Principal Mechanical Design Engineer in Maidenhead

• Company: Ultra Intelligence & Communications
• Cyber (UK) Business
• Powering Decision

Join the team redefining defense technology. From engineering systems that save lives to leading programs that change the battlefield—find your place in the future of defense.

Cyber Business

Our Cyber business unit is at the forefront of pioneering advanced cryptographic and key management solutions, facilitating the confidential exchange of vital information for customers operating at both tactical and strategic echelons.

Join our team and participate in the innovation that ensures the highest security and trust worldwide.

Job Description

As a Principal Mechanical Engineer, you will provide technical expertise across the design, development, testing and qualification of mechanical assemblies for advanced security critical products.

You will lead mechanical engineering activities from concept through to production, ensuring designs meet functional, environmental and regulatory requirements.

Leveraging deep technical expertise, significant previous experience and analytical problem-solving; you will make critical engineering decisions to deliver high-quality design outputs.

In this role, you will also serve as a technical anchor, mentoring junior engineers and continuously driving engineering excellence across the team.

Key Responsibilities

• Define and manage mechanical design requirements, ensuring validation and verification.
• Responsible for developing, documenting and delivering robust mechanical solutions for complex systems using the 3D CAD system and the company engineering toolsets.
• Lead mechanical integration, verification, and acceptance testing, collecting and presenting evidence as required.
• Create and peer review technical artefacts, including mechanical design documentation, design data packs, analysis reports, plans and procedures in accordance with our product development framework.
• Define, analyse and document predicted mechanical functional behaviours and performance.
• Optimize the design of parts based on various manufacturing technologies: machined from solid, injection moulding, extrusion, sheet metal and casting.
• Perform tolerance analysis of close tolerance parts and complex assemblies.
• Produce mechanical designs for complex systems that meet defence standards MIL-STD and DEF-STAN, EMC and TEMPEST requirements and harsh environmental conditions.
• Create and review high-quality drawings to BS8888 standard to guarantee design precision.
• Select optimum engineering materials and finishes to suit cost and performance.
• Identify and integrate Commercial Off-The-Shelf (COTS) mechanical hardware, ensuring compliance with design specifications, rationalising cost, lead time and long-term component availability.
• Design production jigs and fixtures in conjunction with production engineers.
• 3D Print and scan components; and produce rapid prototypes.
• Hold and contribute to peer design reviews ensuring adherence to design processes.
• Dynamically prioritize daily tasks and cross-functional workstreams, ensuring tight project deadlines are consistently met under high-pressure constraints.
• Conduct rigorous design reviews of mechanical drawings, ensuring precise application of Geometric Dimensioning and Tolerancing (GD&T) to guarantee clarity and component functionality.
• Responsible for mechanical test solution and development of test procedures to support the verification of the product.
• Prepare and present mechanical technical solutions to stakeholders.
• Follow configuration control and security procedures diligently.
• Liaise with the production and supply chain teams to ensure a seamless transition to manufacture.
• Interface with the electronic hardware and PCB design teams to understand their constraints and convey the mechanical solutions.
• Champion a culture of continuous improvement, regularly reviewing workflows and implementing data-driven changes to optimize productivity.
• Partner with Project Management to optimize schedules, mitigate development risks, and maintain strict alignment with budget and timeline constraints.
• Collaborate on commercial bids and proposals with the Sales team by developing robust execution plans, scoping technical requirements, and generating reliable cost and labour estimates.

Essential Skills, Qualification and Experience

• Degree in Mechanical Engineering or closely related discipline.
• Profound understanding of key mechanical engineering principles e. g. materials science and selection, engineering mechanics, stress analysis, vibration analysis, thermodynamics, heat transfer, assembly techniques and manufacturing processes.
• Seasoned experience in hands-on design of complex and rugged electronic enclosures for the defence industry.
• Exhibit strong analytical and problem-solving skills.
• In-depth knowledge of military standards applicable to environmental requirements and testing.
• Extensive experience of 3D CAD modelling and drafting. Creo CAD version 7 or later is preferable.
• Deep technical expertise of undertaking stress and thermal analysis using hand calculations, FEA and CFD.
• Long term experience of using PLM systems, preferably Windchill.
• Proven track record managing BOMs on PLM systems and interfacing with ERP systems.
• Well-versed in using electronic workflow and document change management system.
• Proven ability to multi-task, prioritise workload, and work under pressure to deliver on multiple projects simultaneously.
• Meticulous in drafting and reviewing complex engineering drawings to guarantee design precision.
• Proficient in authoring clear, concise technical reports and comprehensive engineering documentation.
• Proven ability to perform tolerance analysis complex assemblies and deploy GD&T.
• Skilled in integrating EMC and TEMPEST shielding principles into mechanical architectures.
• A strong grasp of designing for additive manufacturing (Df AM), with a deep understanding of 3D printing, scanning workflows, and the technical constraints of various rapid prototyping technologies.
• Advanced proficiency in Microsoft Office tools for data modelling, report generation, and stakeholder presentations.
• Model good interpersonal skills and teamwork; and the ability to communicate effectively at all levels.
• Demonstrate a helpful ‘can do’ attitude.
• Desired Skills, Qualification and Experience
• Experience of Mechanical Integration, Verification and Validation activities.
• Skilled in writing mechanical requirements based on systems requirements using proprietary software.
• Knowledge of hazardous materials, ROHS and REACH restrictions.
• Possess UK driving license.
• Security Clearance
• Candidates must be willing and able to obtain, and maintain, DV security clearance
• Notice

Due to the nature of the programs we deliver for our customers, candidates may need to obtain the relevant security clearance or handle export-controlled material as defined by the role’s requirements.

Applicants must be able to obtain and maintain the appropriate level of security clearance for the role.

Due to the nature of our work, you must be a British Citizen who has been resident in the UK for the past 5 years in order to apply for SC clearance and 10 years for DV.

For more information, please visit the UKSV website.

Our Benefits

Every employee is critical to our success, and as such, we offer a range of flexible employee benefits, including:

• Participation in an Annual Bonus Scheme
• Private Medical Cover
• 25 days’ holiday (plus Bank Holidays) with the option to buy an extra 5 days
• Pension Contribution
• 4 x Life Assurance Cover
• Flexible working hours with opportunity for a 1pm finish on a Friday
• Flexible benefits including cycle to work scheme, will writing and more
• Security Clearance Allowance – where relevant and subject to you holding the required security clearance
• Diversity, Equity & Inclusion Statement

At Ultra I&C, we are an equal opportunity employer and value diversity and inclusivity.

Underpinned by our values, behaviours, and policies, we want you to feel empowered to be the best version of yourself.

We also believe that people from different backgrounds and cultures will increase our diversity of thinking, ensuring we successfully deliver to our customers.

We, therefore, do not discriminate based on race, religion, colour, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.

We also support requests for flexible working arrangements wherever possible.

• If you have any issues with your application, please email us at