Description
The M524 series point detonating fuze is used to detonate HE, M362 or Smoke WP, M374 or M375 ammunition fired from 81mm mortars. The fuze is dual purpose, designed to function on impact or graze with superquick action or 0.05 second delay.
The fuze has an aluminum body threaded externally to fit the round and internally to accept a tetryl booster. The nose of the fuze is a spring loaded striker with a slot for selection of superquick or delay action. Depending on that selection, either detonation train within the fuze body is initiated by independent firing pins. The SQ train consists of Detonator M63 and has a detonator lead charge. The delay train includes primer and delay charge M2. Either train fired Detonator M80 and a booster lead charge to detonate the tetryl booster in the base. The fuze is bore safe by means of a delayed arming mechanism consisting of a spring loaded rotor released by setback upon weapon firing and a timing device. Two safety pins* are provided, one to secure the internal plunger and one to secure the setback arming device. A pull wire connects the pins for removal before firing.
Army Models M524A5 and M524A6 incorporate the second safety pin retaining the plunger and provide that the pin cannot be removed if the arming mechanism starts inadvertently. The models are similar except that Fuze M524A6 requires greater setback force to arm. Models M524A1, M524A2, M524A3 and M524A4 are for USN and USMC use only, and have only one safety pin (arming). Fuzes M524A1 and M524A4 incorporate design differences but function similarly. The delay charge in Fuze M524A2 is replaced by a non-delay element. Fuze M524A3 is capable only of superquick action.
Functioning
No information about functioning.
Hazardous Components
No information about hazardous components.
See Also
Cartridge, 81mm HE, M362, M362A1
Cartridge, 81mm Smoke WP, M370
Cartridge, 81mm Smoke WP, M375
Source(s)
TM 43-0001-28, Artillery Ammunition (chg 11, 2003)
TM 9-1300-203, Artillery Ammunition (1967)
TM 9-1385-51, Ammunition (Conventional) for Explosive Ordnance Disposal (1967)
