2-854-206 - Historic England Archive/Heritage Images

A view of the Laing site team constructing the ten-sided outlet shaft at Wraysbury Reservoir, showing them on the working platform using slips to fill the 3ft thick walls. The 84ft outlet shaft with 3ft thick walls was built by slipform construction and was the first time in Britain that sliding formwork had been used on a structure with walls as thick as this. The slide took 93 hours to complete with 906 cubic yards of concrete used to construct the shaft.