Principal Mechanical Engineer

Company: Mott MacDonald
Apply for the Principal Mechanical Engineer
Location: Bristol
Job Description:

Overview

As a Principal Mechanical Engineer, you will lead the mechanical design across water and wastewater projects, shaping solutions that improve public infrastructure and environmental outcomes. You’ll mentor engineers, collaborate with a multi-disciplinary team, and ensure best-practice engineering while meeting project goals. You’ll drive design quality, asset standards adherence, and client engagement within a major regional programme. This role offers impact at scale, working on schemes in the Bournemouth, Poole and South Dorset area with strong growth potential.

Pay / Benefits

  • MMB pension contributions matching 4.5%–7%
  • annual bonus schemes
  • life assurance / private medical / critical illness
  • 33 days holiday with buy/sell/carry-over options
  • flexible working arrangements
  • support toward professional chartership and development

Responsibilities

  • Lead the design, planning and execution of mechanical engineering elements across projects
  • Provide technical guidance and develop the team’s expertise
  • Mentor and develop junior engineers
  • Develop mechanical designs for water and wastewater infrastructure and related projects (P&IDs, valve schedules, pumps, tanks, process equipment, above-ground pipework, lifting and access steelwork)
  • Coordinate with Electrical, Civil, Geotech and Process design teams
  • Ensure application of client asset standards and participate in discussions on best practices and waivers
  • Collaborate with commercial, operational and construction teams to deliver practical, safe solutions
  • Engage with the client to foster a one-team approach and strong relationships

Key requirements

  • Chartered Mechanical Engineer or above
  • Degree in Mechanical Engineering
  • Strong knowledge of the water and/or wastewater industry
  • Strong knowledge of mechanical engineering principles, practices and standards 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 and wastewater industry knowledge
  • Mechanical engineering principles and standards for process industries
  • P&IDs, valve schedules, pumps, tanks, process equipment, above-ground pipework, lifting and access steelwork

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Posted: September 14th, 2026