Need help with underframe detailing

[lars]

I'm starting my first locomotive detailing project.  It's a part of the hobby I don't have much experience with so it's been a bit of a slow process.

I'm putting together a parts list for the cab and hoods but I'm having trouble with underframe details.  I'm not sure how much underframe detailing I will do but I'm realizing that I don't know what to do.  I haven't developed an eye for this part yet.  So if there's anything I'm asking about, it's the methodology one takes when deciding what to detail on a locomotive.

The item I'm detailing is a Mainline GP9.  Truck, fuel and air tank detail is pretty basic.  A good pic for comparison is here.

I attached a somewhat well lit pic of a Geep.  For those with experience, can you point out what details you typically include?  Which ones are the "easy" ones to do in HO scale?  Which ones are more time and skill intense?  What are some of the commonly available HO parts that are readily available?  What in your opinion gives the most visual impact?

[fishbelly]

On these there is not a whole lot to see.

Model what you see. You seem to have the trucks sorted out. So turning my attention to the fuel tank. End sheet help to enhance the tank. I usually use 0.005" styrene sheet. Cut it so it overlaps the tank. Very important that yo get a good bond at the edge of the tank. Cut the overlap to be about 0.005" over the edge of the tank. The way I do this is first use scissors and trim the styrene sheet close to the edge. Not to close though. Leave about 0.020" or more. Then I use a piece of 0.005" sheet styrene and lay it on the tank against the end sheet and carefully trim the rest of the overhang to this styrene gage. It is VERY important to use a new SHARP blade. Very important to do that. Use a slicing motion and do not cut deep. Shallow cuts. Once you get the end sheet cut down. Use a sanding stick to finish the contour. Now the snading stick will slightly sluff the edge. Just use the edge of your blade and carefully scrape it off.

Next looking at the tank again. I see a bolt at the bottom of the tank. This makes me believe it is something like the GP35 tank and there would be one at the center and one at the other side spaced the same as the one you see in the photo.

Next I see some weld lines. One at the center of the tank running vertical, but not all the way across the top. The next running horizontal from from to back. yo can simulate this by lightly scribing a line at these locations and then lay in some very thin stretched sprue.

On the upper front of the fuel tank there looks to be some plumbing, but I cannot tell what it is for.

Air tanks. Not much to say here. Air tanks will always benefit from detailed plumbing. you can use the moisture ejectors from the Cannon & Co. air tank kit.

Jacking pads are a good detail. Send me your mailing address in a private email and I will send you a set of correct looking jack pads. Both variety.

Just aft of the lead axle on the rear truck you have a drain hose coming down from a piece of pipe with an elbow on it. This detail is ONLY on this side. You can make this easily from a piece of wire with a Precision Scale elbow soldered to it. you can make the hose from Miniatronics Ultra Flexible wire. it is the correct diameter for this as well as sanding hoses.

Then you have the ground light. Other than that, the frame is pretty well hidden.

[markfj]

Here are a couple photos that might help.

First is the sand line routing on Reading GP7 621. You can also see some of the jack pad detail and how the speed recorder line runs towards the cab.


Second are two photos from a Reading Company mechanical department report of a derailment that occurred on September 27, 1964. Again you can see the jacking pads, some lines, and the ground light.



Good luck on you project!

Thanks, Mark

[Artur]

I believe you can buy the underframe detail set from Athearn. If you have a manual from one of their Genesis GP9’s it will be laid out with part numbers.

[lars]

Apologies if anyone assumed I'm working on the NBER unit above. It was just one of the better pics I have for reference.

While we're talking about underframes, can someone please speak to the different types of truck journals? This locomotive seems to have three that I can see. What are the designs shown? Are they functionally different? How would you model something like this?

Also, I sometimes see what I labeled as air dryers or air filters on the engineers side around the fuel tank.  Is there a typical placement or does it vary by units?  Are they all the same on a given model or can they be of a different design?  

[fishbelly]

Well For EMD truck journals. As you said. You have three to choose from. On the original post photo, those are Hyatt Roller Bearing. Then you have the early ones of the sloped design and the box design. Typically from what I have see. If you have a box on one side, you have the slop on the other. Exception to this rule is the speed recorder side. It would be box.

So from your photo. Front to back. You have Hyatt Roller Bearing. Box because of the speed recorder. Slope and the last is a box. Detail Associates makes these, but your not going to find them. Details West does make these also nd you can get them easily. Also, Athearn offers them in all configurations.

On EMD units. Air filters are typically placed on the engineers side just in front of the fuel tank.

[markfj]

Some photos for reference:

Sloped journal on GP9:


Detail Associates TK 2804 – Hyatt Roller Bearing


Details West TJ-288 – Square Journal


Details West TJ-289 – Slope Journal



I would consider using Athearn Genesis parts because they are readily available (but a bit pricey, see this eBay listing: Athearn HO Square Bearings Cap (8) ATHG62373). Also you don’t have to go through the process of removing the cast on journal, which could cause damage to the truck frame if you’re not careful.

Thanks, Mark

[markfj]

More reference photos:

Unkown road GP7 being lifted during assembly.



Blomberg truck on PRR F3A with both square and slope journals. Many GP7 & 9s had similar journal configuration.



Source: Electro-Motive Builder Photos Facebook page

Thanks, Mark