Featured Articles Archive

Agents & Ammo In Depth
Binary Chemical Munitions: U.S. and Chinese Notional Designs

Compared to traditional unitary chemical ordnance, binary chemical weapons have been traditionally viewed with having advantages in terms of logistical safety in their handling. About 20 years ago during the Cold War, the United States invested large sums of money and effort into developing binary chemical weapons as part of a modernization program. It also appears that the Chinese military also seriously considered the idea of developing its own binary weapons, including a rocket for a multiple launch rocket system (MLRS). Due to per unit cost and other factors, however, it is not likely that China produced any of these in quantity.

During the 1980s, the Reagan Administration revamped the U.S. military's offensive chemical weapons arsenal as a means to counter Warsaw Pact forces. Two major projects involved the development and procurement of binary nerve agent munitions. One, the 'Bigeye,' was originally developed under the auspices of the U.S. Navy, and was intended to spray VX from an aerial munition that would glide over the target. Using two relatively nontoxic compounds, namely a chemical code-named QL and sulfur, these would combine to form VX within the bomb itself. Although a working prototype was built, the project was plagued with technical problems, not the least of which being a tendency for the munition to burst prematurely because of the high-energy chemical reaction inside. The BLU-80/B Bigeye could deliver some 180 lbs of VX nerve agent.

The U.S. Army's 155 mm howitzer shell, which was produced in significant numbers, also contained two nerve agent precursors. In this case, instead of the very persistent VX, a volatile, non-persistent nerve agent is created out of the reaction with diflour (DF), isopropyl alcohol, and another chemical compound that helped to promote chemical synthesis. After being fired, the projectile mixed the binary components to form sarin (GB), while a special fuse mechanism ensured efficient dissemination of the agent through the back of the projectile and over the target.

Because of its ability to fire a large and redundant number of volleys, the multiple launch rocket system (MLRS) has long been considered one of the more effective delivery platforms to increase the concentration of chemical warfare agent on a given target. The U.S. Army had produced both sarin and VX unitary warheads for the M55 rocket.

A U.S. design that only made it to the prototype stage was for a so-called intermediate-volatile nerve agent munition for the MLRS. Although details are not exactly known, it is possible that the binary components would have produced a nerve agent that had moderate persistence, perhaps soman (GD) or cyclosarin (GF).

Chinese conceptual (?) diagrams for binary chemical munitions
Because of the ongoing interest in refurbishing its chemical arsenal on the part of the United States, the massive Soviet military threat on its borders in the 1980s-or perhaps a combination of the two-the People's Republic of China (PRC) studied the potential for production of binary chemical munitions for the People's Liberation Army. Whether or not these munitions went beyond the blueprint stage is unknown. One diagram found in Chinese military writings on chemical warfare depicts what appears to be a rough design for a binary warhead, perhaps having in mind the HY-1 (Hai-Ying) cruise missile (based on the original Soviet Styx).

Note that the two binary components (A, B) are to mix in the front of the warhead (4), and as the synthesis proceeded nerve agent was to spray out of the tail of the munition (10). Another busy diagram from the PRC also depicts a binary weapon, in this case for the MLRS. This drawing also includes A and B binary components. Additionally, there are spray apertures and explosive tubing to aid in the dispersal of the agent from the rocket warhead.

Having signed and ratified the 1993 Chemical Weapons Convention (CWC), both the United States and the PRC have vowed to declare and destroy any past or remaining chemical weapons in their respective inventories. Little is known in the open literature, however, about past or present Chinese production or deployment of chemical weapons.