About my Shay

A Shay... but which type?

At the beginning of this project, it was clear, that I was going to build a Shay... Well... but what type of Shay ?

As my railroad is a 30" gauge line, the rolling stock contains only short cars, so a large Shay with more then 2 trucks would be to large. Also a class B with 3 cylinders may be to big for my railroad. So at last, there's only a class A possible.

But there was the same problem again... Which prototype would match with my railroad. At first I planed to build a down sized version of the well known Mich-Cal #2 (s/n 122) and add an larger cab. But this idea doesn't look good to me and the Mich-Cal deuce was copied a thousand times. During research for other prototypes on the internet, I found pictures of the small Molino Lumber Shay. This prototype runs on 30" gauge and was a very little 10 tons Shay. So it seams to fit very well to my roster.

But the small E.W.T-boiler on this engine would give me some troubles on my model version, so I start again the research for another one. A boot type boiler Shay would be fine in fact of the boiler construction, that's more or less easier to build. So I start looking for a Tee-boiler Shay.

As I couldn't find a prototype engine, I decided to create my own one by using typical components used by Lima. For example, the boiler will be a 36" boot type boiler and the steam engine will be a 2-8x8, meaning 2 cylinders with 8" bore and 8" stroke. The overall size will be close to a 11 or 13 tons Shay.

A colored version of this drawing is available as PDF here.

Technical data

The Shay will be built in 2"-scale. The boiler will represent a Lima 36" boot type boiler. This boiler will have nearly the same size and data as my Forney boiler, so I hope both engines will be the same in handling. The design of the steam engine on my loco is based on Limas 2-8x8 engine. This means 2 cylinders with 8" bore and 8" stroke. On my model, this will result in 30mm bore and 34mm stroke. The engine will use Stevenson valve gear.

The frame will sit on two trucks with 3' wheelbase and 22" wheels. The overall wheelbase is 16 1/2', so the model loco will be 3 2/3' in length, including the couplers.

All superstructures like cab and tender will be made from plywood and planked with sheet metal if needed. The tender will include a water tank for all boiler feed pumps, so only one pipe is needed between the loco and riding car. For the boiler, I'll add a axle driven pump on the rear truck, an injector and a hand pump.

Model version

For basic information on live steam Shays, I use the great books from Kozo Hiraoka. This shows the construction of live steam Shays in 3/4" scale step by step with many details and good ideas. From his first book, I'll use the cylinder design for my Shay, but double them in size and use only two of them. So I can use most data of valve gear and eccentrics from his plans.