This Schleicher, Schumm at the Coolspring Power Museum was originally built for hydraulic elevator service.
Manufacturer: Schleicher, Schumm & Co., Philadelphia, PA
Serial Number: 1337
Horsepower: 10 hp
Bore & stroke: 8-1/2in x 14in
Ignition: Flame/slide valve
Owner: William Grimley
Schleicher, Schumm & Co. started building 4-cycle slide-valve gas engines in 1878 as the official American licensee of Gasmotoren-Fabrik Deutz in Germany. It is one of only eight remaining horizontal examples and the only 10 hp version.
This engine is a crosshead design, incorporating a linear connecting rod guide preventing side loading to the piston, a feature typically found on steam engines and on some of the earliest internal combustion engines. The combustion end of the cylinder features a slide valve, which is basically a gas tight, precision machined, sliding metal plate. Driven by a small connecting rod from the end of the sideshaft, its reciprocating motion controls the timing of intake air, fuel admission and ignition by an internal ignition flame. Exhaust is by a traditional poppet valve in a valve chest on the side of the cylinder.
This represents the second generation of this style built by Schleicher, Schumm. The slide cover and retaining system were upgraded from the previous six clamping studs to a retainer (called a “Lobster” in the original Schleicher, Schumm drawings) and just two studs. Each stud carries a strong spring and a knurled hand nut. Tightening the nuts makes the “Lobster” compress the slide valve between the cover and cylinder head. A belt-driven oiler supplies a continuous feed of oil to the slide valve to reduce friction and wear and ensure a gas-tight seal of the combustion chamber.
Another unique feature is the addition of a more compact “spur and bevel” gear arrangement driving the sideshaft. On earlier engines the governor-side crankshaft bearing was located far outboard to accommodate a pair of bevel gears to drive the sideshaft.
The 10 hp engine was built for a variety of applications and commonly equipped with two flywheels. On special request, it could be ordered with a single, extra heavy, lead-filled flywheel with integrated cable winch or back-geared piston water pump.
Originally built for hydraulic elevator service, this engine remained in that capacity until the turn of the century when the hydrogen enriched fuel it was designed to operate on became less available. It was then heavily modified to run on natural gas and remained in that configuration where it powered a factory until retirement.
The engine was saved from salvagers in the mid-1970s and displayed as a running exhibit in its “as found” condition for years. Almost four decades later, it was returned it to its original configuration and appearance, an 18-month process of research, engineering, pattern building, casting and machine work by Wayne Grenning. Every detail has been properly presented including the original flame ignition system, mechanical oilers, and “illuminating gas” accumulator.
Learn more about this engine and 38 others in Coolspring: Discovering America’s Finest Antique Engine Museum, Vol. 2. Order at GasEngineMagazine.com/Coolspring