Thermobaric Weapons and the Shock Wave Physics Group (SWPG)

McGill has a long history with thermobaric weapons, also known as “fuel-air explosives” (FAEs). Thermobaric weapons were developed in response to the ineffectiveness of fragmentation weapons when dealing with minefields or troops in trenches and bunkers. They are part of a larger category of weapons called volumetric weapons, which are characterized by high blast performance and a large fireball. Thermobaric weapons were originally developed by the U.S. military for use in the Vietnam War; they were also used during the Soviet occupation of Afghanistan in the 1980s. Since 1999, when Russian armed forces used FAEs as part of their re-conquest of Chechnya, thermobaric weapons have been used once again in Afghanistan (by British and U.S. occupation forces), as well as in Iraq (by U.S. occupation forces) and in Syria (by forces loyal to President Bashar al-Assad).

Conventional explosives kill people and demolish structures by creating an enormous amount of explosive force; they may also be constructed to produce as many sharp and deadly fragments as possible. Thermobaric weapons, however, produce a blast wave that is significantly longer in duration than their conventional counterparts. “Fuel-air explosives” are true to their name. An initial charge saturates the air with fuel, creating a cloud that expands in many directions and flows around objects. Next, a second charge ignites this oxygen-fuel mix, creating a very large explosion and pressure wave that can knock down unreinforced structures, destroy equipment and goods, and incinerate people – or at least severely injure them. If any of the fuel-saturated air has entered a person’s body, the second charge will probably rupture the lungs. If the fuel fails to properly detonate, victims are left inhaling a burning mix of chemicals, which can cause lung afflictions, severe burns, and death.

The nature of a thermobaric weapon is that the oxygen in the air becomes part of the weapon itself. As the concentration of the fuel is dependent on the size the of the cloud that is allowed to disperse, it is more effective in closed-areas such as bunkers; since 2001, NATO forces in Afghanistan, like their Soviet predecessors, have also found thermobaric weapons useful against caves. This same characteristic, however, is what prevents civilians from taking cover from these bombs. As explained in a report by Human Rights Watch, “FAEs are more powerful than conventional high-explosive munitions of comparable size, are more likely to kill and injure people in bunkers, shelters, and caves, and kill and injure in a particularly brutal manner over a wide area.”

McGill’s Role in Thermobaric Weapons Research

Beginning as early as 1967 and continuing into the late 1980s, first the United States Air Force and then Canada’s Department of National Defence gave grants and contracts to the Shock Wave Physics Group (SWPG) in McGill’s Department of Mechanical Engineering for research related to the development of fuel-air and thermobaric explosives.

Though SWPG research is no longer directly funded by U.S. grants or contracts to McGill professors, in recent years it has continued to be conducted at McGill in collaboration with the U.S. military. Specifically, Dr. David Frost in the Department of Mechanical Engineering has conducted research on explosives in collaboration with Canadian and U.S. military researchers. In the United States, one of the main military agencies focusing on thermobaric explosives research for bombs and missiles has been the Defense Threat Reduction Agency (DTRA).

In 2001, Dr. Frost published a paper in the journal Shock Waves entitled “Explosive Dispersal of Solid Particles” in collaboration with Drs. Stephen Murray and Fan Zhang, both military researchers from Defence Research and Development Canada in Suffield, Alberta (DRDC-Suffield). In 2005, the United States Air Force issued a technology contract solicitation (AF05-153) entitled “Methods to Direct and Focus Blast” that included this paper as one of the two references for the contract. The contract was categorized in the “weapons” technology area, and its first goal was to “increase lethality by focusing more of the available energy on target.”

In 2002, Dr. Frost gave a presentation on “Detonations in Heterogenous Explosives” to a committee of the U.S. National Research Council. The committee was conducting a study for the DTRA on “advanced energetic materials.” The resulting report specifically recommended that more research was necessary for the development of more “efficient” (i.e. lethal) thermobaric weapons, and that the findings presented by Frost were an example of this kind of research. It then went on to recommend that a “concerted and focused effort is needed for understanding the phenomenology of enhanced-blast kill mechanisms and what they may offer over conventional munitions in effectiveness.”

In recent years, Frost has been involved in a number of other explosives research projects associated with the U.S. military:

• In 2005, he was one of the authors of a paper presented to the Shock Compression of Condensed Matter conference of the American Physical Society, entitled “Critical Conditions for Ignition of Aluminum Particles in Cylindrical Explosive Charges”. The paper was in collaboration with the aforementioned Dr. Zhang from DRDC-Suffield. It was also partially funded by the DTRA, the same U.S. military agency that had commissioned the study referencing the applicability of Frost’s research for weapons development in 2002.

• In 2006, he was the main author for an article entitled “Optical Pyrometry of Fireballs of Metalized Explosives” and published in the journal Propellants, Explosives, Pyrotechnics. The article was written in collaboration with Dr. Zhang and one Akio Yoshinaka, also from DRDC-Suffield, and it was partially funded by the Technical Support Working Group under the Assistant Secretary of Defense for Special Operations and Low Intensity Conflict & Interdependent Capabilities in the United States’ Department of Defense.

• Frost was the main author for a paper submitted in 2006 to the 13th International Detonation Symposium (IDS) in Norfolk, Virginia, entitled “Effect of Scale on the Blast Wave from a Metalized Explosive”. This paper was in collaboration with Dr. Zhang, and was partially funded by the Advanced Energetics Program of the DTRA.

• He was also the one of the authors of another paper submitted to the 13th IDS, entitled “Casing Influence on Ignition and Reaction of Aluminum Particles in an Explosive”. It was written in collaboration with, once again, Dr. Zhang and Mr. Yoshinaka from DRDC-Suffield, as well as two researchers employed by the DTRA, Drs. Kibong Kim and William Wilson. A DTRA research topic funding solicitation form from 2005, no longer available online, is a pretty clear indication of the harmful military applicability of this research was indicated by A which stated that the “effects of charge-casing material and fragmentation on reaction kinetics” was one of the physical processes of explosives that required more research in order “to improve lethality of blast-effect weapons.” Also significant to this connection is the listing of Dr. Wilson as the primary Technical Point of Contact (TPOC) on the funding solicitation form.

• Finally, in 2006 and 2007, Dr. Frost presented at conferences that are clearly intended to discuss the military applications of explosives research. In 2006, at the 19th Symposium on Military Applications of Blast and Shock (MABS) in Calgary, Alberta, he gave a workshop with Dr. Zhang entitled “The Nature of Heterogeneous Blast Explosives“. In November 2007, he gave another presentation with the same title at the Workshops on Explosive Behaviors in Santa Fe, New Mexico. Of the 38 workshops at the event, 28 were given by researchers directly employed by a military laboratory or military sub-contractor. The introductory presentation of the event was by Dr. Wilson, and entitled “The DTRA Advanced Energetics Program: Past, Present and Future”.