Principal Mechanical Engineer

Principal Mechanical Engineering Specialist - Nuclear We are seeking an experienced Principal Mechanical Engineering Specialist to lead the mechanical design, scale-up and industrialisation of highly specialised vacuum and process equipment within an advanced technology environment.This is a hands-on technical leadership role for an engineer who enjoys taking complex hardware from early-stage prototypes through detailed design, fabrication, integration, testing and production-ready release.The roleYou will own mechanical execution across the full hardware lifecycle - from concept development and 3D CAD through vendor fabrication, assembly, testing, design iteration and industrialisation.You will work closely with multidisciplinary engineering teams, operations, machine shops, specialist fabricators and external contractors to deliver hardware that meets demanding requirements for performance, quality, safety, reliability, manufacturability and schedule.Key responsibilitiesLead mechanical design and scale-up of specialised vacuum and process systems.Translate laboratory and prototype concepts into reliable, manufacturable industrial equipment.Own complex 3D CAD assemblies, production drawings, GD&T, tolerances, interfaces, BOMs and engineering release packages.Drive design for manufacture, assembly, alignment, serviceability, maintainability and cost-effective production.Apply engineering calculations and, where appropriate, FEA to assess structural integrity, thermal effects, vibration, loading, deflection and mechanical stability.Select and develop materials, seals and mechanical interfaces for demanding process and vacuum environments.Lead prototype build, testing, troubleshooting and iterative design improvement through to production-ready configurations.Oversee assembly, fit-up, alignment, integration, leak testing and mechanical acceptance testing.Work directly with fabrication suppliers and contractors, including reviewing shop drawings and resolving manufacturability and quality issues.Interface closely with machine shops and precision fabrication teams. Experience with CNC machining, welding, precision fabrication, 3D printing and additive manufacturing is highly desirable.Coordinate mechanical interfaces with vacuum, gas-handling, instrumentation, structural and facility systems.Produce and maintain robust engineering documentation, including specifications, drawings, design reports, test records and change documentation.Lead design reviews, technical work packages and issue resolution while maintaining strong focus on quality, safety and regulatory requirements.What we're looking forEssential:Advanced degree in Mechanical Engineering or a related discipline.15–20+ years of mechanical engineering experience, ideally involving complex industrial, vacuum, gas-handling, process or other highly engineered equipment.Extensive hands-on experience with 3D CAD, mechanical system development, fabrication, assembly and prototype-to-production transition.Strong understanding of precision mechanical design, tolerancing, manufacturing processes and engineering documentation.Demonstrated ability to take ownership of complex hardware from concept through to operational deployment.Experience working effectively with multidisciplinary engineering teams, suppliers, fabricators and machine shops.Highly desirable:Experience in the nuclear or other highly regulated engineering sectors.Experience with vacuum systems and demanding process environments.Experience with FEA and mechanical/structural engineering calculations.Knowledge of materials compatibility, sealing, leak integrity and contamination/cleanliness requirements.Experience industrialising novel or first-of-a-kind equipment.