Technical Summary

The United States is expanding annual RDX (cyclotrimethylenetrinitramine) production from approximately 8 million lb (~3,600 tonnes) to 15 million lb (~6,800 tonnes) — an 89% capacity increase at the Holston Army Ammunition Plant (HAAP) in Kingsport, Tennessee. HAAP, operated by BAE Systems Ordnance Systems Inc. under a Government-Owned Contractor-Operated (GOCO) arrangement, remains the sole US government facility for RDX and HMX (cyclotetramethylenetetranitramine) production. The expansion addresses a recognised throughput deficit, but the underlying structural dependency on a single production site constructed during World War II remains unresolved.

The contrast with historical capacity is instructive. The Holston Ordnance Works, HAAP’s wartime predecessor, produced in excess of 1 million lb/day of RDX and TNT during peak WWII output — a daily rate exceeding the current facility’s entire annual pre-expansion capacity. The expanded 6,800-tonne annual target, while representing a significant operational achievement within existing infrastructure constraints, recovers only a fraction of the production throughput that the US industrial base delivered eighty years ago under wartime mobilisation.

Concurrent with the RDX capacity limitation, the US relies on a single European source for all TNT (2,4,6-trinitrotoluene) supply. Kevin Capozzoli, CEO of Critical Materials Group, describes “hundreds of single-point failures” across US munitions supply chains. The energetics production bottleneck is not a raw materials access problem — the constituent chemicals for RDX synthesis (hexamethylenetetramine, ammonium nitrate, nitric acid, acetic acid) are industrially available. The constraint is in processing capacity: the specialised plant, equipment, licences, safety cases, and qualified workforce required to manufacture military-specification secondary explosives at scale.

Analysis of Effects

Munition Fill Demand Calculation

The production constraint becomes tangible when mapped against munition fill requirements. The US Army’s stated objective of 100,000 155mm rounds per month provides a reference baseline. Each M795 155mm HE projectile contains approximately 6.6 kg of Composition B (60% RDX / 40% TNT by weight). At 100,000 rounds per month, that equates to approximately 660 tonnes of Comp B per month — consuming ~396 tonnes of RDX and ~264 tonnes of TNT. Annually, this single projectile variant alone would require approximately 4,752 tonnes of RDX and 3,168 tonnes of TNT.

The pre-expansion HAAP capacity of 3,600 tonnes/yr RDX is therefore insufficient to sustain M795 production at target rates before accounting for any other munition fill requirements — Mk 80-series general purpose bombs (Comp H-6: RDX/TNT/aluminium), PBXN-series insensitive munition fills (IMX-101, IMX-104), demolition charges (Comp C-4: 91% RDX), and warhead fills across missile, torpedo, and mine programmes. The expanded 6,800-tonne capacity provides headroom for M795 production but remains constrained when the full spectrum of US military energetic fill demand is aggregated.

The TNT dependency is equally critical. With no domestic TNT production and reliance on a single European supplier — assessed as either Eurenco (Sweden/France) or Chemring Nobel (Norway), both NATO-aligned but neither US-controlled — the Comp B production pipeline is dependent on a trans-Atlantic supply chain for 40% of its constituent material. Any disruption to this sole source — whether through facility incident, export restriction, or competing Allied demand — would halt Comp B formulation regardless of domestic RDX availability.

Processing vs. Raw Material Constraint

The distinction between raw material availability and processing capacity is fundamental to understanding this bottleneck. RDX is synthesised via the Bachmann process (acetic acid/acetic anhydride nitrolysis of hexamethylenetetramine) or direct nitrolysis. The precursor chemicals are bulk industrial commodities. The constraint lies in the continuous-flow processing plant required for military-specification RDX production: reactor vessels rated for nitration processes, wash and recrystallisation trains, particle size classification equipment, and the associated safety systems, environmental controls, and process hazard analyses mandated for HD 1.1 explosive manufacturing. Constructing a new RDX production facility from greenfield — including environmental permitting, safety case approval, construction, commissioning, and qualification — represents a timeline measured in years, not the months that procurement funding cycles assume.

Personnel and Safety Considerations

HAAP operates under US Army safety regulations (DA PAM 385-64) and OSHA Process Safety Management (PSM) requirements for energetics manufacture — the US equivalent of COMAH (Control of Major Accident Hazards) regulations applicable to UK explosives factories. The safety case architecture for continuous energetics production at scale is non-trivial: it requires demonstrated competence in process hazard analysis, quantitative risk assessment for HD 1.1 manufacturing processes, and a qualified workforce holding specific energetics handling certifications.

The October 2025 explosion at Accurate Energetic Systems in McEwen, Tennessee — which killed two workers during small-scale energetics processing — provides proximate context for the personnel safety dimension of capacity expansion. Scaling production from 3,600 to 6,800 tonnes annually at a WWII-era facility requires either increasing throughput rates through existing process lines (raising exposure frequency and consequence severity) or commissioning additional process lines within the existing site footprint (raising co-located risk and requiring updated QD calculations under DDESB 6055.9 / AASTP-1 equivalents). Both pathways increase personnel risk profiles and demand commensurate safety case justification.

The workforce competence constraint mirrors the facility constraint. Qualified energetics chemists, process engineers with nitration experience, and ammunition production technicians represent a specialist labour pool that cannot be rapidly expanded through general industrial recruitment. The US defence industrial base faces the same energetics workforce competency gap that the UK’s SDR 2025 identified in its six-factory expansion programme — the facilities and the funding are necessary conditions, but without the qualified personnel to operate them safely, neither delivers output.

Data Gaps

DATA GAP: Identity of sole European TNT supplier — The specific European entity supplying TNT to the US is not named in open-source reporting. Assessed candidates include Eurenco (Karlskoga, Sweden / Sorgues, France) and Chemring Nobel (Saetre, Norway). Confirmation would clarify the geopolitical and logistical risk profile of this dependency.

DATA GAP: HAAP expansion timeline and commissioning date — The target capacity of 6,800 tonnes/yr is stated, but the projected date for achieving full expanded output is not reported. Whether this represents a 2026, 2027, or later milestone is unknown from open sources.

DATA GAP: HMX production capacity at HAAP — HAAP also produces HMX (octogen), used in insensitive munition fills and shaped charge liners. Whether the RDX expansion affects HMX production scheduling or vice versa is not addressed in open-source reporting.

DATA GAP: US domestic TNT production restart feasibility — Whether the US has assessed or initiated plans to re-establish domestic TNT manufacturing capability is not reported. Historical US TNT production facilities (Joliet AAP, Radford AAP) have been decommissioned or repurposed. The regulatory, environmental, and capital timeline for domestic TNT restart is unknown.

DATA GAP: Allied RDX/TNT production capacity — The aggregate NATO-wide production capacity for RDX and TNT — including facilities in Australia (Mulwala), Norway, Sweden, France, and the UK (ROF Bridgwater, now decommissioned) — is not consolidated in open-source literature. This data is essential for assessing Alliance-level energetics sufficiency.

DATA GAP: Insensitive munitions transition impact — The US programme to transition from Comp B to insensitive munition fills (IMX-101 replacing TNT in M795 variants, IMX-104 replacing Comp B) alters the demand profile for RDX and TNT. The current and projected ratio of legacy Comp B vs. IM-filled production is not quantified in open sources.