, river chain, chain boom, boom chain or variants) is an obstacle strung across a navigable stretch of water to control or block navigation. In modern times they usually have civil uses, such as to prevent access to a dangerous river channel. But, especially historically, they have been used militarily, with the goal of denying access to an enemy's ships: a modern example is the anti-submarine net. Booms have also been used to force passing vessels to pay a toll. Description A boom generally floats on the surface, while a chain can be on the surface or below the water. A chain could be made to float with rafts, logs, ships or other wood, making the chain a boom as well. Historical uses Especially in medieval times, the end of a chain could be attached to a chain tower or boom tower. This allowed safe raising or lowering of the chain, as they were often heavily fortified. By raising or lowering a chain or boom, access could be s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USS Osage (AN-3)
USS ''Osage'' (AN-3/AP-108/LSV-3/MCS-3) was the lead ship of her class of vehicle landing ship built for the United States Navy during World War II. She was named after , an "old monitor of the navy". Laid down as netlayer ''AN-3'' on 1 June 1942 at Pascagoula, Mississippi by the Ingalls Shipbuilding Corporation; redesignated as a transport, ''AP-108'', on 1 May 1943; launched on 1 December 1943; sponsored by Mrs. Dorothy K. McHenry, wife of Lt. John A. McHenry, Officer in Charge of Construction (for both U.S. Navy and Maritime Commission vessels), Pascagoula; redesignated as a vehicle landing ship, ''LSV-3'', 21 April 1944; and commissioned on 30 December 1944. There is no clear record of the period from the launch of the ship till her commissioning but at some point in time during that period, the ship departed her builder's yard and was transferred to the Tampa Shipbuilding Company to be completed Service history February–April 1945 Following shakedown out of Galveston, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aloe-class Net Laying Ship
The ''Aloe''-class net laying ships were a class of thirty-two steel-hulled net laying ships built prior to the US entry into World War II. The lead ship, , was laid down in October 1940 and launched the following January; the final member, , was launched in October 1941. They were assigned tree and plant names in alphabetical order, but eight ships (in order ''Cottonwood'', ''Dogwood'', ''Fir'', ''Juniper'', ''Maple'', ''Poplar'', ''Sycamore'', and ''Walnut'') were renamed prior to launching, producing discontinuities in the name order. These ships were originally classed as YN and numbered 1-32, but were reclassified and renumbered in 1944 as AN-6 through AN-37. These ships had a unique appearance with a pair of "horns" jutting out from either side of the bow, each functioning as a fixed crane with a capacity of . They were powered by a pair of diesel engines which provided electricity for both propulsion and lifting machinery; there were also two auxiliary diesels and an eva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Auxiliaries Of The United States Navy
This is a list of auxiliaries of the United States Navy. It covers the various types of ships that support the frontline combat vessels of the United States Navy. Ship status is indicated as either currently active (including ready reserve), inactive or precommissioning Ships in the inactive category include only ships in the inactive reserve, ships which have been disposed from US service have no listed status. Ships in the precommissioning category include ships under construction or on order. Crane Ships (AB) * USS ''Kearsarge'' (AB-1), ex-BB-5 Colliers (AC) * USS ''Hannibal'' (1898) * USS ''Justin'' (1898) * USS ''Leonidas'' (1898) * USS ''Marcellus'' (1879) * USS ''Merrimac'' (1898) * USS ''Quincy'' (1918) * USS ''Saturn'' (1898) * USS ''Southery'' (1898) * USS ''Sterling'' (1898) * USS ''Vestal'' (AC-1), later AR-4 * USS ''Ontario'' (AC-2), later AR-3 * USS ''Jupiter'' (AC-3), later CV-1, AV-3 * USS ''Cyclops'' (AC-4), lost March 1918 * USS ''Vulcan' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Yard And District Craft Of The United States Navy
This is a list of yard and district craft of the United States Navy. It covers the various types of craft and ships that support the bases and harbors of the United States Navy. The hull classification symbols for these craft begin with (Y). Ship status is indicated as either currently active (including ready reserve), inactive or precommissioning Ships in the inactive category include only ships in the inactive reserve, ships which have been disposed from US service have no listed status. Ships in the precommissioning category include ships under construction or on order. Historical overview This list demonstrates that the US Navy constantly recycles and repurposes its small craft for new roles. Some craft on this list have had as many as six such conversions in their history. Some of these conversions have been surprising from an environmental viewpoint, such as the conversion of fuel oil barges into water barges. Some conversions have been surprising from an economic vie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hull Classification
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. 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 b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oerlikon 20mm 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 today. 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 (''Seebac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3"/50 Caliber Gun
The 3"/50 caliber gun (spoken "three-inch fifty-caliber") in United States naval gun terminology indicates the gun fired a projectile in diameter, and the barrel was 50 calibers long (barrel length is 3 in × 50 = ). Different guns (identified by Mark numbers) of this caliber were used by the U.S. Navy and U.S. Coast Guard from 1890 through to 1994 on a variety of combatant and transport ship classes. The gun is still in use with the Spanish Navy on ''Serviola''-class patrol boats. Early low-angle guns The US Navy's first 3"/50 caliber gun (Mark 2) was an early model with a projectile velocity of per second. Low-angle (single-purpose/non-anti-aircraft) mountings for this gun had a range of 7000 yards at the maximum elevation of 15 degrees. The gun entered service around 1900 with the s, and was also fitted to s. By World War II these guns were found only on a few Coast Guard cutters and Defensively Equipped Merchant Ships. Low-angle 3"/50 caliber guns (Marks 3, 5, 6 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propeller
A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working fluid such as water or air. Propellers are used to pump fluid through a pipe or duct, or to create thrust to propel a boat through water or an aircraft through air. The blades are specially shaped so that their rotational motion through the fluid causes a pressure difference between the two surfaces of the blade by Bernoulli's principle which exerts force on the fluid. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft (ship), propeller shaft with an approximately horizontal axis. History Early developments The principle employed in using a screw propeller is derived from sculling. In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-called compression-ignition engine (CI engine). This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine (gasoline engine) or a gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas). Diesel engines work by compressing only air, or air plus residual combustion gases from the exhaust (known as exhaust gas recirculation (EGR)). Air is inducted into the chamber during the intake stroke, and compressed during the compression stroke. This increases the air temperature inside the cylinder to such a high degree that atomised diesel fuel injected into the combustion chamber ignites. With the fuel being injected into the air just before combustion, the dispersion of the fuel is une ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knot (unit)
The knot () is a unit of speed equal to one nautical mile per hour, exactly (approximately or ). The ISO standard symbol for the knot is kn. The same symbol is preferred by the Institute of Electrical and Electronics Engineers (IEEE), while kt is also common, especially in aviation, where it is the form recommended by the International Civil Aviation Organization (ICAO). The knot is a non- SI unit. The knot is used in meteorology, and in maritime and air navigation. A vessel travelling at 1 knot along a meridian travels approximately one minute of geographic latitude in one hour. Definitions ;1 international knot = :1 nautical mile per hour (by definition), : (exactly), : (approximately), : (approximately), : (approximately) : (approximately). The length of the internationally agreed nautical mile is . The US adopted the international definition in 1954, having previously used the US nautical mile (). The UK adopted the international nautical mile definition in 1970, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of United States Navy Amphibious Warfare Ships
This is a list of United States Navy amphibious warfare ships. This type of ship has been in use with the US Navy since World War I. Ship status is indicated as either currently active (including ready reserve), inactive or precommissioning Ships in the inactive category include only ships in the inactive reserve, ships which have been disposed from US service have no listed status. Ships in the precommissioning category include ships under construction or on order. Capabilities overview There have been four generations of amphibious warfare ships, with each generation having more capability than the previous: * The first generation simply landed troops and equipment ashore with standard (i.e., non-specialized) boats and barges. These ships are not listed in this article since they were indistinguishable from the troopships and other surface combatants of their day. * The second generation was designed during World War II to land personnel and vehicles ashore, either dire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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