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Propellers
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 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 blade to the water at t ...
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Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. Common examples of aircraft include airplanes, helicopters, airships (including blimps), gliders, paramotors, and hot air balloons. The human activity that surrounds aircraft is called ''aviation''. The science of aviation, including designing and building aircraft, is called '' aeronautics.'' Crewed aircraft are flown by an onboard pilot, but unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as lift type, aircraft propulsion, usage and others. History Flying model craft and stories of manned flight go back many centuries; however, the first manned ascent — and safe descent — in modern times took place by larger hot-air ...
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Ship
A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished from boats, based on size, shape, load capacity, and purpose. Ships have supported exploration, trade, warfare, migration, colonization, and science. After the 15th century, new crops that had come from and to the Americas via the European seafarers significantly contributed to world population growth. Ship transport is responsible for the largest portion of world commerce. The word ''ship'' has meant, depending on the era and the context, either just a large vessel or specifically a ship-rigged sailing ship with three or more masts, each of which is square-rigged. As of 2016, there were more than 49,000 merchant ships, totaling almost 1.8 billion dead weight tons. Of these 28% were oil tankers, 43% were bulk carriers, and ...
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Thrust
Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that system. The force applied on a surface in a direction perpendicular or normal to the surface is also called thrust. Force, and thus thrust, is measured using the International System of Units (SI) in newtons (symbol: N), and represents the amount needed to accelerate 1 kilogram of mass at the rate of 1 meter per second per second. In mechanical engineering, force orthogonal to the main load (such as in parallel helical gears) is referred to as static thrust. Examples A fixed-wing aircraft propulsion system generates forward thrust when air is pushed in the direction opposite to flight. This can be done by different means such as the spinning blades of a propeller, the propelling jet of a jet engine, or by ejecting hot gases from a rocket ...
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Single-blade Propeller
A single-blade propeller may be used on aircraft to generate thrust. Normally propellers are multiblades but the simplicity of a single-blade propeller fits well on motorized gliders, because it permits the design of a smaller aperture of the glider fuselage for retraction of the powerplant. The counterbalanced teetering mono-blade propeller generates fewer vibrations than conventional multiblade configurations. Often, single blade propeller configurations are touted as having a much greater efficiency than multiblade propellers, but this is a falsehood outside the inertial losses in spinning a heavier propeller, and the minimal additional drag from added blades. Single bladed propellers are principally used to fulfill engineering requirements that fall outside the scope of efficiency. Patents US Patent 2742095 Mechanism for balancing single blade aircraft rotorUS Patent 6619585 Helicopter single-blade rotorUS Patent 5971322- Propeller propulsion unit for aircraft in general ...
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John Ericsson
John Ericsson (born Johan Ericsson; July 31, 1803 – March 8, 1889) was a Swedish-American inventor. He was active in England and the United States. Ericsson collaborated on the design of the railroad steam locomotive ''Novelty'', which competed in the Rainhill Trials on the Liverpool and Manchester Railway, which were won by inventor George Stephenson's (1781-1848), ''Rocket''. In North America, he designed the United States Navy's first screw-propelled steam-frigate , in partnership with Captain (later Commodore) Robert F. Stockton (1795-1866), who unjustly blamed him for a fatal accident. A new partnership with Cornelius H. DeLamater (1821-1889), of the DeLamater Iron Works in New York City resulted in the first armoured ironclad warship equipped with a rotating gun turret, , which dramatically saved the U.S. (Union Navy) naval blockading squadron from destruction by an ironclad Confederate States naval vessel, , at the famous Battle of Hampton Roads at the southern m ...
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Propeller Shaft (ship)
A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power and torque and rotation, usually used to connect other components of a drivetrain that cannot be connected directly because of distance or the need to allow for relative movement between them. As torque carriers, drive shafts are subject to torsion and shear stress, equivalent to the difference between the input torque and the load. They must therefore be strong enough to bear the stress, while avoiding too much additional weight as that would in turn increase their inertia. To allow for variations in the alignment and distance between the driving and driven components, drive shafts frequently incorporate one or more universal joints, jaw couplings, or rag joints, and sometimes a splined joint or prismatic joint. History The term ''driveshaft'' first appeared during the mid-19th centu ...
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Josef Ressel
Joseph Ludwig Franz Ressel ( cs, Josef Ludvík František Ressel; June 29, 1793 – October 9, 1857) was a forester and inventor of Czech-Austrian descent, who designed one of the first working ship's propellers. Ressel was born in Chrudim, Bohemia then part of the Holy Roman Empire ruled by the Habsburg monarchy, which became part of the Austrian Empire at his death (now the Czech Republic). His father Anton Hermann Ressel was a native German speaker, and his mother Marie Anna Konvičková was a native Czech speaker. He studied at the Linz Gymnasium, Budweis (in today's České Budějovice) artillery school, University of Vienna and the Mariabrunn Forestry Academy at Mariabrunn Monastery then near (now in) Vienna. He worked for the Austrian government as a forester in the more southern parts of the monarchy, including in Motovun, Istria (modern-day Croatia). His work was to secure a supply of quality wood for the Navy.''Josef Ressel. One of the designers of a ship's propel ...
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Paddle Wheel
A paddle wheel is a form of waterwheel or impeller in which a number of paddles are set around the periphery of the wheel. It has several uses, of which some are: * Very low-lift water pumping, such as flooding paddy fields at no more than about height above the water source. * To move and mix algae culture in the raceway ponds used for algaculture. * Propulsion of watercraft (as a paddlewheel) * Low head hydro power (as a waterwheel) * Flow sensors * Aerators The paddle wheel is an ancient invention but is still used today in a wide range of industrial and agriculture applications. Ship propulsion Paddle wheels would enable ships to travel without needing wind or oars. They were made obsolete by propellers, which had greater propulsion with lower weight and fuel usage. This was demonstrated by an 1845 tug-of-war competition between and with the screw-driven ''Rattler'' pulling the paddle steamer ''Alecto'' backward at .
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Bamboo-copter
The bamboo-copter, also known as the bamboo dragonfly or Chinese top (Chinese ''zhuqingting'' (竹蜻蜓), Japanese ''taketonbo'' ), is a toy helicopter rotor that flies up when its shaft is rapidly spun. This helicopter-like top originated in Jin dynasty China around 320 AD, and was the object of early experiments by English engineer George Cayley, the inventor of modern aeronautics.Leishman, J. Gordon (2006)''Principles of Helicopter Aerodynamics'' Cambridge University Press. pp. 7–9. In China, the earliest known flying toys consisted of feathers at the end of a stick, which was rapidly spun between the hands and released into flight. "While the Chinese top was no more than a toy, it is perhaps the first tangible device of what we may understand as a helicopter." The Jin dynasty Daoist philosopher Ge Hong's (c. 317) book '' Baopuzi'' (抱樸子 "Master Who Embraces Simplicity") mentioned a flying vehicle in what Joseph Needham calls "truly an astonishing passag ...
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David Bushnell
David Bushnell (August 30, 1740 – 1824 or 1826), of Westbrook, Connecticut, was an American inventor, a patriot, one of the first American combat engineers, a teacher, and a medical doctor. Bushnell invented the first submarine to be used in battle, as well as a floating mine triggered by contact. He was a veteran of the Revolutionary War. Early life David Bushnell was born in a secluded part of Saybrook, Connecticut on the 30th August, 1740 and baptized in 1743 into a farming family in what is now Westbrook, Connecticut where his parents Nehemiah Bushnell (1710 – d. bef 1762) and Sarah (Susan) Ingham Bushnell owned a farm. He was the first of five children born. Following the death of his father circa 1769, he sold his half interest in the family Westbrook farm to his brother Ezra and entered Yale College in 1771 at the relatively old age of 31. The ''Turtle'' submarine Bushnell is credited with creating the first submarine ever used in combat, while studying at Yale ...
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Yarmouth, Nova Scotia
Yarmouth is a town in southwestern Nova Scotia, Canada. A port town, industries include fishing, and tourism. It is the terminus of a ferry service to Bar Harbor, Maine, run by Bay Ferries. History Originally inhabited by the Mi'kmaq, the region was known as "Keespongwitk" meaning "Lands End" due to its position at the tip of the Nova Scotia peninsula. European settlement The region was visited in 1604 by Samuel de Champlain, who named it "Cap-Fourchu", meaning "forked or cloven cape." The first Europeans to make a settlement on these shores were the French Acadians. They set up a small fishing settlement known as "Tebouque" in the mid 1600s and by 1750 the population was 50 people. During the Seven Years' War, New England Planters settled at what is now the town of Yarmouth in 1759; the grantees were from Yarmouth, Massachusetts and they requested that Yarmouth be named after their former home. Yarmouth was founded on June 9, 1761, when a ship carrying three families arrived fr ...
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Saint John, New Brunswick
Saint John is a seaport city of the Atlantic Ocean located on the Bay of Fundy in the province of New Brunswick, Canada. Saint John is the oldest incorporated city in Canada, established by royal charter on May 18, 1785, during the reign of King George III. The port is Canada's third-largest port by tonnage with a cargo base that includes dry and liquid bulk, Breakbulk_cargo, break bulk, containers, and cruise. The city was the most populous in New Brunswick until the 2016 census, when it was overtaken by Moncton. It is currently the second-largest city in the province, with a population of 69,895 over an area of . French explorer Samuel de Champlain landed at Saint John Harbour on June 24, 1604 (the feast of St. John the Baptist) and is where the Saint John River (Bay of Fundy), Saint John River gets its name although Mi'kmaq and Maliseet, Wolastoqiyik peoples lived in the region for thousands of years prior calling the river Wolastoq. The Saint John area was an important area ...
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