Job Description

Principal Mechanical Engineer (Contract)
Location: Glasgow (Hybrid - 3 days onsite, 2 days remote)
Rate: 65-80 per hour (Umbrella, inside IR35)
Duration: 12 months
Clearance: Must be eligible for SC clearance (Sole British Nationals only)
About the Project
This role sits within a joint venture delivering the Nuclear Technical Support Provider (NTSP) framework-a long-term programme supporting the UK defence sector, including the refurbishment and upgrade of critical infrastructure at HMNB Clyde. The framework spans 7 years (with a potential 3-year extension) and is valued at 250m-400m.
The Role
As a Principal Mechanical Engineer, you will lead the design and delivery of mechanical building services systems-including HVAC, water, drainage, and fire protection-for nuclear facilities. You will be accountable for technical quality, mentoring junior engineers, ensuring compliance with industry and nuclear standards, and integrating mechanical systems across multidisciplinary teams.
Key Responsibilities:

• Lead the design of complex mechanical building services systems, aligned to nuclear safety and operational requirements.
• Carry out and oversee technical calculations, schematics, and flow designs in line with engineering codes and standards.
• Collaborate with electrical, structural, and safety teams to deliver integrated project solutions.
• Produce and review technical deliverables including CAD/Revit models, specifications, and engineering reports.
• Mentor and support developing engineers while checking and approving technical work.
• Engage with stakeholders, ensuring projects meet safety, quality, and regulatory requirements.

Requirements (Essential):

• Degree (or equivalent) in Mechanical Engineering or related discipline.
• Chartered Engineer status.
• Strong background in building services, with hands-on HVAC design and calculation experience.
• Proven track record delivering across the full project lifecycle within nuclear, defence, or highly regulated sectors.
• Solid understanding of mechanical engineering fundamentals, regulations, and industry standards (e.g. CIBSE, BS EN, ASHRAE).
• Demonstrable leadership skills, with experience managing and developing engineering teams.
• Excellent communication skills and ability to work collaboratively across disciplines.
• Available to work in the Glasgow office at least 3 days per week.

Desirable:

• Experience in EPC projects, defence, or nuclear environments.
• Knowledge of fabrication, welding, FEA, and test & trials.
• Experience in manufacturing environments and NDT practices.
• Membership of a relevant professional institute.

This is a rare opportunity to join a major defence infrastructure programme and contribute to projects of national importance.
How to Apply
If you have the right background and are eligible for SC clearance, please apply with your CV today.

Skills Required