Rise of Insensitive Munitions

The IMX-101 explosive represents an important technological advancement in the area of Insensitive Munitions (IM) to support the U.S. military.

Beyond IMX-101, various other IM explosive formulations are being developed and qualified for a wide array of munitions applications, including bombs, artillery, grenades and mortar systems. Once fielded, these new IM technologies could ultimately save lives around the world.

Have your cake and eat it too

Interest in the possibilities of IM explosives first began during the Vietnam War.

In July of 1967, for example, a rocket accidentally discharged on the flight deck of the aircraft carrier USS Forrestal. An initial explosion and fire were made worse by a chain reaction of exploding bombs and ordnance. In the end, 134 sailors were killed and many more were injured.

The incident in 1967 does not stand alone. In 1991, during the first Gulf War, a fire at the Army’s Camp Doha, near Kuwait City, led to a series of follow-on fires and blasts from stored artillery.

As a result, in the late 1990s, the Department of Defense (DoD) initiated a significant expansion in government-funded IM research. During this time, new developments in the manufacture of energetic materials were occurring at the Holston Army Ammunition Plant in Tennessee. There, researchers were demonstrating that certain alternatives to traditional explosive ingredients, such as HMX and RDX, could be viable for munitions applications. These munitions could match the power of legacy explosive products, like TNT and Composition B, while proving much safer for use.

These IM energetic formulations were aptly deemed insensitive munitions. They were more stable and less susceptible to unplanned response when subjected to stimuli, such as fire, sympathetic detonation, and bullet or fragment impacts. On the battlefield, ammunition filled with these explosives would be much safer to use and transport, and more resistant to enemy fire or accidents.

Contrary to initial opinions, it was realized that less sensitive munitions could be developed without giving up performance. You really could have your cake and eat it too. Mike Ervin, director of Research and Development


The path to IMX-101

From the beginning, BAE Systems invested in the people and the infrastructure to get the job done.

When BAE Systems began in 1999 as the operating contractor of the Holston plant, IM research was a major part of the mission. Today, a team of about 20 Holston scientists and engineers are part of what’s become an industry leading research team for IM and munitions development. The company, in partnership with various DoD research laboratories, has developed and demonstrated a number of robust manufacturing processes for new IM energetic ingredients and formulations at Holston. Several IM products have already been qualified and fielded. Today, men and women of the U.S. military are using comparably safer explosives in warhead, bomb, mortar, artillery, fuze, grenade and submunition applications.

IMX-101 is part of a new, next-generation family of IM technologies that utilize new IM explosive ingredients, such as NTO and DNAN. In 2010, after several rounds of testing, the Army approved IMX-101 as a safer and effective replacement to TNT in artillery. Importantly, the new formulation passed all of the targeted safety criteria associated with bullet and fragment impact, slow and fast cook-off, sympathetic detonation, and shaped-jet charge impact (at 81mm scale, this represents the equivalency of a rocket-propelled grenade being fired into an artillery munition and not achieving a high-order detonation). The Army has also deemed the IMX-101 explosive as a suitable replacement for any large-caliber munitions requiring the energetic performance of TNT.

The development of IMX-101 was named one of “The 50 Best Inventions of 2010” by TIME Magazine. And in 2012, BAE Systems and the Army received an international technical achievement award for IMX-101 from NATO’s Munitions Safety Information Analysis Center. The award recognized the team for its “significant technical contributions in research and engineering related to munitions safety.”

This year, IMX-101 entered full production mode at Holston. The technology is now used in the IM M795 155mm artillery munition as a replacement to the legacy TNT explosive. It’s a significant step, as the 155mm artillery is typically fired from BAE Systems’ M777 howitzer, which is shipped to U.S. and allied forces across the globe.

Next Steps

Protecting those who protect us

On the heels of the success of IMX-101, the Army is looking to BAE Systems to replace other explosives with insensitive munitions. IMX-104 is currently undergoing final tests as an alternative to legacy Composition B in mortars. The company is also evaluating several other IM explosive technologies at Holston as potential replacements for a variety of munitions needs and uses.

In addition, BAE Systems is now using its experience and expertise at the Radford Army Ammunition Plant in Virginia, where the company began as the operating contractor in 2012. Today, with Holston and Radford, the BAE Systems Research Team is working with the Army and other DoD and Department of Energy agencies to develop safer propellants and propulsion systems.

The ultimate goal is to field fully compliant IM munitions systems (both explosives and propellants) for U.S. warfighters and allies. Such munitions would provide men and women of the military with the performance needed to fully complete their missions, along with an improved opportunity for returning home safely.

The vast majority of munitions systems are touched or influenced by our products from the Holston and Radford plants. We truly are protecting those who protect us. Mike Ervin, director of Research and Development