U6B

This has been and continues to be an interesting project. Small GE engines have fascinated me since the vacation my family took to the Owens valley when I was a kid. The SP narrow gauge 50 tonner was working in Owenyo the day we were there. My dad had worked the branch as a brakeman off the extra board in Sparks, Nevada and he was a modeler of great skill. For him, this was a research trip, it was just fun for the rest of us.

When I began research for the U6B I found both too little and too much information. Too much because there are thousands of small GE engines out there and an awful lot of them look alike which confuses identification. Most photo’s are captioned by tonnage, an odd measure of a locomotive to my way of thinking but probably sparked by the 44 tonner which had political and management implications. The other weights of locomotives didn’t and they tell us very little about them.

A search of the internet turned up very little about the U6B except a fine web site from South Africa on a variation of the engine with a short hood and very different trucks the likes of which I have never seen and which bear no resemblance to the “stock” plate type that seems to be typical of the breed. There are many references to the U6B and vague references to a mysterious U4B but precious few photo’s and no drawings beyond a couple of general arrangement sketches with no top views. Every drawing sports different dimensions!. Most photo’s show different door arrangements and vent positions. No photo that I have seen has ever shown a hand brake. GE’s big engines locate the handbrakes on the engineers side of the unit somewhere so I will make that assumption but can’t back it up with fact.

I quit trying to get any info out of GE a long time ago. Once they discover you are not a big time potential corporate customer they treat you like the plague.

All this makes me wonder if the U6B designation was just a handy designator and not really a catalog standard model. They were mostly export models and I assume pretty much custom built to order. So I decided to custom build a couple for my railroad. Trying to ferret out a single engine and duplicate it would be more than a monumental task, at least for me. Where would I find one? I remember when I was working the Plaster city job many moons back, the USG engines. Thought I’d struck gold. Someone told me they were U6B’s. Not. Nor were they U4’s but a custom built unit just for USG. They were awful cute. I watched the “roundhouse” guys rebuild those things after wrecks and they modified the snot out of them. Welding things here and there didn’t bother them in the least. What a liberating idea. That experience gave me a little license when it came to building these models. My RR is something akin to USG. It will haul salt instead of gypsum rock but the idea is the same. A single owner, single commodity modern narrow gauge though this one is a common carrier. No run down junk or wood cars or even cabooses. There is a 2-6-0 in the back shop for a future tourist operation but that is sometime down the road.

In other words I’m going to sort of fake it and make up excuses for anomalies that show up by claiming my railroad either custom ordered them that way or modified them after wrecks or during routine maintenance. I am making no claims that the models are an exact replica of any U6B in particular but rather a good realistic interpretation of the breed that will stand a general and logical inspection.

You’d think that after many years of bad experience with the big U-boats the last thing I’d want to model would be a baby one. The big ones were rough riding, nasty things to deal with. They loaded slowly and had weird two foot long throttle handles and skinny little reverse levers that were really easy to drop into dynamic braking by accident. So much so that they were dangerous. On top of which the SP didn’t maintain anything. Not GE’s fault, of course, but U-boats didn’t fair well under those conditions. With their cast engine blocks and overprotective shut down features, when they quit, they were done. There was no nursing them along. The cast block was too expensive to risk ruining. They quit a lot.

EMD didn’t make small narrow gauge engines that I know of that will fill the gap I need for power. Narrow gauging a Geep would not work as they are too heavy to run on really light rail and I’m not sure you could adapt GE trucks to a Geep chassis without major problems. It might really cause more problems than not with interfacing the generator to the traction motors etc. It just doesn’t seem plausible to me. And I know of no prototypical precedent.

I think lower speeds would make the ride on these smaller engines a moot point and they were powered with Cat prime movers. I’d be willing to bet without having ever seen the inside of the cab of one that the control stand is a clone of the big U-boats, 2 foot long throttle handle and all.

I began the actual construction by making drawings based on the available ones on the internet. I settled on a frame length of 31 feet. Other drawings showed variations up to 33 feet. Frame width of 8’6” which will result in an overall width of 9’. The Extra 6” is mainly taken up by grab iron clearances.

I transferred the basic frame drawing to a lamination of two layers of ¼” MDF and the glued small blocks of MDF I cut on my table saw to make an assembly fixture. The basic frame is made from 3/16” square brass bar stock. As you no doubt can tell by the scorch marks in the photo’s I used a torch to sweat solder the thing together. Keep water on hand to put out the fire!. I think the fixture will stay accurate enough to make maybe three brass frames. I intend to build the second one in styrene so I can get at least three locomotives out of this set up I hope. Maybe a resistance set up work a lot better but as little as I would use it I don’t think it is an investment I am willing to make. If you don’t use a torch you’d have to use a pretty big wattage iron to do this . My 75 watter was not very effective. You’ll notice that the blocks are also nailed down. When I glued them I used CA and I was concerned they might come loose when things got hot. They are tiny aircraft brads. I had them on hand. (I used to build full sized airplanes too. If you can’t find them locally they are available from Aircraft Spruce and Specialty.com) Or you can just take a chance or use another kind of glue. Maybe a slightly bigger brad and pre drill the holes. Take your pick.

The frame came out absolutely flat and square. I cleaned it up with a mill file and sand paper mounted flat on the bench. The bolsters will be made out of .093 sheet brass drilled for a screw and the frame tapped to receive that screw on the underside. Once I start to laminate the styrene details to the frame soldering or unsoldering things will no longer be an option. The truck mounting locations may be a problem with drive details as yet solved and truck details yet to be determined and the fact that I am still wanting to upgrade the Athearn power truck to a more proto 48 arrangement.

I am very happy with the under frame. It is very hefty and strong. The styrene version will have to have cerro bend added to it to provide tractive effort. I think I will probably add more weight even to this frame. My old 44 tonner frame was all styrene and was very strong but light. I used brass bar stock to get it up to weight but it was never really satisfactory in that regard. Casting weight into an all plastic engine is really the only way to go.

I got the basic styrene floor cut and ready to install along with the end plates although they have a lot of work left to do before installation. A Grandt Line order was sent today for many detail parts needed for them. NBW’s, eye bolts etc..

The truck side frames and equalizer masters are completed and ready for casting. I’ve done this before but it has been many years ago. Now that I’m finished I can think of a better way. Next time I will leave the journal boxes off and make a separate master and I will try photo etching for the rest of the flat pieces that are typical of GE trucks. I’ve never personally done any photo etching though I had some custom work done for me when I was in N scale. It would be fun to try something new.

I tried to make some springs out of .030 styrene rod by heating it slightly and wrapping it around an 1/8” brass rod I’d oiled. That part worked real well but the instant I touched plastic cement or CA to the beautifully formed spring it literally exploded ! I guess the tension bound up in the coiling process was released instantly when the chemicals softened the surface. I suppose if the proper amount of heat was applied the plastic would take a set but I don’t know what that temp is and until I do I’ll probably stick to brass springs. The plastic ones sure looked good for a short while anyway!

As mentioned on the group e-mail the trucks are Athearn SD40-2 units with the middle axle removed. Take out that middle axle! Don’t just pull the wheels off as I had some binding followed up by seizures as the gears wobble way too much without the stabilizing effect of the wheel sets actually touching the rails. The wheelbase that results is reasonably accurate for the U6B. There is a cool web site that shows step by step how to tune up the Athearn drive units to perform really well. It is the NMRA’s central division web site. You’ll find creative new uses for toothpaste. In my case I’m going to have to build a new drive unit above the gear towers because of clearance problems. The towers are not tall enough to clear the frame and the locomotive is much longer than the original drive unit. With all the goodies available from the model manufacturers these days I don’t really see a problem. I am complicating things somewhat by insisting on showing engine room details but someone a little less nutty wouldn’t have any difficulty designing a drive train with available parts.

The trucks are a very simple design, come apart easily, are simple to understand and reassemble. No one should have too much problem with them. Athearn sells the whole power truck as a separate component and all the separate pieces for really cheap prices direct from the factory. If you break something don’t sweat it. While they claim a six week delivery time I have never suffered for more than 10 days.

I have, as of this writing, e-mailed NWSL to enquire about a custom built set of replacement ½ axles with their proto 48 36” wheel sets which is prototypically correct for the U6B. Waiting……..

After a long and enlightening discussion on the FinescaleOn30 Yahoo group I have decided to use the HO standard coupler height with On3 couplers. Kadee sells a coupler gauge for just that situation. How ‘bout that! Soon as I get to it I can start chopping plastic on those end plates!

About my railroad: It doesn’t exist….yet. I have had a number of layouts from O standard to N. My most successful and biggest was On30 in a separate building at my old home in Yuma, Az. It was powered by what has become known as “critters” though I really dislike that term and my trusty old 44 tonner. About 20x30 feet, in two rooms. It was torn down for a divorce and most of the equipment was lost when the house was sold.

We are in the process of moving again so no new construction has or will be started until we are settled in our new Oregon home. The desert has become a drag and I need the ocean for my boats. It will take a while so even the name, Tucson and Baja Northern, may take on something of a regional shift in emphasis. I am more or less committed to the theme of modern narrow gauge though as I think it offers fertile ground for exploration an and unending march forward in time frame in much the same way Eric Brooman treats his Utah Belt. In addition I am going to try something a little different by introducing social and political commentary into the core of layout itself. It will be done in very subtle ways but the message will be clear if you are willing to look. It should be useful to advance the dialog in a civil manner as well as fun.