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The "Shay": Ephraim Shay's Classic Geared Design

Last revised: November 6, 2024

By: Adam Burns

The Shay steam locomotive, a gear-driven steam locomotive developed by Ephraim Shay, revolutionized the logging industry and transformed the way heavy loads were transported across difficult terrains.

The development of this locomotive is not only a tale of engineering innovation but also a reflection of the demands of a burgeoning industrial America in the late 19th and early 20th centuries.

The Shay was the most well-known and widely used of the geared designs with 2,767 constructed from 1878 through 1945.  Part of the design's successful was due to Shay's partnership with the Lima Locomotive Works, which built the entirety of the Shay catalog.  

Interestingly, when Shay's patent expired, the the Willamette Iron & Steel Works of Portland, Oregon picked up the design and introduced its own Shay-inspired variant, the Willamette locomotive. 

Ultimately, only 33 were produced between November, 1922 and December, 1929. Today, 115 Shays are known to be preserved while 18 others are operational at various tourist railroads.

Photos

Feather River Railway 3-truck #3 leads a string of empty boxcars over the South Fork Trestle spanning the Feather River as it heads for the mill at Feather Falls, California on October 23, 1959. C.G. Heimerdinger, Jr. photo.

History

The invention of the Shay locomotive dates back to the 1870s when Ephraim Shay, a logger, and inventor from Michigan, found traditional locomotives inadequate for the steep, uneven tracks of logging and mining railroads.

His experience in the logging field highlighted the need for a more robust and maneuverable form of locomotion that could handle sharp curves and steep gradients more effectively than the conventional rod-driven steam locomotives of the time.

As early as 1872 he began development of a new locomotive that used gears rather than standard rods to propel the device forward.

He built the design from the ground up using a flatcar as a base. Upon this he placed a boiler, vertical cylinders, and two-axle trucks on each end where one was rigidly mounted and the other (front) could swivel.

After much further experimentation Shay finally came up with a setup he found practical; in later designs both trucks were allowed to freely swivel.

Top Speed

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."

Essentially this means the vertical cylinders drive a horizontal crank shaft attached to drive shafts extending to each truck axle. These axles have gearboxes which propel the engine forward.

Because the Shay enjoyed power to all axles they provided excellent adhesion, enabling the negotiate grades in excess of 5%.  However, its high adhesion also limited top speed to just 18 mph. 

Cylinders

The distinctive design of the Shay positioned its cylinders directly in front of the cab, necessitating the boiler to be uniquely offset to the left. This seemingly unconventional arrangement fortuitously enhanced the locomotive’s operation by naturally counterbalancing its weight distribution.

Additionally, the innovative design granted unparalleled flexibility; each truck could navigate the track independently, ensuring that the locomotive maintained traction and stability on even the most challenging terrain.

This feature allowed the Shay to traverse nearly all types of rail conditions effectively, demonstrating a significant advancement in locomotive engineering and adaptability.

Michigan-California Lumber Company 2-truck Shay #2 is seen here on display, circa 1981. The narrow-gauge (36 inch) locomotive was built by Lima in 1884 and operated near Camino, California. It currently resides on display at Turtle Bay Park & Museum in Redding, California. William Myers photo. American-Rails.com collection.

The design of the Shay locomotive showcased exceptional versatility, allowing it to maneuver across a myriad of track configurations, no matter how rudimentary their construction. Remarkably, this adaptability extended to the locomotive's ability to ford streams and creeks, an invaluable feature in rugged terrains lacking proper infrastructure.

This capability was particularly crucial for logging companies, which prioritized cost-effectiveness and speed in their operations. Their approach was straightforward: extract resources from a location and then swiftly relocate, reusing their rail equipment to set up new tracks in fresh logging areas. This operational method underscored the need for a locomotive that could easily adapt to swiftly laid, temporary tracks.

Content with his initial design, Ephraim Shay recognized the potential of his innovative locomotive but needed a strategic partner to bring it to the broader market.

In search of a manufacturer that could appreciate the ingenuity of his concept, Shay approached the then-small Lima Locomotive Works in Ohio during the late 1870s. This partnership would soon revolutionize the capabilities of locomotives in industrial applications, particularly in the logging industry.

Cass Scenic Railroad three-truck Shay #11 eases downgrade towards Cass as it is about to hit the Gum Crossing in October of 2008. The 103-ton unit was built for the Hutchinson Lumber Company (California) in 1923. Loyd Lowry photo.

Initially, Lima interest in Shay's concept. However, after some persuasion, they agreed to construct a prototype. This first model proved its worth when it was bought by the J. Alley Company, a lumber firm in Michigan, in 1880.

Buoyed by the success of this prototype, Shay secured a patent for his design in 1881, sparking significant interest in the industry. As the locomotive's advantages became apparent, sales began to soar.

Over the ensuing years, both Shay and Lima Locomotive Works continually refined the design, enhancing the locomotive’s weight, power, tractive effort, and adhesion capabilities.

Notable milestones included the introduction of a three-cylinder Shay locomotive in 1884 and the debut of the first three-truck Shay locomotive by Lima a year later.

Further innovation came in 1901 when Shay received a patent for an improved geared truck, marking another advancement in the design’s evolution, which solidified the locomotive’s role as a crucial asset in rugged, industrial environments.

Diagram

A diagram and schematic of a typical Shay locomotive. This particular model is a 3-truck variant.

The evolution of the Shay over the years represents a remarkable journey in locomotive engineering. Originally, the design began modestly with the two-truck Class A model, which weighed a mere 13 tons.

However, the locomotive witnessed significant advancements. By 1903, the unveiling of the first Class D version marked a notable milestone; with four trucks, it tipped the scales at 140 tons, making it the heaviest ever built at that time. Later models even reached up to 150 tons.

Post-1920s, the design standardized somewhat, with most Shays featuring three trucks. This included one forward truck, another positioned to support the cab and firebox, and a final aft truck that supported the tender.

Each iteration was tailored to meet the increasing demands and challenges of industrial hauling, showcasing not just the adaptability but also the pioneering spirit embedded in the design of the Shay steam locomotive.

Classes

The very 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, 3 Cylinders

Class D: 4 Trucks, 3 Cylinders

More than any other geared design the Shay proved the most successful, even among main line railroads where systems such as the Western Maryland, Northern Pacific, and New York Central acquired examples to handle the stiff grades of secondary branch lines.

By the time production had ended on the Shay some 2,767 examples had been built by Lima spanning a period from 1880 to 1945.

Its success launched Lima as a major locomotive builder and after the initial patent had expired a number of companies began marketing their own versions; notably the Willamette Iron & Steel Works of Portland, Oregon and Michigan Iron Works of Cadillac, Michigan.

Klickitat Logging & Lumber Company three-truck Shay #7 leads empty log cars through the Klickitat River Canyon (Washington) on June 6, 1962. Photographer unknown. American-Rails.com collection.

Preservation

Today, 115 Shays are known to be preserved throughout the world and a number of them are still in operation. Perhaps the best place to catch these locomotives in action is at 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.

Other Shays still in service include a handful in California, Colorado, Washington, and the Midwest. Additionally, a few others are under restoration.

Klickitat Logging & Lumber Company three-truck Shay #7 is seen here operating over the Spokane, Portland & Seattle at Goldendale, Washington on March 31, 1964. Photographer unknown. American-Rails.com collection.

Legacy

Sales of the Shay declined in the mid-20th century as road transport became more viable and widespread due to improvements in vehicle technology and road infrastructure. Additionally, the introduction of more efficient and powerful diesel locomotives also contributed to the gradual phasing out of steam-powered locomotives.

Despite declining interest, many Shay locomotives have been preserved and can be seen in railway museums across North America and in other parts of the performance. Several operational Shays continue to be key attractions on heritage and tourist railways, where they serve as a living reminder of the industrious spirit of their era.

Today, the legacy of the Shay locomotive is not merely about its technical specifications or its utility in the logging industry. It symbolizes a significant period of industrial development and represents the ingenuity and inventive spirit of its creator, Ephraim Shay.

For historians and train enthusiasts, the Shay locomotive remains an enduring symbol of the steam era's technological advancements and the transformative impacts of rail transport on industrial societies.

Surviving Examples

Sources

• Adams, Kramer A. Logging Railroads Of The West. New York: Bonanza Books, 1961.

• Fetters, Thomas.  Logging Railroads Of South Carolina.  Forest Park:  Heimburger House Publishing Company, 1990.

• Fetters, Thomas.  Logging Railroads Of The Blue Ridge And Smoky Mountains, Volume I (Gold Mountain, Black Mountain And White Top).  Hillsboro: TimberTimes, 2007.

• Fetters, Thomas.  Logging Railroads Of The Blue Ridge And Smoky Mountains, Volume 2 (Tallulah Falls, Anna Ruby Falls, And Jeffrey's Hell).  Hillsboro: TimberTimes, 2010.

• Gove, Bill.  Logging Railroads Of The Adirondacks.  Syracuse:  Syracuse University Press, 2006.

• Gove, Bill.  Logging Railroads Of New Hampshire's North Country.  Littleton: Bondcliffs Books, 2010.

• Kline Jr. Benjamin F.G.  Tall Pines And Winding Rivers: The Logging Railroads Of Maryland.  Strasburg:  The Friends Of The Railroad Museum Of PA, 2007 (Second Edition).

• King, Frank A.  Minnesota Logging Railroads.  Minneapolis:  University Of Minnesota Press, 2003 (First University Of Minnesota Press Edition).

• Labbe, John T. and Replinger, Peter J.  Logging To The Salt Chuck.  Seattle:  North West Shore Line, 1990.

• Lawson Jr., Thomas.  Logging Railroads Of Alabama.  Birmingham: Cabbage Stack Publishing, 1996.

• Warden, William E. West Virginia Logging Railroads. Lynchburg: TLC Publishing, 1993.