GP35 Group Build kicked off today.

[Deleted]

Today I kicked off my participation in the GP35 Group Build on Facebook. My entries are videos with updates posted on the page.

The first two videos are up and running.

#1 This video covers the introduction to the project and my subject entry.


#2 This video covers thecreation of the Bill of Materials and planning. 


#3 This video covers stripping paint from Kato models.


#4 This video starts the actual build. Frame & fuel tank part 1 of 8.


#5 This video continues the frame and fuel tank work. Part 2 of 8.


#6 This one dives into cutting the fuel tank and frame. Part 3 of 8.


#7: More frame and fuel tank work. Part 4 of 8.


#8: More frame and fuel tank work. Part 5 of 8.


#9: finishing up the plate steel and sheet metal work on the frame and fuel tank. Part 6 of 8.


#10: Here I correct my slope sheet mistake and build the fuel filler pipes.Part 7 of 8.


#11: Ending chapter one. The frame and fuel tank deconstruction and reconstruction is finished.


#12 This This video is the start of the truck rebuild program.


#13 This video covers weathering the wheels.


#14 In this video I cover the building and installation of the brake cylinder air line plumbing and brackets.


#15 This video completes the trucks through applying a primer coat.


#16 Truck addendum: This is a short overview of what needs to be done to adapt the Kato RS2 AAR truck to the Kato GP35.


#17 This video starts the next chapter in this build. Here I am deconstructing the sill unit to prepare it for detailing.


#18 This video takes me through the end of deconstructing the sill unit including all the necessary cutouts in the pilot plate.


#19 This is the first part of the tread plate video. This video deals with the prototype information.


#20 Video 1 of 3 Tread Plate Installation 


#21 Video 2 of 3 Tread Plate Installation


#22 Video 3 of 3 Tread Plate Installation


#23 Prototype aspects of the air reservoirs and associated plumbing


Brian

[tankcarsrule]

Brian, you are the man!

Bobby

[Deleted]

Whenever I have a new video posted. I will edit the original post and add a new line with a link.

Brian

[ncrc5315]

Brian, really looking forward to this. I have some units I want to do later this year, and this will be a big help.

[roadkill]

Apr 8, 2018 14:16:45 GMT -8 ncrc5315 said:

Brian, really looking forward to this. I have some units I want to do later this year, and this will be a big help.

Same here, I have several Kato GP35's waiting to be PC-ed .

[Deleted]

Another update. See original post at top for link.

Brian

[nebrzephyr]

Brian, although I don't have the equipment you have, I appreciate you doing the videos. There are many "tips" that are applicable even to us less equipment endowed modelers.

Bob

[Deleted]

Update #6 is posted. See original post.

Brian

[Deleted]

The next video is up. Se original post for link.

[nstophat]

Brian;

So far great series. Looking forward to the rest of it.

Regards,
Russ

[Deleted]

The next video is up. See original post for link.

Brian

[nstophat]

Brian;

Thanks for keeping this going. I am inspired to build a GP35 for either RF&P or as a CSX Slug Set. The modeling insight is much appreciated.

Regards,
Russ

[markfj]

In regards to the fuel tank modifications, I’m wondering if using a Genesis tank might be an alternative for those who want to do an expedited build. It’s a really nice tank and already has the end plates and hangers included.




Just out of curiosity, I pulled the tank off of a Genesis GP38-2 and did a test fit on a Kato drive. As you can see in the photo, it doesn’t fit because the frame is too wide. However, the frame is .948” wide at the tank and the Genesis tank .934”, so it’s only a .014” difference. Either the frame will need some light milling in the tank area on the sides or the tank could be trimmed (probably an easier route). You would also need to mill about .039” from the bottom of the frame to get the Genesis tank to sit at the proper height. Removing the material from the bottom is necessary because the Genesis tank doesn't have an open bottom like the Kato one. This could be an advantage as you don't need to permanently attach the tank to the frame using glue. It could be secured by taping holes in the frame bottom and using countersunk flathead screws.



Another benefit of using the Genesis tank is that you can skip the milling steps required to remove the molded air tanks.


The part number for the 3200 gallon Genesis tank is G40397, but that’s just the tank, no fuel fill, sight glass, or breather pipe. The fuel tank detail set is part number G40331. Another nice thing about using these parts is that they’re all plastic and will glue easily.


Thanks for the videos Brian!

Mark

[Deleted]

Mark,

Unless you are building a phase II 35. You cannot use the Athearn tank. The phase II series 35's use slope top tanks like the one in your photos. The phase I series of 35's use a flat top upside down "T" style tank. The same type of tank as the GP30 as well as the same design as the larger tanks on the GP7/9/18/20. They are not slope top tanks.

Also just for information. The genesis fuel tanks DO come with all the fittings necessary. Again though. Just not the correct style tank for the Phase I series 35's. For a phase II series you want the 2600 gallon tank which was standard. I know of three railroads that purchased phase II units that opted for a 3000 gallon tank. RF&P, RI, Milwaukee. I know there was three and there might be a fourth. I do not have my notes with me.

Brian

[markfj]

Hmm, didn’t catch that the top shape was different on the Genesis tank. Heck, I was just excited that it "almost" fit the Kato frame!

So, now I’m wondering if the Genesis tank from a GP7 or 9 would work. I was also thinking that somebody might have the correct tank done as a 3D print model. Rebel Locomotives has some nice tanks, but not the correct shape for the phase 1 GP35 (i.e. the flat top).



Mark

[roadkill]

May 7, 2018 14:36:34 GMT -8 markfj said:

Hmm, didn’t catch that the top shape was different on the Genesis tank. Heck, I was just excited that it "almost" fit the Kato frame!

So, now I’m wondering if the Genesis tank from a GP7 or 9 would work. I was also thinking that somebody might have the correct tank done as a 3D print model. Rebel Locomotives has some nice tanks, but not the correct shape for the phase 1 GP35 (i.e. the flat top).



Mark

A Proto GP30 tank would be a good choice if you can find one.

[Deleted]

May 7, 2018 14:36:34 GMT -8 markfj said:

Hmm, didn’t catch that the top shape was different on the Genesis tank. Heck, I was just excited that it "almost" fit the Kato frame!

So, now I’m wondering if the Genesis tank from a GP7 or 9 would work. I was also thinking that somebody might have the correct tank done as a 3D print model. Rebel Locomotives has some nice tanks, but not the correct shape for the phase 1 GP35 (i.e. the flat top).



Mark

The GP9 tank would be the correct shape, but not the correct length. The GP30 and 35 tanks are longer (larger in capacity) hence the rear truck bolster moved back 1 foot.

A 3D printed tank would be OK. Just make it about .002" to .003" larger so you have material to sand off to smooth it out.

Brian

[nstophat]

Brian;

How much length would be needed to use the Athearn tank? I am wondering if you could splice a pair of them together at the bulkhead and trim the bulkhead to match the tank cross section to match what you did in Step 1 of video 8?

Russ

[Deleted]

May 8, 2018 12:13:25 GMT -8 nstophat said:

Brian;

How much length would be needed to use the Athearn tank? I am wondering if you could splice a pair of them together at the bulkhead and trim the bulkhead to match the tank cross section to match what you did in Step 1 of video 8?

Russ

Well, the standard 2350 gallon tank measures 186.75" long. That is 2.144" in HO scale. Whatever an Athearn tank measures out to be, make the adjustments.

Brian

[Deleted]

See original post for latest update.

Brian

[markfj]

Here are a couple shots of a GP(something?) either being scrapped or repaired. These photos show the frame construction method Brian was talking about in video 9. I think these images came from a discussion on the Diesel Detailer, but I’m not sure. You can also see the coupler pocket details and buffer plate clearly. Also looking forward to getting some of Brian’s 3D buffer plates; just need to find someone to mill down the coupler pads first.





Also curious to know if the end plate on the frame was changed to the design Brian shows (the plate with the semicircular cutout) on later GP30 & 35 models. I took some photos last summer of Reading GP30 5513 (1st GP30 built, 1962) and GP35 3640 (phase 1b1, built 1964) and it looks like neither have end plates that cross the frame. Since these locomotives were early versions I’m guessing EMD changed the design on subsequent models for some reason (maybe to improve frame strength?).


GP30 5513 rear of tank


GP30 5513 front of tank


GP35 3640 rear of tank (hard to see, but looks like frame is similar to GP30 5513)


Thanks, Mark

[Deleted]

Good stuff Mark.

The next video will answer your question as to the slope plate design. Yes it does change. I made the mistake of using the GP7 design and have since fixed it on the model and you will see it in the next video. I have a manufacturers drawing of the slope plate in the video also.

The first couple photos you show are of I think a GP38-2. The buffer plate changed after the GP35 series and early GP40. The best way to see it is look at the CB&Q GP40. The early units have the exact same nub pilot plate as the phase II GP35 which also use the same buffer plate. When the GP40 pilot plate design was changed, it received the notched buffer plate. The notch is at the front on each side plate. The front edge of the side plate steps in about an 1" at the coupler opening.

I still have to add this notched buffer plate to my Shapeways page. This will happen when I start work on my EJ&E GP38-2's.

Brian

[markfj]

Here is more GP35 frame info that I saved from a post on ProtoModeler. (I think that website is now on Facebook only, so I can’t post a direct link to this discussion.) The poster was confirming Brian’s measurements on the GP35 frame and deck height (he claims to have the actual EMD drawings!). Real good info; glad I took the time to copy and save it, wish I got the photos too. (Detailed info like this is what made ProtoModeler a great site, too bad it’s gone.)


Posted 18 January 2015 - 03:36 PM
on ProtoModeler
Just arrived on the forum - that is a really gorgeous model! Looking forward to seeing the final result.

I noticed that there has been a lot of discussion about the frame height between the Phase 1 and Phase 2 GP35, and I think I can clear things up.

I have detailed EMD mechanical drawings for the underframe of several models, including the early GP35 and the GP39 (which, aside from a few small details, is the same as the frame for the GP38 and GP40). From the diagrams, I can confirm the following:

- The top of the underframe is explicitly stated as 60.75" for the GP35 and 62.25" for the GP39 - a difference of 1.5".

- The height from the rail to the bottom of the underframe and the dimensions of the coupler pocket/draft gear are the same on both models, with a nominal 33.875" coupler height.

- While not listed in the drawings, extrapolating the height of the main frame based on other dimensions gives a frame height of about 14.5" for the GP35 above the trucks (the "fishbelly" part is about 24") and 16" for the GP39 - so the height difference is entirely the result of a thicker main frame on the GP38-40.

- The side frame is thicker on the early GP35 (10" at the ends, 7" in the middle) than on the GP40 (8" at the ends, 5" in the middle). As a result, much more of the main frame (an additional 3.5") is visible below the side frame on the GP40 than the GP35.

Other measurements I've been able to find have given a nominal deck height of 60.25" to 60.75" for the GP35, and 61.75" to 62.5" for the GP40. The difference of 1.5" also correlates with railroad diagrams that list the height over the cab as 14' 4.5" for the GP35 and 14' 6" for the GP40 - which, given the EMD cab/hood height of 9' 4.25" above the frame, results in deck heights of 60.25" for the GP35 and 61.75" for the GP40.

The above dimensions are for the early GP35, and I don't have actual dimensions for a Phase 2 GP35. However, I've taken photo measurements of the main underframe dimensions of the Phase 2 GP35 - main frame thickness, side frame thickness, fuel tank profile, jacking pad height and design, stepwell dimensions - and they all line up exactly with the dimensions for the GP40, save for the thinner side frame above the air reservoirs (3" instead of 5"). This suggests that the main frame dimensions for the Phase 2 GP35 were carried over to the GP40, and that the Phase 2 GP35 therefore has the same deck height as the GP40 - about 62", or 1.5" higher than the early GP35.

In response to some of the photos posted, the close-up photos of the front truck of two BNSF GP39 rebuilds are a bit misleading, since the apparently higher ride height on the later unit is a result of the photo perspective (the first photo was taken at a stronger zoom and less of an upward angle).

The photo of BNSF GP60B's 337 and 338 is a perfect illustration of what I've found to be by far the biggest factor affecting frame height: Wheel wear. While the other wheels aren't visible, the rearmost wheel of 337 is visibly more worn than 338, and 337 is also slightly slanted up to the left (which would lower the coupler). But more to the point, I tried measuring the full-size version of the photo, and the height between the bottom of the underframe and the axle centerlines is, for all intents and purposes, identical between the two units (538 px for 337, 540 px for 338). This leaves wheel wear (and rail height) as the sole explanation for the height difference.

A wheel may lose 3" in diameter by the time it's condemned, assuming a new rim thickness of 2.5" and a minimum thickness of 1". In other words, all else being equal, a GP35 with new wheels will ride about the same height as a GP40 with worn wheels, despite the nominal 1.5" difference. This variation is why I've always measured the walkway height based on the axle centerlines. Whenever I've measured between the axle centerlines and the top of the walkway - whether from photos I've taken of in-service units or physically measuring preserved units - I've found the measurement has always fallen within 1" (and usually within less than 0.5") of the nominal value.

(Edit: Additionally, I think the real-world measurements posted by Brian above actually confirm this distinction. The average of all six Phase 1 GP35 deck heights (59.625") plus the average of the six values for wheel wear (0.79" / 2 = 0.395") gives a height of 60.02", while the average of the two deck heights for the Phase 2 unit (60.875") plus the average wheel wear (1.125" / 2 = 0.563") gives a height of 61.44", for a difference of 1.42").

Hope this clears things up a bit!

[bar]

Interesting thread. The construction of locomotive and car frames hasn't changed much in 100 years, except for the shift from rivets to welded construction.


Is there a good way to estimate actual dimensions from a photograph in, say, Photoshop? If you know one key dimension (such as wheel diameter)?

[jonklein611]

May 17, 2018 7:14:30 GMT -8 bar said:

Interesting thread. The construction of locomotive and car frames hasn't changed much in 100 years, except for the shift from rivets to welded construction.


Is there a good way to estimate actual dimensions from a photograph in, say, Photoshop? If you know one key dimension (such as wheel diameter)?

Potentially, but it really depends on the angle of the photo, what lens was used, if any correction was used to account for the lens' distortion, etc.

[Deleted]

Update video #10. See original post.

Brian

[CRcsxns]

Thanks Brian! Great stuff!!

[Deleted]

Again, see original post for latest video update. Video #11.

Brian

[Deleted]

Next video added. See original post.

Brian

[nebrzephyr]

Hi Brian. On the latest video concerning painting the wheel sets. I use MicroScale Micro Mask on the axle tips. Just apply a small amount with a toothpick. After painting, the mask just flips off using the tip of a #11 blade. Thought you might like to try,

Bob