350 likes | 747 Views
Progression of Airships. Thomas McAdam. Types of Airships. The main types of airship are non-rigid (or blimps), semi-rigid and rigid.
E N D
Progression of Airships • Thomas McAdam
Types of Airships • The main types of airship are non-rigid (or blimps), semi-rigid and rigid. • Blimps are "pressure" airships where internal pressure, maintained by forcing air into internal ballonet, is used to both maintain the shape of the airship and its structural integrity. • Semi-rigid airships maintain the envelope shape by internal pressure, but have some form of internal support such as a fixed keel to which control and engine gondolas and stabilizers and steering surfaces are mounted. • Rigid airships have structural skeletons which maintain the shape and carry all loads from gondolas, engines, control surfaces and stabilizers.
Francesco Lana de Terzi • Francesco Lana de Terzi (Brescia, Lombardy 1631 – 22 February 1687 Brescia, Lombardy) was an Italian Jesuit, mathematician, naturalist and aeronautics pioneer. Having been professor of physics and mathematics at Brescia, he first sketched the concept for a vacuum airship and has been referred to as the Father of Aeronautics • In the year 1670 Francesco Lana de Terzi published a book titled Prodromo,which contained the description of a “flying ship”. Encouraged by the experiments of Otto von Guericke with the Magdeburg hemispheres, in the year 1663 Lana de Terzi had developed an idea for a lighter than air vessel.
Lieutenant Jean Baptiste Marie Meusnier • Jean Pierre François Blanchard, was a French inventor, most remembered as a pioneer in aviation and ballooning. • Blanchard made his first successful balloon flight in Paris on 2 March 1784, in a hydrogen gas balloon launched from the Champ de Mars. • Jean Blanchard and John Jeffries took the first flight over the English Channel, taking about 2½ hours to travel from England to France on 7 January 1785, flying from Dover Castle to Guînes. • Blanchard toured Europe, demonstrating his balloons. Blanchard holds the record of first balloon flights in Belgium, Germany, the Netherlands, and Poland.
Henry Giffard • The first person to make an engine-powered flight was Henri Giffard who, in 1852, flew 27 km (17 mi) in a steam-powered airship. • He was able to make turns and circles, proving that a powered airship could be steered and controlled. • He invented the injector and the Giffard dirigible, an airship powered with a steam engine, and weighing over 180 kg (400 lb)
Dupuy de Lôme • In 1870 Dupuy de Lôme devoted a large amount of time to perfecting a practical navigable balloon, and the French Government gave him great assistance in carrying out the experiments. • These experiments led to the development of one of the first navigable balloons, named the Dupuy de Lôme. • The Dupuy de Lôme airship was 36 meters in length, 14.84 meters in diameter, 29 meters wide, and had a total volume of 3,454 cubic meters. It was powered by a 2 horsepower (1.5 kW) engine, providing a speed of between 9 to 11 km/h.
World War I • The prospect of airships as bombers had been recognised in Europe well before the airships were up to the task. • Count Zeppelin and others in the German military believed they had found the ideal weapon with which to counteract British Naval superiority and strike at Britain itself. • More realistic airship advocates believed the airship was a valuable long range scout/attack craft for naval operations. • Raids began by the end of 1914, reached a first peak in 1915, and then were discontinued in August 1918. German airship Schütte Lanz SL2 bombing Warsaw in 1914. Type "R" observation balloon at Arcadia Balloon School, Arcadia, Calif. 1921
Scouting Blimps • Before the World War, the British Army was interested in blimps for scouting purposes. • The Royal Navy, recognising the potential threat that scouting Zeppelins might pose, decided in 1908 to produce an example of rigid airship so that the threat might be evaluated in practice instead of theory. • The British Army abandoned airship development in favour of aeroplanes by the start of the war, but the Royal Navy had recognised the need for small airships to counteract the submarine and mine threat in coastal waters. • Beginning in February 1915, they began to deploy the SS (Sea Scout) class of blimp. SSZ variant which served as a patrol ship for submarines. • Performance • Maximum speed: 50 mph (80 km/h) • Service ceiling: greater than 5,000 ft (1,500 m)
Schütte-Lanz airships • Schütte-Lanz (SL) is the name of a series of rigid airships designed and built by the Luftschiffbau Schütte-Lanz company from 1909 until the last LS22 was delivered in 1917. • The Schütte-Lanz company was an early strong competitor of the more famous airships built by Ferdinand von Zeppelin. • Most of the Schütte-Lanz ships are not usable under combat conditions, especially those operated by the Navy, because their wooden construction cannot cope with the damp conditions that comes with maritime service. • Twenty-four Schütte-Lanz airships were designed before the end of the World War I, most of which the company was not paid for due to the collapse of the German Monarchy. By the time the last eight ships were ready, most of them could not be operated due to the loss of trained crews.
Schütte-Lanz Airships • Wood composites had a theoretical superiority as the structural material in airships up to a certain size. After that, the superiority of aluminum (and later duralumin) in tension was more important than the superiority of wood in compression. • Schütte-Lanz airships until 1918 were composed of wood and plywood glued together. Moisture tended to degrade the integrity of the glued joints.Schütte-Lanz airships became structurally unstable when water entered the airship's imperfectly water-proofed envelope. German airship Schütte Lanz SL2 bombing Warsaw in 1914.
Parseval airships Diagram of an early Parseval airship. The two internal balloons were not for lift generation. • The Parsevals were 22 airships built between 1909 and 1919 • In contrast to the Zeppelins, the Parsevals were non-rigid or semi-rigid airships, with little or no stiffening structure inside the fabric envelope. • The longest Parseval airship was 157m and went top speed of 100km/h compared with the Schütte-Lanz ships which achieved 232m with one ship and 122km/h with another. Schütte-Lanz ships where however rigid in structure. • The Parseval ships where not intended for as bombers rather they were used as scouting ships in the navy. A PL25, in an accident upon landing it was destroyed in a fire, with no casualties.
Ferdinand von Zeppelin Count Zeppelin dressed as Adjutant in 1865 • In 1865 Zeppelin was appointed adjutant of the King of Württemberg and as general staff officer participated in the Austro-Prussian War of 1866. • From 1882 until 1885 Zeppelin was commander of the 19th Uhlans in Ulm, and lastly as envoy of Württemberg in Berlin. • From the 1880s onward, Zeppelin was preoccupied with the idea of guidable balloons. • He had already outlined an overall construction system in 1874, and had written to the King of Württemberg stating that Germany was behind France and that only large airships were practical for military use. • After his resignation from the army in 1891 at age 52, Zeppelin devoted his full attention to airships.
Zeppelin Airships The first ascent of LZ1 over Lake Constance (the Bodensee) in 1900 • The most important feature of Zeppelin's design was a rigid light-alloy skeleton, made of rings and longitudinal girders. • The advantage of this design was that the aircraft could be much larger than non-rigid airships (which relied on a slight overpressure within the single gasbag to maintain their shape) because the light-alloy used for the structure, (usually Magnesium or Aluminium alloys), enabling Zeppelins to lift heavier loads and be fitted with more engines and/or more powerful engines. • During World War I, as a result of improvements by the rival firm Schütte-Lanz Luftschiffbau, the design was changed to the more familiar streamlined shape and empennage of cruciform fins used by almost all airships ever since. • Within this outer envelope, several separate balloons, also known as "cells" or "gasbags", contained the lighter-than-air gas usually hydrogen but in America was mostly only helium. ZR-3 USS Los Angeles over southern Manhattan
Inter-War Period • The inter-war period saw the development of the first helium airship, the USS Shenandoah. • Helium was still so rare at this point that the Shenandoah contained most of the world's reserves. • Eventually the US Navy lost all three American-built rigid airships to accidents. • USS Shenandoah on a poorly planned publicity flight flew into a severe thunderstorm over Noble County • USS Akron was caught in a severe storm and flown into the surface of the sea off the shore of New Jersey on 3 April 1933 • USS Macon was lost after suffering a structural failure off the shore of Point Sur Lightstation State Historic Park on 12 February 1935. The failure caused a loss of gas, which was made much worse when the aircraft was driven over pressure height causing it to lose too much helium to maintain flight. USS Macon over New York City in 1933 Shenandoah moored to the oiler Patoka.
Helium vs. Hydrogen • The first lifting gas used was hydrogen, although this had well-known concerns over its flammability. Helium was rare in most parts of the world, but large amounts were discovered in the USA. • This meant that this non-flammable gas was rarely used for airships outside of the USA. However, until after WWI the technology to extract helium in large quantities was not available. • All modern airships, since the 1960s, use helium.
LZ 129 Hindenburg • The Hindenburg was a large German commercial passenger-carrying rigid airship, the lead ship of the Hindenburg class, the longest class of flying machine and the largest airship by envelope volume. • The Hindenburg had a duralumin structure, incorporating 15 Ferris wheel-like bulkheads along its length, with 16 cotton gas bags fitted between them. • Helium was initially selected for the lifting gas because it was the safest to use in airships, as it is not flammable. At the time, however, helium was also relatively rare and extremely expensive as the gas was only available as a byproduct of mined natural gas reserves found in the United States. • The US designated Helium as a material with "military value", the Germans designed the airship to use the far safer gas in the belief that they could convince the US government to license its export. • When the designers of the Hindenburg learned that the National Munitions Control Board would refuse to lift the export ban, however, they were forced to re-engineer the Hindenburg to use hydrogen for lift. The Hindenburg in March 1936. The name of the airship was not yet painted on the hull. Dining room
Hindenburg LZ 129 arrival at Lakehurst, May 9, 1936. USS Los Angeles (ZR-3) is moored upper right. The Hindenburg under construction.
Hindenburg Disaster • The Hindenburg disaster took place on Thursday, May 6, 1937, as the German passenger airship LZ 129 Hindenburg caught fire and was destroyed during its attempt to dock. • Of the 97 people on board (36 passengers, 61 crew), there were 35 fatalities as well as one death among the ground crew. • The actual cause of the fire remains unknown, although a variety of hypotheses have been put forward for both the cause of ignition and the initial fuel for the ensuing fire. • Fuel Leak Hypothesis. • Structural Failure Hypothesis • Luger pistol among wreckage Hypothesis Hindenburg begins to fall seconds after catching fire. A partially burned piece of mail on board the Hindenburg's last flight.
World War II • After the Hindenburg disaster the era of the Rigid airship and airships as a transport system was over. During World War II however, non-rigid airships still saw some use. • While Germany determined that airships were obsolete for military purposes in the coming war and concentrated on the development of airplanes, the United States pursued a program of military airship construction. • At the Japanese attack on Pearl Harbor on 7 December 1941 that brought the United States into World War II, it had 10 non-rigid airships • In the years 1942–44, approximately 1,400 airship pilots and 3,000 support crew members were trained in the military airship crew training program and the airship military personnel grew from 430 to 12,400. • During the war some 532 ships without airship escort were sunk near the US coast by enemy submarines. Only one ship, the tanker Persephone, of the 89,000 or so in convoys escorted by blimps was sunk by the enemy. A view of six helium-filled blimps being stored in one of the two massive hangars located at NAS Santa Ana, during World War II.
Modern Use • Although airships are no longer used for passenger transport, they are still used for other purposes such as advertising, sightseeing, surveillance and research. • In the spring of 2004, Lindstrand Technologies supplied the world's first fully functional unmanned airship to the Ministry of Defense in Spain. This airship carried a 42 kilograms (93 lb) classified payload and its surveillance mission was also classified. Four years later, this airship, which is designated GA-22, still flies on an almost daily basis. • In November 2005, De Beers, the diamond mining company, launched an airship exploration program over the remote Kalahari desert. A Zeppelin, loaded with high-tech equipment, is used to find potential diamond mines by scanning the local geography for low-density rock formations One of The Goodyear Tire and Rubber Company's blimp fleet Thermal airship (manufacturer GEFA-FLUG/Germany)
Future • On 31 January 2006 Lockheed Martin made the first flight of their secretly built hybrid airship designated the P-791. • The P-791 was originally part of the U.S. Army's LEMV program, but lost to Northrop Grumman's design. The P-791 is now being modified to be a civil cargo aircraft with a lift capability of 20 tons. • A hybrid airship is a general term for an aircraft that combines characteristics of heavier-than-air (airplane or helicopter) and lighter-than-air technology. Examples include helicopter/airship hybrids intended for heavy lift applications and dynamic lift airships intended for long-range cruising. • The Manned Cloud is a concept design for a flying hotel, complete with sun-deck on top, 40 guest rooms, a library and fitness centre. It would fly up to 170 km/hour, and have a range of 5,000 km. The Manned Cloud