A box kite is a high performance

kite A kite is a tethered heavier than air flight, heavier-than-air or lighter-than-air craft with wing surfaces that react against the air to create Lift (force), lift and Drag (physics), drag forces. A kite consists of wings, tethers and anchors. ...

, noted for developing relatively high

lift Lift or LIFT may refer to: Physical devices * Elevator, or lift, a device used for raising and lowering people or goods ** Paternoster lift, a type of lift using a continuous chain of cars which do not stop ** Patient lift, or Hoyer lift, mobile ...

; it is a type within the family of cellular kites. The typical design has four parallel struts. The box is made rigid with diagonal crossed struts. There are two sails, or ''ribbons'', whose width is about a quarter of the length of the box. The ribbons wrap around the ends of the box, leaving the ends and middle of the kite open. In flight, one strut is the bottom, and the bridle is tied between the top and bottom of this strut. The dihedrals of the sails help stability. The box kite was invented in 1893 by

Lawrence Hargrave Lawrence Hargrave, MRAeS, (29 January 18506 July 1915) was a British-born Australian engineer, explorer, astronomer, inventor and aeronautical pioneer. Biography Lawrence Hargrave was born in Greenwich, England, the second son of John Fletch ...

, an English-born Australian, as part of his attempt to develop a manned flying machine. Hargrave linked several of his box kites (Hargrave cells) together, creating sufficient lift for him to fly some 16 ft (4.9 m) off the ground. A winged development of this kite is known as the Cody kite following its development by

Samuel Franklin Cody Samuel Franklin Cowdery (later known as Samuel Franklin Cody; 6 March 1867 – 7 August 1913, born Davenport, Iowa, USA)) was a Wild West showman and early pioneer of manned flight. He is most famous for his work on the large kites known ...

. Military uses also involved a kite/radio transmitter combination issued to pilots during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

for use in liferafts. Large box kites are constructed as cellular kites. Rather than one box, there are many, each with its own set of sails. Most of the altitude records for kite flying are held by large box kites, with Dacron sails, flown with Spectra cable. However in 2014 Robert Moore and a team of kite experts flew a 12 sq metre DT delta to 16,009 ft above their launch point. The location of the flights was near

Cobar Cobar is a town in central western New South Wales, Australia whose economy is based mainly upon base metals and gold mining. The town is by road northwest of the state capital, Sydney. It is at the crossroads of the Kidman Way and Barrier Hig ...

in Western NSW, Australia. While this was primarily a triangular winged delta kite, it has a triangular box centre cell for additional stability. Future attempts on either the single kite record or multiple kite record (trained), may use Hargrave box kites or a variant. Before

Dacron Polyethylene terephthalate (or poly(ethylene terephthalate), PET, PETE, or the obsolete PETP or PET-P), is the most common thermoplastic polymer resin of the polyester family and is used in fibres for clothing, containers for liquids and foods ...

, Spectra, and

Kevlar Kevlar (para-aramid) is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, the high-strength material was first used commercially in the early 1970s a ...

were available, high performance box kites used oiled

silk Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. The best-known silk is obtained from the coc ...

linen Linen () is a textile made from the fibers of the flax plant. Linen is very strong, absorbent, and dries faster than cotton. Because of these properties, linen is comfortable to wear in hot weather and is valued for use in garments. It also ...

hemp Hemp, or industrial hemp, is a botanical class of ''Cannabis sativa'' cultivars grown specifically for industrial or medicinal use. It can be used to make a wide range of products. Along with bamboo, hemp is among the fastest growing plants o ...

sails, and were flown with

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...

cable. Silk, linen and hemp were used because they could be spun finer than

cotton Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus ''Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor perce ...

and stretched relatively little when wet. Steel had the highest available strength for its weight. After Hargrave invented the box kite, weather stations from around the world saw the potential for his design. Blue hill observatory and the German weather station at Lindenberg used kites routinely until weather balloons took over in the 1920s and 1930s.

References

External links

Cellular kites
at the Virtual Kite Zoo Australian inventions Kites {{kite-stub

See also

References

External links