Norfolk & Western's triple clasp GEs

Norfolk & Western may be best known as the last railroad to retire their steam locomotives and replace their locomotive fleet with diesels. In the diesel era they were known as one of the last railroads (along with future merger partner Southern Railway) to purchase high short hood locomotives. When other railroads had embraced the idea of using a J-relay valve in the locomotive's independent brake system to produce greater brake cylinder pressure against a single brake shoe per wheel, Norfolk & Western stayed the course of using clasp type brakes and lower operating brake cylinder pressure. Evidence of this could be seen in the trucks used on N&W's six axle diesels. The twelve brake shoes per truck gave them a distinctive look.

I modified a couple Athearn SD40-2s to have clasp type brakes a few years ago. I covered those models in my blog here. The modification to the Athearn trucks is pretty easy and it can be done using either Blomberg trucks or Flexicoil switcher trucks to donate the brake shoes, although the Flexicoil switcher trucks will also provide the brake cylinder with the long push rod. It also helps that the Athearn sideframes are made from styrene, which is easy to cut and splice and glue together.

Triple clasp sideframes on Athearn RTR SD40-2

It's another story entirely if you're modeling anything GE, with the exception of the last order of C36-7s. In fact, not having the ability to model the Adirondack clasp type sideframes found on N&W's U30Cs, C30-7s and early C36-7s is the reason I chose to model one of the later C36-7s. Atlas originally made two different sideframes for the U33C and C30-7 models, which they called GSC and Adirondack sideframes after the casting foundry of each prototype. However, Atlas mislabeled the parts which caused great confusion for people trying to get the "correct" version for a particular model.

Atlas GSC C30-7 sideframe

Atlas Adirondack C30-7 sideframe

When Atlas came out with the U30C, another style of sideframe was offered. This time it was a later Adirondack sideframe with low mounted brake cylinders.

This style of sideframe holds the most promise for someone wanting to build some N&W clasp style sideframes. It has the correct shape overall as well as in the area over the brake cylinder lever. Unfortunately the brake cylinder lever at the top of the sideframe exists only to tie onto the handbrake chain, so this shape is only found on the left axle when looking straight at the sideframe. You'd need this shape along with a mirror image of it to cut and splice these sideframes into models of the clasp type, and that's assuming you could actually get the slick engineering plastic the sideframes are cast in to glue back together.

These sideframes, like the National Uni-Truck II (found on some Trailer Train Front Runners, Southern's Autoguard articulated autoracks and under the ends of Burlington Northern's Trough Train articulated coal hoppers) represented something of a holy grail for me. Once I became familiar with the idea that 3D printing could reproduce fine enough details in a durable enough material for modeling I knew I had to take up the challenge to create a CAD model of them.

It's one thing to decide to make a 3D model of something rare and unique and quite another to find enough reference material to make it happen. What was frustrating about these sideframes (and the Uni-Truck II) was they really weren't that rare, they just weren't considered worthy of film during their day. In the digital photography age you just click!-click!-click! until you get the shot. When everyone was shooting film unless you had it in mind you were going to burn a roll or two on detail shots you took your best shots only, well-composed and well-lit. Roster shots of good and poor quality abound from the film era and are easy to find online from a variety of sources. But detail shots of the kind I needed are not so easy to find. If these prototypes still existed in their as-built form today it would be a simple matter of tracking them down and taking some detail photos.

That's actually how the story ends for the National Uni-Truck II. There is a single example of a Front Runner equipped with National Uni-Truck II trucks at the National Museum of Transportation in Kirkwood, Missouri, TTOX 130059. Detail photos of this car provided the information I needed to create the CAD model of the trucks that I ended up printing and offering for sale in my Shapeways store.

3D printed National Uni-Truck II trucks with Intermountain wheels installed on Walthers Front Runner

With the Norfolk & Western U30Cs, C30-7s and C36-7s I wasn't as fortunate finding an example to photograph. I'm not certain on the disposition of all of these locomotives, but many that I've found were shipped overseas after their useful lives here in the United States. Once they arrive at their destination it's not uncommon for them to be converted to a B-B B-B configuration and have the C trucks discarded. I put out a request for photos on discussion forums and email lists a few times over the years but I didn't get a response. That is until the very end of 2017 when Jay Barnaby and Scott Marion hooked me up with some detail photos from their collections. These turned out to be the shots I needed to create 2D drawings.

Some discussion on this topic with Andy Harman was very helpful, too. With the straight-on shots taken care of it became a priority to determine the depth of the features: how much did the brake cylinders protrude from the sideframes, how far did the reinforced section over the center axle protrude, and so forth. More photos were shared and analyzed. And finally in the midst of reverse-engineering the Atlas sideframes to create a drop-in fit of a sideframe I had enough to develop the 3D model.

Here's where I screwed up (there's always that part): I created what may be a perfectly reverse-engineered 3D model of an Atlas GE three axle sideframe. Then I proceeded to install brake rigging on the base sideframe model that fouled the copper pickup and bearing strips that held the axle ends in place, thus preventing the installation of the printed sideframes. Well, that's what prototyping is for! (that's what I tell myself when I screw up with a design) What I should have done is create a 3D model of the truck with the copper pickup strip and checked the fit of the sideframe into the truck model in CAD, not after printing the design. Fortunately, I didn't have to modify the back side of the sideframes much and there was still enough material to hold the brake shoes and levers in place after I removed the material fouling the copper strips. I immediately revised the CAD files to remove this interference.

First printed prototype U30C and C30-7/C36-7 sideframes

Spending all this time working on these clasp sideframes helped me get to know both the Atlas model and the prototypes pretty well. One thing I found interesting about the Atlas model -- and I'm not sure what the reason is for this little nugget of joy -- is the axle spacing in the C truck found on the U33C, C30-7 and U30C. I'm sure it has to do with the prototype of the U33C or C30-7 trucks originally tooled in the 90s by Atlas. The difference is so minor that it probably just wasn't worth addressing when it came time to release the U30C. But it is significant enough that putting the wrong sideframe on the wrong truck will result in a sideframe that won't fit without modification. You'll also notice the bearing detail isn't centered on the center axle and wheelset.

On freight cars there is a B end and an A end. Looking at the B end you have a left and right side. Axles are numbered from the B end to the A end. Similarly, locomotives have a front and a rear. The front is designated by a letter "F" stenciled near the stepwell on the sides of the locomotive nearest the front. Ever the oddballs of the bunch, some Norfolk & Western and some Southern locomotives had their long hoods designated the front, which is in contrast to nearly every other railroad. Fortunately on these GE six axle units the front is the short hood where the operator cab is located. So, when you're looking at the front there is a left side and a right side. Axles are numbered from front to rear.

The prototype uses trucks with a wider spacing between axles 2 and 3 and a narrower spacing between axles 1 and 2. On the rear truck this arrangement is mirrored on the U30C and C30-7, with the greater spacing being between axles 4 and 5 and the lesser spacing between axles 5 and 6. The prototype C36-7 has the same front truck axle spacing as the U30C and C30-7, but the rear truck is reversed. It is not mirrored by the fuel tank. Instead, the front truck is identical to the rear truck. That is, the distance between axles 1 and 2 equals the distance between axles 4 and 5. Likewise, the distance between axles 2 and 3 equals the distance between axles 5 and 6.

The axle spacing on the model is just like the C36-7. This means on the model there is a distinct front truck and a rear truck; the axle spacing is not mirrored by the fuel tank.

If you look at prototype photos of U30Cs and C30-7s, the brake cylinder over the center axle points toward the fuel tank and toward the brake cylinder over the axle nearest the fuel tank. The axle spacing is greater between the two axles with brake cylinders pointing at each other than the spacing between the two axles with brake cylinders pointing the same direction. So if you're following this convoluted description, there is a problem. The axle spacing of the rear truck on the Atlas model will not work with the U30C and C30-7. The Atlas model is actually perfectly set up for the C36-7 since the brake cylinder over the center axles points toward the rear of the locomotive and the axle spacing matches the prototype. But to accurately model the trucks on either a U30C or a C30-7 the rear truck must be a mirror image of the front truck. The easiest way to do this is to replace the rear truck with another front truck. Fortunately, these truck gearboxes are easy to come by direct from Atlas. [Kudos to Atlas for continuing to make parts available and for making them inexpensive. I owe a lot of my GE kitbashes to being able to get Atlas parts.]

I figure that of the handful of others who wish to model N&W U30Cs and C30-7s, only a few will be willing to swap out the rear truck for another front truck. So for those who want to keep the drive stock and simply swap sideframes, I've made a version of the clasp sideframes set up to fit the Atlas drive as-is. For those who want to go crazy and swap rear trucks, I've made a version for them, too.

Finally, here is an image to describe the problem and solution. The sideframes depicted below illustrate the modified parts designed to fit an Atlas model that has not been modified with a front truck replacing the rear truck.

To accommodate the model, the sideframe depicted in the bottom of the image has been modified to match the axle spacing but have the general arrangement of the prototype. You can see the slight difference in distance between the brake cylinder cutouts over axles 2 and 3 and over axles 4 and 5, with 4 and 5 being closer together. On the prototype C30-7 and U30C, the bottom truck should be a mirror image of the top truck.

I'm exhausted from explaining that. You can imagine how exhausting it was to discover during the design process and create a solution for it.

After going through all that, I'm going with the extra front truck on my C30-7 model. Here are the C30-7/C36-7 sideframes:

And here are the U30C sideframes:

Printed Adirondack sideframe compared to Atlas GSC sideframe

One benefit of working up these sideframe designs with such a limited audience is I realized this basic Adirondack design was found elsewhere, namely on early C30-7s purchased by Union Pacific and the C36-7s purchased by Missouri Pacific. It didn't take much effort for me to modify the design to match each prototype.

screenshot of Adirondack sideframe CAD file as seen on early Union Pacific C30-7 locomotives

screenshot of Adirondack sideframe CAD file as seen on Missouri Pacific C36-7 locomotives

One of these days I'll try to run down all the prototypes that used some version of this basic Adirondack truck casting...

GP60 Demonstrator EMD 7

When EMD introduced their four axle 60 series to the world, they did it with six demonstrator locomotives painted in the attractive blue and white scheme worn by the SD60 demonstrators and later the Oakway SD60 lease fleet. The three GP59 and three GP60 locomotives had another feature not seen since the GP30: an aerodynamic cab with a pointed cab face. The hood corner radius of the nose was increased from the standard 4" to 9" and the standard 4" radius was applied to the leading edges of the cab. The effect of the streamlining was a striking appearance, accentuated by the color scheme.

The demonstrators made their way across the Santa Fe and Southern Pacific systems among others. In an attempt to make the locomotives ready to serve any railroad they were equipped with many of the options specified by different railroads, including a variety of different fuel fillers, extended range dynamic braking, a cab air conditioner, auxiliary warning headlights and a UDE light.

The extended range dynamic braking hatch was larger than on previous models and protruded about a foot from the hood sides. The rounded edges and sloped faces of the streamlined cab were continued to the dynamic hatch. Although none of the railroads that purchased production GP59s or GP60s opted for the streamlined cab, all were equipped with the large dynamic hatch. Eventually the streamlined styling of the hatch was discarded for a much simpler to fabricate version with squared edges and flat faces. No production GP59s received the streamlined dynamic hatch, but ATSf 400-4019, SP 9600-9619 and SSW 9621-9634 were so equipped. All others had the later, angled hatch.

After the demonstrators made their case for EMD to the prospective railroads, the GP59s were sold to Norfolk Southern and the GP60s were on a long term lease with Southern Pacific. Eventually the GP60s were returned to the lessor, sold to another lessor, then finally sold to CSX as their 6897-6899.

I modeled one of the demonstrators by drawing the hatch and the cab/nose combo in AutoCAD, then 3D printing the model through Shapeways. I applied the parts to a factory painted Life-Like Proto2000 GP60 model. I had to shorten the fuel tank at the rear to better match the prototype, but otherwise I just painted and decaled the new parts to match the factory paint, added a few fuel tank details, a new horn, and some cab mirrors.

I sell these parts on Shapeways, along with many others, and one of the modelers who purchased these parts noticed an error in the dynamic hatch with the size of the exhaust. Wouldn't you know it, I transposed some numbers while drawing the part. I have since revised the dynamic hatch, but at this point I have not replaced it on the model. Thanks to Roderick Quebral for his keen eye and help with this hatch and the SD40-2 hatches I drew in recent months.

GE Universal Series/Dash 7 Series Cab

From the U33C and C30-7 models released in the 90s to the U30C, U30B, B23-7 and B30-7 released in the 2000s to the newly released U33B and U36B, Atlas has done more than anyone else to fill holes in the rosters of those modeling GE locomotives of the 70s and 80s. To a large extent Atlas gets these models "right" as far as dimensional fidelity to the prototypes is concerned. Having said that, one area Atlas has fallen down is the cab.

I've read where others have pointed out the issues with the Atlas cab but I couldn't ever find any hard data on what was wrong. The front face of many of the cabs looks wrong - windows too small, windows too big, funny shaped doors, numberboards and headlights that look squeezed or in the wrong place. Nothing about the cabs seems right, but what specifically is wrong? Then there's the Hi-Tech cab, a nice little kit with several options. But I've read people have issues with it, too. So who got it right?

First of all, I set out to find some hard data on the prototype. First choice would be some nice straight-on photos of the cab and some overall measurements. I figured I could proportion out the dimensions of the windows and numberboards with the right photo and a good known measurement. The problem is you're not likely to find a position to photograph a locomotive cab where anything is straight-on since most photos are taken from ground level. Eventually I found Bill Kaufman's locomotive simulator website which features some cool simulators he built using old GE cabs. I asked him if he could measure across his simulator or provide me with a photo taken straight-on. He did one better than that, way better. Bill shared with me some cab drawings from GE that answered all my questions. I was able to create my own CAD file from the scans Bill provided. I also made CAD files of the various Atlas and Hi-Tech cabs.

The early U33C models came with one of two cabs: standard front face window arrangement and SP "L window" arrangement.



The first run C30-7s had cabs with open auxiliary side windows or the later version without the auxiliary windows.



Between the two models all the cabs had windows that were off in size and location. The most obvious issue was the top of the cab door and top of the engineer's front window were even with the top of the center windows. The size of the numberboards and both the size and shape of the headlight housing was also off. The shape of the door differed between the front and rear cab face (Atlas seemed to execute the door better on the back of the cab than the front though the size of the door window was off).



The second run of C30-7s addressed the position of the windows, but they were still undersized. The rounded headlight housing was squeezed too thin and was undersized.



Across all of these versions of the GE cab, the central rounded portion of the roof was too wide and the angled outer portions were flat instead of rounded.

Hi-Tech made several detailed GE cab kits similar in design to Cannon's line of EMD cab kits. The flat kit design incorporating thin walls, separate doors and detail parts made it easy to build a nicely detailed kit.



Hi-Tech also offered a version of the four window cab with plugged auxiliary windows, an effect not convincingly pulled off by Atlas when they simply painted over the glazing in the auxiliary windows.  I corrected this on some of my Atlas cabs by cutting in the Hi-Tech cab sides:



In spite of the nicely executed details and well proportioned windows of the Hi-Tech cab, the roof suffered from the same problems as the Atlas cabs from the U33C to the C30-7 to the U30C, only with an even wider central curved section. The narrow numberboards were also a problem with the Hi-Tech kit.

When Atlas released the B23-7 and B30-7, the cab was a new design unlike the models preceding it. The numberboard/headlight housing was a separate part, the cab base on the engineer's side had a noticeable difference in height just as the prototype and the proportions of the windows, cab doors and roofline matched the prototype much closer than previous attempts.



The headlight housing is still too narrow and the headlight assembly is mounted too low between the numberboards, but still not bad.

Before I get too far ahead of myself, let's take a look at these cabs and compare them to the prototype. In light of the errors in the cab windows of the first C30-7 cab, it's not even worth considering. But the later C30-7 cab, the Hi-Tech cab and the B23-7 cab are all worth looking at.

Here is a drawing of the prototype overlaid on a drawing of the Atlas 2nd run C30-7/U30C cab. The prototype is in green, the Atlas cab is in red:



Here is the prototype, again in green, compared to the Hi-Tech cab in blue:



And finally the Atlas B23-7 cab in purple compared to the prototype in green:



So, between the three, the Atlas B23-7 cab is good enough, right?

I'd use it if I could.

Trouble is, like the B23-7/B30-7 fuel tanks, the cabs aren't readily available as spare parts from Atlas. So what to do if the one good cab isn't available and all the others that are readily available have serious issues?

I initially thought I could cut in the good parts of the Hi-Tech cab into the Atlas U30C cab. But there's really no way to get the side walls of the Atlas cab thin enough to allow the front and rear Hi-Tech walls to fit without a ton of work. Then the roof is still wrong. And I'd still need a source for the numberboards since as bad as the Atlas numberboards are the Hi-Tech numberboards are worse. I wanted to avoid 3D printing not because of the quality possible but because of the cost. I figured a detailed printed flat kit like the Hi-Tech kit would cost around twenty bucks, which means I would be spending hundreds getting my fleet up to par. But as long as the Atlas B23-7 cab is so hard to find, it seems like printing is the next best solution.



An advantage printing the cabs offers is the ability to create versions of the cab that were specific to particular locomotives, such as the Santa Fe B23-7s with nose-mounted air conditioners and antenna ground planes or Southern Pacific's "L-window" cabs that were fixed to accept two panes of glazing in place of the single large L-shaped glass. The other advantage is the cab isn't close to the prototype, it is a scaled down version of the prototype. The green outline in the prototype vs. model images is not just the drawing of the prototype, it's the CAD file I used for the model. So aside from the limitations presented by the materials I'm using to print the cabs, these things are as close as I can get to the real thing.

Here are a few shots of the first printed prototype:







Compared to the Atlas U30C cab:





3D printed GE cabs in several variations are for sale in my shop at Shapeways:

https://www.shapeways.com/shops/he6agon?section=Diesel+Cabs&s=0

SP B36-7 7766

So while I was working on the Cotton Belt B30-7 I decided to reuse the original cab to build another Southern Pacific locomotive. At the time I was just beginning to learn about the evolution of GE diesels in the Dash 7 series. Michael Eby covers four-axle Dash 7 phases on his website Trainiax. According to Trainiax, the overall length of the locomotive changed from 62'-2" to 61'-2". The difference could be seen in the position of the stepwells relative to the end of the short hood and the long hood.

Truck centers are another detail that changed throughout production. This was a trend that continued through early Dash 8 production as the series was developed. I don't have the ability to cut up or mill diecast frames and I certainly don't have the ability to put them back together. Well, not square anyway. What I can do is design and print a new frame.

I would love to be able to print in metal, and several metal materials are available through Shapeways, but size, cost and printing tolerances make it impossible at this time. Maybe later. Instead, I printed the frame in Shapeways' White Strong and Flexible nylon. It's a pretty strong material if the walls are designed thick enough. Detail isn't much of an option with this nylon material, so I designed it to accept an Atlas B30-7 fuel tank. Unfortunately, when I placed my parts order with Atlas these were unavailable. Back to the computer to design and print a fuel tank. I also worked up some new air reservoirs for another project.

In light of the difficulty I had obtaining an Atlas fuel tank, I figured I'd design the frame to accept Athearn trucks and drive shafts. I have a few trucks on hand already and the drive shafts come in a variety of lengths. The only trouble is the Smokey Valley sideframes are terrible. Atlas FB-2 sideframes from the original Kato/Atlas U23B aren't that great either, but they are better. The current Atlas B23-7/B30-7 sideframes look much better. At some point I'm going to have to come up with a version of the frame that accepts Atlas trucks. For now, I'm going with the tolerable Smokey Valley sideframes. Here are a couple shots of the frame:





To construct the B36-7 shell I simply cut down an Atlas C30-7 shell removing a portion of the auxiliary cab behind the operator cab and toilet compartment (the area between the second batten strip behind the cab and including the third batten strip from the front). I replaced the exhaust with a Hi-Tech part and added the gyralight/UDE light mount on the rear. I also added some Hi-Tech grilles to the radiator doors and scratchbuilt a cabinet to place behind the conductor's rear window on the walkway.

The sill is an Atlas part cut down and shortened at the stepwells. The door under the walkway on the conductor's front corner of the cab was replaced with one made from styrene to match the other doors. The modified C30-7 shell and nose were glued to the shell since the mounts for the B30-7 sill and C30-7 aren't compatible. The cab is removable at this point. Speaking of the cab, even though the front windows were correct for the B36-7, the locomotive was delivered without the auxiliary windows so those had to be filled in. I used Bondo spot glazing to do the job. After painting the cab I could see some shrinkage around the window perimeter. I went back and filled them in again and touched up the paint.















I still have more work to do, including the handrails. I was able to keep the end railings, but with the shorter overall length it's not possible to reuse the Atlas side rails. I'll make new ones from Utah Pacific stanchions and brass wire.

This project started off with a cab. The GE Universal series/Dash 7 series cab became something of an obsession for me throughout the second half of 2017. More later.