The Leavitt-Riedler Pumping Engine (1894) is a historic steam engine located in the Chestnut Hill Pumping Station, 2436 Beacon Street, Boston, Massachusetts. It has been declared a national landmark by the American Society of Mechanical Engineers.
The engine, which ran from a coal-fired boiler, was designed by noted engineer Erasmus Darwin Leavitt, Jr. (1836-1916) of Cambridge, Massachusetts, built by N.F. Palmer Jr. & Co. and the Quintard Iron Works, New York, and installed in 1894 as Engine No. 3 of the Chestnut Hill Station to pump water for the Boston Water Works Corporation. At its normal speed of 50 revolutions per minute, it pumped 20,000,000 gallons in 24 hours.
According to C. P. Miller, when first brought into operation, the engine attracted national attention as "the most efficient pumping engine in the world" (Power).
The engine's pump valve mechanism was invented by Prof. Alois Riedler (1850-1936) of the Royal Technical College of Charlottenburg (now the Technical University of Berlin) in Berlin, Germany, and was key to its high-speed operation at a hydraulic head of 128 feet. The engine itself is of an unusual triple expansion, three-crank rocker design, with pistons 13.7, 24.375, and 39 inches in diameter and 6 foot stroke. Each rocker is connected both to a crankshaft with 15-foot flywheel and to a large pump's plunger rod.
The engine was removed from service in 1928 but remains in its original location.