Principal Mechanical Engineer

JN Bentley

West of England

On-site

GBP 90,000 - 120,000

Full time

14 days+
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Benefits offered by this job

Pension contributions 4.5–7%
Employee ownership shares
Annual professional subscription paid
33 days holiday per year
Private medical insurance
Flexible working

Job summary

Mott MacDonald Bentley is seeking a Principal Mechanical Engineer to lead mechanical design on water and wastewater projects. You will drive technical delivery, mentor engineers, and ensure high standards while coordinating with electrical, civil, geotechnical, and process teams.

You will apply client asset standards, manage design tasks to meet deadlines, and collaborate with commercial and construction teams to deliver safe, practical solutions across all design stages.

Qualifications

  • Chartered Mechanical Engineer or above.
  • Degree in Mechanical Engineering or a related field.
  • 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.

Responsibilities

  • Lead and oversee the design, planning, and execution of the mechanical engineering aspects of projects.
  • Provide technical expertise and guidance to mechanical engineers and project teams, fostering knowledge and excellence within the team.
  • Mentor and develop junior engineers and team members.
  • Lead the development of mechanical designs for water and wastewater infrastructure and non‑infrastructure projects, including P&IDs, valve schedules, pumps, tanks, process equipment, above‑ground pipework, lifting and access steelwork.
  • Coordinate with the wider design team of electrical, civil, geotechnical, and process engineers.
  • Work closely with project teams to ensure application of client asset standards, and engage in technical discussions on best practice and standards waivers.
  • Collaborate with commercial, operational, and construction teams to develop efficient, practical, and safe solutions throughout design stages and beyond.
  • Positively engage with clients, managing relationships and adopting a one‑team approach to support them in achieving their aims.

Skills

Leadership
Project management
Communication
Problem solving
Mentoring

Education

Chartered Mechanical Engineer
Degree in Mechanical Engineering

Tools

P&IDs
Valve schedules

Job description

Internal applicants are welcome.

Mott MacDonald Bentley (MMB) is a capital delivery partner for Wessex Water. We manage projects across the region up to 2030, with potential for extension. Wessex Water serves 2.9 million customers across the southwest of England.

Role Overview

As a Principal Mechanical Engineer, you will contribute to projects that significantly impact the environment and communities, focusing on water and wastewater treatment systems.

Responsibilities
  • Lead and oversee the design, planning, and execution of the mechanical engineering aspects of projects.
  • Provide technical expertise and guidance to mechanical engineers and project teams, fostering knowledge and excellence within the team.
  • Mentor and develop junior engineers and team members.
  • Lead the development of mechanical designs for water and wastewater infrastructure and non‑infrastructure projects, including P&IDs, valve schedules, pumps, tanks, process equipment, above‑ground pipework, lifting and access steelwork.
  • Coordinate with the wider design team of electrical, civil, geotechnical, and process engineers.
  • Work closely with project teams to ensure application of client asset standards, and engage in technical discussions on best practice and standards waivers.
  • Collaborate with commercial, operational, and construction teams to develop efficient, practical, and safe solutions throughout design stages and beyond.
  • Positively engage with clients, managing relationships and adopting a one‑team approach to support them in achieving their aims.
What You’ll Need
  • Chartered Mechanical Engineer or above.
  • Degree in Mechanical Engineering or a related field.
  • 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.
Benefits

Financial wellbeing

  • MMB matches employee pension contributions between 4.5% and 7%.
  • Independent ownership shares financial success with all colleagues, including annual bonus schemes.
  • Annual professional institution subscription costs paid.

Health and wellbeing

  • Minimum of 33 days holiday per year, inclusive of public holidays, with flexibility to buy, sell or carry over leave.
  • Access to life assurance, private medical insurance, critical illness insurance, and health screening options.
  • Support for flexible working arrangements.
  • Wide range of employee networks supporting diversity and inclusion.

Enhanced family and carers leave

  • Up to 26 weeks paid maternity and adoption leave, two weeks paid paternity/partner leave, and optional shared parental leave.
  • Up to 2 additional paid leave days for those with significant caring responsibilities.

Learning and development

  • Structured development schemes supporting journey toward professional chartership, with mentorship and tailored training opportunities.

Immigration Status

Mott MacDonald Bentley are not currently offering sponsorship for the Skilled Worker visa route in the UK. We welcome applications from candidates eligible for alternative immigration routes that do not require sponsorship.

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