Principal Mechanical Engineer

Overview

As Principal Mechanical Engineer, lead the mechanical design and lifecycle execution of water and wastewater projects, shaping systems that protect communities and the environment. You will mentor engineers, coordinate across disciplines, and ensure adherence to client asset standards. This role offers exposure to large-scale Thames Water projects and a collaborative, one-team culture. You’ll influence technical strategy and drive practical, safe solutions from feasibility through commissioning.

Pay / Benefits

• MMB matched pension contributions (4.5%–7%)
• annual bonus schemes
• payment of professional subscription costs
• minimum 33 days holiday including holidays
• life assurance / private medical / critical illness / health screening
• flexible working arrangements

Responsibilities

• Lead the mechanical design, planning, and execution across projects
• Provide technical guidance and mentorship to engineers and teams
• Develop mechanical design for water/wastewater infrastructure (P&IDs, valve schedules, pumps, tanks, process equipment, pipework, lifting/steelwork)
• Coordinate with Electrical, Civil, Geotech, and Process engineers
• Ensure applications of client asset standards and discuss best practices and waivers
• Collaborate with commercial, operations, and construction teams for safe, practical solutions
• Engage with the client and support a one-team delivery approach

Key requirements

• Chartered Mechanical Engineer or above
• Degree in Mechanical Engineering or related field
• Strong knowledge of the water and/or wastewater industry
• Strong knowledge of mechanical engineering principles for process industries
• Excellent communication, leadership, and problem-solving skills
• Proven ability to manage multiple design tasks and meet deadlines

• communication
• leadership
• problem-solving
• water/wastewater industry knowledge
• P&IDs, valve schedules, pumps, tanks, process equipment
• above ground pipework, lifting and access steelwork

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