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Semi-submersibles
Semi-submersible may refer to a self-propelled vessel, such as: *Heavy-lift ship, which partially submerge to allow their cargo (another ship) to float into place for transport *Narco-submarine, some of which remained partially on the surface *Semi-submarine, which cannot fully submerge *Semi-submersible naval vessel, which partially submerges to minimize being observed *Semi-submersible platform, which is typically transported to a location where it is placed in service * Oil platform, a large structure with facilities for well drilling to explore, extract, store, and process petroleum and natural gas, in deeper water (more than 1,500 metres (4,900 ft)), the semisubmersibles or drillships are maintained at the required drilling location using dynamic positioning. See also * Submarine boat * Submersible A submersible is an underwater vehicle which needs to be transported and supported by a larger ship, watercraft or dock, platform. This distinguishes submersibles from submari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semi-submersible Platform
A semi-submersible platform is a specialised marine vessel used in offshore roles including as offshore drilling rigs, safety vessels, oil production platforms, and heavy lift cranes. They have good ship stability and seakeeping, better than drillships. Characteristics Offshore drilling in water depth greater than around requires that operations be carried out from a floating vessel, since fixed structures are not practical. Initially in the early 1950s monohull ships such as CUSS I were used, but these were found to have significant heave, pitch and yaw motions in large waves, and the industry needed more stable drilling platforms. A semi-submersible obtains most of its buoyancy from ballasted, watertight Floats (nautical), pontoons located below the ocean surface and wave action. Structural columns connect the pontoons and operating deck. The operating deck can be located high above the sea level owing to the good ship stability of the design, and therefore is kept well away ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Platform
An oil platform (also called an oil rig, offshore platform, oil production platform, etc.) is a large structure with facilities to extract and process petroleum and natural gas that lie in rock formations beneath the seabed. Many oil platforms will also have facilities to accommodate the workers, although it is also common to have a separate accommodation platform linked by bridge to the production platform. Most commonly, oil platforms engage in activities on the continental shelf, though they can also be used in lakes, inshore waters, and inland seas. Depending on the circumstances, the platform may be fixed to the ocean floor, consist of an artificial island, or float. In some arrangements the main facility may have storage facilities for the processed oil. Remote subsea wells may also be connected to a platform by flow lines and by umbilical connections. These sub-sea facilities may include one or more subsea wells or manifold centres for multiple wells. Offshore drillin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semi-submersible Naval Vessel
A low-profile/semi-submersible naval vessel is a hybrid warship, that combines the properties of a surface ship and submarine by using water ballast to partially immerse and minimize its above-waterline profile, thereby improving its stealth characteristics when in hostile waters. The was an antecedent to such craft with its low-profile deck and gun turret. Russian and North Korean semi-submersible naval vessels evolved from torpedo boats and special forces boats that could partially submerge (sometimes to snorkel depth) to perform their missions. The United States Navy SEALs, US Navy SEALs use such vessels for clandestine special forces actions. Efforts to embody advantageous surface-ship characteristics into submarines have not been widely adopted. Antecedent USS ''Monitor'' was an iron-hulled, Steamship, steam-powered warship—built during the American Civil War—as the first ironclad warship commissioned by the Union Navy. The ''Monitor'' is noted for its role in the Battle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heavy-lift Ship
A heavy-lift ship is a vessel designed to move very large loads that cannot be transported by normal ships. They are of two types: *''Semi-submersible'' ships that take on water ballast to allow the load—usually another vessel—to be floated over the deck, whereupon the ballast is jettisoned and the ship's deck and cargo raised above the waterline. *''Project cargo'' ships that use at least one heavy-lift crane for handling heavy cargo and sufficient ballast to assure stability and sea-keeping properties. Description There are several types of heavy-lift ships: Semi-submersible ships Semi-submersible heavy-lift ships have a long and low well deck between a forward pilot house and an aft machinery space. In superficial appearance, it is somewhat similar to a dry bulk carrier or some forms of oil tanker. Its ballast tanks can be flooded to lower the well deck below the water's surface, allowing oil platforms, other vessels, or other floating cargo to be moved into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narco-submarine
A narco-submarine (also called a drug sub or narco-sub) is a type of custom Seakeeping, ocean-going, Marine propulsion, self-propelled, semi-submersible or fully-submersible vessel built by (or for) drug smugglers. Newer semi-submersibles are "nearly-fully" submersible in order to reduce likelihood of detection by Visible light, visual, radar, sonar, or infrared systems. Cargo capacity varies widely with vessel size, although several tons is typical. In 2015, the largest-known cargo of was seized on a semi-submersible craft. Some contemporary narco-subs are capable of crossing the Atlantic Ocean. Meanwhile, recently captured vessels in the central Pacific during the mid 2020s indicate said vessels are increasingly durable enough for their operators to attempt voyages across the Pacific to Oceania. History During the Prohibition in the United States, Bootlegging (alcohol), bootleggers used low-profile riverboats to evade authorities. In the 1980s, go-fast boats were the smu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semi-submarine
A semi-submarine (semi-sub) is a surface vessel that is not capable of diving, but has accommodation space below the waterline featuring underwater windows. The watercraft is similar to glass-bottom boats, but with deeper draft. Both types of boats are mainly used to provide sight-seeing trips for tourists in clear, calm, and often shallow, waters. Design The most common design is similar to a small ship. The passenger cabin is deep within the hull, a few meters below the waterline. The cabin is equipped with large underwater windows, so the passengers can observe the marine environment that is passed during the voyage. There are significant engineering differences between a true submarine and a semi-submarine. Submarines are human-occupied pressure vessels subjected to high external pressure, while semi-submarines are only subjected to the same pressures as other surface vessels of similar draft operating in similar conditions. As the hydrostatic pressure close to the wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submarine
A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or informally to refer to remotely operated vehicles and Autonomous underwater vehicle, robots, or to medium-sized or smaller vessels (such as the midget submarine and the wet sub). Submarines are referred to as ''boats'' rather than ''ships'' regardless of their size. Although experimental submarines had been built earlier, submarine design took off during the 19th century, and submarines were adopted by several navies. They were first used widely during World War I (1914–1918), and are now used in many navy, navies, large and small. Their military uses include: attacking enemy surface ships (merchant and military) or other submarines; aircraft carrier protection; Blockade runner, blockade running; Ballistic missile submarine, nuclear deterrenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submersible
A submersible is an underwater vehicle which needs to be transported and supported by a larger ship, watercraft or dock, platform. This distinguishes submersibles from submarines, which are self-supporting and capable of prolonged independent operation at sea. There are many types of submersibles, including both human-occupied vehicles (HOVs) and uncrewed craft, variously known as remotely operated vehicles (ROVs) or unmanned underwater vehicles (UUVs). Submersibles have many uses including oceanography, underwater archaeology, ocean exploration, tourism, underwater work, equipment maintenance and underwater search and recovery, recovery and underwater videography. History The first recorded self-propelled underwater vessel was a small oar-powered submarine conceived by William Bourne (mathematician), William Bourne (c. 1535 – 1582) and designed and built by Dutch inventor Cornelis Drebbel in 1620, with two more improved versions built in the following four years.Konstam (201 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boat Types
A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size or capacity, its shape, or its ability to carry boats. Small boats are typically used on inland waterways such as rivers and lakes, or in protected coastal areas. However, some boats (such as whaleboats) were intended for offshore use. In modern naval terms, a boat is a vessel small enough to be carried aboard a ship. Boats vary in proportion and construction methods with their intended purpose, available materials, or local traditions. Canoes have been used since prehistoric times and remain in use throughout the world for transportation, fishing, and sport. Fishing boats vary widely in style partly to match local conditions. Pleasure craft used in recreational boating include ski boats, pontoon boats, and sailboats. House boats may be used for vacationing or long-term residence. Lighters are used to move cargo to and from large ships un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nautical Terminology
Seamanship is the art, competence, and knowledge of operating a ship, boat or other craft on water. The'' Oxford Dictionary'' states that seamanship is "The skill, techniques, or practice of handling a ship or boat at sea." It involves topics and development of specialised skills, including navigation and international maritime law and regulatory knowledge; weather, meteorology and forecasting; watchkeeping; ship-handling and small boat handling; operation of deck equipment, anchors and cables; ropework and line handling; communications; sailing; engines; execution of evolutions such as towing; cargo handling equipment, dangerous cargoes and cargo storage; dealing with emergencies; survival at sea and search and rescue; and fire fighting. The degree of knowledge needed within these areas is dependent upon the nature of the work and the type of vessel employed by a seafarer. History Ship knowledge, ship stability and cargo operations Seamanship on a commercial level i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
