Description
Except for the dimensions noted (threads and threaded length), the Base Detonating Fuze Mk 21 is like the Mk 19, and has practically the same operation; however, this fuze is designed with an additional plunger locking unit. The plunger body is drilled in four places, and four balls are placed in the holes. On forward motion of the plunger and under centrifugal action, the locking balls fly out of their recesses into the forward or larger diameter portion of the body, locking the plunger in the forward position. This locking feature is provided to insure alignment of booster lead-ins and detonator lead-outs during the long delay period, when the projectile is subjected to violent shocks of penetration.
The detent springs in this fuze are considerably weaker than those used in the Base Detonating Fuze Mk 28.
The Mod 1 of this fuze is identical to the Mod 0, except that it is fully moisture resistant.
Functioning
No information about functioning.
Hazardous Components
No information about hazardous components.
See Also
Nothing else to see.
Source(s)
OP 1664, Volume 1 - US Explosive Ordnance (1947)
