Hinkley Point C completes 620-metre tunnel beneath Bristol Channel
New images show engineering progress at the nuclear power station
Last updated 1st Oct 2026
Hinkley Point C has achieved a significant milestone in its construction with the completion of a 620-metre tunnel designed for the power station's innovative fish return system beneath the Bristol Channel.
This critical infrastructure forms part of a comprehensive system aimed at providing unparalleled fish protection, making Hinkley Point C the leading power station in the world for marine life conservation.
The tunnel boring machine responsible for this feat, affectionately named "Sarah Guppy" by local school children, embarked on the mission five months ago and has now made its way through the seabed.
Following its retrieval by a floating crane, the machine will be cleaned and prepared for future projects elsewhere, continuing its journey of engineering accomplishments.
The fish return tunnel is part of three specialised systems, including an acoustic fish deterrent and four low-speed water intake systems.
These components are designed to protect fish by ensuring they can swim away from the station, even when close, safeguarding marine biodiversity within the expansive 20km wide channel.
The naming of the tunnel boring machine pays homage to Sarah Guppy, a pioneering 19th-century engineer from Bristol, whose legacy continues to inspire through such initiatives.
The completion of the fish return tunnel marks an eight-kilometre series of marine tunnels now finished, as the Hinkley Point C project moves into a crucial fit-out phase.
This advancement includes installing both nuclear reactors and preparations for the world’s largest turbine, signifying the power station’s transition towards becoming fully operational.
The latest images released show the impressive progress at the site, reflecting a blend of cutting-edge engineering and environmental stewardship that Hinkley Point C promises to deliver.