TSG Multimedia - ATSF 3854

ATSF 3854

November, 2009

Please do not redistribute without permission. Usage Info

Athearn GP50, ATSF 3854

Back in the days when the only way to get a plastic model of a GP60 was to kitbash one from an Athearn "blue box" GP50, I built a model of SSW 9642. While I thought it turned out pretty good at the time, since then my skills have improved and better models have become available. A few years ago I got a sweet deal on a trio of Proto 2000 GP60s on eBay, two Southern Pacific and one Cotton Belt. I used one of these, SP 9735, in HO DCC Installs Volume 2.

Compared to the Proto 2000 GP60s, my kitbashed model no longer looked so good. The side sills are one width for the entire length of the locomotive, for one, not varied like an early GP50. The hood doors aren't really correct, either. Also, this model had a standard Athearn "blue box" cab, which looks clunky to me now, especially the oversized molded-in arm rests. The battery boxes could have been better, too.

I had used aftermarket truck sideframes on this model, and from day one they never wanted to stay on. I would run it around the layout I had at the time and more often than not, it would shed one or two sideframes somewhere along the line.

Because for some reason I didn't want to part with this model, I decided to do something else with it. When I bought it, the model was painted as a Santa Fe GP50. There was even some yellow and blue paint still stubbornly clinging to the inside. I thought, why not put it back the way it was?

Would it have been easier to put this thing on eBay and start over with an undecorated model? Of course, but that never stopped me before. I stripped the body of useable parts and threw the shell into some Scalecoat Paint Remover. One good thing about these old Athearn shells is that most hobby chemical paint strippers don't bother them at all. There was still a bit of paint clinging to the steps and a couple other spots, but that wouldn't matter because those parts would be removed anyway.

I used the SP plow and a few other parts on another of my Proto 2000 GP60s, Cotton Belt 9663, so very little was wasted.

Since this model was already fitted with a Cannon angled blower housing, I decided to keep that part. This meant that I would need to turn the model into a late-production GP50. For better realism I wanted to use a Cannon cab, nose and battery boxes.

I made a list of all the stuff I would need to change. Santa Fe's later GP50s also had straight side sills like a GP60, so I would need to modify those. The step wells on most GP50s look different than the ones on the Athearn model, so those would have to go. The hood doors, correct for an early GP50, would need some modification.

Luckily I had saved the original GP50 dynamic brake hatch, so that could go back on in place of the aftermarket GP60 hatch that was on the model before. I bought a Cannon dynamic brake fan for that, but decided to keep the molded-on "Q" fans as I have not been that impressed with any of the aftermarket "Q" fans that I have seen.

I trimmed the steps off and did some filling and sanding on the pilots before removing the battery boxes, as once that's done the front part of the shell is extremely fragile.

Santa Fe's late GP50s had no class lights or number boards on the end of the rear hood. I was faced with either having to get rid of that stuff and fill it, or replacing the rear hood end. I chose the latter since Cannon makes the part and I thought it would be easier than trying to fill and sand around all the other details on the stock hood. While I was at it, I also trimmed off the original inertial filter hatch so I could install a new Cannon part.

I bought new brass pilots from Railflyer Model Prototypes, but after thinking long and hard I decided not to use them on this model. For one, they are designed with exact-scale coupler openings, which are too small for Kadees. This is one of those times where operation takes precedence in my book. Also, the Railflyer pilots are basically just a sheet of brass with some holes in it, and I saw no easy way to fit them to the model without creating even more work for myself. I was concerned about strength, as the Athearn pilots have some reinforcement behind them and I would have to get rid of that to use the Railflyer pieces, plus I would have had to redo the coupler mounts.

Instead, I just used the Railflyer parts as a template to cut holes in the stock pilots in the appropriate places. Other than being a hair too thick, the plastic pilots look just fine to me.

I did decide to use Railflyer steps, as they make a set that is spot-on for ATSF GP50s. These are nice see-through photo-etched parts, a little tricky to assemble but they look good when done.

The steps have a brass top plate that would have to be recessed into the deck. Since I didn't have any good way to mill .010 worth of material off the top of the deck in selected spots, I decided to remove the top plate and just glue the new steps into the existing plastic deck.

It took quite a bit of time but I finally got the steps mounted to the model. Doing so required quite a bit of patience and perserverance, and despite my best efforts I broke one of the step wells along one of the fold lines and had to solder it back together. Despite all that, they do look good.

I used CA type glue to join the brass steps to the plastic shell, but I was concerned about strength, especially if someone were to grab the model by the steps to lift it. I reinforced them with some bits of styrene from behind. The triangular gussets brace the steps against the pilot, while smaller pieces of plastic support each step underneath where it attaches to the pilot. I glued the reinforcements to the plastic shell with solvent-type cement, then used some CA to join them to the brass. Once all that was dry, added some epoxy in spots for additional strength. The steps are fairly sold now, though I am still careful about handling them. They were way too much work to break now out of carelessness!

I mounted the new Cannon long hood end and fitted the Cannon engine compartment doors. I had to reinforce the doors from behind with some sheet styrene for strength. Gluing on the Cannon cab and cab and sub-base was a priority since it restored structural strength to the front part of the locomotive body. The nose is not yet glued. I will wait until after painting to do that since it will make masking easier. Many of the smaller details are also in place, like class light blanks (BLMA), anticlimbers (Cannon), and uncoupling levers (Detail Associates). The Santa Fe nose headlight is in place and drilled to accept .030 fiber optics. The Cannon blower duct is leftover from when the model was masquerading as a GP60.

I installed a Cannon diamond-plate tread kit on the model. The kit is for a GP40-2, but it was the closest I could find. I had to do a little filing, mostly around the hood ends, for a good fit. The material is very delicate so it has to be handled carefully when making modifications. Also time-consuming but worth it was the installation of Details West air reservoirs, air filters, and plumbing. There are also Details West traction motor cables on the frame, though these are not too visible.

The base for the Cannon dynamic brake fan is mounted and I reattached the dynamic brake housing. There is a weight that fits under this part and I glued that back on and painted it Santa Fe blue before installation of the dynamic housing. I also brush-painted the fan base the same color on the inside since it will be impossible to paint the underside later. I mounted an A/C unit on the roof and Details West M/U cables on both ends.

I removed the truck sideframes so I could strip and repaint them silver. I also removed the fuel filler pipes and sight glasses from the fuel tank, as these were in the wrong positions for a Santa Fe GP50. I will need to reinstall those before painting the tank.

The next thing is the roof. The locomotive has one large and one small antenna stand, and I want to make these out of brass or something durable so they will stand up to normal handling.

There is still a lot of work to do, but at least this is starting to look like a locomotive again. I always feel like I've turned a corner when the destructive phase of the project is over and the constructive phase has begun. I will update this page as I make more progress.