Hinkley Point tunnelling machine breaks through the seabed

Hinkley Point C has just finished digging the 620m tunnel for the power station's fish return system, which runs under the Bristol Channel.

In another impressive feat of engineering, the tunnel boring machine has dug its way through the seabed five months after setting off from dry land and has now been retrieved by a floating crane, so that it can be taken away to be cleaned and used on another site.

The fish return system is just one of three fish protection systems which will give the power station more fish protection than any other power station in the world. The other measures are an acoustic fish deterrent and four low speed water intakes, designed so that fish can swim away from as close as 2m in the 20km wide channel.

The tunnel boring machine was named “Sarah Guppy” by local school children after the pioneering 19th century engineer from Bristol.

The seabed breakthrough completes 8km of marine tunnels on the project. Latest pictures show how the power station is progressing into its fit-out phase with both nuclear reactors installed and work underway to install the world’s largest turbine.

The tunneling machine being retrived from the seabed