Caley were contracted by Balfour Beatty to deliver Handling Alignment Frames for Hinkley Point C Marine Works. The Marine Works contract involves the construction of 3 tunnels under the Bristol Channel; 2 tunnels bring the cooling water into the power station and the third is an outfall tunnel.

Where the tunnels connect to the sea there are large, heavily reinforced concrete structures known as heads, placed onto the seabed. A shaft down through the centre of these heads connects into the tunnels. There are 2 heads per tunnel for a total of 6 structures.