Principle Mechanical Engineer

Overview

We are seeking an experienced Principal Mechanical Engineer to provide technical leadership and strategic oversight for the delivery of mechanical systems across multiple infrastructure assets within a major rail and tunnelling project environment.
This role will suit a highly experienced engineer with a strong background in mechanical engineering design, construction delivery, systems integration, stakeholder management, and multidisciplinary infrastructure projects. The successful candidate will act as the senior mechanical authority, leading technical decision-making throughout the project lifecycle from detailed design development through installation, testing, commissioning, and asset handover.

Key Responsibilities

• Provide technical leadership for the delivery of mechanical systems including Fire Main, Public Health, Drainage, Pumping Systems, Ventilation, and associated MEP infrastructure.
• Act as the principal mechanical engineering authority across multiple project assets, ensuring engineering excellence and compliance with project requirements.
• Lead Stage 5 design development and construction integration activities between client teams, design consultants, subcontractors, suppliers, and delivery partners.
• Review and approve complex technical submissions including drawings, calculations, BIM models, hydraulic analyses, stress/thrust calculations, and system performance assessments.
• Drive engineering governance and ensure compliance with project specifications, industry standards, statutory requirements, and assurance processes.
• Lead technical resolution of RFIs, EWNs, NCRs, design changes, technical queries, and interface issues.
• Undertake and lead constructability reviews, value engineering initiatives, and risk mitigation activities throughout design and construction phases.
• Provide strategic oversight of subcontractors, suppliers, and installation teams to ensure safe, efficient, and compliant delivery.
• Support procurement strategy, technical evaluations, equipment selection, supplier engagement, and approval processes.
• Lead development and review of RAMS, ITPs, quality plans, testing strategies, commissioning procedures, and handover documentation.
• Monitor project progress, identify engineering risks and opportunities, and provide recommendations to senior project leadership.
• Manage complex interfaces across civil, structural, architectural, systems, and MEP disciplines.
• Chair technical workshops, design reviews, coordination meetings, and stakeholder engagement forums.
• Support systems integration, testing, commissioning, and operational readiness activities.
• Mentor and provide technical guidance to mechanical engineers, design coordinators, and graduate engineers.
• Contribute to engineering best practice, lessons learned, innovation initiatives, and continuous improvement across the programme.

Required Experience

• Degree qualified in Mechanical Engineering or a related discipline.
• Significant experience delivering mechanical systems on major infrastructure, rail, tunnelling, utilities, transportation, or heavy civil engineering projects.
• Proven experience leading multidisciplinary engineering teams and managing complex stakeholder environments.
• Strong technical knowledge of mechanical building services, pressurised pipework systems, pumping systems, fire suppression systems, and public health infrastructure.
• Extensive experience in design management, technical assurance, and construction delivery.
• Strong understanding of engineering standards, specifications, design verification, and systems assurance processes.
• Ability to review and approve complex technical documentation, calculations, drawings, and BIM models.
• Experience managing contractor, consultant, and supplier performance.
• Strong understanding of QA/QC, commissioning, and handover processes.
• Excellent communication, leadership, negotiation, and stakeholder management skills.

Desirable Experience

• Chartered Engineer (CEng) status or working towards chartership.
• Experience working on major rail, tunnelling, or transportation infrastructure projects.
• Knowledge of HS2, Network Rail, London Underground, or equivalent major infrastructure standards.
• Experience with systems integration, assurance, and commissioning of complex infrastructure assets.
• Familiarity with BIM coordination, digital engineering, and common data environments.
• Experience leading technical governance and engineering assurance reviews.

Key Attributes

• Strong technical leadership and engineering judgement.
• Strategic and solutions-focused mindset.
• Ability to influence senior stakeholders and drive technical decision-making.
• Strong commercial, programme, and risk awareness.
• Excellent coordination and multidisciplinary interface management skills.
• Commitment to quality, safety, and engineering excellence.
• Ability to manage multiple workstreams and priorities within a complex project environment.