ASME-Landmark:Leavitt-Riedler Pumping Engine

The Chestnut Hill High-Service Pumping Station of the Boston Water Works Corporation featured an unusual triple-expansion, three-crank rocker engine, which in its day was a high-capacity unit that provided outstanding performance. Designed by Erasmus Darwin Leavitt, Jr. (1836-1916), Engine No. 3 was installed in 1894 to the high-service pumping facility on the south side of the Chestnut Hill Reservoir in Brighton—a necessary measure as demand increased as towns adjacent to old Boston were annexed into the city, creating a considerable number of elevated areas to which water had to be raised.

This steam engine made use of Leavitt's vertical and inverted cylinders with four gridiron valves each activated by its own cam. Steam jackets were applied to the heads and barrels of each cylinder with tubular reheaters in between. Steam at boiler pressure was supplied to all jackets and to the tubular reheaters, enabling expanded steam to pass through the high-pressure and then the low-pressure cylinders. High velocity was achieved through the pump valve mechanism, somewhat similar to the valve rod system of a Corliss engine, introduced by Leavitt a year earlier, based on the design from Austrian Professor Riedler of the Royal Polytechnic school of Berlin. This engine was designed to run easily at 60 revolutions per minute, a speed made possible only by use of the Riedler valve gear. See ASME website for more information