Mk 40 (Obsolete)

Projectiles used in

Over-all length, inches

Diameter at base ogive, inch

Threaded length, inch

Threads

Material

Weight, pounds

Minimum range, yards

Energizer

Wave-suppression feature

Self-destruction feature

Description: This fuze initiates detonation if the trajectory passes within the maxi-mum influence radius of seventy feet. Against aircraft below 200-foot altitude, operating radius is reduced, depending on the altitude of the plane and the height of the waves, because of the awave-supression feature. Burst height over land or water may vary bet-ween 10 and 30 feet.

Random burst will occur along the trajectory after arming, but before approaching a target. With a target at 12,200 yard range, 20 per cent of the rounds will function pre-maturely; and at closer ranges a somewhat smaller percentage will function prematurely. If the target at 12,200-yard range is approached within the sensitivity limits of the fuze, 65 per cent of the rounds will function.

These units have wet energizers of the reserve type; so effectiveness is not greatly diminsihed by normal storage for at least 18 months. Production has been suspended on this item.

Employment: This fuze is recommended for antiaircraft work from a minimum range of 800 yards to the extreme range of the gun. The wave-suppression feature makes this fuze useful against low-flying aircraft and surface targets, as it will not detonate on wa-ter influence above 15 to 20 feet; but it must pass somewhat closer to the target in or-der to function than in the case of high-flying targets. It may be used effectively for barrage of land targets where bursts at 10 to 30 feet will be effective against personnel and lightly protected installations.

Remarks: The Auxiliary Detonating Fuze Mk 54, replacing the Auxiliary Detonating Fu-zes Mks 17 and 46, is used in conjunction with this fuze.

This fuze is currently being replaced by the V.T. Fuze Mk 53 in new projectiles; Mk 53 cavity is smaller.