The Union Pacific Type – Building a Steam Locomotive in LEGO

This will be the first in a series of articles about my process of building a LEGO steam locomotive. I intend to cover a variety of topics in this series including research, the use of custom elements, aftermarket electrical devices, and building techniques. While I will focus on a specific locomotive project I am currently working on, this series will not include a full set of step-by-step instructions to that locomotive. My intention is to share some experiences and techniques that I hope people can apply to any steam locomotive project, and perhaps other types of LEGO models as well. At any rate, my designs are usually pretty fragile and don’t really lend themselves to redistribution via instructions. Instead, I will lay out my approach to building a steam locomotive and why I think it is effective. I hope that this will help people who are struggling with what I think is a particularly difficult type of model to build or, at least, be of some interest to the readers of this site.

Part I: “Before You Touch a Brick” – Research for a LEGO Locomotive Project

The first step in building a LEGO steam locomotive is to decide which locomotive you want to build. It was this project, more so than any I have previously built, that showed me how complex that process can actually be. If you’re like me, you have way more half-baked build ideas than you will likely ever get around to. Knowing this, I try to do my best with each one, and choose them carefully. For this series, I have chosen the Union Pacific’s 9000, or Union Pacific Type, locomotive.

UP 9000 on display in CA. Photo by Matthew J. Brown.

I wanted to model the 9000 because I have actually done it before. In fact, it was one of my first attempts at a train MOC, completed in, I think, 2008:

My original UP 9000 at least sort of looked the part, but ran terribly. It’s time to do better!

Out of all the engines I have built it was, by far, the worst runner of them all. It’s unique 4-12-2 wheel arrangement posed an equally unique set of challenges that I wasn’t able to overcome. It sat on static display in PennLUG’s early train layouts for a while, but I need my engines to run and, if they don’t, I eventually take them apart. It’s been many years since it’s been together.

I felt it was time to take on this project again because I think, this time, I can actually do it. Feasibility is certainly one important consideration in choosing what you want to build. Admittedly, a 4-12-2 steam locomotive pushes the boundaries of what is doable, but I wouldn’t try it now if I didn’t feel like I could succeed. So, in selecting a prototype to model, it is definitely worth asking yourself if it can be done with the tools available, in this case, LEGO bricks. While I conduct my research, I am not usually working with bricks, but I am thinking a lot about how I will attempt to build the various features of my prototype. It’s also worth asking if you, the builder, are up to the challenge. When I was just starting out, I was not up to the challenge, and might have been better off choosing something a little more straightforward to build. It’s only because I have since built several successful steam locomotives that I am making another attempt at the 9000.

A couple years ago I rebuilt another one of my early locomotive projects, the Erie P-1 “Triplex” locomotive. Here is the circa 2009 original:

My first Erie Triplex. Once again, not a great runner.

And the rebuild:

The new Triplex is probably my favorite engine to date.

It may be clear from those two past projects, but I like weird wheel arrangements!

I certainly think the new one looks better but, more importantly, it’s a really good runner, and I run it every chance I get. I want a UP 9000 I can do that with, too, but I also have other goals. I want to try out aftermarket electrical solutions for powering, controlling and augmenting my UP 9000 model. I want this engine to be a showcase of what can be done if you are willing to not be a purist. And, of course, I want it to be the most accurate model I think I can make.

Before I go on, a little background on the Union Pacific Type for those who may not know about it. In the 1920s, Union Pacific, like most American railroads, was experiencing a traffic boom. They wanted to move more freight, faster, and none of their engines were up to the task. The American Locomotive Company (ALCO) sold the railroad on the idea of a three cylinder steam engine to improve power and efficiency. Three and four cylinder rigid frame locomotives are fairly common in Europe, but few American railroads were ever sold on the idea. UP in the 1920s was an exception.

Their work with an ALCO experimental 4-10-2 three cylinder design, numbered 8000, convinced them the idea could work but they wanted a heavier engine and, given their loading gauge axle weight restrictions at the time, that would mean adding more drive wheels. The 4-12-2, a unique wheel arrangement, was born.

The first engine, 9000, was delivered as a single unit for test purposes in 1926. It was deemed successful, and a total of 88 engines of this type were delivered by 1930. They were extensively modified, were moved all around the vast Union Pacific system throughout their service life, and were retired in the 1950s, with the last leaving service in 1956.

Back in 2008, I did relatively little research to prepare for my UP 9000 build, but I have changed my approach to building quite a bit since then, so I began from scratch, with all new research.

In a recent article, Elroy Davis laid out the basic resources he uses in his modelling projects, and he provides a variety of useful links which I need not reproduce here. Instead of laying out every possible information resource, I will focus on the steps that I took, and what worked for me. Just as Elroy suggests, I started my research online. Google image search is your friend. Gather every unique photo you can get your hands on, the more the better, and the more different individual locomotives, the better. Ultimately, you will have to decide which specific locomotive you want to model, so you want to have as many options available as possible.

My googling often leads me away from photos of actual locomotives to photos of models and toys. A model is certainly no substitute for the real thing but often, the makers of high-quality locomotive models document their work extensively, and I do find it to be valuable. In my case,  Kohs & Company produced an excellent model of the UP 9000. There are lots of great pictures of the model there as well as some bibliography.

This information led me the same resources they used in making their model, the two volume work The Union Pacific Type, by William W. Kratville and John E. Bush. I can’t claim to have read every railroading book out there, but I’ve read a few, and these are, by far, the most comprehensive I have come across. I have used books for past projects to be sure but, after finding these amazing volumes, I recommend that anyone looking to model a steam locomotive find a similar book for their prototype, if it exists. Railroad historical societies will often include bibliography on their websites, and that is probably the best place to locate such books. In my case, the two volumes of The Union Pacific Type were not easy to get, but I am so glad I went to the effort. To understand why, I will lay out the organization of these books.

Taken together, volumes I and II of The Union Pacific Type cover the development of not only the 9000 itself, but other locomotive types that eventually led to the 9000 design. Using extensive research and in-person interviews, the authors lay out the decisions that led to the UP 9000’s creation in the beginning of volume I. Locomotives are primarily functional objects: They were built for a specific purpose; a specific time, place and job. Understanding that gave me a better appreciation of the locomotive I am modelling. The remainder of volume I covers the design and construction phase of the UP 9000. The engines were ordered in several batches, and many design changes were made between them. These changes will influence the final look of my model, and so my decision on which specific engine to work on.

Volume II, which is even larger than volume I, covers the service life the UP 9000s. Every design change, every upgrade, every little technological experiment from major rebuilds to the addition of a toolbox on the side of the tender, is covered in its own section. The level of detail really helps to understand the wide variation in visible features seen on the locomotives. It gives context to the position of each pipe and wire. When I, the modeller, know all of this, it helps to make my model better. I will be less likely to leave out or misrepresent a small detail if I fully understand why it is there, and why it looks different from the one on another locomotive of the same type.

Another possible resource is surviving prototypes. For builders of steam locomotives and other older prototypes, this is often seen as the Holy Grail of information sources. You might think if you can go and visit the original, and take pictures of it yourself, you will have all the information you need. I used to think so, but my research into the 9000s changed this view. There is one surviving 9000, number 9000 itself. It sits outside at the LA County Fairplex in Pomona, CA. That’s pretty far from where I live, so I have unfortunately never seen it in person. However, most of the photos of 9000s you will find are unsurprisingly of this survivor and Kratville and Bush dedicate a section to it at the end of Volume II. As a result, it is possible to get a pretty detailed look at it even without seeing it in person. They note, however, that the surviving 9000 does not have features typical of the type and, that some of its components were not even typical of 9000, itself, during its service life. For example, the driving wheels on axles 2 and 3 were replaced on most engines with Boxpok type wheels. There are historical photos of 9000 showing it with this modification, yet today, all of its wheels are of the older, spoked type. So the 9000 as it survives, may not be a great example of the whole class and, if you are interested in modelling a different number locomotive than the survivor, as I am, it may be a bad idea to rely too heavily on a different surviving example. Instead, use all the resources available to figure out what was most typical, or what features you would most like to model, and find an example of the type with those features. That said, go see the real things whenever you can! It may not always be the best information source, but it is certainly the most inspirational.

Kratville and Bush got most of their information from the archives of the Union Pacific Railroad and its historical society. Places like this are often not open to the public, but a quick call or visit to their website will tell you if it is possible to make an appointment to visit. If going to a place like that is a reasonable option for you (in this case it was not for me) it can provide the greatest wealth of information on your prototype, though you will have to put it all together yourself!

While The Union Pacific Type has extensive plans in it, a more general plan book can serve as a great quick reference, and can provide inspiration for future projects. (because you needed more of those) I found this one for the Union Pacific, but searching around for “[Railroad] plan book” will likely provide results. Sometimes these may even be available online.

Now that you have gathered together all of your various research resources, make sure to keep them on hand! Refer back to them frequently. Keep a selection of your most useful images right where you are working. I find it’s very easy to lose track of some small detail if you don’t have your plans and photos handy.

Having completed my research, I decided to model locomotive number 9087, the highest-numbered unit of the class, and part of the last order, delivered in 1930. I chose it for a couple features I found specifically in photos of that engine, and for some features which are not so easy to see. First, as mentioned above, the 9000s were at some point given Boxpok type wheels on the second and third driving axles. Not every engine ever got them, or had them on both axles at one time, as the maintenance department generally used up existing replacement parts before making a mandated change. 9087 happened to be an engine which was photographed with Boxpok drivers on both axle 2 and 3. I really like this look, and also like that it represented a technological upgrade for the engine. We will look at my solutions for drive wheels in a future installment. Additionally, the 9000 class had several different types of sand delivery systems for the driving wheels. Initially, not every driving axle had its own sand line, but most engines were ultimately upgraded to give sand to all 12 driving wheels. 9087 did get that upgrade, and I really like the look of all the angled sand pipes. You can see remains of this system in the picture of 9000 above.

In terms of what you can’t see, 9087, along with the other locomotives from that last order, called UP-5, had single piece cast frames and cylinder assemblies, while the previous 9000 orders did not. In terms of making a LEGO model, this makes little aesthetic difference, but on the actual engines it provided a significant performance improvement. Originally, the three cylinders were cast as two pieces, with the right and center cylinder cast as one piece, and the left cylinder cast as a separate piece, and the two were bolted together. The 9000s use Gresley valve gear to actuate the middle valve based on the timing of the outer valves. Because the cylinders were made in two uneven halves and bolted together, the distance between them could change slightly, and even a tiny deviation threw the valve timing off. Ultimately, all the 9000s with this two piece cylinder assembly had to be upgraded to a single piece casting at great cost. Additionally, the connection between cylinders, driving wheel frame, and the separate frame casting for under the firebox had to be structurally reinforced in several places. The single piece frame-cylinder castings on the UP-5 locomotives never needed these changes. I was drawn to the UP-5 locomotives because they represented the best that the 9000 class ever was.

So, to conclude, I would stress again the value of print resources. Model railroading is still kind of an old fashioned hobby, by which I mean the people who do it often prefer print media over the internet. Many also work very hard to assemble collections of pictures and information and justifiably want to publish them in a way so they can get paid a little for the effort. There are more resources available online every day, but as far as railroading is concerned, there’s still a long way to go. As a result, you will find things in books that you won’t find anywhere else, and you will learn more from them than you might expect. Sometimes, a picture is worth a thousand words, but it can be the other way around. Firsthand accounts of design changes, letters, memos, and repair documents can paint a picture of a locomotive that pictures alone cannot.

I know I haven’t said much specific to my project yet. I have made more progress than just doing some reading, but that will wait for future posts, because that’s how I have actually gone about it. I did all my research before I even touched a brick, and that’s how I usually do it. It helps me get even more inspired, and helps me to better understand where to start building.

Next time, we will look at aftermarket electrical components that are changing the way we build LEGO trains, and how I am going about building them in to my model.

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