Job Title: Principal Mechanical Engineer

Location: Portsmouth – Hybrid working pattern – minimum 3 days weekly on site

We offer a range of hybrid and flexible working arrangements – please speak to your recruiter about the options for this particular role.

Salary: Up to £57,000 depending on skills and experience + bonus scheme

Who we are:

Join BAE Systems and you’ll be part of something bigger. As a valued member of our global colleague network, you’ll bring your unique skills and perspectives to help pioneer progress and protect what matters most. You’ll be trusted to play your part in delivering the advanced, technology-led defence, aerospace and security solutions of tomorrow, shaping a safer future, for all of us.

From the depths of the ocean, to the far reaches of space, there’s no limit to where a career at BAE Systems could take you.

Role description:

As a Principal Mechanical Engineer, you will lead the delivery of critical platform engineering services, providing expert technical guidance, assurance and governance across a diverse range of systems. You’ll drive innovation, support future transformation, and inspire high performance through technical and people leadership across the WTA (Warship Technical Authority) Mechanical Engineering discipline.

Core duties:

  • Delivering early lifecycle engineering and supporting engineering bids
  • Leading studies for design and feasibility, supported by technical analysis, to deliver compliance arguments
  • Supporting the leadership of multi-disciplinary projects
  • Providing expert mechanical engineering support across complex platform systems, equipment and associated technologies
  • Delivering engineering expertise across multiple projects, naval programmes and platform support activities
  • Collaborating with stakeholders to capture, manage and deliver platform systems requirements effectively
  • Leading investigations, assessments and integration activities to inform robust engineering decisions
  • Ensuring design integrity, configuration control and safe implementation of platform systems changes
  • Mentoring engineers, driving engineering excellence and providing leadership across the Mechanical discipline

Essential skills:

  • Strong mechanical engineering expertise across complex systems and equipment
  • Knowledge of naval platform systems across UK and international programmes
  • Understanding of defence and maritime standards for MOD customers
  • Familiarity with CSM, LCM and wider engineering governance frameworks
  • Ability to deliver high-quality engineering outputs across diverse projects
  • Effective stakeholder engagement with MOD, navies, OEMs and industry partners

The Warship Technical Authority Service team:

Join the Warship Technical Authority (WTA) Service Hub and help shape the future of naval engineering. Supporting Royal Navy and international programmes, the team work on complex whole-ship, systems and equipment challenges, delivering expert engineering, innovation and consultancy that directly contributes to the availability, performance and evolution of world-class warships.

Why BAE Systems?

Here you’ll build a career with purpose and limitless possibilities. With lifelong learning and meaningful work, this is a place where you can grow your career with confidence and be empowered to be your best. You’ll be recognised for your contribution and enjoy rewards tailored to what’s most important to you and your family, support for your financial and personal wellbeing, as well as a balanced lifestyle. In an environment embracing sustainable ways of working and with a strong sense of shared purpose, our supportive culture is a place you can feel you belong and proud of the difference you make.

A place where everyone can thrive:

We’re committed to building an inclusive workplace where everyone feels valued and supported. We know that a diversity of backgrounds, perspectives and experiences strengthens our teams and is vital to the work we do.

Please be aware that many roles at BAE Systems are subject to both security and export control restrictions. These restrictions mean that factors such as your nationality, any nationalities you may have previously held, and your place of birth can restrict the roles you are eligible to perform within the organisation. All applicants must as a minimum achieve Baseline Personnel Security Standard. Many roles also require higher levels of National Security Vetting where applicants must typically have 5 to 10 years of continuous residency in the UK depending on the vetting level required for the role, to allow for meaningful security vetting checks.

Closing Date: 21st August 2026

We reserve the right to close this vacancy early if we receive sufficient applications for the role. Therefore, if you are interested, please submit your application as early as possible.

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Within a growing network of around 100,000 colleagues in more than 40 countries, our teams bring together people with diverse skills, ways of thinking and backgrounds - while our work spans the depths of the ocean to the far reaches of space.

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