I've been looking at effects of tunnel settlement on some old piled structures East of London. The drawings (dated 1957) show a 'Holmpress' pile, described as a 14 inch diameter reinforced concrete cast in situ pile, with 40 ton load capacity. Has anyone any information on this pile type ? Onlt thing I could find was a 'Pressure Piling' type bored pile in a 1965 copy of "Oscar Faber's Reinforced Concrete". This used a compressed air lock on top of the pile.
Tom The Holme Press pile was a driven cast in situ pile developed by a piling company in Harrogate, North Yokshire. I think the company was bought by Norwest Holst in the 1960's or 1970's.
A steel casing was driven to the required depth with a sacrificial shoe. The shaft was then formed with wet concrete as the casing was withdrawn in the usual way. Then a smaller diameter tube was driven through the wet concrete with the idea of expanding the pile radially into the ground increasing the normal stress on the pile shaft in an attempt to improve the shaft capacity. The central core tube was then withdrawn as another shot of concrete was installed. A messy business that was obviously not economically viable. It was probably a precurser to the Franki Pile.