Modular charge artillery system

FA Journal, March-June, 2004 by James S. Pearson

From the dawn of the Field Artillery, soldiers have had to measure how much powder to load into their artillery pieces. This required Cannoneers to cut bag charges and then dispose of the unused increments. Until recently, even though advances in chemistry and technology have changed the way we live and fight, soldiers still had to cut bag charges and burn the unused increments. MACS is changing that archaic practice for 155-mm cannons.

Currently, there are four different types of bag charges used with 155-mm howitzers: the M3 (Green Bag), M4 (White Bag), M119 (Charge 7 Red Bag) and the M203 (Charge 8S Combustible Case). All but the M119 and M203 charges require Soldiers to burn unused powder.

The Army has begun fielding MACS--Soldiers no longer will waste unused powder. MACS consists of two propelling charges, the M231 and M232, and associated packaging. (See the figure.) The system is compatible with all current and planned 155-mm weapons.

MACS uses a "build-a-charge" concept in which all M231 increments are identical in the lot and all M232 increments are identical in the lot (never mixing the two charges), eliminating the need to dispose of unused increments. Unused increments are retained for future use.

The M232 and M231 increments have a center core igniter and main charge granular propellant enclosed in a rigid combustible case. The M232 includes additives to reduce flash, gun wear and barrel coppering. For ease in loading, the center core igniter is bidirectional. The large surface area of the igniter is compatible with all current cannon primers and planned laser ignition systems.

The M231 is fired either singularly (Charge 1) or in pairs (Charge 2) to engage targets from three to 12 kilometers. The M232 is fired in groups of three or more increments from Charge 3 (three M232s) to Charge 5 (five M232s). Charges 3 through 5 can be fired from all weapons to engage targets to ranges exceeding 29 kilometers.

M231s are green and M232s are light brown. To facilitate night operations and preclude a mix up of M231 and M232 increments (Cannoneers cannot mix M231 and M232). M231 increments have smooth surfaces with black bands in contrast to the M232 increments that have no bands and four bumps on each end. Increments are packed in plastic sleeves allowing quick removal and easy manual loading.

The MACS packaging system facilitates handling and supports long-term storage. Canisters have easily opened lids for faster access. All M231 canisters are green and have a solid lid handle. The M232 canisters are tan and longer than the M231 canisters and have a hole in the lid handle for tactile identification during night operations.

MACS propellants are transported and handled in the same manner as other conventional propellants.

MACS fielding began in two phases. Phase I M231 fielding began in June 2003. While there is a limited number of the M231 MACS available for training, units will continue to use current "bag" propellants until they are depleted.

Phase II M232 fielding began in March 2004. However, due to the vast number of M119 and M203 charges in the inventory and the M232 production rate, the M232 will not be available to for training until late 2004.

An exportable new equipment training (NET) package for training both the M231 and M232, including an interactive courseware program and dummy charges, is being issued instead of deploying a NET team. During Phase I fielding, MACS support and training materials were provided through the installation, marked for delivery to units, plus separate packages for the installation ammunition supply point and range control. Support and training materials for Reserve Component units are being shipped directly to the units.

Training for the affected military occupational specialties (MOS) and areas of concentration will be integrated into existing institutional courses.

MACS will require new fire control solutions for the M198, M109A5 and M109A6 howitzers. Automated fire control solutions are being provided to the gaining commands and installations by the appropriate program managers for the Paladin automatic fire control system (AFCS) and tactical data systems. Graphical firing tables (GFTs) and tabular firing tables (TFTs) also are being provided through standard distribution channels. The advanced FA tactical data systems (AFATDS) Version 6.3.1 supports tactical and technical fire control while the battery computer system (BCS) Version 11.024 and Paladin AFCS software Version 11M also support firing MACS.

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For additional information about MACS, contact the author at DSN 639-3389 or commercial (580) 442-3389 or email him at pearsons@sill.army.mil.

James S. Pearson

Combat Developer, TSM Cannon

Fort Sill, OK