Cass Scenic Railroad No. 5 is a three-truck Shay geared steam locomotive built by Lima Locomotive Works in 1905.
The locomotive was built for the logging railroad serving the timber industry around Cass, West Virginia, rather than for high-speed main-line operation.
Shay locomotives used vertical steam cylinders driving a longitudinal shaft through bevel gears to the wheels.
The geared arrangement sacrificed speed but provided high tractive effort, flexible trucks, and the ability to negotiate steep grades, sharp curves, and temporary track common in logging operations.
No. 5 worked for the Greenbrier & Elk River Railroad and later Mower Lumber Company as ownership and corporate names around the Cass operation changed.
Its assignments included heavy road service on mountain logging lines rather than only switching work at the mill.
The locomotive remained associated with the Cass system for much of its working life, making it especially useful for interpreting the actual industrial history of the preserved railroad.
When commercial logging operations ended, West Virginia preservation efforts saved the railroad and historic equipment as Cass Scenic Railroad.
No. 5 became one of the preserved Shays used to demonstrate geared-steam operation on the same mountain environment for which the technology was designed.
For TransitSatellite, No. 5 should be modeled as an individual Lima Shay, not as a generic geared locomotive. Truck count, cylinder placement, shaft arrangement, and specific service lineage distinguish it from Climax and Heisler designs.