Atlas GP30/38/40 truck compatibility

[craigolio1]

Hey all.  I have several Atlas GP40 mechs that I need to back date to GP38. These are the new DCC ready/equiped mechs.   I know the GP40 and 38 can swap trucks as I have done it.  But Atlas is out of the needed parts for the GP38 right now.  They do list as available the GP30/35 truck side frames.   Can anyone tell me are these compatible with the GP40 trucks?

Thanks, Craig

[craigolio1]

I think I,ve answered my own question.  The GP40 and GP35 gear cases are both part number 480301.

Craig

[craigolio1]

So as it turns out the GP40s has the same trucks as the GP38s. Looks like the trucks changed with the -2 so I don’t need to back date at all. In fact it’s the opposite on a couple of my models. Haha. I have all mechs with the older leaf spring truck and I need to bring two of them up to -2 status. Should have looked more closely at the models. Haha. Oh well, learning new things all the time.

Curious though, can anyone tell me, did all of the early GPS run on the same trucks? Say GP7-GP40? Edit: I’m speaking about the prototype now, and possibly also Atlas DCC ready models.

Craig.

[fire5506]

The EMDs ran on Blomberg trucks. There were some minor differences depending on what the railroad ordered. The early ones had the leaf springs and clasp brakes with 4 brake cylinders, then they had several different "spring" setups one is what you are referring to as the -2 rubber pack springs. That was actually and option on the locomotives. We had -2s with rubber packs and also with leaf springs. The rubber packs the crews hated because the road harder. The spring plank and swing hangers are different between them. Also about that time they went to I thinks was the Blomberg M trucks which were the "low maintenance" trucks with only brake arms on the inside and 2 cylinders per truck. A lot of railroads modified their trucks so there no outside brake arm, only the inside, but still kept the 4 cylinders per truck. The whole truck could be physically put under any of the GPs. You can't mix the brake types because the brake pressures are different for the different types of brake.


Richard

[nkalanaga]

On the prototype, you could even put the AAR-B trucks from Alcos or GEs under the EMD units, and I assume vice-versa.

[craigolio1]

Wow great information guys.

One of the models I’m building needs be trucks that have a single break cylinder on one end, and it looks like a shock absorber on the other end (vertically from the bearing to the frame - a damper?).

I’ll have to modify that one as I don’t see any Atlas models with this style of truck.

Craig.

[thomasjmdavis]

On the prototype, you could even put the AAR-B trucks from Alcos or GEs under the EMD units, and I assume vice-versa.

For example, per the Diesel Spotter's Guide (2nd ed) GM&O, MILW and Soo all had GP-30s, MP GP-18s, and Ann Arbor GP-35s, with AAR-B trucks from Alco trade ins. There are no doubt other examples, and I could swear seeing photos of GP-7s or -9s so equipped as well.  I can't say for sure about GP-38-2s as they had just entered production when that edition was printed.

[cjm413]

So as it turns out the GP40s has the same trucks as the GP38s. Looks like the trucks changed with the -2 so I don’t need to back date at all. In fact it’s the opposite on a couple of my models. Haha. I have all mechs with the older leaf spring truck and I need to bring two of them up to -2 status. Should have looked more closely at the models. Haha. Oh well, learning new things all the time.

Curious though, can anyone tell me, did all of the early GPS run on the same trucks? Say GP7-GP40? Edit: I’m speaking about the prototype now, and possibly also Atlas DCC ready models.

Craig.

Off the top of my head, here are a few exceptions that did not have Blomberg B trucks

GP7 with AAR-A (US Army, NCStL)
GP9 with Flexicoil (CN)
GP18 with AAR-B (MP)
GP30 with AAR-B (Soo, GM&O, MILW)
GP35 with AAR-B (Soo 722, GM&O,  SLSF, TP&W)...also AA per the prior post, I forgot about those...
GP40 with Blomberg M (several of the last units built for SCL)

I did not count units retrofitted with different trucks, e.g. Alaska ex-US Army GP7's with AAR-B trucks instead of AAR-A, various MP retrofitted with Blomberg M, etc.

[nsbob]

Wow great information guys.

One of the models I’m building needs be trucks that have a single break cylinder on one end, and it looks like a shock absorber on the other end (vertically from the bearing to the frame - a damper?).

I’ll have to modify that one as I don’t see any Atlas models with this style of truck.

Craig.

Then you need the Blomberg M trucks.  I know that Kato used those on their GP38-2 and GP50 models and Life Like/Walthers used them on their GP38-2 and GP60 models.  Hopefully someone here will chime in and tell you if they are compatible with your Atlas chassis.

[CR4100]

You can get the part you need here: https://shop.atlasrr.com/p-3629-n-truck-side-frame-gp40-2.aspxand here: https://shop.atlasrr.com/p-3630-n-snubber-gp40-2.aspx.

The Life-Like/Walthers GP38-2s have the correct trucks and they will fit the Atlas chassis. For some reason the LL/Walthers GP60 comes with the wrong truck type, regular Blomberg and not the Blomberg M.

[cjm413]

You can get the part you need here: https://shop.atlasrr.com/p-3629-n-truck-side-frame-gp40-2.aspxand here: https://shop.atlasrr.com/p-3630-n-snubber-gp40-2.aspx.

The Life-Like/Walthers GP38-2s have the correct trucks and they will fit the Atlas chassis. For some reason the LL/Walthers GP60 comes with the wrong truck type, regular Blomberg and not the Blomberg M.

1st run GP60 came with B, later came with M
LL/Walthers GP38-2's have come with both types

[davefoxx]

On the prototype, you could even put the AAR-B trucks from Alcos or GEs under the EMD units, and I assume vice-versa.

Seaboard Coast Line ran Blomberg-Bs under some of its U-Boats and B-Boats:



I always thought that made them extra-hawt. 

DFF

[Steveruger45]

During a de-coffee grindering exercise some many months ago now, on various older 4 axle atlas emd and ge locos I found the truck side frames are interchangeable between the emd’s and ge’s  but the truck towers not so much.  The old Kato gp38-2 and gp50 trucks are completely different and won’t work on the atlas locos.  Trust this helps

[craigolio1]

Guys this is all really helpful info. Thank you so much. I think it will take me less effort to remove a brake cylinder and add a damper, vs tracking down a pair of LL GP38-2 trucks.

Craig.

[cjm413]

Guys this is all really helpful info. Thank you so much. I think it will take me less effort to remove a brake cylinder and add a damper, vs tracking down a pair of LL GP38-2 trucks.

Craig.

https://shop.atlasrr.com/p-3629-n-truck-side-frame-gp40-2.aspx