Customer:
Is designated a critical national asset supporting the UK’s sovereign defence capability. As part of a sensitive program aligned with the AUKUS partnership, Oxford Engineering is the sole export-authorised supplier approved to deliver mission-critical welded and machined assemblies. These assemblies involve deep technical complexity, with multi-level bills of materials exceeding 500 components for the primary system and over 300 for the secondary – reflecting the precision and trust placed in our manufacturing capability.
Scope Summary:
Oxford Engineering delivered comprehensive DfM support for mission-critical nuclear submarine assemblies comprising over 800 unique part numbers across two highly complex, multi-level BOMs. Operating within a tolerance band as tight as ±0.004mm, the project demanded exacting dimensional control, rigorous material compatibility assessments, and full compliance with UK defence standards. Our engagement included 3D CAD interrogation, optimisation of datum structures, CNC machining strategy development, and surface finishing planning—including nickel plating on stainless steel substrates. We supported the machining of high-precision steel and stainless-steel components, focusing on the evaluation of initial production drawings and advising on achievable tolerances, datum schemes, and feasible finishing techniques. The assemblies featured multiple interface points with near-zero tolerance stack-up allowance, requiring a manufacturing strategy engineered to eliminate cumulative error.
Candidate’s Performance Against Targets:
• Conducted detailed tolerance analysis using stack-up simulations, restructuring datum schemes to reflect manufacturability
• Resolved over-constrained geometric dimensioning issues that were causing repeated non-conformances
• Defined bespoke test protocols for helium (82 bar) and nitrogen (118 bar) pressure containment validation
• Redesigned critical nickel-plated components with selective masking strategies and electroplating allowances
Support Against Functional Objectives:
Our DfM intervention directly enabled mission-critical submarine system reliability by ensuring consistent fitment across mating assemblies, achieving full QA approval for CNC-machined parts across 3 production lots, reducing lead times by 25% through elimination of unnecessary machining features, and maintaining surface finishing compliance with defence specifications without requiring post-polish adjustments.