Jones Bros completes key milestone for Mona Offshore Wind Project29th Jun 2026

A leading civil engineering firm has completed the fourth and final phase of a complex ground investigation survey campaign as principal contractor for the Early Contractor Involvement (ECI) phase on the Mona Offshore Wind Project.

Jones Bros Civil Engineering UK is delivering the ECI works in preparation for the onshore activity for the large-scale scheme, which will consist of up to 96 turbines in the east Irish Sea.

Located entirely in Welsh waters, the Mona Offshore Wind Project has the potential to generate up to 1.5GW of electricity, enough to power the equivalent of around 1.5 million UK homes each year. The project, which is being developed by JERA Nex bp, will connect to the existing National Grid substation at Bodelwyddan, Denbighshire.

Jones Bros Contracts Director Eryl Roberts said: “It’s wonderful to have been appointed to work on such a significant renewables project.

“We have played a vital role on several offshore wind farms in the UK, so to add this development to our impressive portfolio is fantastic.

“Our highly skilled team will relish being part of this important scheme, especially with it being in North Wales and close to home.”

Ground investigation surveys – a key element of the ECI phase – have now been completed on the project’s proposed cable corridor, with detailed design work currently underway. The ECI activity also encompasses monitoring of the surveys, including noise and vibration, as well as ongoing liaison with key stakeholders.

Senior Contracts Manager Rhys Roberts is overseeing a team of around 10 as preparation for the main project activity continues.

Headquartered in Ruthin, just over 20 miles from the wind farm’s landfall location between Llanddulas and Pensarn Beach on the North Wales coast, Jones Bros is drawing on local expertise. Staff and apprentices from the region are playing a key role in delivery and the company is also engaging the Welsh supply chain where possible.

Rhys said: “It is always great to impart our team’s knowledge and expertise at the ECI phase. Having completed the ground investigation surveys, we now have the detailed knowledge needed to inform further design work with confidence.

“This helps smooth out every step of the project, allowing for an integrated approach between us and the client, who we are hoping to work closely with throughout delivery of the scheme.”

Richard Haydock, Mona Project Director, said: “This milestone represents an important step in progressing Mona towards construction and future power generation. Jones Bros has brought valuable expertise, local insight, and a collaborative approach throughout the ECI phase, helping to build a strong foundation for the next stages of the project.”

Established in the 1950s, Jones Bros owns one of the largest plant fleets in the UK and employs approximately 550 people.

The company is currently working on contracts in various sectors including highways, flood and marine defence, reservoirs, waste management and renewable energy around the UK.

The company runs an award-winning apprenticeship scheme, which has produced a large percentage of its current workforce, with several of its senior managers having started out as apprentices or in a trainee role. It has recruited hundreds of apprentices over the years.