It has also acquired Marine Plant Hire (UK) Ltd (MPH) a marine plant charter and hire company, primarily supporting marine construction activities.

The trio of companies specialise in repairs, construction, and redevelopment projects across waterways and tidal coastal environments.

As part of the deal Sullivan Street has integrated these businesses under the Ancora Group, with the aim of expanding its presence across the UK and building a network of self-delivering marine contractors.

Hesselberg-Hydro, TMS and MPH have combined revenues in excess of £50m and established relationships with key stakeholders, including water utilities, the Environment Agency, tier-one contractors, harbour authorities and private owners.

Founded in 1991, TMS provides a range of services, including piling, dredging, waterway management and flood risk management and will continue its recent growth under founder Peter Stenner, who will remain CEO.

Hydro-Hesselberg, established in 1986, specialises in advanced coastal defence and flood risk management solutions, pioneering open stone asphalt solutions such as implemented recently at Canvey Island, a project that will protect 3km of coastline for the next 50 years.

Roger Smith, Founder of Hesselberg-Hydro, will remain as Managing Director and is confident in the future growth potential of the business. MPH was incorporated within TMS, but the demand for such specialist equipment from outside TMS made it a logical decision to separate the firm and serve the market as a stand-alone trading company.

Richard Sanders, Founder and Managing Partner at Sullivan Street Partners said: “TMS, Hesselberg-Hydro and MPH are excellent businesses, with a high-calibre workforce, motivated to solve problems and make good the challenges our coastline and inland waterways are facing. Together with Peter and Roger we will create a national marine infrastructure group with its own equipment and self-taught engineering staff, to get the UK to where we need to be.”

Peter Stenner Founder and CEO of TMS added: “Over the past 30 or more years, we’ve built the group with the support of dedicated friends and colleagues who have helped us attain the position that we are in today. With the partnership between Sullivan Street and ourselves, I’m confident that we are now in a strong position to tackle new challenges and take the group to even greater heights.”