Mace has concluded the Pier 6 extension foundation works at London Gatwick, representing a milestone in the £140m ($192m) infrastructure programme.
Mace collaborated with specialist contractor Bachy Soletanche and consulting engineer WSP on this project.
Over a period of two months, Bachy Soletanche installed more than 200 continuous flight auger piles using a Liebherr LB24 rig across three distinct piling platform levels.
The company's in-house design team was responsible for the geotechnical solution, which introduced value-engineered enhancements to reduce material usage and lower the project's embodied carbon.
Sustainability was a central focus throughout the project, with the team surpassing low-carbon concrete targets by selecting a 'CIII/B' mix, resulting in carbon dioxide equivalent savings of approximately 40 tonnes.
Additional carbon reductions were stated to be achieved by minimising crane usage, which saved around 1,500 litres of fuel, and by sourcing materials from local and airside-approved suppliers.
The project's location within a live airside environment necessitated logistical planning and coordination with multiple stakeholders.
Bachy Soletanche is said to have adhered to strict operational and safety protocols, including crane height restrictions, airside permits and risk assessments.
To further enhance efficiency and safety, methods such as replacing hot works with hydraulic rebar cutters were implemented.
Mace was appointed for the Pier 6 extension in March 2025.
Expected to complete in 2027, the extension will feature eight new aircraft gates and enable 7.5 million passengers annually to board and disembark directly from aircraft.
This upgrade is expected to minimise reliance on remote stands, while eliminating more than 12,000 bus journeys a year.
Mace Construct project director John Newman said: “This complex pier extension will add much-needed capacity to London Gatwick whilst minimising the environmental impact.
"Through working closely with the client team and with our experienced supply chain, we have successfully delivered these foundation works in a live environment, on a very constrained site using the latest sustainable techniques.”
