 An example of such an 1867 Kay & Co. engine from Dancers End pumping station in the Chiltern Hills is now at Kew Bridge

Larger engines rarely used the six-column form, as the upper framework would become unwieldy.The weight of their large beams was more than the slim columns supporting the beam pivot could cope with.A rare form was the "eight-column engine", where the pivot was supported by four close-set pillars rather than two.