THE RATE OF THE M43A3 MECHANICAL TIME FUZE, AND ITS DIFFERENTIAL EFFECTS

Abstract : The rate of the M43A3 mechanical time fuze, during flight, depends slightly upon driving torque, markedly upon the rate of spin, and trivially upon the fuze temperature. There is a small elastic strain effect, arising from the straining of the mechanism between the timing disk and the escapement. The amounts of these effects, determined experimentally, are applied to compute the relation between time to burst and fuze setting on the 3-inch A.A. gun M3, the 90mm A.A. gun M1, and the 75mm aircraft gun M2. The differential effects of changes in muzzle velocity, air density, and angle of departure are also determined. Preliminary computations are described relating to the 4.7-inch A. A. gun. The derivation is described of the time-to-burst, fuze-setting relation for the 3-inch A.A. gun M3, included in the fuze specifications.