Projectile used in

Over-all length

With booster

Without booster

Maximum diameter

Thread diameter

Markings

The body of the fuze is screw-threaded externally at the base to receive the fuze boos-ter. The firing pin is held in position by a centrifugal bolt which is locked by two detents which are fitted with springs. The firing pin is fitted with two shear wires.

The detonator holder fits into a centrifugal bolt which acts as a safety shitter to the flash hole. Another centrifugal bolt is fitted to perform the function of raising the detona-tor holder. The detonator holder is in the form of a cup, the mouth of which fits over the lower end of the firing pin.

On acceleration, the two setback detens set back, leaving the upper lateral channel clear for subsequent movement of the centrifugal locking bolt. The detens are held back during flight by the friction resulting from centrifugal force. During the period of decele-ration, the centrifugal locking ball and lifting bolt are thrown outwards and the detonator holder, assisted by the lifting movement imparted by the step on the lower centrifugal bolt, creep forward to the limit imposed by the lower shear wire, thus disengaging the recess in the masking bolt. The masking bolt is them thrown clear of the flash-hole lead-ing to the booster. On impact, the detonator overcomes the lower shear wire, hitting the firing pin. Dependent on the resistance offered by the surface struck and the angle of the strike, the firing pin may be driven in, severing its shear wire, and piercing the deto-nator as the holder moves forward.

Figure 209
Percussion Nose Fuze M39