The Famous Shay Steam LocomotiveThe Shay steam locomotive was the most well known and widely used geared steam locomotive designs to operate in our country (the others being the Climax and Heisler). Designed by Ephraim Shay the geared design proved to be an invaluable tool in the logging industry through the first half of the 20th century as it could operate on almost any type of track. Today, many Shays have been preserved and several can still even be found in operation on a number of different tourist railroads!
Geared steam locomotives function differently in one significant way from their standard rod-driven brethren (the common steam locomotive), they use a vertical or angled geared system as opposed to a standard horizontal driven rod for propulsion. How geared steam locomotives work, according to William E. Warden in his book West Virginia Logging Railroads, is that these cylinders drive a flexible line shaft with universal couplings and slip joints through bevel gears. This flexibility thus allows each truck to negotiate the track independently of the other, thus keeping the locomotive on the rails and allowing it to operate over almost any type of track (which was usually nothing more than rails laid directly onto a hillside). In the instance of the Shay steam locomotive design it gained propulsion through three vertical cylinders mounted on the right side of the boiler, which was then offset to the left to kept the locomotive properly balanced (also of note, Shays used Stephenson valve gear). And, because all geared steam locomotives have all of their trucks powered, they provided excellent adhesion and could climb grades well over 5% (something all but unthinkable on main line railroads), although this high adhesion factor limited its speed to under 20 mph.
Likewise, because the locomotive was nimble enough to operate on almost any type of track one could commonly see geared steamers fording streams and creeks as logging companies would lay down track right through these bodies of water! The reason for doing this was that logging companies were after making money as quickly and as cheaply as possible. Thus, once a tract of land had been logged, they simply picked up the rails and moved on elsewhere, laying down a new line in the same fashion. While the Shay came in a variety of shapes and sizes after the 1920s most were equipped with three trucks (one forward truck, another to support the cab and firebox, and finally an aft truck to support the tender). The short table below lists the four different classes of Shays including their number of trucks and cylinders. · Class A: 2 Trucks, 2 Cylinders · Class B: 2 Trucks, 3 Cylinders · Class C: 3 Trucks, 4 Cylinders · Class D: 4 Trucks, 3 Cylinders Today, over 100 Shay locomotives have been preserved across the country and a number of them are still in operation. Perhaps the best place to catch these locomotives in action is to visit the Cass Scenic Railroad in Cass, West Virginia. Cass Scenic (which was originally the timber operations of the West Virginia Pulp & Paper Company and Mower Lumber Company) is home to the largest collection of operating Shays in the country and is well worth the trip to ride this historic operation if you have the chance. For more information on the Shay steam locomotive please click here to visit GearedSteam.com which provides information on not only Shays, but also all types of geared steamers.
Also, consider the book American Steam Locomotives from author Brian Solomon. While this publication does not include quite as much technical data as Parker's book, How a Steam Locomotive Works, it is still a very good resource with lots of information and best of all, is loaded with photographs! If you're interested in perhaps purchasing either (or both) of these books please visit the links below which will take you to ordering information through Amazon.com, the trusted online shopping network.
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