Shay locomotive
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The Shay locomotive was the best known and most numerous type of geared steam locomotive. They were built to the patents of Ephraim Shay, who can be fairly credited with the popularization of the concept of a geared steam locomotive. Although the design of Ephraim Shay's early locomotives differed from later ones, there is a clear line of development that joins all Shays.
Shay locomotives were built by Lima Locomotive Works of Lima, Ohio, USA, although six Shay Patent locomotives, known as Henderson style Shays, were built by the Michigan Iron Works in Cadillac, Michigan, USA. Geared locomotives built by Willamette and other manufactures are often incorrectly referred to as Shays.
Shay locomotives featured a regular locomotive boiler mounted conventionally, except for being offset to the left side of the frame. On the right side two or three cylinders were mounted vertically, driving a longitudinal driveshaft mounted at axle height. This connected via universal joints and sliding square shafts to bevel gears attached to the ends of the axles of swivelling trucks. In the Shay design every axle was driven by the driveshaft, and there were no siderods.
Shay locomotives were often known as sidewinders or stemwinders on account of their side-mounted driveshafts. Most were built for use in the United States, while hundreds found their way to 30 additional countries, territories or provinces.
[edit] Classes
2768 Shay locomotives were built by Lima in four classes, from 6 to 160 tons between 1878 and 1945.
- Class A: two cylinders, two trucks. Weights between 6 and 24 tons.
- Class B: three cylinders, two trucks. Weights between 10 and 80 tons.
- Class C: three cylinders, three trucks. Weights between 40 and 160 tons.
- Class D: three cylinders, four trucks. Weights of 100 and 150 tons.
Note: Two 15 ton Shays were built with two cylinders and three trucks.
Twenty Class D shays were built. They were no more powerful than Class C, but had greater fuel and water capacity resulting in improved adhesion.
Four Shays were built left handed, all special ordered for the Sr. Octaviano B. Cabrera Co., San Luis de la Paz, Mexico.
[edit] Survivors
Only 115 Shays survive today, some a combination of parts of two Shays. The oldest surviving Shay sn-122, built in 1884, is currently displayed in Redding CA. The last Shay, sn-3354 built in 1945, still operates on the Cass Scenic Railroad State Park. One of the largest Shays built, this 150 ton Class C locomotive was in service only five years when it was retired and placed in the Baltimore & Ohio Museum. In 1981 it was removed from static display, in exchange for a smaller Shay and a Porter locomotive, and placed in service on the Cass Scenic Railroad. It has now served in tourist and enthusiast service for a longer period than it did for its original owners. It is still in near-new condition.
The Roaring Camp and Big Trees Narrow Gauge Railroad operates the class B Dixiana and the class C Sonora
