The development at Shanklin involved the construction of new combined sewers, holding facilities, sea wall and deep sea outfall. The prime feature of the project was the construction of a 25 m internal diameter, 11 m deep underground holding tank immediately adjacent to the sea.
Sea protection works by way of a new concrete sea wall was required. The new project was required to blend sympathetically with the surrounding area, to incorporate a new slipway to the beach and to provide ancillary buildings in character with the location.
The tank was constructed using a ring of CFA piles as temporary works with the internal tank walls being cast ‘top down’ to the new base slab, the roof being cast as the final stage.