Kite Line - Kite Lines For High Altitude Attempts

Kite Lines For High Altitude Attempts

Historically, high altitude kite flights were made by atmospheric scientists and meteorologists in the late 19th to early 20th centuries. Routine flights around the world were made using steel wire with single kites and kite trains. The highest recorded flight was made by a German meteorological station at Lindenberg in 1919. It is reported that the top kite reached 31,955 ft above the launch point. The line was over 20 km of high tensile steel piano wire with a breaking strength varying between 134 and 225 kg. In 2000 the single-line single-kite altitude world record for kiting was made using a kite line of woven Kevlar line 3/32 inch in diameter at 270 pound breaking-strength. The kite was described by Richard Synergy in his account of the flight, as employing an angle of attack device to limit line tension to 100 lbs. This gives a safety factor of almost 3 to 1 if the breaking strength of this line is 270 lb. More recent high altitude kite flights by Robert Moore and his team in Australia have been made using Dyneema, a braided Ultra High Molecular Weight Polyethylene (UHMWPE) line, and the identically structured line, Spectra. Both these lines are stronger and lighter than Kevlar for a given diameter. One of the most important characteristics of line for high altitude kite flying is small diameter and high strength to weight ratio. The greatest barrier to high altitude kite flights is aerodynamic line drag. The use of Dyneema over an extended period has shown that it is highly resistant to ultra violet degradation in comparison to Kevlar. Richard Crawford, a high altitude flyer from the USA, made an attempt on the world single kite altitude record using a 220 lb test, Technora line manufactured by Twinline. He reported that he flew a delta kite to approximately 6,500 ft in September 2008.