Class D 4-Truck Shay

I happened upon information about a Class D Shay while researching Shays in general just to gather historical background about my Class C Shay (3-truck Shay). I got to wondering if anybody had modeled a Class D. It appears that Accucraft did at one time make a live steam version. I can find no current reference to it on their web site, could only find one still photo, and found one YouTube video of a live steam Class D in action. Other than that, no G-scale models seem to exist (there are O- and HO-scale models). So I decided it would be a fun idea to build a G-scale Class D Shay.

The Shay locomotive was invented by Ephraim Shay who built the first one for his own use in his lumber operation in Michigan. Lumbering railways were built quickly and poorly, needing to last just long enough to get the timber out of the area. Traditional rod style locomotives went too hard on the track. The goal of the Shay was smaller drive wheels that delivered equal torque to both sides. Shay wanted to keep his invention a secret because the locomotive reduced his labor cost so significantly, he could sell lumber far cheaper and beat out all competition. An article published in 1877 in the Lumberman's Gazette ended the secrecy, and the entire lumber industry wanted Shays. The local machine shop that built Shay's first locomotive, plus a few for his friends, was overwhelmed. That's when production started at Lima Machine Works, and the first Lima Shay was completed in 1878.

There were 2,767 Shays were built over 67 years under four company names, all variations of Lima Machine or Lima Locomotive. As of now, 114 of the Shays survive, with a few still operational as a tourist attraction. According to the Shay database, there were 81 Shay's operating in Minnesota in the early 1900's.

Visit the Shay Locomotive site for a complete database of Shay's with over 1500 photos.

By far, the most interesting old picture I stumbled upon was the Shay "snow train". It was converted to have tracks like a bulldozer with skis in the front for steering - sort of like a giant snowmobile. It pulled a train of sleds loaded with logs, and apparently was used in Michigan in the late 1800's for winter logging.

It's hard to tell, but I think this might have been one of the early Class A Shay's, or maybe even one of Ephraim's own originals. This one required more than one engineer - one in back (where the engineer normally was) to run the steam engine, and another in front to steer!

This picture is cross-linked from the blog where it was originally posted. If the picture is gone, it means the blog went away.

I gathered all the old photographs I could find of Class D Shays, along with a lot of Class C and B Shays. At first glance looking at old photos, converting a 3-truck Shay to 4-truck looked easy - stretch the water tank and add a fourth truck. But after further research, I realized the Bachmann 3-truck Shay prototyped a 55-ton while all the Class D's were either 100 or 150 ton. Looking at the old photos again, it was clear the boilers were all much bigger. Ok, retrofit the model with a bigger boiler. Original boiler is the smaller one.

My band saw, Dremel tool, and glue bottle got a workout. I stole the boiler off another non-Shay loco that I had bought used, and turned out to not run very well. I scrapped this one, and along with this and two brand new Shay's, I had all the parts I needed.

To complete my Class D project, good timing and good luck got me two brand new Bachmann 3-truck Shays on eBay at a very reasonable price. I robbed the tank car (tender) from one to make a bigger tank car on the other, and swapped a couple of trucks around. The Shay I stole from will not be wasted - all I need to do is extend the coal hopper to include a water tank, and it will be a perfect replica of a Class B (2-truck) Shay while the other Class C turns into a Class D. I still end up with two perfectly functional and prototypical Shays!

Now I wondered how the same cylinders handled all the extra steam. Back to the old photos - sure enough, they all had bigger cyliners, too. Still only 3 of them, but bigger. I retrofitted my model with a bigger boiler and bigger cylinders that rose higher along the side of the boiler. Now the cab doesn't fit. Back to the old photos again - the forward facing windows and side window over the cylinders were all smaller. So I needed to do some work on the cab, too.

When I was growing up (...wait, still working on that - when I was a kid ...), my father ran an auto body repair shop. It wasn't my favorite after-school job, but I found I still have use for one of the skills I learned there. Auto body filler works great on railroad models, too, for filling gaps between pieced together parts and patching up around the modifications. The challenge was finding small enough tools for this sort of body work.

I converted this Shay to battery power and remote wireless control like the rest of my locos. The 9000mAhr lithium battery rides in the tender along with speaker and controller. As long as I had everything all torn apart, I replaced the chuff sensors with good micro switches. The chuff sensor in my other Shay worked so poorly, I wasn't sure it had one (and don't have any connected in the other one). The sensor wires as shipped are sort of hidden, like they don't want you to find them. They apparently knew the original sensors were junk.

Here is a side by side comparison showing the finished cab modifications. Class D on the left, Class C on the right.

Another side by side showing relative size comparison.

Here's the side by side comparison looking head on.

Last but not least, the side by side comparison of the tenders or water tank cars.

This was going to be my winter project in 2016-2017. I started in late September. I was having so much fun, I couldn't walk away from it, and just kept on working at it every spare minute I had. It was mid-November by the time I had it finished except for a couple of minor details. With the unusally warm November we had in 2016, the maiden run originally expected to be in the spring happened November 13. It was 60 degrees out that day.

Just in case you didn't put this together, "B&SC" is Birchwood & St. Croix Railroad.

Click the movie icon below to see a short video clip of the Class D Shay in action, close up. The chuff sound isn't working, but the visual of the drive train is good.

Update 2019

In the beginning, I did the best I could with stock plastic for creating bigger cylinders, but these were not very prototypical. When I started experimenting with 3D printing, one of the first things I tackled was creating better cylinder parts (see 3D Printing page). I was initially going to just replace them; however, the entire cylinder assembly was structurally dependent on the molded parts that I thought it was wise to not cut apart. So I opted for simply extending the cylinders with parts designed to look like the original cylinder bodies.

My initial attempt at chuff sensors to replace the original not-so-good chuff sensors did not prove to be robust. So while I had everything apart, I removed my initial attempt. Then I glued a tiny rare earth magnet on top of one of the stroke rods, and glued a tiny reed switch inside the cylinder. I also purchased a new Phoenix sound board to replace the generic (rod style) steam sound. I ordered the Phoenix board with Shay sound preloaded, and then set the chuff multiplier to give the correct number of chuffs off of one sensor. I now have real Shay sound!

The end result isn't perfect, but it's a whole lot closer than before!

Early on, I was worried about how to be perfectly prototypical. After reviewing lots of old photos of Shays, I realized original Shays did not all look exactly alike. My model doesn't look exactly like any of the photos, but no one photo of a real Shay looks like any of the other photos either. I am satisfied that my end result can be reasonably called prototypical.