Man-lifting kite

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Roald Amundsen, the polar explorer, is lifted from the ground using a man-lifting kite during tests in 1909.
Roald Amundsen, the polar explorer, is lifted from the ground using a man-lifting kite during tests in 1909.
Man-lifter War Kite designed by Samuel Franklin Cody (1867-1913).
Man-lifter War Kite designed by Samuel Franklin Cody (1867-1913).
Lawrence Hargrave (seated) with his man-lifting kites in Stanwell Park, 1894.
Lawrence Hargrave (seated) with his man-lifting kites in Stanwell Park, 1894.

A man-lifting kite is a kite designed to lift a person from the ground. Historically, man-lifting kites have been used chiefly for reconnaissance and entertainment. Interest in their development declined with the advent of powered flight at the beginning of the 20th century.

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[edit] Early history

The first records of man-lifting kites come from China. Their use is mentioned in Sun Tzu's The Art of War as a means of viewing the movements of enemy troops. In a story about the Japanese thief Ishikawa Goemon (1558-1594), he used a man-lifting kite to allow him to steal the golden scales from a pair of ornamental fish images which were mounted on the top of Nagoya Castle. His men manoeuvered him into the air on a trapeze attached to the tail of a giant kite. He flew to the rooftop where he stole the scales, and was then lowered and escaped. In the 17th century, Japanese architect Kawamura Zuiken used kites to lift his workmen during construction. George Pocock, who invented a kite-drawn buggy in 1822, had previously used kites as a method of lifting men to inaccessible cliff tops, but it was not until around the 1880s that there was serious interest in developing man-lifting kites.

[edit] Modern development

The first well-documented record of a man lifted by kite was at Pirbight Camp in 1894. In the early 1890s, Captain B.F.S Baden-Powell, brother of the founder of the scouting movement, had designed the "Levitor" kite, a hexagonal-shaped kite intended to be used by the army in order to lift a man for aerial observation or for lifting large loads such as a wireless antenna. On June 27, 1894 he used one of the kites to lift a man 50 feet (15.25 m) off the ground. By the end of that year he was regularly using the kite to lift men above 100 ft (30.5 m). Baden-Powell's kites were sent to South Africa for use in the Boer War, but by the time they arrived the fighting was over, so they were never put into use.

Lawrence Hargrave invented his box kite in 1885, and on 12 November 1894, lifted himself from the beach in Stanwell Park, New South Wales using a four box kite rig, attached to the ground by piano wire. Using this rig he lifted himself 16 feet (4.9 m) above the ground, despite the combined weight of his body and the rig weighing 208 lb (94.5 kg).

Samuel Cody invented a kite known as the Bat, that he proposed be used for observation of the enemy during war. After a stunt in which he crossed the English Channel in a boat drawn by a kite, he attracted enough interest from the War Office for them to allow him to conduct trials between 1904 and 1905. He lifted a passenger to a new record height of 1,600 ft (488 m) on the end of a 4,000 ft (1,219 m) cable. The War Office officially adopted Cody's design in 1906, and the war kites were used for observation until they were replaced by aircraft. Cody also made flights in an untethered kite powered by a 12-horsepower engine.

[edit] Water ski kites

  • Flat kites - In the late 50's, individuals used the concept of being trailed by a kite above water.[1] (Images:)[4][5][6] The Australians developed flat kites originally for water ski shows; They were able to marginally control these unstable flat kites by using swing seats that allowed their entire body weight to effect pitch and roll. When a Rogallo wing was fitted with a swing seat by John Dickenson, in Grafton, Australia, the modern hang gliding was born.
  • Rogallo kite - The Rogallo wing was invented by aerospace engineer Francis Rogallo and was the first kite to be developed with the assistance of wind tunnel testing, and is an indication of how far kites have come. Australian John Dickenson first flew his version of the Rogallo wing kite in 1963 while towed behing a motorboat. This first water ski kite -which he called Ski Wing[2] - played a significant role in promoting hang gliding into a popular sport starting in the late 1960s and early 1970s.[3]

[edit] Dynamic Anchor Manned Kite

Hang glider launching from Mount Tamalpais.
Hang glider launching from Mount Tamalpais.

When the kite-line attaches to a falling mass, then the kite-line and falling mass are moving through some medium, as the air. The towing forces caused by the falling mass create the relative wind or fluid flow past the kite system's wing. This describes some hang gliders; thus, such qualified hang gliders are a subset of kites where the anchor is dynamically moving or falling; paragliders are of this sort of kite system. The falling mass can be the hang glider pilot or gliding-parachute parachutist (frequently the Domina Jalbert wing, David Barish wing, or Rogallo wing gliding parachutes are used). Thus these systems lift the pilot. Such a definition was used in discussion in Hang Glider Weekly as discussed in History of hang gliding that published out of Santa Monica, California, together with Low & Slow; editions are now on CD available through the United States Hang Gliding Association. Towing is also achieved for kite systems: boats, airplanes, trucks, cars, animals, ships, etc.; what the towing mechanism does is to force a relative wind or fluid flow through a tensional member (kiteline most frequently, but the tensional member could be a rope, cable, rod, mast, thread, beam, etc.) to the kite's wing. Thus the Rogallo wing hang glider that suspends tensionally the pilot with webbing or ropes or even Paresev-like trussed complex from the wing above have the falling pilot's mass be a dyamic towing device that tows the kite wing; that the wing gives a net positive lift wins the system's kite status together with the tensional tow that forces the wing to react with the fluid or air. When a hang glider pilot goes out to fly his or her hang glider, if the hang glider fits the above description, then the application of the word "kite" is appropriate. A hang glider can also be tested as an unmanned kite using either static or dynamic anchors without the person being in the system. In such manned-lifting kites, the most frequent part of the airframe is called triangle control frame; the pilot pushes and pulls on that TCF to control the free-flying kite (hang glider of this sort).

A toy kite with a payload or a practical man-carrying kite being statically or dynamically achored by a tertiary vehicle could subsequently be released by the remote anchor or towing vehicle or system of forces (say a drogue in a river or stream); then upon release within a gravitational field in some atmosphere, the payload hung tensionally (cords in gliding parchute, harness tether line in some hang gliders, etc.) becomes the new dynamic anchor and the system again is a kite system with low or great lift to drag ratio for a glide of some sort. Such releases might be accidental or deliberate; the first stiffened Rogallo wing man-piloted aircraft were in the Paresev program and were first towed to high altitude and then released; the system in the first towing instance were kite systems; the system upon release were still kite systems; in the first sector the system was static relative to the towing aircraft; in the second sector the system was dynamic relative to the pilot's mass and the ground..

[edit] After powered flight

After the Wright Brothers first flight in 1903, the development of kites designed to lift heavy weights continued, but interest in designs specifically for lifting humans declined.

Alexander Graham Bell developed a tetrahedral kite, constructed of sticks arranged in a honeycomb of triangular sections, called cells. From a one cell model at the beginning of the 1890s, Bell advanced to a 3,393 cell "Cygnet" model in the early 1900s. This 40 foot (12.2 m) long, 200 lb (91 kg) kite was towed by a steamer in Baddeck Bay, Nova Scotia on December 6, 1907 and carried a man 168 feet (51.2 m) above the sea. Roald Amundsen, the polar explorer, commissioned tests on a man-lifting kite to see whether it would be suitable for use for observation in the Arctic, but the trials were unsatisfactory, and the idea was never developed.

It was not until the development of the Rogallo kite in the late 1940s that there was large scale interest in unpowered kite flying once again. The possibility of untethered flight on man-lifting kites lead to the development of hang gliders and paragliders, but static-ancored-tethered man-lifting kites have seen little development, chiefly due to the lack of control inherent in the tethered design. Nowadays, most man-lifting is carried out on a dual line system, where the passenger on a single kite ascends a line held under tension by a train of kites. No kites are available commercially for the static-ground-based-anchored tethered flight of people. Note that many hang gliders are kited in various ways to get to an altitude to give the participant desired altitude; sometimes just a short glide is needed; sometimes an altitude is desired that will provide an opportunity for the kited hang glider pilot to seek and find assistive thermals. Note also, that when a sailplane is kited by some system to get altitude, then that sailplane in that kited mode is a man-lifting kite. So, actually, design for man-lifting kites today is a big industry; it is just that the ulteriour purpose is usually not to sit in the towed status (as kite) but to release later for free-flight in hopes of long duration gliding and soaring activity. Serious commercial planning by Dave Culp with Kite tugs involves manned kites. Kite Tugs

[edit] References

[edit] Footnotes

  1. ^ Flat ski kites, history: [1]
  2. ^ Ski Wing [2]
  3. ^ John Dickenson - aviation award: [3]
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