Army Finds New Ways to Destroy Old Ammo

By Raeanna Morgan
Crane Army Ammunition Activity

In the past, there was no way to demilitarize an L8A3 grenade in a safe and environmentally-friendly way. Now, there’s an efficient and cost-effective way to destroy this obsolete munition and ensure future readiness for the warfighter. Crane Army Ammunition Activity photo by Raeanna Morgan

Nestled within 100 square miles in Southern Indiana, Crane Army Ammunition Activity supports the hi-tech mission of destroying obsolete munitions for the Department of Defense. For more than two decades, white phosphorus rounds have been successfully demilitarized within a closed system and converted into agriculture fertilizer, both ensuring the future readiness for the storage of increasingly modernized munitions and providing a product that supports America’s farmers.

An obstacle presented itself in an otherwise smooth operation when the need to demilitarize red phosphorus rounds became imperative in continuing future readiness for the warfighter. Due to small molecular differences that caused differing burning points, Crane Army engineers had to work to design a process that would ensure the safe extraction of red phosphorus so that the mission could continue on for decades to come.

The History

In 1989, the mission to demilitarize white phosphorus in a closed system and turn it into phosphoric acid was brought to Crane Army Ammunition Activity. Since that time, the white phosphorus-to-phosphoric acid conversion plant has been considered a successful mission. Not only does it demilitarize an obsolete munition in a safe and environmentally friendly way, it produces two revenue generating materials: agricultural fertilizer and metal for recycling. In one day, the facility produces 48,000 pounds of phosphoric acid.

About twenty years later, a new problem presented itself. There was a growing stockpile of a variety of munitions containing red phosphorus taking up square footage in storage that could be used to house more modern munitions.

“Previously, we had no capability of getting rid of red phosphorus,” CAAA’s demilitarization program manager Paul Allswede said. “We couldn’t open burn it because of the negative environmental impacts, so there were developmental steps taken to address the shortfall for the Department of Defense. That was when the question of, ‘Can you process it through the white phosphorus-to-phosphoric acid conversion plant’ came about.”

The Partnership

After the need was established, SciTech Services won the Department of Defense Ordnance Technology Consortium contract to develop an economical and environmentally friendly process that would convert the red phosphorus found in smoke grenades to phosphoric acid.

Specifically, they wanted to utilize an existing demilitarization capability, the white phosphorus-to-phosphoric acid conversion plant at Crane Army. SciTech Services then sub-contracted Gradient Technology to perform the design, fabrication, and integration of a prototype machine that had the ability to disassemble the smoke grenades and remove the material. Since 1999, Gradient Technology and Crane Army have worked together on several different demilitarization projects.

Unlike white phosphorus munitions that can be sliced open or have holes punched into the projectile to start the conversion process immediately, red phosphorus has an extremely low ignition point. This meant the extraction process of the red phosphorus from certain munitions containing red phosphorus would be much more difficult than that of munitions containing white phosphorus. Gradient Technology was able to develop a process that safely removes the red phosphorus from the round with the lowest probability of ignition.

Last year, a limited test was done which proved that the system was viable, and the process was put in place to begin demilitarizing L8A3 Smoke Grenades.

The Process

The L8A3 Smoke Grenade is an obscurant that, when used, generates a smoke screen to provide cover for the soldier. It contains red phosphorus. Items containing red phosphorus require protocols to be in place in order to ensure the safe storage and handling of the munition because of the hazardous byproducts that red phosphorus can create.

“Red phosphorus outgasses phosphine, meaning that as the composition sits in storage it will throw off a gas,” CAAA’s demilitarization program manager Paul Allswede said. “When the composition is stored in the ammo cans there are gas-absorbing modules that absorb the phosphine, which is odorless, flammable and very hazardous. However, if the temperature of the ammo can gets too high the phosphine will out-produce what can be absorbed by the gas-absorbing modules.”

While storage is an option for the grenade, a concentrated amount of phosphine can be very dangerous to those who deal with it in close proximity. It is flammable and toxic, which is why having a method to dispose of it in a timely manner in order to avoid storage is very important.

Here is a look at the process.

The Future

After this process takes place, the red phosphorus is treated like the white phosphorus. It goes to the same conversion plant and is converted into phosphoric acid that will eventually be used for fertilizer.

All around there are benefits to this type of closed demilitarization system. Not only is CAAA getting rid of a munition that can become hazardous as it begins to deteriorate, it is also generating revenue that will offset production costs which ultimately will save taxpayer dollars.

Currently, this effort is funded by the Product Director for Demilitarization and managed by the Joint Munitions Command Industrial Capabilities Directorate – Demilitarization Division.

The Red Phosphorus Demilitarization process is a Department of Defense Ordnance Technology Consortium contract to develop an economical and environmentally friendly process to download the red phosphorus from smoke grenades to further utilize an existing demilitarization capability, the white phosphorus-to-phosphoric acid conversion plant at CAAA, to convert the red phosphorus into phosphoric acid.


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