The fuze is an essential and critical part of any effective munition. They are found in artillery, projectiles, rockets and bombs, guided missiles, and the new high-tech precision-guided munitions being developed today. Fuzes are a defense-unique product with little use in non-military applications.

A fuze provides safe, reliable detonation of a munition at the desired time and place. It controls safe separation of the munition from the delivery platform and triggers its detonation. Safety features are built into all fuzes to protect personnel while handling ammunition during storage, transit and deployment. Additional safety features are needed to prevent the shell from exploding too soon after deployment, which could also endanger the gun crew.

Many of the techniques used to design fuzes were developed by Picatinny engineers, scientists, and technicians. Picatinny's commitment to excellence resulted in safe, reliable and affordable fuzing systems for the U.S. Army and other services, both U.S. and foreign. The constant exploration and development of new technologies keeps Picatinny in the forefront of this highly important field. We have the largest fuzing group of all the services. In fact, some of the other services look to Picatinny to develop fuzes for their projectiles since the industrial base supporting such efforts in the past has dropped off dramatically.

Examples of Fuzes Developed and/or Fielded by Picatinny

Current Artillery Fuzes
The M762A1 and the M767A1 Electronic Time (ET) Fuzes enable the soldier to take advantage of the latest digital electronic technology. The new fuzes are easier to operate and more accurate and reliable than their predecessors. The M762A1 is used in rounds that carry and dispense submunitions such as mines and grenades over the target areas; the M767A1 provides fuzing for standard high explosive rounds. Both can be used in all existing 105mm and 155mm weapon systems.

The M782 Multi-Option Fuze Artillery (MOFA) is the latest fuze artillery design and is compatible with all current 105mm and 155mm bursting artillery projectiles. It employs state-of-the-art advanced electronic technologies. It replaces seven earlier fuzes, simplifying logistics and training. MOFA incorporates a proven legacy S&A device to maintain required safety and reliability and can be inductively set in the proximity, point detonating, delay or time mode. This multi-option capability reduces the number of artillery fuzes the U.S. forces have to maintain in inventory.

The M739A1 Fuze is a point detonating (PD) fuze that is used on bursting type projectiles. The fuze has a rain insensitive nose that allows firing in heavy rain with reduced probability of early functioning. This fuze may be used in superquick or delay mode, which are hand settable by turning a screw. The fuze contains a delay arming mechanism that prevents the fuze, after firing, from arming until a certain distance from the weapon.

The MK399-1 MOUT Fuze was developed specifically for Military Operations in Urban Terrain (MOUT). It can be used on both 105mm and 155mm high explosive rounds. It provides conventional point detonating capability. It also provides a short delay mode which, coupled with its heavy steel penetrator body, allows for target effects inside wood, concrete, and brick structures.

The M732A2 Proximity Fuze is a short intrusion proximity fuze that does not require the removal of the supplementary charge when placed on hand emplaced (HE) projectiles. Its predecessor, the M732, could not keep pace with the growth in the severity of the ballistic environment. The M732A2 fuze was designed as an improvement for compatibility with rocket-assisted projectiles, top zone ballistic environments and a more consistent height of burst.

Current Mortar Fuzes
The M734A1 Fuze is a state-of-the-art proximity fuze based on Frequency Modulated Continuous Wave (FMCW) Directional Doppler Ranging (DDR) techniques, similar to the M782 Multi-Option Fuze for artillery. The M734A1 is very safe and reliable; over 5,000 rounds have been field rested, yielding more than 99 percent reliability. It has excellent electronic countermeasure hardening, is very accurate and delivers a consistent height of burst (HOB) performance under all service conditions over terrain with various reflection coefficients. The M734A1 can be used on all 60, 80, and 120mm high explosive (HE) mortar cartridges and the 120mm White Phosphorous Smoke cartridge.

The M783 Point Detonating (PD) Fuze is a dual safe point detonating and delay fuze that is based on the M734A1 fuze for commonality of components. This commonality contributes to economies of scale and results in cost savings in purchasing the components. M783 is intended for tactical training and can be used during tactical operations as well. The M783 is qualified for use on all 60, 81, and 120mm HE cartridges and the 60mm White Phosphorous Smoke Cartridge.

Other Fuzing Applications: Missiles, Mines and Small Caliber
The Stinger Missile is a shoulder-fired antiaircraft weapon. It uses a M934E6 fuze containing a safe and arming mechanism and dual logic circuits to sense proper launch profile, S&A rotor position, impact switch, and hard-target sensor interrogation. Upon impact with a target, a mechanical impact switch enables a timing circuit, resulting in a preprogrammed firing delay. The hard target sensor overrides the delay and fires the fuze if an impact threatens breakup of the warhead. A self-destruct circuit destroys the warhead after 15 seconds of flight if a target is not encountered.

Picatinny is playing a key role in developing Fuzing for the Objective Individual Combat Weapon (OICW). This shoulder-fired individual weapon will replace the current M240 and M16A2/M203 combination, which will provide infantry with a decisive overmatch capability. The fuze for the OICW will have 3 arming modes - normal, MOUT, and PD backup with the arming distance dependent on the selected mode. The fire control assembly incorporates a laser rangefinder, ballistic computer, direct view optics, video sight, electronic compass, thermal capability and a target tracker. The laser rangefinder measures the distance to the target and converts the distance. This information, together with the selected firing mode, is transmitted from the fire control to the fuze through a drive coil wound around the barrel of the gun. The fuze then determines where to function in the airburst mode by counting turns as it progresses to the target.

Picatinny has also provided Fuzing for the Objective Crew Served Weapon (OCSW). OCSW is a lightweight, two-man portable, integrated machine gun system that combines the firepower of airbursting munitions with optoelectric fire control to provide all-environment operation and enhanced lethality. It fires 25mm HE airbursting munitions using a fire control system that automatically transmits the airburst time to the fuze. This unique technology and design provides accurate fuzing and, therefore, a high level of effectiveness upon each target. The fuze also has PD and self-destruct capabilities as back-up functions.