Senior Mechanical Engineer

12 Month Contract

Up to £75 per hour umbrella (Inside IR35)

Mostly Remote – onsite 2 days per month in Plymouth

The Senior Engineer will act as a key interface to the Design Manager and Principal Mechanical Engineer (Mechanical Services Lead), providing technical leadership, risk ownership, supplier oversight, and mentoring to engineers and designers.

• Own/manage the technical baseline and requirements for assigned packages; act as Responsible Engineer and technical focal point from need identification through handover.
• Check and review key deliverables: calculations, drawings, specifications, BoMs, method statements, T&IPs, installation details and as‑built records.
• Lead design optioneering and LFE (lessons learned), ensuring solutions are buildable, maintainable and operable.
• Provide formal checking/verification and sign‑off per project quality plans; act as Checker where authorised.

• Build and own the design work plan (scope, assumptions, estimates, resources), align with schedule, and track/report progress.
• Manage change control, configuration, and auditable records; maintain risk/issue/action registers.
• Provide clear status reporting to the Design Manager/Project Manager and drive recovery actions where needed.

• Ensure compliance with the Business Management System and Technical Manuals, applicable codes/standards and site rules.
• Organise and lead package‑level Design Reviews, HAZIDs, constructability and ALARP reviews; close actions as required.
• Deliver right‑first‑time outputs (coordinated, clash‑checked, specification‑compliant).

• Discharge Designer duties under CDM; lead elimination/reduction of risk through design and document residual risks.
• Own safety assumptions, interlocks and protection logic (e.g., cranes/machinery), ensuring compliance with LOLER/PUWER principles

• Lead coordination with EC&I, Civils/Structural, Construction, Commissioning, Operations, Safety, Security and Supply Chain.
• Direct supplier engineering: manage technical queries, submittals, factory tests, concessions and design integration; review and accept vendor drawings/data.

• Mentor engineers/designers; provide task leadership, technical coaching, and quality feedback on deliverables.
• Support competence assessment and contribute to resource shaping and onboarding for the package team.

• Support the PM in forecasting, cost/value inputs, early warning/change notices and claims/variation reviews for technical content.

• Design basis, scope definitions; requirements & interface schedules.
• Calculations (loads, strength, stability, clearances, sizing, pressure/flow) and supporting reports.
• GAs, details, assemblies, schematics, marking/zoning plans, interface definition.
• Specifications (equipment, coatings, NDT, QA requirements), BoMs and technical bid evaluations.
• Test & Inspection Plans, FAT/SAT plans and commissioning method statements.
• As built redlines, asset data packs and handover files (including safety case inputs as required).

• Demonstrate experience and knowledge in the design and implementation of Mechanical Systems/Services, preferably fluid systems such as water/pipe systems, pneumatics or hydraulics.
• Demonstrate understanding of how to substantiate complex requirements, preferably from the nuclear industry.
• Demonstrate experience of the design support to construction, operation, refit/repair of conventional and nuclear submarines and/or facilities.
• Demonstrate relevant knowledge and skills required in the technical management of complex design development throughout the…