Principal Mechanical Engineer

Mott Mac Donald Bentley is a fully integrated design and build business combining the design expertise of Mott Mac Donald with the contracting experience of JN Bentley to deliver award winning projects. With an annual turnover surpassing £500 million, Mott Mac Donald Bentley cements its position as a leader within the industry. The sustained, robust business performance creates an ideal environment for career growth.

MMB has extended its contract with Thames Water for an additional five years. As the largest water and wastewater provider in the UK, Thames Water serves 15 million customers throughout London and the Thames Valley. This extension will carry the current workload beyond the end of AMP8 in March 2030. We are delivering work in the Thames Valley region (extending from Cirencester in the west to the M25 and from Basingstoke in the south to Banbury in the north).

This sees us undertake a varied programme of sizable projects in wastewater treatment, clean water production and infrastructure.

As a Principal Mechanical Engineer, you will contribute to projects that significantly impact our environment and communities. Working primarily in the UK water market, MMB provides the feasibility, design, construction, and commissioning services needed to keep water flowing and wastewater treated.

You will play a pivotal role in shaping the mechanical functions throughout the lifecycle of various projects.

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

• 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 relating to process industries.
• Excellent communication, leadership and problem‑solving skills.
• Proven ability to manage multiple design tasks and meet deadlines.

• MMB matches employee pension contributions between 4.5 % and 7 %.
• As an independently owned business we share the financial success of the business with all our colleagues including an annual bonus scheme.
• Payment of annual professional institution subscription costs.

• A minimum of 33 days holiday each year, inclusive of public holidays, with the ability to buy, sell or carry over annual leave through our flexible benefits programme.
• Access to life assurance, private medical insurance, critical illness insurance and health screening options.
• We are happy to talk openly about flexible working and how we can support your responsibilities beyond the workplace.
• Join a wide range of groups including our Advanced Employee Networks which support our LGBTQ+, gender, race and ethnicity, disability, and parents/carers communities.

• Enhanced family leave policies, including 26 weeks paid maternity and adoption leave, and two weeks paid paternity/partner leave plus the option for shared parental leave.
• Up to two paid additional days leave are provided for those…