Yokaichi Giant Kite Festival held on the fourth Sunday every May in
Higashiomi, Shiga, Japan
A man flying a kite on the
beach, a good location for flying as winds travelling across the sea contain few
up or down draughts which cause kites to fly erratically.
A
kite is a flying tethered
aircraft that depends upon the tension of a tethering system. The necessary
lift that makes the kite wing fly is generated when air (or in some cases water) flows over and under the kite's wing, producing low pressure above the wing and high pressure below it. This deflection also generates horizontal
drag along the direction of the wind. The resultant force vector from the lift and drag force components is opposed by the tension of the one or more
lines or
tethers. The anchor point of the kite line may be static or moving (e.g., the towing of a kite by a running person, boat, or vehicle).
Kites are usually heavier-than-air, but there is a second category of lighter-than-air kite called a
helikite which will fly with or without wind. Helikites work on a different stability principle to normal kites as helikites are helium-stabilised as well as wind stabilised. They are a stable combination of a helium balloon and kite-sail to create a single aerodynamically sound kite. When flown in wind a helikite will lift far more than its helium alone, and it will fly very well if weighted down to be considerably heavier than air.
Kites may be flown for
recreation,
art or other
practical uses.
Sport kites can be flown in aerial
ballet, sometimes as part of a competition.
Power kites are multi-line steerable kites designed to generate large
forces which can be used to power activities such as
kite surfing,
kite landboarding,
kite buggying and a new trend
snow kiting. Kites towed behind boats can lift passengers which has had useful military applications in the past.
History
thumb|230px|Woodcut print of a kite from John Bate's 1634 book, [[The Mysteryes of Nature and Art in which the kite is labeled a "FIER DRAKE". The caption is from the its reprint in
Joseph Strutt's 1801 book,
The sports and pastimes of the people of England from the earliest period.]]
Kites were used approximately 2,800 years ago in
China[Fadul, J. (2009). Kites in History, in Teaching, and in Therapy. Lulu Press. ISBN 978-0-557-08589-7], where materials ideal for kite building were readily available:
silk fabric for sail material, fine, high-tensile-strength silk for flying line, and resilient
bamboo for a strong, lightweight framework. Alternatively, the kite authors Clive Hart and Tal Streeter hold that leaf kites existed far before that time in what is now
Indonesia, based on their interpretation of cave paintings on
Muna Island off
Sulawesi. The kite was said to be the invention of the famous 5th century BC Chinese philosophers
Mozi and
Lu Ban. By at least 549 AD
paper kites were being flown, as it was recorded in that year a paper kite was used as a message for a rescue mission.
[Needham, Volume 4, Part 1, 127.] Ancient and medieval Chinese sources list other uses of kites for measuring distances, testing the wind, lifting men, signaling, and communication for military operations.
The earliest known
Chinese kites were flat (not bowed) and often rectangular. Later, tailless kites incorporated a stabilizing bowline. Kites were decorated with mythological motifs and legendary figures; some were fitted with strings and whistles to make musical sounds while flying.
[ Retrieved March 29, 2007, from Encyclopedia Britannica Online.]One ancient design, the fighter kite, became popular throughout Asia. Most variations, including the fighter kites of India, Thailand and Japan, are small, flat, rough, diamond-shaped kites made of paper, with a tapered bamboo spine and a balanced bow. Although the rules of
kite fighting varied from culture to culture, the basic strategy was to maneuver the swift kite in such a way as to cut the opponent's flying line.
.
thumb|left|Rider with kite in [[Konrad Kyeser's technical treatise
Bellifortis (ca. 1405)]]
In
Europe unambiguous drawings of kites first appeared in print in
the Netherlands and
England in the 17th century, pennon-type kites that evolved from military banners dating back to
Roman times and earlier were flown during the
Middle Ages.
says that the earliest European description of a kite comes from the
Magia Naturalis written in 1589 by the Italian polymath
Giambattista della Porta (1535–1615).
Hang gliders are based on the
Rogallo wing, originally marketed as a mylar self-inflating kite named the Flexikite.
In 1750,
Benjamin Franklin published a proposal for an experiment to prove that lightning is
electricity by flying a kite in a storm that appeared capable of becoming a
lightning storm. Benjamin Franklin wisely never performed his experiment, but on May 10, 1752,
Thomas-François Dalibard of France conducted Franklin's experiment (using a 40-foot (12 m)-tall iron rod instead of a kite) and extracted electrical sparks from a cloud.
The period from 1860 to about 1910 became the "golden age of kiting". Kites started to be used for scientific purposes, especially in meteorology, aeronautics, wireless communications and
photography; reliable manned kites were developed as well as
power kites. Invention of powered airplane diminished interest in kites. During
World War II saw a limited use of kites for military purposes (see
Focke Achgelis Fa 330 for example). Since then they are used mainly for recreation.
Materials
Art kites at a
German kite festival
Octopus kite at Clovis, New Mexico kite festival.
Kites typically consist of one or more spars to which a paper or
fabric sail is attached, although some, such as
foil kites, have no spars at all. Classic kites use
bamboo,
rattan or some other strong but flexible
wood for the spars, paper or light fabrics such as
silk for the sails, and are flown on string or twine. Modern kites use synthetic materials, such as
ripstop nylon or more exotic fabrics for the sails,
fiberglass or
carbon fiber for the spars and
dacron or
dyneema for the kite lines.
Kites can be designed with many different shapes, forms, and sizes. They can take the form of flat geometric designs, boxes and other three-dimensional forms, or modern sparless inflatable designs. Kites flown by children are often simple
geometric forms (for example, the diamond). In Asia, children fly dried symmetrical leaves on sewing thread and sled-style kites made from sheets of folded writing paper.
Designs often emulate flying insects, birds, and other beasts, both real and mythical. The finest Chinese kites are made from split bamboo (usually golden bamboo), covered with silk, and hand painted. On larger kites, clever hinges and latches allow the kite to be disassembled and compactly folded for storage or transport. Cheaper mass-produced kites are often made from printed
polyester rather than silk.
Tails are used for some single-line kite designs to keep the kite's nose pointing into the wind. Spinners and spinsocks can be attached to the flying line for visual effect. There are rotating wind socks which spin like a
turbine. On large display kites these tails, spinners and spinsocks can be 50 feet (15m) long or more.
Modern acrobatic kites use two or four lines to allow fine control of the kite's angle to the wind. Traction kites may have an additional line to de-power the kite and quick-release mechanisms to disengage flyer and kite in an emergency.
Practical uses
Chinese dragon kite more than one hundred feet long which flew in the annual
Berkeley, California, kite festival in 2000. It is a kite-train of hundreds of linked circles with outriggers ending in feathers for balance. The dragon's head is a bamboo frame with painted silk covering.
A quad-line traction kite, commonly used as a power source for
kite surfing Military applications
Kites have been used for
military uses in the past for signalling, for delivery of
munitions, and for
observation, by lifting an observer above the field of battle, and by using
kite aerial photography.
According to
Samguk Sagi, in 637,
Kim Yu-sin, a Korean general of
Silla rallied his troops to defeat rebels by lofting a kite with a
straw man which looked like a burning ball flying to the sky.
Kites were also used by
Admiral Yi of the
Joseon Dynasty (1392-1910) of Korea. During the
Japanese invasions of Korea (1592-1598), Admiral Yi commanded his
navy with kites. His kites had specific markings directing his fleet to perform his order. The
war eventually resulted in a Chinese and Korean victory; the kites played a minor role in the war's conclusion.
In more modern times the British navy also used kites to haul human lookouts high into the air to see over the horizon and possibly the enemy ships, for example with the kite developed by Samuel Franklin Cody. Barrage kites were used to protect London as well as the Pacific coast of the United States during the last century. Kites and kytoons were used for lofting communications antenna.
Submarines lofted observers in rotary kites. The Rogallo parawing kite and the Jalbert parafoil kite were used for governable parachutes (free-flying kites) to deliver troops and supplies.
Science and meteorology
Kites have been used for scientific purposes, such as
Benjamin Franklin's famous experiment proving that
lightning is
electricity. Kites were the precursors to the traditional
aircraft, and were instrumental in the development of early flying craft.
Alexander Graham Bell experimented with very large
man-lifting kites, as did the
Wright brothers and
Lawrence Hargrave. Kites had a historical role in lifting scientific instruments to measure atmospheric conditions for
weather forecasting.
Radio aerials and light beacons
Kites can be used for radio purposes, by kites carrying antennas for MF, LF or VLF-transmitters. This method was used for the reception station of the first transatlantic transmission by
Marconi.
Captive balloons may be more convenient for such experiments, because kite-carried antennas require a lot of wind, which may be not always possible with heavy equipment and a ground conductor. It must be taken into account during experiments, that a conductor carried by a kite can lead to a high voltage toward ground, which can endanger people and equipment, if suitable precautions (grounding through resistors or a parallel resonant-circuit tuned to transmission frequency) are not taken.
Kites can be used to carry light effects such as lightsticks or battery powered lights.
Kite traction
Kites can be used to pull people and vehicles downwind. Efficient
foil-type kites such as
power kites can also be used to sail upwind under the same principles as used by other sailing craft, provided that lateral forces on the ground or in the water are redirected as with the keels, center boards, wheels and ice blades of traditional sailing craft. In the last two decades several kite sailing sports have become popular, such as kite buggying, kite landboarding and kite surfing. Snow kiting has also become popular in recent years.
Kite sailing opens several possibilities not available in traditional sailing:
- Wind speeds are greater at higher altitudes
- Kites may be manoeuvered dynamically which increases the force available dramatically
- There is no need for mechanical structures to withstand bending forces; vehicles or hulls can be very light or dispensed with all together
The German company
SkySails has developed ship-pulling kites as a supplemental power source for
cargo ships, first tested in January 2008 on the
ship MS Beluga Skysails. Trials on this 55 m ship have shown that, in favorable winds, the kite reduces fuel consumption by up to 30%. This system is planned to be in full commercial production late 2008. Kites are available as an auxiliary sail or emergency
spinnaker for
sailing boats. Self-launching
Parafoil kites are attached to the mast.
MS Beluga Skysails is the world's first commercial
container cargo ship partially powered by a giant computer-controlled kite (160 m² or 1,722 sq ft). The kite could reduce fuel consumption by 20%. It was launched on 17 December 2007 and was set to leave the northern German port of
Bremerhaven to
Guanta,
Venezuela on January 22, 2008. Stephan Wrage, managing director of
SkySails GmbH announced: "During the next few months we will finally be able to prove that our technology works in practice and significantly reduces fuel consumption and emissions." Verena Frank, project manager at Beluga Shipping GmbH, SkySails GmbH's partner further stated that "the project's core concept was using wind energy as auxiliary propulsion power and using wind as a free of charge energy".
Power generation
A conceptual research and development project by
Makani Power, based in
California and funded by
Google.org, is investigating the use of kites in harnessing high altitude wind currents to generate electricity.
A separate
Delft University of Technology project has used a 10
m² kite to generate 10 kilowatts of power.
See also
laddermill.
Cultural uses
Launch of ram-air inflated
Peter Lynn single-line kite, shaped like an octopus and long
Kite festivals are a popular form of entertainment throughout the world. They include small local events, traditional festivals which have been held for hundreds of years and major international festivals which bring in kite flyers from overseas to display their unique art kites and demonstrate the latest technical kites.
Asia
Making a traditional
Wau jala budi kite in
Malaysia. The bamboo frame is covered with plain paper and then decorated with multiple layers of shaped paper and foil.
Kite flying is popular in many Asian countries, where it often takes the form of '
kite fighting', in which participants try to snag each other's kites or cut other kites down.
Fighter kites are usually small, flat, flattened diamond-shaped kites made of paper and bamboo. Tails are not used on fighter kites so that agility and maneuverability are not compromised.
In
Afghanistan, kite flying is the most popular game of Asia, and is known in
Dari as
Gudiparan Bazi. Some kite fighters pass their strings through a mixture of ground glass powder and glue. The resulting strings are very abrasive and can sever the competitor's strings more easily. The abrasive strings can also injure people. During the
Taliban rule in Afghanistan, kite flying was banned, among various other recreations.
In
Vietnam, kites are flown without tails. Instead small flutes are attached allowing the wind to "hum" a musical tune. There are other forms of sound-making kites. In Bali, large bows are attached to the front of the kites to make a deep throbbing vibration, and in Malaysia row of gourds with sound-slots are used to create a whistle as the kite flies.
The
Indian festival of
Makar Sankranti is devoted to
kite fighting in some states. This spring festival is celebrated every January 15, with millions of people flying kites all over northern India. The states of Bihar, Jharkhand, Gujarat, some part of West Bengal, Rajasthan, and the cities of
Ahmedabad,
Vadodara,
Jaipur,
Dhanbad and
Hyderabad are particularly notable for their kite fighting festivals. Kite flying in Hyderabad starts a month before the official kite flying festival (Sankranthi). The thread used to fly kites in Hyderabad is known as 'Manjaa'. Highly maneuverable single-string paper and bamboo kites are flown from the rooftops while using line friction in an attempt to cut each other's kite lines, either by letting the line loose at high speed or by pulling the line in a fast and repeated manner. In some Indian cities kite flying/fighting is an important part of other celebrations, including
Republic Day, Independence Day,
Raksha Bandhan, and
Janmashtami. A international kite festival is held every year before
Uttarayan for 3 days in
Ahmedabad. In
Gujarat, kite flying is most popular. The
Vadodara,
Surat and
Ahmedabad are the main cities where kite flying is observed on the 14 and 15 January every year. The 14th known as 'Uttarayan' and 15th known as 'Vasi Uttarayan'. People start flying kites early in the morning and continue until the evening. Playing music to accompany kite-flying is a common sight. The kite is known as 'Patang' in Gujarat and other places in India. The kite flying with Cotton Cords. Cotton cords has various brands like Chain 8, Genda 1,2,Panda etc. People start preparations before 15 days ahead to buy Kites and Cords.
In
Pakistan, kite flying is a popular ritual for the spring festival known as
Basant. However, kite flying is currently banned as some kite fliers engage in kite battles by coating their strings with glass or shards of metal, leading to injuries and death.
Kite fighting is a very popular sport in Pakistan, mainly centered in
Lahore. Kup, Patang, Guda, and Nakhlaoo are some of the kites used in fighting and they vary in balance, weight and speed through the air.
Weifang,
Shandong,
China promotes itself as the kite capital of the world. It is home to the largest kite museum in the world, which has a display area of 8100 m
2. Weifang hosts an annual international kite festival on the large salt flats south of the city. There are several kite museums in Japan and others in UK, Malaysia, Indonesia, Taiwan, Thailand and the USA.
Europe
In
Greece and
Cyprus, flying kites is a tradition for
Clean Monday, the first day of
Lent. In the
British Overseas Territory of
Bermuda, traditional
Bermuda kites are made and flown at
Easter, to symbolise Christ's ascent. Bermuda kites hold the world records for altitude and duration.
South America
In
Chile, it is very popular, especially during Independence Day festivities (September 18).
Popular culture
- The Peanuts cartoon character Charlie Brown was often depicted having flown his kite into a tree as a metaphor for life's adversities.
General safety issues
There are safety issues involved in kite-flying, more so with power kites. Kite lines can strike and tangle on electrical power lines, causing power blackouts and running the risk of electrocuting the kite flier. Wet kite lines or wire can act as a conductor for static electricity and lightning when the weather is stormy. Kites with large surface areas or powerful lift can lift kite fliers off the ground or drag them into stationary objects. In urban areas there is usually a ceiling on how high a kite can be flown, to prevent the kite and line infringing on the airspace of helicopters and light aircraft.
In
Asia, specially in the
Indian subcontinent the twine is coated with powdered glass to cut opponent's lines and these deadly strings known as
Manja are reported to kill number of pedestrians or motorcyclists each year all over the region.. The same problem has been reported in the Philippines and in Brazil
.
Kite designs
thumb|right|Delta (triangular) kite
Train of connected kites
Kite types
Types of kite line materials
- Manja or Manjha, Hindi word for the glass powder coated kite flying & fighting string from Indian subcontinent and surrounding regions
See also
- Remotely operated vehicle Some tethered ROVs are kited with remote controls on fins for underwater kiting. Ships tow the ROVs; the tether often has communication cables in it.
- Solar balloon A solar-heated hot air balloon that can be flown like a kite, but on windless days.
- Uttarayan The kite flying festival of northern India
.png/){kind=link}
