A purposeful machine. Mt. Emily Lumber Company's Shay #1 rolls slowly through the sagebrush steppe of Central Oregon, en route to her home in the City of Prineville. The afternoon sun highlights the features of the Shay's design that make it one of the most purposeful locomotives in the world. This 90-ton machine room on rails was definitely not designed with either beauty or speed in mind. Power and agility were key considerations with these locomotives, as was the ability to operate for long periods in remote locations, where facilities were few and the quality of the track was often less than optimal.
A typical Shay had 3 cylinders, vs. two for most rod engines. These cylinders were located on the right side of the engine, and were oriented vertically. Instead of directly driving the wheels, the power from these cylinders spun a massive drive shaft, which ran from end to end, also on the right side. This shaft was geared directly to the wheelsets....and not just a few wheels....ALL of the wheels. The Shay was like a 4-wheel drive truck in permanent low gear. All of the machinery was on one side, and all of it was completely exposed and easy to work on. To balance all of that weight on the right, the boiler was offset to the left side of the chassis, making her look rather lop-sided from the front. Fuel was carried in a tank-engine-like bunker located right behind the cab and right above the center truck. Water was carried in a tank which was mounted on its own single truck in the back. With the wheels divided into three independent trucks, this large machine could negotiate some rather tight corners that no rod engine could handle. With a top speed of only roughly 15 mph, nearly any rod engine could leave her in the dust on a flat railroad, but put the two on a 7 or 8% grade and the mighty Shay would make the rod engine look like it was parked....because it would be!