Principal Mechanical Design Engineer

Job Description:

Location: Derbyshire- Onsite

(Visa Sponsorship not available)

About the Role

Are you a hands-on design leader with a passion for solving complex engineering challenges?
We’re seeking an accomplished Principal Mechanical Design Engineer and a Senior Design Engineer to take ownership of the design and delivery of advanced mechanical and engine subsystems — from early concept through to production and beyond.

In this pivotal role, you’ll lead projects that span across diesel and hydrogen, propulsion technologies.

You’ll join a technically driven, collaborative team where engineering rigour meets real-world impact — and where your ideas, leadership, and design expertise will directly influence the future of clean and efficient propulsion.

What You’ll Do

• Lead and own mechanical design activities across full lifecycle programmes — from concept creation and analysis through validation and launch.
• Design, develop, and integrate complex systems and components, such as crankcases, cylinder heads, housings, valvetrain, lubrication, or cooling systems.
• Champion engineering excellence, applying first principles to solve challenging problems with creativity and precision.
• Collaborate with multidisciplinary teams including analysis, test, manufacturing, and suppliers to deliver optimised, production-ready solutions.
• Guide and mentor engineers, sharing your experience to develop capability and ensure technical quality across projects.
• Drive continuous improvement, embedding lessons learned into new technologies, tools, and processes.
• Influence design strategy for future propulsion systems and contribute to the evolution of sustainable power solutions.

What You’ll Bring

• A degree in Mechanical Engineering (or related discipline) with a strong background in mechanical design and product development.
• Proven experience designing and delivering engine components, subsystems, or relevant powertrain systems across any of the following sectors: automotive, aerospace, off-highway, marine, or power generation.
• Strong 3D CAD capability (preferably Siemens NX) and a detailed understanding of GD&T, tolerance stacks, and design calculations (e.g., for bearings, bolted joints, camshaft, and belt drive systems).
• Knowledge of FEA, CFD, or thermal/structural analysis tools, and how simulation informs design optimisation.
• Experience leading design reviews, technical decisions, and mentoring engineers, with a proven record of delivery across the product lifecycle.
• A proactive approach to innovation, sustainability, and the application of sound engineering judgement

Why Join

You’ll be part of a forward-thinking engineering environment that blends hands-on design with strategic influence.
This is an opportunity to:

• Work on technically challenging, cross-sector propulsion projects.
• Lead design activities that contribute to sustainable, high-performance technologies.
• Collaborate with a diverse network of engineers and innovators.
• Shape the next generation of propulsion and power systems.

If you’re ready to lead from the front — combining mechanical design excellence with systems-level insight — this is the role where you can truly make your mark.