MSIAC Workshop on Mechanical Initiation Below the Shock Regime

The Workshop: Mechanical Initiation Below the Shock Regime

The NATO Munitions Safety Information Analysis Center (MSIAC) hosts focused technical workshops on critical munitions safety topics throughout the year, drawing expertise from member nations and the global WOME community. One of the most technically demanding workshops in the MSIAC calendar addresses a phenomenon that appears in every munitions accident investigation but is rarely treated with the rigorous analysis it demands: mechanical initiation below the shock regime.

To understand this workshop topic, distinguish between two different initiation mechanisms. Shock-to-detonation transition (SDT) is the traditional framework taught in explosives engineering: a supersonic pressure wave, generated through initial high-explosive detonation or impact at very high velocity, propagates through an explosive material and triggers the energy release transition from burning to detonation. The shock wave acts as the mechanical stimulus. The defining characteristic of SDT is its speed: shock waves travel faster than the speed of sound in the material. They deposit energy almost instantaneously across the shock front, creating the extreme pressure and temperature conditions necessary for detonation.

Below the shock regime, initiation occurs through sub-detonative mechanical stimuli: drop from height onto hard surfaces, vibration during transport, rough handling, thermal cycling during storage, or impact from fragments at sub-critical velocities. Energy deposition rate — not the absolute energy in the impact — becomes the controlling factor. The rate at which mechanical energy converts to thermal energy in localised “hot-spot” regions of the explosives material determines whether initiation occurs. This is fundamentally different from shock physics.

The mechanisms by which sub-shock mechanical insults create hot-spots are well documented in the energetic materials literature. They include: adiabatic compression of trapped gas spaces (air bubbles or voids compress rapidly, generating heat); viscous heating of extruded material (material sheared between fractured crystal surfaces converts kinetic energy to thermal energy); inter-granular friction (individual crystals within a granulated explosive rub against each other, creating localized temperature rise); and localized adiabatic shear (high-strain-rate deformation in thin shear bands creates extreme local heating).

Real-world munition accidents typically result from mechanical insults during storage, transport, and handling. A 155mm howitzer round dropping from a vehicle during ammunition resupply, a cluster of air-dropped submunitions in a parachute malfunction causing inter-munition collisions on ground impact, a vibrating ammunition truck on rough roads, frost cycling and thermal stress during winter storage, or fragment impact from a nearby explosion in a forward ammunition dump — these are the mechanical stimuli that dominate accident causation. MSIAC O-053, “A Connection Between Shock Sensitivity, Ignition Sensitiveness and System Explosiveness,” examined this connection explicitly, demonstrating that shock sensitivity data alone cannot predict real-world accident risk. The NATO STO Educational Note EN-AVT-214-03, “Ignition and Detonation in Energetic Materials,” provides the theoretical framework for understanding energy deposition mechanisms below the shock regime. The MSIAC workshop translates this theoretical understanding into practical assessment methodologies for ammunition designers, safety case authors, and operational safety managers.

The specific workshop on mechanical initiation below the shock regime is offered as a member-access event through MSIAC (URL: https://www.msiac.nato.int/mechanical-initiation-below-the-shock-regime-workshop/), though the workshop page itself is restricted to MSIAC member nations, requiring authentication to access full technical content and registration details.

What Is MSIAC? NATO’s Munitions Safety Centre of Excellence

MSIAC began as Pilot-NIMIC in 1988 with five founding nations: France, the Netherlands, Norway, the United Kingdom, and the United States. It became NIMIC (NATO Interchange for Munitions Information and Consultations) on 1 May 1991, relocated to NATO Headquarters in Brussels, and is now the Alliance’s primary technical authority on munitions and energetic materials safety. In late 2002, CNAD merged two separate governance lanes: AC/258 (responsible for munitions transport and storage safety) and AC/310 (responsible for safety and suitability for service assessment). This reorganization created AC/326 (the Ammunition Safety Group — CASG), and NIMIC became the technical operating centre for AC/326, renamed MSIAC to reflect its expanded mandate beyond information interchange to direct technical analysis and centre-of-excellence status.

MSIAC’s mission statement is direct: “Eliminating Safety Risks from Unintended Reactions of Munitions and Energetic Materials throughout their Lifecycle.” The organization maintains seven Areas of Expertise:

1. Warhead Technology — shaped-charge design, vulnerability assessment, safety case development
2. Propulsion Technology — solid rocket motors, gun propellants, hybrid systems
3. Materials Technology — structural materials, environmental degradation, metallurgical assessment
4. Energetic Materials — explosives, propellants, pyrotechnics, insensitive munitions (IM) policy
5. Munitions Transport and Storage Safety — quantity-distance calculation, hazard classification, risk management
6. Munitions Systems — integrated system safety, fuze assessment, end-to-end lifecycle analysis
7. E3 Effects — electromagnetic effects on munitions, RADHAZ (RF hazards), spectrum management

MSIAC delivers technical services including ad-hoc technical questions from member nations (typically answered within 2–4 weeks with full technical analysis), international conferences (Pushing the Limits, Technical Meetings on Energetic Materials Qualification), direct support to NATO Working Groups, accredited training courses, technical report series, and a repository of technical information accessible to member nations. The organization’s staff structure, as of May 2024, comprises a Project Manager, six technical specialists, trainees, and a Stokes Fellow (a rotating fellowship from the energetic materials industry). Christopher Hollands (UK) has held the Project Manager position since 4 November 2024, replacing the previous Project Manager Chuck Denham (USA).

Current Member Nations: A Critical Gap in Alliance Coverage

As of 2025, MSIAC membership consists of 17 member nations:

Australia, Belgium, Canada, Denmark (rejoined 2025), Finland, France, Germany, Italy, Netherlands, Norway, Poland, Republic of Korea, Spain, Sweden, Switzerland, United Kingdom, United States.

Governance operates through a Steering Committee in which each member nation holds one representative and one vote. The committee elects a non-voting Chairman; Daniel Pudlak (USA) currently holds this position. National Focal Point Officers (NFPOs) serve as the liaison between each member nation’s defence ministry and MSIAC, ensuring that technical questions are routed appropriately and that relevant findings and guidance are disseminated back to the national level.

MSIAC is funded independently through annual financial contributions from member nations — services are provided at no additional cost beyond this annual contribution. This funding model ensures both sustainability and that the technical services remain genuinely driven by member nation priorities rather than by contracting pressures.

However, this reveals a critical gap in Alliance coverage. NATO comprises 32 member nations. Only 14 of the 17 MSIAC members are NATO allies. The three non-NATO participants are Australia (a major coalition partner with dedicated US interoperability), Switzerland (a neutral nation with a substantial domestic defence industry and ammunition stockpile), and the Republic of Korea (a major global arms manufacturer and US-aligned Indo-Pacific partner with a rapidly expanding domestic ammunition and energetic materials industry).

18 NATO members (32 total minus 14 MSIAC NATO participants) have no access to MSIAC’s technical expertise, databases, or member-only services. These include nations that are actively expanding ammunition production (Czech Republic, Romania, Bulgaria, Türkiye, Greece) and nations rebuilding military capability (the Baltic states, Hungary, Slovakia, Croatia). Türkiye, a major NATO arms manufacturer with an expanding domestic ammunition production base, operates entirely outside the MSIAC framework — meaning that Türkiye-manufactured ammunition entering NATO supply chains has not been assessed using MSIAC tools, databases, or safety methodologies. The Czech Republic, a significant European ammunition producer with rapidly expanding capacity driven by Ukraine-era contracts, similarly operates without access to MSIAC’s accident database (MADx) or energetic materials testing guidance (EMC).

The non-NATO participation of Australia, Switzerland, and Republic of Korea demonstrates that MSIAC’s value extends beyond the Alliance. These nations recognize independently that standardised munitions safety across borders reduces accident risk, liability, and supply chain friction — and they invest to participate. Their continued membership despite non-NATO status underscores the technical credibility of the organization.

MSIAC’s Technical Tools and Databases

MSIAC operates several specialised databases and analysis tools that are available to member nations at no additional cost, shareable among national technical teams, and regularly updated based on international research and member contributions. Understanding these tools clarifies why non-member nations are disadvantaged in technical assessment:

• AIMS (Advanced IM Search) — A web-based searchable database of insensitive munitions (IM) impact test results from member nations, aggregating shock sensitivity, friction sensitivity, and thermal stability data across thousands of ammunition variants and energetic material combinations.
• ARM (Analytical Response Models) — Computational modelling tools for predicting munitions safety behaviour under various thermal, shock, and mechanical stimuli conditions. Used for safety case development and accident reconstruction.
• EMC (Energetic Materials Compendium) — A comprehensive database of explosives, propellants, and pyrotechnic materials with chemical composition, thermal properties, sensitivity data, performance characteristics, and international quality standards for each material.
• MADx (MSIAC Accident Database eXchange) — A multi-national accident database compiling munitions and explosives accidents reported by member nations, coded by type (drop, fire, thermal, mechanical, environmental), severity, outcome, and contributing factors. This is the primary intelligence source on real-world accident mechanisms below the shock regime.
• MQDCAT (Quantity Distance Consequence Analysis Tool) — Software supporting both qualitative and quantitative risk analysis for ammunition storage facilities, implementing AASTP-1 and national regulations.
• M-STRAD (SRAD/TRAD Tool) — Safety distances for electrically exploded detonators (EEDs) exposed to electromagnetic radiation, meeting STANAG 2617 / ALP-16 requirements for operational safety management.
• MTM (Mitigation Techniques for Munitions) — A database of known mitigation technologies for reducing accident risk in existing ammunition designs (fuze shielding, shock-absorbing packaging, thermal stabilisers, etc.).
• SASO (Safety Assessment Software) — Standardisation of the S3 (Safety and Suitability for Service) assessment process, ensuring that safety case methodology is consistent across member nations.

Non-member nations cannot access these tools. They must conduct safety assessments using only open literature and in-house tools, creating duplication of effort, loss of institutional knowledge, and inconsistent safety standards across the Alliance.

Support to NATO Standards and Working Groups

MSIAC provides direct technical support to several NATO standardization bodies and working groups, shaping the Alliance’s technical standards for ammunition and explosives:

• AC/326 Main Group and its three sub-groups (SG/A on warheads and munitions systems, SG/B on propulsion and energetic materials, SG/C on transport and storage safety) — MSIAC staff serve as technical experts on all three sub-groups and host AC/326 meetings and technical discussions.
• STANAG 2617 / ALP-16 implementation support — Electromagnetic effects and RADHAZ (RF hazards) assessment for ammunition in operational environments.
• NATO Certified Training Courses on AASTP-1 and AASTP-5 — MSIAC runs accredited training on NATO Guidelines for Storage of Military Ammunition and Explosives (AASTP-1) and NATO Guidelines for Storage, Maintenance and Transport on Deployed Operations (AASTP-5). These courses are held 5–7 times per year at various host nation locations globally, with a maximum capacity of 25 students per course. Completion of these courses is the primary route to professional certification in NATO ammunition safety standards outside the formal military education systems of individual nations.
• AC/327 WG/6 support (on MCAT – Munitions Classification and Assessment Tool – and E3AT – E3 Assessment Tool) for lifecycle environmental profile testing and electronic hazards assessment.
• AC/305 Logistics Committee support on Explosives and Safety Munitions Risk Management (ESMRM) — the integrated safety management framework for operational ammunition operations.
• STO AVT Munition Health Management activities including AVT-RLS-375 Lecture Series on condition monitoring and predictive maintenance for aged ammunition stockpiles.
• LBDM (Loitering Munitions Technical Data Management) and AC/225 LCGDSS (Land Capability Group Delivery Support Group) working groups on emerging munitions types.
• I-AMMO WG (International Ammunition WG) on munitions interoperability beyond NATO (engagement with UN SaferGuard, ATAN, and non-aligned nations on standardisation).
• MCMSB E3 RADHAZ WG (Mine Countermeasures and Surface Decontamination Board) on electromagnetic effects in mine-clearing munitions.

Work elements across these groups include standardization of STANAG 4170 / AOP-7 (Principles and Methodology for Qualification of Explosive Materials for Military Use — the primary NATO explosives qualification standard), review and update of AOP-39 (Guidance on Assessment and Development of Insensitive Munitions — NATO IM policy), and alignment of Quantity Distance standards across member nations.

ISC Defence Intelligence Commentary: The Case for Universal MSIAC Membership

Ammunition production across NATO increased six-fold between 2022 and 2026, driven by lessons from the Ukraine conflict. Standardised munitions safety is now operationally critical to coalition interoperability. Between March 2022 and March 2026, NATO nations have increased ammunition production commitments from an estimated 300,000 rounds annually across the Alliance to targets approaching 1.8 million rounds annually by 2027. This represents a six-fold increase in manufacturing capacity activation within five years.

Nations expanding ammunition production lines without access to MSIAC's technical expertise, testing databases, and safety assessment methodologies risk reinventing wheels, repeating known failure modes documented in MADx, and creating interoperability gaps that undermine coalition operations. A Türkiye-based ammunition manufacturer producing howitzer ammunition for export within NATO has no access to the AIMS database showing which propellant formulations have shock-sensitivity issues, no connection to MSIAC’s energetic materials specialists, and no formal mechanism to share accident data or safety concerns with the Alliance technical community. Similarly, Czech Republic manufacturers expanding 155mm ammunition production to meet Ukraine-era demand operate without access to the EMC energetic materials compendium or the MADx accident database. These nations manufacture ammunition to national standards only, even when those standards may diverge from the consensus technical practice documented within MSIAC member nations.

MSIAC's workshop programme — including Pushing the Limits 2024, the Energetic Materials Qualification Technical Meeting 2024, and the Non-Destructive Testing Technical Meeting 2025 — addresses emerging technical tensions that matter operationally. The mechanical initiation below the shock regime workshop, in particular, addresses a gap between traditional shock sensitivity testing (which dominates ammunition qualification standards) and real-world accident data (which shows that most accidents occur from sub-shock mechanical stimuli). Closing this gap requires the kind of peer-reviewed international analysis that only MSIAC can provide.

A single munitions accident costs more than years of MSIAC membership. A large-scale ammunition facility fire or explosion in a NATO nation not only destroys stockpiles and equipment but generates diplomatic incidents, erodes public confidence in defence capabilities, and creates liability exposure for manufacturers. A single accident in a forward-deployed ammunition dump during NATO operations can degrade coalition readiness across multiple nations. The value of MSIAC membership — access to accident prevention databases, energetic materials testing methods, and technical guidance from the world's leading munitions safety specialists — pays for itself through accident prevention alone.

Every NATO nation procuring, storing, transporting, or disposing of ammunition benefits from MSIAC's standardisation work regardless of whether they contribute financially to the organization. Non-member nations gain the benefits of consistent technical guidance and accident prevention methodologies that MSIAC members adopt. However, non-members cannot task MSIAC for technical assessments of new ammunition designs, cannot contribute to or access the MADx accident database, and cannot participate in the working groups that shape NATO ammunition standards. They are recipients of technical progress they did not help fund or guide.

The recommendation is unequivocal: All 32 NATO member nations should join MSIAC. NATO partner nations actively manufacturing or procuring munitions — Japan, Singapore, and others participating in STO activities — should also consider membership. The cost is manageable, the technical credibility is unmatched, and the safety benefits are concrete and measurable through the accident data compiled in MADx.

Individuals and organisations interested in following MSIAC’s work can sign up for MSIAC communications directly through the NATO/MSIAC website.

ISC Commentary

Further analysis pending.