Shay 7 Logging Locomotive

Built in 1929 and weighing sixty seven tons, Shay 7 is the largest locomotive at the Hesston Steam Museum.  It is a unique type of locomotive named after its inventor, Ephraim Shay, who owned a logging company and designed the Shay locomotive to satisfy his railroad’s need for a powerful engine that could also negotiate tight curves.  A native of Harbor Springs, Michigan, Shay had his prototype built by the Lima Locomotive Works in 1880.  They would go on to produce nearly three thousand of these rugged locomotives over the subsequent half century.  

Shay 7 is of the largest class of Shay locomotives built for narrow gauge.  It is unique in its ability to pull heavy tonnage up steep mountains and around sharp curves.  This particular class features three pistons and twelve wheels. Traditionally, pistons are mounted horizontally on both sides of a steam engine.  Shay locomotives have their pistons mounted vertically on the right side only.  The benefits of this configuration are greater traction and power.  The pistons operate a driveshaft that runs the entire length of the locomotive and is geared to all of the wheels, including those under the tender. A traditional, fixed frame engine will have only two cylinders connected to 6 to 8 wheels.  Shay 7's wheels are separated into three sets of four wheels.  These sets are called trucks and can swivel independently from each other.  The drive shaft has universal joints that allow it to change length as the locomotive turns.  This swiveling action allows the Shay type engines to navigate significantly tighter turns than a conventional engine. In addition to the extra piston, the Shay achieves greater torque (power) than other locomotives through its 2.53:1 gear ratio, which means the drive shaft turns over two and a half times for every revolution of the wheels.  The downside to this design is that it is limits the locomotive to speeds of about 15 mph.  It can be compared to operating your car in first gear all the time.

Shay 7 was completed as Shay 3345 in November 1929 in Lima, Ohio.  It was the last three foot gauge Shay built and was 2,759th of 2,767 total Shay locomotives produced by Lima.  Shay 7 first ran under the flag of the New Mexico Lumber Company,‍‍‍ however it did not stay there for long. After defaulting on payments, Shay 7 was repossessed and went to work for the Oregon Lumber Company, operating on their Sumpter Valley Railroad.  In 1960 the locomotive was sold to Elliot Donnelly, Chicago Printing magnate and benefactor of the Hesston Steam Museum. After a short stay at the Black Hills Central railroad in South Dakota, Shay 7 was trucked to the Hesston Steam Museum where it underwent a five year full restoration.  The rebuilt locomotive was unveiled in 1975 where it ran for ten years until the Shay was badly damaged when the engine house burned to the ground in 1985.  After another restoration the engine finally returned to the rails in 2006.