Ian brings more than 15 years of experience in infrastructure and engineering services, with a strong background spanning rail, highways and broader infrastructure projects. A qualified geologist, he has built a career at the forefront of complex engineering environments, combining technical expertise with proven operational leadership.

A Strong Track Record in Infrastructure Leadership

Prior to joining Mainmark, Ian held senior roles at leading organisations including AECOM and SIS Group. Most recently, as Operations Managing Director at SIS Group, he played a pivotal role in driving significant business growth while enhancing operational capability and delivery performance.

During his tenure, SIS Group saw notable expansion across revenue, team size and regional presence -demonstrating Ian’s ability to scale businesses and deliver sustainable growth in competitive markets.

His appointment at Mainmark signals the company’s intent to build on this momentum, leveraging his expertise to strengthen its offering and expand into new markets.

Supporting Mainmark’s Growth Ambitions

As General Manager, Ian will lead Mainmark’s UK and European operations, with a focus on delivering long-term growth and enhancing client value. A key priority will be advancing the company’s evolution into a full lifecycle asset management provider -delivering services from monitoring and inspection through to testing and repair.

This strategic direction aligns with increasing demand for proactive infrastructure management solutions, particularly as asset owners seek more efficient and resilient ways to maintain critical infrastructure.

Leadership Perspective

Commenting on the appointment, Peter Bierton, CEO at Mainmark, said:

“We are delighted to welcome Ian Thornhill as the new General Manager at Mainmark. He has a wealth of experience and we look forward to Ian playing a key role in our growth in the infrastructure sector across the UK and Europe.”

Ian’s leadership is expected to play a central role in strengthening Mainmark’s capabilities and positioning the business as a trusted partner for infrastructure owners navigating increasingly complex operational challenges.

Building on a Strong Global Foundation

Mainmark Ground Engineering (UK) Ltd was established in 2016 and forms part of the global Mainmark group, headquartered in Sydney, Australia. Over the past 20 years, Mainmark has grown its international footprint significantly and now operates from 18 locations worldwide.

The company is recognised for its innovative ground engineering and asset preservation solutions, supporting infrastructure longevity and performance across a wide range of sectors.

Looking Ahead

With Ian Thornhill at the helm of its UK and European operations, Mainmark is well positioned to accelerate its growth strategy, deepen its market presence and continue delivering high-quality engineering solutions.

His appointment reflects both the strength of the company’s ambitions and its commitment to investing in experienced leadership to drive the next phase of its development.