The M18 series of colored smoke grenades are an important signal tool for the modern Warfighter. Current M18 grenades contain one color (violet, red, yellow or green) smoke per grenade, with about 350 grams of dye in each. Since each smoke grenade serves a distinct purpose, the Warfighter is often required to carry most or all colors, at all times, adding a physical burden that could affect their speed, mission and make less space for other mission critical items. Pyrotechnics and Explosives Branch Chief Joe Domanico, hopes to mitigate the physical challenges of carrying multiple smoke grenades with a new Selectable Color Single Canister Smoke Hand Grenade.
Domanico’s new design placed first in ECBC's Innovation Contest. The contest, which called for Skunk Works from across the Center, split $50,000 among the top three winners to continue to research and improve their designs. The Selectable Color Single Canister Smoke Hand Grenade utilizes solid state fluid logic within the lightweight grenade body for the selection of the desired color. Using an additional blue color, a single grenade has the ability to produce up to seven different smoke colors.
“In the new design there are three dye compartments, each filled with a primary color: yellow, red and blue,” said Domanico. “The top part of the grenade has two dials. If a user twists one dial, the apparatus reveals one dye color. If they twist both dials, two colors are revealed, at once creating a new color.”
For example, if a Warfighter needed to use an orange smoke grenade, they would twist the grenade to unlock the red and yellow dye, revealing the orange color. Yellow and blue make the standard green color dye, red and blue make the violet dye.
“All of these color possibilities are made available to the Warfighter in one canister – that has not been done before,” said Domanico.
The grenade also produces a seventh color. When all three dyes are released at the same time, the grenade produces a nearly black smoke – the seventh color. Not only does black create a new signal color, but using all of the dyes at the same time produces the maximum amount of smoke, providing for a concentrated screen or a signal.
The Selectable Color Single Canister Smoke Hand Grenade does not just make seven colors of a grenade available on one device it makes seven grenades available on one device.
“A common misconception about color smoke grenades is that it is one grenade design in four different colors,” Domanico said. “Actually each color grenade is a different thermodynamically balanced systems, and each dye handles the heat and gas differently. Since they are all different formulations, they are all different grenades.”
The grenade is broken into compartments, one of which contains the balanced fuel/oxidizer/coolant pellet. The new fuel pellet uses a newly developed low-burning-temperature thermochemistry system that provides the correct amounts of heat and gas. The dyes are blended with other non-energetic components which compensate for their different thermochemical needs. This allows a single fuel pellet to be used for every color dye. This arrangement minimizes the unused portion of the grenade. Basically, the soldier is carrying a “screening” grenade (similar to the M83 TA Smoke Grenade that is standard now) which emits a large dark gray smoke cloud, or by twisting the fluid logic block at the top of the grenade, they can use the grenade as a signal to emit one of six colors. (Note: the M83 TA Smoke Grenade was initially developed by the Pyrotechnics and Explosives Branch for use by NASA in aerodynamic testing of fighter aircraft at 30,000 feet altitude; later adopted by the US Armed Forces as an interim AN-M8 HC Screening Grenade replacement due to its lower toxicity to the soldier and the environment.)
The Branch recently conducted testing work to lower the toxicity of the red and violet smoke colors. Previously, the green and yellow smokes were redesigned for lower toxicity. Currently, they are working on the blue dye. All of these new compounds will be used in the Selectable Color Single Canister Smoke Hand Grenade, making the entire mechanism better for Warfighters and the environment than previous styles.
When evaluating the colored smoke dyes, the Branch developed and uses a Smoke Protocol Test that determines the dye’s suitability for use in a smoke grenade. Only 25 grams of a candidate dye is needed to complete the analysis in under a week’s time. The Protocol Test determines the upper and lower temperature limits of the dye, its density in producing a smoke cloud, and the suitability of the smoke cloud’s color.
Domanico and his team will use the money from the ECBC Innovation Contest to demonstrate a full scale prototype grenade designed and manufactured within the Pyrotechnic Loading Facility. They will then demonstrate the grenade to the proper Project Managers who have already shown interest in the design.
“The success of this project will be a program of record to get this technology into the hands of the Warfighter.”
