A Treatise On The Principles And Practice Of Dock Engineering

68 DOCK ENGINEERING. shut and the mixing resumed, the hopper being meanwhile refilled for the next charge. “ With the hand mixer, above described, a gang of six men, with a boy for attending to the water cistern, can make from 30 to 40 cubic yards of concrete blocks, and a larger quantity of concrete in bulk in a trench in a day, of better quality and at a cheaper rate than can be done by shovel mixing, and when the mixers are turned by steam, twice the above quantities are made.'’ The usual standard sizes have eapacities of J and 1 cubic yard. Fig. 30. —Taylor Concrete Mixer. The Messent mixer has been used at Tynemouth breakwater; Aberdeen harbour works; the Surrey Commercial Docks, London; dock works at Kurrachee, and elsewhere.