L-069 NIMIC: Custodian of the Hazard Assessment Protocols.

November 2000
Michael Fisher (Propulsion Technology)

In 1987, the nations of The Technology Cooperative Program (TTCP), Australia, Canada, the United Kingdom and the United States, established Subgroup W (Conventional Weapons) Action Group 11, hereafter referred to as WAG-11, to identify critical technology shortfalls and opportunities in the areas of hazards of energetic materials and their relation to munitions survivability. The principal objective of WAG-11 was to "recommend a methodology for energetic materials hazard assessment technologies appropriate to the design of Insensitive Munitions that meet operational requirements." During the initial meeting of WAG-11, the members reached consensus that both a mechanistic understanding of reactions and a predictive capability for responses were needed, and that such understanding and capability were not being provided by standard, "go/no go" hazard testing. Additionally, the members believed that the mechanistic understanding of the phenomena involved in the hazards assessment of energetic materials had advanced to the point that a physically based assessment methodology was possible.

To accomplish their goals, WAG-11 began by identifying several threat areas, including bullet/fragment impact, cookoff, shaped charge jet impact and sympathetic detonation, and reviewing and evaluating the current knowledge in these areas. Following this review, the group then developed its hazard assessment methodology in the form of a protocol for each threat area. It was recognized at the time that the maturity of the knowledge in the various threat areas was different, and that the resulting protocols would vary in completeness and depth of detail. It was hoped that the protocols would change and evolve with time, as the level of understanding of the phenomena and mechanisms developed.


A hazard assessment protocol is an ordered procedure that results in a flow chart directing the user through the evaluation of a hazard area. The protocol can assist the user by identifying not only the response "paths" that are most likely to be encountered and must, therefore be considered, but also the information required in order to perform an assessment of the hazard. Since such an assessment is based on a logical process and is conducted for a munition in a real environment, subject to real threats, it will likely have more value than the results of a small number of go/no-go full scale hazard tests.

Each protocol consists of a decision tree flow chart that examines the science of successive events in the hazard/munition interaction. In this way, it characterizes the hazard, then its interaction with the munition, and finally the response of the munition. Each box (decision point) in the flow chart identifies the information required, and in what order, to make a decision and follow the process to the next box. In the simplest terms, then, a hazard assessment protocol is nothing more than an orderly process for viewing the hazard areas, and defining what information is needed to assess hazards. The protocol approach, as defined by the efforts of the TTCP WAG-11 participants, is intended to be used as a design aid early in the design cycle for anticipating potential hazard problems, and also to help project management personnel in the mitigation of existing munition hazard problems.