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Victory Ships
The Victory ship was a ship class, class of cargo ship produced in large numbers by United States, American shipyards during World War II. They were a more modern design compared to the earlier Liberty ship, were slightly larger and had more powerful steam turbine engines, giving higher speed to allow participation in high-speed convoys and make them more difficult targets for German U-boats. A total of 531 Victory ships were built in between 1944 and 1946. VC2 design One of the first acts of the United States War Shipping Administration upon its formation in February 1942 was to commission the design of what came to be known as the Victory class. Initially designated EC2-S-AP1, where EC2 = Emergency Cargo, type 2 (Load Waterline Length between ), S = steam propulsion with AP1 = one aft propeller (EC2-S-C1 had been the designation of the Liberty ship design), it was changed to VC2-S-AP1 before the name "Victory Ship" was officially adopted on 28 April 1943. The ships were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cargo Ship
A cargo ship or freighter is a merchant ship that carries cargo, goods, and materials from one port to another. Thousands of cargo carriers ply the world's List of seas, seas and Ocean, oceans each year, handling the bulk of international trade. Cargo ships are usually specially designed for the task, often being equipped with crane (machine), cranes and other mechanisms to load and unload, and come in all sizes. Today, they are almost always built of Welding, welded steel, and with some exceptions generally have a life expectancy of 25 to 30 years before being scrapped. Definitions The words ''cargo'' and ''freight'' have become interchangeable in casual usage. Technically, "cargo" refers to the goods carried aboard the ship for hire, while "freight" refers to the act of carrying of such cargo, but the terms have been used interchangeably for centuries. Generally, the modern ocean shipping business is divided into two classes: # Liner business: typically (but not exclusive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compound Turbine
In steam turbine design, compounding is a method of extracting steam energy in multiple stages rather than a single one. Each stage of a compounded steam turbine has its own set of nozzles and Turbines, rotors. These are arranged in series, either keyed to the common shaft or fixed to the casing. The arrangement allows either the steam pressure or the jet velocity to be absorbed incrementally. Purpose Compounded steam turbines are used to reduce rotor speeds to achieve optimal operating revolutions per minute. The steam produced in the boiler has sufficiently high enthalpy when superheated. In all turbines the blade velocity is directly proportional to the velocity of the steam passing over the blade. Now, if the entire energy of the steam is extracted in one stage, i.e. if the steam is expanded from the boiler pressure to the condenser pressure in a single stage, then its velocity will be very high. Hence the velocity of the rotor (to which the blades are keyed) can reach to abo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gantry Crane
A gantry crane is a Crane (machine), crane built atop a wikt:gantry, gantry, which is a structure used to straddle an object or workspace. They can range from enormous "full" gantry cranes, capable of lifting some of the heaviest loads in the world, to small shop cranes, used for tasks such as lifting automobile engines out of vehicles. They are also called portal cranes, the "portal" being the empty space straddled by the gantry. The terms gantry crane and overhead crane (or bridge crane) are often used interchangeably, as both types of crane straddle their workload. The distinction most often drawn between the two is that with gantry cranes, the entire structure (including gantry) is usually wheeled (often on Rail profile, rails). By contrast, the supporting structure of an overhead crane is fixed in location, often in the form of the walls or ceiling of a building, to which is attached a movable hoist (device), hoist running overhead along a rail or beam (which may itself move) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dock (maritime)
The word dock () in American English refers to one or a group of human-made structures that are involved in the handling of boats or ships (usually on or near a shore). In British English, the term is not used the same way as in American English; it is used to mean the area of water that is next to or around a wharf or quay. The exact meaning varies among different variants of the English language. "Dock" may also refer to a dockyard (also known as a shipyard) where the loading, unloading, building, or repairing of ships occurs. History The earliest known docks were those discovered in Wadi al-Jarf, an ancient Egyptian harbor, of Pharaoh Khufu#Wadi al-Jarf, Khufu, dating from c.2500 BC located on the Red Sea coast. Archaeologists also discovered anchors and storage jars near the site. A dock from Lothal in India dates from 2400 BC and was located away from the main current (water), current to avoid deposition of silt. Modern oceanographers have observed that the ancient Indu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crane (machine)
A crane is a machine used to move materials both vertically and horizontally, utilizing a system of a boom, hoist, wire ropes or chains, and sheaves for lifting and relocating heavy objects within the swing of its boom. The device uses one or more simple machines, such as the lever and pulley, to create mechanical advantage to do its work. Cranes are commonly employed in transportation for the loading and unloading of freight, in construction for the movement of materials, and in manufacturing for the assembling of heavy equipment. The first known crane machine was the shaduf, a water-lifting device that was invented in ancient Mesopotamia (modern Iraq) and then appeared in ancient Egyptian technology. Construction cranes later appeared in ancient Greece, where they were powered by men or animals (such as donkeys), and used for the construction of buildings. Larger cranes were later developed in the Roman Empire, employing the use of human treadwheels, permitting the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derrick
A derrick is a lifting device composed at minimum of one guyed mast, as in a gin pole, which may be articulated over a load by adjusting its Guy-wire, guys. Most derricks have at least two components, either a guyed mast or self-supporting tower, and a boom hinged at its base to provide articulation, as in a stiffleg derrick. The most basic type of derrick is controlled by three or four lines connected to the top of the mast, which allow it to both move laterally and cant up and down. To lift a load, a separate line runs up and over the mast with a hook on its free end, as with a Crane (machine), crane. Derricks are especially useful for high-rise rigging, jobs that cover a long period of time, or jobs when the impact to street or pedestrian traffic is a concern. Forms of derricks are commonly found aboard ships and at Dock (maritime), docking facilities. Large derricks mounted on dedicated Crane vessel, vessels are known as floating derricks and Sheerleg, shearlegs. The term de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mast (sailing)
The mast of a sailing vessel is a tall spar, or arrangement of spars, erected more or less vertically on the median line of a ship or boat. Its purposes include carrying sails, spars, and derricks, giving necessary height to a navigation light, look-out position, signal yard, control position, radio aerial, or signal lamp. Large ships have several masts, with the size and configuration depending on the style of ship. Nearly all sailing masts are guyed. Until the mid-19th century, all vessels' masts were made of wood formed from a single or several pieces of timber which typically consisted of the trunk of a conifer tree. From the 16th century, vessels were often built of a size requiring masts taller and thicker than from single tree trunks. On these larger vessels, to achieve the required height, the masts were built from up to four sections (also called masts). From lowest to highest, these were called: lower, top, topgallant, and royal masts. Giving the lower section ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ship Measurements
Ship measurements consist of a multitude of terms and definitions specifically related to ships and measuring or defining their characteristics. Definitions Beam (nautical), Beam – A measure of the width of the ship. There are two types: :Beam, Overall (BOA), commonly referred to simply as Beam – The overall width of the ship measured at the widest point of the nominal waterline. :Beam on Centerline (BOC) – Used for multihull vessels. The BOC for vessels is measured as follows: For a catamaran: the perpendicular distance from the centerline of one hull to the centerline of the other hull, measured at deck level. For a trimaran: the perpendicular distance between the centerline of the main hull and the centerline of either Ama (sailing), ama, measured at deck level. This term in typically used in conjunction with LOA (Length overall; see below). The ratio of LOA/BOC is used to estimate the stability of multihull vessels. The lower the ratio, the greater the vessel's stabil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hold (ship)
120px, View of the hold of a container ship A ship's hold or cargo hold is a space for carrying cargo in a ship or airplane compartment. Description Cargo in holds may be either packaged in crates, bales, etc., or unpackaged (bulk cargo). Access to holds is by a large hatch at the top. Ships have had holds for centuries; an alternative way to carry cargo is in standardized shipping containers, which may be loaded into appropriate holds or carried on deck. Holds in older ships were below the orlop deck, the lower part of the interior of a ship's hull, especially when considered as storage space, as for cargo. In later merchant vessels it extended up through the decks to the underside of the weather deck. Some ships have built in cranes and can load and unload their own cargo. Other ships must have dock side cranes or gantry cranes to load and unload. Cargo hatch A cargo hatch or deck hatch or hatchway is type of door used on ships and boats to cover the opening to the c ... [...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] |
United States Navy Armed Guard
The United States Navy Armed Guard was a force of United States Navy gunners and related personnel established during World War II to protect U.S. merchant shipping from enemy attack.World War II U.S. Navy Armed Guard and World War II U.S. Merchant Marine, 2007-2014 Project Liberty Ship, Project Liberty Ship, P.O. Box 25846 Highlandtown Station, Baltimore, M/ref> A shortage of escort vessels to provide unarmed merchant vessels with adequate protection shifted the burden to onboard crews to help counter the constant danger presented by Axis (World War II), Axis submarines, surface raiders, fighter aircraft and bombers. The NAG was headquartered in New Orleans, and had three training centers, at Norfolk, Virginia; San Diego, California; and Gulfport, Mississippi. At the end of the war, there were 144,857 men serving in the Navy Armed Guard on 6,200 ships.Armed Guard - Sea Lane Vigilantes, Project Liberty Ship, 201/ref> Unit composition The United States Navy Armed Guard ... [...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] |
