Since a small child, owner, Rob Williams, would be out on the digger with his father, during all weathers. This sparked an obsession for construction and machinery. At age 16, Rob attended college to study the Heavy Plant Mechanics and gained an apprenticeship at an independent dealer of Komatsu parts & machines.

It was in 2000 when Rob decided to move to a local company, where initially starting in the workshop, he soon got deployed on day hire jobs as a plant operator. Due to Robs impressive attention to detail, flexibility to adapt and forward thinking, Rob was soon working full time carrying out works for the local council and Wessex Water. After a couple of moves he found himself with a firm operating a JCB JS220, working on pipelines, heavy civils and agricultural projects, building on his already extensive experience.

In 2012, Rob made the move to set up as a sole trader, buying a second-hand excavator and, in recognition of his experience and reputation, quickly built up a customer base. As the demand increased and Rob became busier, the time came to form Williams Plant, which enabled him to take on projects as a subcontractor with his own fleet of machinery.

In 2016, Rob teamed up with his wife Fiona, who had always been an asset behind the scenes, and took the decision to become a limited company. With an experienced and reliable team of operators and ground workers, offering a full groundworks package for most civil engineering projects, Williams Plant Dorset Ltd secured substantial contracts as both a main and principal contractor throughout the South of England.

In 2020, following further expansion, the company was renamed Onyx Civils Limited, a name carefully chosen by Rob and Fiona to reflect their ethos and principles for the business and industry they love. Onyx is the Greek work for ‘claw’ and is also a rare precious stone representing positivity, determination, stamina, perseverance and courage, the companies key work, ethos and principles.

2025 Onyx acquired a dedicated Plant and Materials yard and in 2026 we moved to our new offices in Shaftesbury.