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As we celebrate another major milestone at Hinkley Point C, Roger Frost, Project Director of Balfour Beatty’s Tunnelling and Marine Project discusses the size, scale and enormity of the work that our expert team have undertaken in recent weeks.

When you think about Hinkley Point C, what do you see? Do you see the vast Tunnel Boring Machines setting out on their underground adventures or the world’s tallest crane, carefully lifting concrete structures into place? You would be right to think of these integral activities but sometimes, it’s the work that goes on behind the scenes that can really make the biggest impact.

That’s the work I want to celebrate today – the essential work that our team have been delivering safely around the clock, to help us achieve yet another major milestone on our Tunnelling and Marine Project at Hinkley Point C.

You might have heard of our off-site manufacturing facility in Avonmouth. It’s a first-of-its-kind facility dedicated to creating the 38,000 nuclear grade concrete segments required to line the three underground cooling water tunnels at up to 33 metres below the seabed of the Bristol Channel.

At the same location that manufactures the 38,000 segments, the Heads which will cap the three cooling water tunnels have successfully been completed. Our expert people who, despite the challenges of the global pandemic, have come together in the spirit of collaboration, teamwork and cooperation to complete the final concrete pours – a technique used to quickly and efficiently pour nuclear grade concrete into complex rebar structures -  for the six, first of a kind Heads structures – ahead of schedule. 

You may wonder why I’m choosing to pin-point this specific milestone when our people achieve so much every day.

I can’t stress enough that completing the final pour for the Heads really is a feat of engineering. One that not only means that we can successfully move to the next phase of our works but one that required significant skill to ensure that each concrete pour was to the exacting specifications for the nuclear grade structures. With 125,000 individual reinforcing bars in each Intake Head - there was no room for error.

Now complete, the nuclear grade Heads structures will be lifted into place in the Bristol Channel by some of the largest marine cranes in the world, Gulliver and Rambiz – vessels that are bigger than a football pitch! The two vessels will lift the Intake Heads – totalling just under 5,000 tonnes each – in a combined, complex operation, known as a tandem lift.

Once secured, the Heads will cap the tunnels currently being created by the Tunnel Boring Machines, allowing 120,000 litres of sea water to flow into the critical water-cooling system required for the UK’s landmark nuclear power station, every second.

What a fantastic achievement for everyone involved, testament to Balfour Beatty’s unique capability in both heavy civil engineering and our expertise tunnelling. A great early Easter present for EDF, too!