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Dravo Corporation
Dravo Corporation was a shipbuilding company with shipyards in Pittsburgh and Wilmington, Delaware. It was founded by Frank and Ralph Dravo in Pittsburgh in 1891. The corporation went public in 1936 and in 1998 it was bought out by Carmeuse for $192 million ($ million today). On March 5, 1942, it became the first corporation to receive the Army-Navy "E" Award for outstanding war time production. Dravo ranked 72nd among United States corporations in the value of World War II military production contracts. Facilities *Neville Island shipyard, Pittsburgh started 1919, constructed LST's during World War II employing 16,000 people, closed 1982. () *Wilmington Shipyard, Delaware employed 10,500 during World War II, constructing Destroyer escorts. Now closed. Traces back to Harlan and Hollingsworth () Ships From 1942 to 1945 Dravo Corporation built Landing Ship, Tank, (LST). LST were built to support amphibious operations able to land tanks, vehicles, cargo, and landing troops o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shipbuilding
Shipbuilding is the construction of ships and other floating vessels. It normally takes place in a specialized facility known as a shipyard. Shipbuilders, also called shipwrights, follow a specialized occupation that traces its roots to before recorded history. Shipbuilding and ship repairs, both commercial and military, are referred to as " naval engineering". The construction of boats is a similar activity called boat building. The dismantling of ships is called ship breaking. History Pre-history The earliest known depictions (including paintings and models) of shallow-water sailing boats is from the 6th to 5th millennium BC of the Ubaid period of Mesopotamia. They were made from bundled reeds coated in bitumen and had bipod masts. They sailed in shallow coastal waters of the Persian Gulf. 4th millennium BC Ancient Egypt Evidence from Ancient Egypt shows that the early Egyptians knew how to assemble planks of wood into a ship hull as early as 3100 BC. Egyptia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landing Troops
A landing operation is a military action during which a landing force, usually utilizing landing craft, is transferred to land with the purpose of power projection ashore. With the proliferation of aircraft, a landing may refer to amphibious forces, airborne forces, or a combination of both. Landing of ships In a military invasion conducted by sea, the landing and establishment of a beachhead is a critical phase. In the '' Iliad'', the landing operation of the Achaean navy is described in book three. Since the Trojans had been warned of the invasion, the beach was defended. In Greek polytheism, the ἱερά ἐπιβατήρια were sacrifices offered to the gods after a successful landing. A λόγος ἐπιβατήριον was a dignified speech delivered upon disembarkation, contrasting with an ἀποβατήριον (''apobaterion''), the speech delivered upon departure. Air landing troops Missions of air landing troops, as defined by the U.S. FM 100–5, ''O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Theatre Of World War II
The European theatre of World War II was one of the two main theatres of combat during World War II. It saw heavy fighting across Europe for almost six years, starting with Germany's invasion of Poland on 1 September 1939 and ending with the Western Allies conquering most of Western Europe, the Soviet Union conquering most of Eastern Europe and Germany's unconditional surrender on 8 May 1945 (9 May in the Soviet Union) but the fighting on the Eastern front continued until 11 May during the Prague offensive and the end of the Battle of Odzak on 25 May. The Allied powers fought the Axis powers on two major fronts ( Eastern Front and Western Front) as well as in a strategic bombing offensive and in the adjoining Mediterranean and Middle East theatre. Preceding events Germany was defeated in World War I, and the Treaty of Versailles placed punitive conditions on the country, including significant financial reparations, the loss of territory (some only temporarily), war gu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific War
The Pacific War, sometimes called the Asia–Pacific War, was the theater of World War II that was fought in Asia, the Pacific Ocean, the Indian Ocean, and Oceania. It was geographically the largest theater of the war, including the vast Pacific Ocean theater, the South West Pacific theater, the Second Sino-Japanese War, and the Soviet–Japanese War. The Second Sino-Japanese War between the Empire of Japan and the Republic of China had been in progress since 7 July 1937, with hostilities dating back as far as 19 September 1931 with the Japanese invasion of Manchuria. However, it is more widely accepted that the Pacific War itself began on 7 December (8 December Japanese time) 1941, when the Japanese simultaneously invaded Thailand, attacked the British colonies of Malaya, Singapore, and Hong Kong as well as the United States military and naval bases in Hawaii, Wake Island, Guam, and the Philippines. The Pacific War saw the Allies pitted against Japan, the la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ship Grounding
Ship grounding or ship stranding is the impact of a ship on seabed or waterway side. It may be intentional, as in beaching (nautical), beaching to land crew or cargo, and careening, for maintenance or repair, or unintentional, as in a marine accident. In accidental cases, it is commonly referred to as "running aground". When unintentional, grounding may result simply in stranding, with or without damage to the submerged part of the ship's hull. Breach of the hull may lead to significant flooding, which in the absence of containment in watertight bulkheads may substantially compromise the ship's structural integrity, stability, and safety. As hazard Severe grounding applies extreme loads upon ship structures. In less severe accidents, it might result only in damage to the hull; however, in most serious accidents, it might lead to hull breaches, cargo spills, total loss of the vessel, and, in the worst cases, human casualties. Grounding accounts for about one-third of commercia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rudder
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane. A rudder operates by redirecting the fluid past the hull or fuselage, thus imparting a turning or yawing motion to the craft. In basic form, a rudder is a flat plane or sheet of material attached with hinges to the craft's stern, tail, or after end. Often rudders are shaped so as to minimize hydrodynamic or aerodynamic drag. On simple watercraft, a tiller—essentially, a stick or pole acting as a lever arm—may be attached to the top of the rudder to allow it to be turned by a helmsman. In larger vessels, cables, pushrods, or hydraulics may be used to link rudders to steering wheels. In typical aircraft, the rudder is operated by pedals via mechanical li ... [...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] |
Beaching (nautical)
Beaching (or Landing) is the process in which a ship or boat is laid ashore, or grounded deliberately in shallow water. This is more usual with small flat-bottomed boats. Larger ships may be beached deliberately; for instance, in an emergency, a damaged ship might be beached to prevent it from sinking in deep water. Some vessels are designed to be loaded and unloaded by beaching; vessels of this type used by the military to disembark troops under fire are called landing craft. During the age of sail, vessels were sometimes beached to allow them to be rolled over for the hull to be maintained, a process called '' careening''. Ships scheduled for break-up are sometimes intentionally beached to make the procedure easier. See also * Landing craft * Shipwrecking * Cetacean stranding Cetacean stranding, commonly known as beaching, is a phenomenon in which whales and dolphins strand themselves on land, usually on a beach. Beached whales often die due to dehydration, collapsing un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keel
The keel is the bottom-most longitudinal structural element on a vessel. On some sailboats, it may have a hydrodynamic and counterbalancing purpose, as well. As the laying down of the keel is the initial step in the construction of a ship, in British and American shipbuilding traditions the construction is dated from this event. Etymology The word "keel" comes from Old English , Old Norse , = "ship" or "keel". It has the distinction of being regarded by some scholars as the first word in the English language recorded in writing, having been recorded by Gildas in his 6th century Latin work '' De Excidio et Conquestu Britanniae'', under the spelling ''cyulae'' (he was referring to the three ships that the Saxons first arrived in). is the Latin word for "keel" and is the origin of the term careen (to clean a keel and the hull in general, often by rolling the ship on its side). An example of this use is Careening Cove, a suburb of Sydney, Australia, where careening was carried o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flat-bottomed Boat
A flat-bottomed boat is a boat with a shallow draft, two-chined hull, which allows it to be used in shallow bodies of water, such as rivers, because it is less likely to ground. The flat hull also makes the boat more stable in calm water, which is good for hunters and anglers. However this design becomes less stable in choppy water. This is because it causes the boat to travel ''on'' the water, instead of ''through'' it, as a boat with a rounded or V-shaped hull would. Flat hulls are simple to construct, making them popular with boat-building hobbyists. In Britain they came to popular notice during the planned French invasion of Britain in 1759, when a large-number of flat-bottomed boats were prepared by the French to ferry their invasion force across the channel and a number were destroyed during the British Raid on Le Havre. The flat-bottoms are mentioned in the song ''Heart of Oak'' written by David Garrick during 1759. Types *Barge * Bateau * Bull boat * Car float ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ramp
An inclined plane, also known as a ramp, is a flat supporting surface tilted at an angle from the vertical direction, with one end higher than the other, used as an aid for raising or lowering a load. The inclined plane is one of the six classical simple machines defined by Renaissance scientists. Inclined planes are used to move heavy loads over vertical obstacles. Examples vary from a ramp used to load goods into a truck, to a person walking up a pedestrian ramp, to an automobile or railroad train climbing a grade. Moving an object up an inclined plane requires less force than lifting it straight up, at a cost of an increase in the distance moved. The mechanical advantage of an inclined plane, the factor by which the force is reduced, is equal to the ratio of the length of the sloped surface to the height it spans. Owing to conservation of energy, the same amount of mechanical energy (work) is required to lift a given object by a given vertical distance, disregarding losse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bow (ship)
The bow () is the forward part of the hull of a ship or boat, the point that is usually most forward when the vessel is underway. The aft end of the boat is the stern. Prow may be used as a synonym for bow or it may mean the forward-most part of the bow above the waterline. Function A ship's bow should be designed to enable the hull to pass efficiently through the water. Bow shapes vary according to the speed of the boat, the seas or waterways being navigated, and the vessel's function. Where sea conditions are likely to promote pitching, it is useful if the bow provides reserve buoyancy; a flared bow (a raked stem with flared topsides) is ideal to reduce the amount of water shipped over the bow. Ideally, the bow should reduce the resistance and should be tall enough to prevent water from regularly washing over the top of it. Large commercial barges on inland waterways rarely meet big waves and may have remarkably little freeboard at the bow, whereas fast military ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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