Principal Mechanical Engineer

JAM Recruitment Ltd; Clydebank; Hybrid; GBP 125,000 - 150,000; Full time

Job summary

A recruitment agency is looking for a Principal Mechanical Engineer to join a defence infrastructure program. This hybrid role involves leading the design of mechanical building services for nuclear facilities and mentoring junior engineers. Candidates must have a degree in Mechanical Engineering and chartered status, with strong experience in HVAC design. This is a contract position based in Clydebank offering a competitive hourly rate.

Qualifications

• Strong background in building services with hands-on HVAC design experience.
• Proven track record delivering projects in nuclear or highly regulated sectors.
• Available to work on-site at least 3 days per week.

Responsibilities

• Lead the design of mechanical building services systems.
• Carry out technical calculations and schematic designs.
• Mentor and support junior engineers.

Skills

Leadership skills

Building services design

Excellent communication

Education

Degree in Mechanical Engineering

Chartered Engineer status

Job description

Overview

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.

• 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.

Job Information

• Job Title: Principal Mechanical Engineer
• Company: JAM Recruitment Ltd
• Location: Clydebank, Dunbartonshire
• Posted: Oct 2nd 2025
• Closes: Nov 2nd 2025
• Sector: Military, Emergency & Government
• Contract: Contract
• Hours: Full Time

End of description.