Airships :: essays research papers

AirshipsINDEXPROLOGUE 2TYPES OF AIRSHIP 2 starchy AIRSHIP 2NONRIGID AIRSHIP 3HISTORY OF RIGID AIRSPS 3HISTORY OF NONRIGID AIRSHIPS 4AIRSHIPS TODAY 5HINDENBURG 6HINDENBURG DISASTER 7PROLOGUEAn airship is a type of lighter-than-air aircraft with propulsion and directionsystems, it is used to carry passengers and cargo. It obtains its buoyancyfrom the presence of a lighter-than-air gas such as hydrogen or helium. Thefirst airship was developed by the French, called a ballon dirigible, it couldbe steered and could also be flown against the wind.TYPES OF AIRSHIPTwo basic types of airship have been developed the hardened airship, the shape ofwhich is fixed by its inner(a) structure and the nonrigid blimp, which dependson the pressure created by a series of air diaphragms inside its gas space tomaintain the shape of its fabric hull. Inventors sought-after(a) to combine the bestfeatures of these models in a semirigid type, but it met with only limitedsuccess. Today only the nonrigid airs hip is used.Rigid AirshipThe rigid airships structure resembled a cage that enclosed a series ofballoons called gas cells. These cells were tailored to fit the cylindricalspace and were secured in place by a netting that transmitted the lifting forceof their gas to the structure. Each gas cell had two or more valves, whichoperated automatically to relieve pressure when the gas grow with altitude,the valves could also be operated manually so that the pilot could release gaswhenever desired.Also on board was a ballast system that used body of water as ballast. On the groundthis ballast served to make the airship heavier than air. When part of it wasreleased, the airship ascended to a cruising altitude where the engines suppliedpropulsion, and further ballast could be released to gain more altitude. As fuelwas consumed, the airship became lighter and tended to climb. This wascountered in hydrogen-inflated airships by simply releasing gas into theatmosphere.The method was uneconomica l, however, with helium-inflated airships, and theywere therefore equipped with ballast generators, apparatuses that condensedmoisture surface of the engines exhaust gases to compensate for fuel that wasconsumed. But this ballast-generating equipment was expensive, complex, heavy,and difficult to maintain and was thus one of the most serious disadvantages ofairships filled with the safer but more expensive helium.nonrigid AirshipIn contrast to the rigid airship, the nonrigid blimp has no internal structureto maintain the shape of its hull envelope, which is made of two or three pliesof cotton, nylon, or dacron impregnated with rubber for gas tightness. Insidethe gas space of the hull are two or more air diaphragms called ballonets that