Geared Locomotives in the USA

Geared steam locomotives were mainly used in the logging and mining industries. In the 1880s they replaced mules and oxen as the primary source of motive power between the source of the lumber or minerals and the mills. The railroads at these locations often used rough, lightweight, temporary tracks that followed the contours of the land. As a result they were not suitable for a typical side-rod steam locomotive. In the 1870s, Ephraim Shay began working with the Lima Machine Works to design a locomotive that would be suitable for this type of track while being cheaper to operate than a team of mules or oxen. The Shay steam locomotive went on to become the most popular of several types of geared steam locomotives.

There were several types of geared steam locomotives in North America -- the Shay, the Climax, the Heisler, and the Willamette. Lima built around 2,770 Shays between 1880 and 1944. The Climax Manufacturing Company built around 1,100 geared locomotives between 1888 and 1928. Heisler Locomotives Works built more than 600 geared locomotives between 1891 and 1941. The Willamette Iron and Steel Works built 33 geared locomotives between 1922 and 1929.

Shay

The Shay (or sidewinder as it was sometimes called) was the most widely used of the four major types of geared steam locomotive found in North America. The Shay design was patented by Ephraim Shay. Although a number of changes were made to the original design, the characteristics of Shay locomotives are easily recognizable. They were built by the Lima Locomotive Works or Lima, OH. They had three vertical cylinders (very early models had two) on the right side of the boiler. The boiler was offset to the left to offset the weight of the cylinders. The drive shaft ran from the front of the locomotive to the rear connecting the crank shaft of the motor to gears on the outside of the wheels. Of the 2,770 built in the USA only 117 survive today.

Heisler

Heisler geared steam locomotives had a V-2 cylinder configuration with the crank shaft centrally located underneath the boiler. The two cylinders were oriented at a 45 degree angle, one on each side of the boiler. The drive shaft was connected to the outboard axles on the front and rear trucks through a gearbox. Side rods were used to transmit power to the inboard axles on these trucks. Apparently, the Heisler was the fastest of the geared steam locomotive designs. A few builders produced locomotives of the Heisler design. Early models were built by the Dunkirk Engineering Company of Dunkirk, NY. Stearns Manufacturing Company of Erie, PA which later became the Heisler Locomotive Works produced most of the 600 Heisler locomotives that once existed. Only 20 Heislers survive today in North America but a few are operational.

Climax

Climax locomotives had two cylinders that were located somewhat more conventionally (than the cylinders on other geared steam locomotives) in front on either side of the boiler although angled upward. The piston rods attached to a horizontal crank shaft located under the center of the boiler. At the center of the crank shaft was a transmission. The transmission had two drive shafts: one coming out the front and one coming out the rear. The two drive shafts were connected to gear boxes in the front and rear trucks. The gear boxes in each truck was connected to both axles, providing power to all wheels. All Climax steam locomotives were built by the Climax Locomotive Works (formerly Climax Manufacturing Company) of Corry, PA. Of the 1,100 Climax locomotives built only 13 survive today but several of them are operational.

Willamette

Willamette locomotives were essentially the same as Shay locomotives with a number of improvements. They were built by the Willamette Iron and Steel Works of Portland, OR after the original Shay patent expired. The improvements that the Willamettes had included:

• Superheaters (Shays usually did not have superheaters)
• Welded boilers (Shays used bolts)
• Walschaerts valve gear (Shays normally used Stephenson valve gear)
• Cylinders all facing the same direction (rear cylinders on Shays faced the rear) Compare: Willamette Willamette Willamette Shay
• All cylinders were positioned forward of the cab (the last cylinder on Shays protruded into the cab) Compare: Willamette Willamette Shay
• Valve chests turned outward
• Truck springs inclined toward the bolster
• Improved efficiency

Some of the later Shays included some of these improvements. Only 33 Willamettes were built. Of those 33, 6 still survive today.

Other / Experimental

• Davenport Duplex Locomotive (Independent truck rod/geared hybrid)
• Oak Grove & Georgetown 5 (Radial planetary gear drive)

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• Railroads that used Geared locomotives in other countries