This is a report on an attempt to measure line tension on various types of kites when in the air, and at various windspeeds, to determine if there were any correlations with size, weight, or type of kite. The results were not as expected.
The first problem, of course, is a suitable means of measuring tension exerted on a kite line. Most available scales are either in pounds with approximations for fractions of pounds; or in half ounces, with the top limit one pound. Since neither type seemed suitable for the purpose, I tested various springs (attached at one end in V-type molding with a line tied at the other end through a screw-eye to a clip) until I found one which would measure fairly accurately from a half-ounce to four pounds. Designations in half-ounces were marked on the inside of the V-molding so they could be read easily in the field. A second scale was made by selecting a stronger spring which would measure tensions from four to eight pounds. Designations in quarter-pounds were marked on the scale.
Thirty-five kites were selected for testing, which included several sizes and weights of flat, bowed, box, parafoil, keeled and rotary kites. An arbitrary decision was made to measure line tension at three different wind speeds-as close to 8,15 and 20 miles per hour as possible.