Green Hydrogen Construction

How Is the Lower Thames Crossing Rewriting the Rules of Major Infrastructure Engineering?

The Lower Thames Crossing is one of the most significant infrastructure projects in the UK’s recent history. A 23-kilometre road and tunnel links Kent and Essex. It will almost double road capacity across the Thames east of London. Moreover, it creates a direct freight route between the south-east ports, the Midlands and the North. However, the engineering ambition behind the project extends well beyond its scale. National Highways has set a target no major British infrastructure project has previously achieved — carbon neutral construction.

British hydrogen firm GeoPura has won the contract to supply 2,500 tonnes of green hydrogen to the project. GeoPura’s flagship production facility sits at HyMarnham Power in Nottinghamshire — built on the site of a former coal-fired power station. Furthermore, this is the largest volume of green hydrogen ever produced for a British construction project.

Replacing Diesel at Scale

The engineering logic behind the hydrogen decision is straightforward. Diesel powers the heavy construction machinery that major infrastructure projects depend on. Excavators, dumper trucks, telehandlers, generators and compressors all run on it. On a project the scale of the Lower Thames Crossing, that consumption is enormous.

GeoPura’s 2,500 tonnes of hydrogen replaces over 12 million litres of diesel. It saves an estimated 30,000 tonnes of CO2 compared to conventional fuel. Furthermore, the hydrogen arrives as a fully managed service. GeoPura handles supply, storage and on-site distribution throughout the main construction phase. Six hydrogen-powered generators already operate on the project. They charge batteries for electric machinery at a work site in Essex. Consequently, the transition from diesel to hydrogen is not theoretical on the Lower Thames Crossing. It is already underway.

The Engineering of Green Hydrogen

GeoPura produces green hydrogen through electrolysis — splitting water into hydrogen and oxygen using locally sourced renewable electricity. Unlike grey hydrogen, which engineers produce from natural gas with significant carbon emissions, green hydrogen emits only water when used in a fuel cell or combustion engine. Therefore, it offers a genuine zero-emission alternative to diesel for heavy construction applications. Battery electric technology cannot yet deliver the power density or refuelling speed that heavy machinery requires. In those situations, hydrogen fills the gap directly.

The hydrogen feeds 450 kilowatt generators on site — charging batteries for electric machinery and directly powering hydrogen combustion equipment. A world-first hydrogen-powered JCB digger has already operated on the project in Kent. It was the first use of a hydrogen combustion excavator outside a test environment on a major UK infrastructure project. Moreover, GeoPura is installing a new production facility at the Port of Tilbury — directly adjacent to the construction zone — to provide local supply throughout the main works.

A Project Built to Set New Standards

The Lower Thames Crossing’s sustainability ambition deliberately reaches beyond the project itself. National Highways required its three main delivery partners to invest in hydrogen-powered machinery and the skills to operate and maintain it. Those partners are Balfour Beatty, Skanska and the Bouygues-Murphy joint venture — three of the largest construction firms in Europe. The project plans to deploy around 140 zero-emission machines. This is one of the largest deployments of its kind anywhere in the world.

Furthermore, the project targets a 70% reduction in construction emissions against its original calculations. The tunnel sections target an 80% reduction. Supply Chain Development Director Katharina Ferguson put it clearly — engineers have tried everything on the project elsewhere before. However, the Lower Thames Crossing is supersizing it and making solutions commercially viable. As a result, the ambition is not simply to build a road and tunnel. It is to demonstrate that major infrastructure can deliver at this scale without the carbon footprint that has historically accompanied it.

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What This Means for Engineering

The Lower Thames Crossing’s hydrogen construction programme signals something significant for UK engineering. It demonstrates that green hydrogen is no longer a laboratory technology or a pilot project. At 2,500 tonnes — replacing over 12 million litres of diesel — it is a commercially viable engineering solution operating at real industrial scale.

For precision engineering businesses across energy, infrastructure and manufacturing, this is a meaningful signal. The engineering infrastructure that hydrogen requires is extensive. It covers production systems, storage, distribution, fuel cell integration and hydrogen-compatible machinery. Therefore, it creates demand for exactly the kind of precision mechanical design and bespoke system development that the UK supply chain must be ready to deliver. CNR has over 35 years of that engineering experience — across energy, infrastructure and advanced manufacturing programmes.