Principal Mechanical Engineer

Job Title:                     Principal Mechanical Engineer  

Location:                     City, County + Hybrid Working Arrangements

Compensation:           £57.300 - £71,600 Depending on experience + Benefits

Role Type:                   Full time / Permanent

Role ID:                        SF74422

Engineer the Future of Naval Infrastructure and National Security

At Babcock we’re working to create a safe and secure world, together, and if you join us, you can play your part as a Principal Mechanical Engineer at our Devonport Royal Dockyard site.

The role

As a Principal Mechanical Engineer, you’ll have a role that’s out of the ordinary. You’ll provide expert technical leadership across the full engineering lifecycle, from concept and design development through to implementation, operation, decommissioning and disposal. You’ll help ensu.re compliance with regulatory requirements, engineering standards and safety obligations while delivering high-quality solutions that make a real difference to national defence and critical infrastructure.

Day-to-day, you’ll be required to:

• Leading and supporting mechanical engineering design activities throughout the full project lifecycle.
• Specifying technical requirements, producing engineering guidance and supporting tender and commercial activities.
• Providing technical oversight of mechanical services designs, ensuring compliance with regulatory and industry standards.
• Conducting design reviews, validation activities, technical audits, site inspections and stakeholder meetings.
• Mentoring junior engineers while providing expert advice to stakeholders across the business.

This role is full time, 35 hours per week and is predominantly office-based but will require site visits across Devonport. Hybrid working arrangements are available, with a minimum of two days per week on site and additional presence as required to support business needs.

Essential experience of the Principal Mechanical Engineer

• Extensive knowledge of mechanical engineering systems including steam and condensate, industrial gases, fresh water, demineralised water and domestic water services.
• Experience applying the full engineering design lifecycle across complex projects.
• Strong understanding of relevant regulations, legislation, codes and standards governing mechanical systems design.
• Experience working within nuclear, defence or other highly regulated, high-hazard industries.
• Experience supporting commissioning, performance evaluation and engagement with clients and key stakeholders.

Qualifications for the Principal Mechanical Engineer

• Level 6 qualification in Mechanical Engineering or a closely related discipline, or a Level 5 qualification with substantial relevant experience.
• Chartered Engineer status or actively working towards Chartered Engineer accreditation.

Security Clearance

The successful candidate must be a sole UK national who is able to achieve and maintain Security Check (SC) security clearance for this role.

Many of the positions within our company are subject to national security clearance and Trade Control restrictions. This means that your eligibility for certain roles may be affected by your place of birth, nationality, current or former citizenship, and any residency you hold or have held. Further details are available at United Kingdom Security Vetting: clearance levels - GOV.UK ( .

What we offer

• Generous holiday allowance
• Matched contribution pension scheme, with life assurance
• Access to a Digital GP, annual health check, and nutritional consultations through Aviva DigiCare+
• Employee shopping savings portal
• Payment of Professional Fees
• Reservists in the armed forces receive 10-days special paid leave
• Holiday Trading is a benefit that allows UK Babcock employees to buy additional leave or to sell up to one working week of annual leave from their annual entitlement. This Window opens February through to March annually.
• ‘Be Kind Day’ enables employees to take one working day's paid leave a year (or equivalent hours) to undertake volunteering work with their chosen organisation or registered charity

Babcock

We’re Babcock — a global FTSE 100 organisation with over 26,000 people working together to make a difference.

Here, you’ll be part of something bigger. From initial design to final decommissioning, your work will contribute to products and services that are essential to national security and public infrastructure. Together, we’re building a future that lasts — not just through the impact we make, but through meaningful careers that respect your work-life balance.

We call that lifetime engineering.

Join us and see how far we can go, together.

We are a disability confident committed employer. If you have a disability or need any reasonable adjustments during the application and selection stages, please email View email address on jobs.babcockinternational.com with the subject header ‘Reasonable adjustments requirement’. We’re committed to building an inclusive culture where everyone’s free to thrive. We are happy to talk about flexible working – please ask about alternative patterns of work at interview.

Closing date: 20/07/2026

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