Design of Parachutes for Large Bombs

A resumé is given of the results of experiments made during the past two years in which the aim has been to develop a parachute to control a heavy bomb, which is itself unstable. A solution to the problem has been found in the use of a jute hessian parachute which has the additional features of being very cheep and easy to manufacture. Experiments, using parachutes up to 20 ft. in diameter, have enabled sufficient data to be accumulated to draw a series of curves giving the safe speeds at which bombs fitted with jute hessian parachutes could be released, and also the striking velocities of such bombs. A standard design of parachute has been evolved and also a suitable housing for easy attachment to the tail of a cylindrical bomb without increasing the overall diameter. Important developments include an investigation into the effect of the relative extension of the shroud lines and the canopy fabric on the strength of the parachute under stock loading, and a search for alternative materials to jute hessian.