Principal Mechanical Design Engineer

Holt Engineering; Horsham; On-site; GBP 65,000 - 75,000; Full time

Job summary

Holt Engineering in Horsham, England seeks a Principal Mechanical Engineer to lead the full design lifecycle of advanced electro‑mechanical systems for demanding defence applications. You will guide concept to production, mentor engineers, and drive design governance across multi-disciplinary teams.

The role emphasizes hands-on design, technical problem solving, and collaboration with project managers, customers, and suppliers to deliver high‑performance solutions.

Qualifications

• Degree educated in Mechanical Engineering.
• Significant experience in the design of complex mechanisms and structures.
• Proven background in delivering designs from concept through to production.
• Strong knowledge of SolidWorks and other relevant modelling tools.
• Confident in performing engineering calculations and analysis.
• Experience working with gear drives, bearings, motors, servo and motion control systems.
• Good understanding of machining, casting, fabrication, and moulding techniques.
• Experience in defence or a related high-specification engineering environment.
• Able to lead and support a small to medium-sized design team.
• Strong communication skills with the ability to present technical information clearly.
• Experienced in coaching, mentoring, and supporting talent development.
• Able to manage priorities, workload, and deadlines effectively.
• Competent in producing risk assessments, safety documentation, and technical support materials.

Responsibilities

• Lead mechanical engineering activities from concept through the full design lifecycle.
• Create and develop innovative designs for complex mechanisms and structures using 3D CAD.
• Carry out engineering analysis including stress, fatigue, vibration, and performance assessment.
• Produce and manage detailed engineering and assembly drawings for manufacture.
• Support lab development, testing, verification, and conformance activities.
• Lead engineering reports, technical documentation, and formal design outputs.
• Select materials, coatings, and manufacturing techniques suitable for harsh environments.
• Work closely with wider engineering teams to integrate electronic, control, and drive systems.
• Formulate prototype designs and present the rationale behind design decisions.
• Resolve technical issues and provide effective engineering solutions.
• Lead and support design reviews and release mechanical designs into production.
• Liaise with project managers, sales teams, customers, and suppliers to support successful project delivery.
• Support production, test, and field engineering teams as required.
• Contribute to bids, quotations, proposals, and sales literature.
• Drive continuous improvement through strong collaboration across engineering and manufacturing functions.

Skills

Design leadership

Mechanical design principles

Team leadership

Technical communication

Problem solving

Education

Bachelor's degree in Mechanical Engineering

Tools

SolidWorks

Job description

Principal Mechanical Engineer

Location: Horsham, West Sussex. Salary: £65,000 - £75,000 DOE.

We are seeking an experienced Principal Mechanical Engineer to join a highly skilled engineering team in Horsham. This is a senior technical leadership role offering the opportunity to shape the design, development, and delivery of advanced electro‑mechanical systems used in demanding defence applications across land and maritime environments.

This position would suit a mechanically focused engineer who enjoys taking concepts from initial design through to production, leading by example, and working closely with multi‑disciplinary teams to deliver high‑performance, innovative solutions. You will play a key role in design governance, technical problem‑solving, customer engagement, and mentoring engineers while helping to establish best practice across the business.

The role

• Lead mechanical engineering activities from concept through the full design lifecycle.
• Create and develop innovative designs for complex mechanisms and structures using 3D CAD.
• Carry out engineering analysis including stress, fatigue, vibration, and performance assessment.
• Produce and manage detailed engineering and assembly drawings for manufacture.
• Support lab development, testing, verification, and conformance activities.
• Lead engineering reports, technical documentation, and formal design outputs.
• Select materials, coatings, and manufacturing techniques suitable for harsh environments.
• Work closely with wider engineering teams to integrate electronic, control, and drive systems.
• Formulate prototype designs and present the rationale behind design decisions.
• Resolve technical issues and provide effective engineering solutions.
• Lead and support design reviews and release mechanical designs into production.
• Liaise with project managers, sales teams, customers, and suppliers to support successful project delivery.
• Support production, test, and field engineering teams as required.
• Contribute to bids, quotations, proposals, and sales literature.
• Drive continuous improvement through strong collaboration across engineering and manufacturing functions.

The ideal candidate

• Degree educated in Mechanical Engineering.
• Significant experience in the design of complex mechanisms and structures.
• Proven background in delivering designs from concept through to production.
• Strong knowledge of SolidWorks and other relevant modelling tools.
• Confident in performing engineering calculations and analysis.
• Experience working with gear drives, bearings, motors, servo and motion control systems.
• Good understanding of machining, casting, fabrication, and moulding techniques.
• Experience in defence or a related high‑specification engineering environment.
• Able to lead and support a small to medium‑sized design team.
• Strong communication skills with the ability to present technical information clearly.
• Experienced in coaching, mentoring, and supporting talent development.
• Able to manage priorities, workload, and deadlines effectively.
• Competent in producing risk assessments, safety documentation, and technical support materials.

This is an excellent opportunity for a Principal Mechanical Engineer looking to take the lead on complex defence‑related design projects and contribute to the delivery of innovative, high‑performance engineering solutions.