# USA Trains SD40



## zoro (Feb 8, 2010)

Looking to add a USAT SD40 to my collection. Will I need to run a bigger transformer or can I use my existing starter set pack? Will they handle 4FT curves? How much more pulling power will the SD have compared to current Stainz?


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## Gary Armitstead (Jan 2, 2008)

Posted By zoro on 23 Dec 2013 10:06 PM 
Looking to add a USAT SD40 to my collection. Will I need to run a bigger transformer or can I use my existing starter set pack? Will they handle 4FT curves? How much more pulling power will the SD have compared to current Stainz? I ran my USAT SP SD40-2 from a LGB Jumbo Pack many years ago before finally turning to battery. Not sure if a starter pack would do it.

As far as 4 ft. curves, are you talking about radius or diameter. 4 ft. diameter, NO WAY!








4 ft. radius/8 ft. diameter....YES.


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## mgilger (Feb 22, 2008)

Gary is correct. The answer is no way will the SD40-2 handle the 4 foot curves. You would want 8 as your minimum. 

Regards,
Mark
*http://mmg-garden-rr.webs.com/ *


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## chuck n (Jan 2, 2008)

You will need a stronger power supply. The SD40 has two motors, that is about 2 amps, if you use the smoke and add sound that will require more power. Lighted cars will need more. A 5 amp would probably work, but 10 amps would be better. Chuck


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## aceinspp (Jan 2, 2008)

You will definatley need a larger power pack. The loco will run on 8 ft diameter but will have a little over hang. It's a good runner but I would change out the wheels that use traction tires they are a pain. Yes may loose some pulling power but you can also always add a little extra weight like I did. Later RJD


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## Treeman (Jan 6, 2008)

You are looking at a big jump. From a quite small steam engine to a fair sized diesel. You might consider a NW-2, or a S4.


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## oldrk (Dec 25, 2013)

Are those SD40s or SD40-2s?


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## Scottychaos (Jan 2, 2008)

USA Trains makes a SD40-2. 
there is no SD40 available in Large Scale.. 

Scot


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## SD90WLMT (Feb 16, 2010)

USA Trains builds a model of the SD40-2 version.... 

Very nice..probably only a couple amps load if not pulling too many cars. 
But as built, could go well past that number if allowed to pull a lot of cars..even without any mods out of the box. 

Dirk


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## SD90WLMT (Feb 16, 2010)

Scotty ... a tie.. 

Almost..beat me by mere seconds there buddy!! 

D


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## SD90WLMT (Feb 16, 2010)

And drum roll guys......!! 

...welcome to our home on the forums "oldrk".... 

Dirk


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## Scottychaos (Jan 2, 2008)

wow, that *was* close!  
Scot


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## oldrk (Dec 25, 2013)

Thanks for the big ole welcome!


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## Randy Stone (Jan 2, 2008)

Also, if you are pulling a caboose that has lights, the drag from the brushes picking up power from the wheels will be worse than pulling 10 frt cars.


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## zoro (Feb 8, 2010)

Posted By rlvette on 25 Dec 2013 07:13 PM 
Also, if you are pulling a caboose that has lights, the drag from the brushes picking up power from the wheels will be worse than pulling 10 frt cars. 
That's one thing I've noticed. Got a Bachman RPO(?) that's like that and the noise is enough to drive ya crazy. I've seen some that pick up the power at the end of the axle, how is the drag on those?


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## zoro (Feb 8, 2010)

Posted By Treeman on 25 Dec 2013 11:28 AM 
You are looking at a big jump. From a quite small steam engine to a fair sized diesel. You might consider a NW-2, or a S4. 
Until I re-engineer my layout that might just be the route I go. How much more pulling power would the NW-2 have over the Stainz?


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## Treeman (Jan 6, 2008)

My guess is that the NW-2 would pull double the Stanz. With a bigger power pack you could double head them. Better yet we carry a Cow and Calf.


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## zoro (Feb 8, 2010)

Cow and a half, is that a term for a slug? 

There's a bunch of power packs out there, which one would be right for me? Regular DC(for the time being) and the ability to double head without overloading.


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## Scottychaos (Jan 2, 2008)

Posted By zoro on 26 Dec 2013 09:25 PM 
Cow and a half, is that a term for a slug? 

There's a bunch of power packs out there, which one would be right for me? Regular DC(for the time being) and the ability to double head without overloading. 
Technically no.
The "calf" is actually a "B unit".

B units are fully functional locomotives, with an engine, but they dont have a cab..
most well known for cab units, but there were freight units that were also made in B-unit configuration:

GP9B








SD45B









B-units exist for two reasons:
In the early days, when diesels were replacing steam, Union rules said every "locomotive" had to have a full crew..
Railroads could buy an ABBA set:








and claim it was "one locomotive" needing only one crew..
which was true of course..but it took awhile for union rules to change to fit new realities..

later, the crew issue was gone, then railroads sometimes bought B-units just for the cost savings..
a locomotive without a full cab was cheaper..and if you were going to run a 4-unit set of GP9's, did every one of them need a cab?
but eventually B-units fell out of favor, because they are not as practical as a unit with a normal, full cab..
you cant run a B-unit by itself..or only two B-units together, etc..but you can do that with "normal" units..

The "calf" in a "cow and calf" switcher set, is also a B-unit.









(note the smokestacks on the "calf"..that tells you there is a diesel engine in there..)

A slug is a locomotive without an engine.
It does not have a diesel engine inside of it..
It does have its tracton motors however, and it recieves power (electricity) for the motors from its "mother unit"
So it helps with traction, but it does not create its own power with its own engine..
slugs were sometimes cut down, with just a lot of dead weight added to the carbody, for traction:


















body was originally an Alco! trucks from an old SD.

but often, lately, they retain their full cab and carbody..
they can be spotted because all the old air intakes and fans have been plated over or removed:


















Note that the radiator grills.and the fans, at the rear of the hood are gone..2271 is now a slug, built from a GP30.
crews often like to put a slug in the lead, and ride in it, because they are quieter! 

Scot


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## zoro (Feb 8, 2010)

Thanks for the info! 

I'm really leaning towards the NW2 w/calf. Do those have smoke?


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## Dick413 (Jan 7, 2008)

this is my favorite slug set










Dick


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## eheading (Jan 5, 2008)

Dick, Pretty soon we'll see engine sets like that except that the center car will be holding liquid natural gas!!

Ed


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## Randy Stone (Jan 2, 2008)

Yes, Thank you Scot 

I'm learning something new all the time here


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## zoro (Feb 8, 2010)

I forget where I was but I saw a really cool lashup that was 3 units total with 2 of the rattiest looking (ex)diesels I've ever seen at the ends and a clean unit in the middle that was powering the diesels on the end. Pretty sure the 2 on the end had their prime movers taken away and the cab windows were boarded over. The whole thing was being controlled in the yard with a belt pack.


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## aceinspp (Jan 2, 2008)

Yep the NW 2 have smoke . Later RJD


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## zoro (Feb 8, 2010)

Posted By aceinspp on 28 Dec 2013 07:16 AM 
Yep the NW 2 have smoke . Later RJD 
Cool. What about a power supply?


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## Totalwrecker (Feb 26, 2009)

Get a bigger power supply. 
Why has already been explained. 
The smoke unit is already installed, you add smoke oil. 

Happy Rails, 

John


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## Treeman (Jan 6, 2008)

The Cow and Calf are sold separately. http://www.reindeerpass.com/USA-Tra...ack-1.aspx


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## zoro (Feb 8, 2010)

Posted By Totalwrecker on 28 Dec 2013 06:33 PM 
Get a bigger power supply. 
Why has already been explained. 
The smoke unit is already installed, you add smoke oil. 

Happy Rails, 

John 
What I meant was what power supply do you guys recommend? There's a ton out there and I dunno where to start looking. All I pretty much know is that I want DC operation, not ready for DCC just yet.


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## Greg Elmassian (Jan 3, 2008)

John / Zoro - email me I have some answers for you. 

(note my signature) 

Greg


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## Totalwrecker (Feb 26, 2009)

Greg, I'll pass, nice to see you. 
I don't believe we know Zoro's first name... 

I hope you've been well. 

John


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## Greg Elmassian (Jan 3, 2008)

just fine, see you used your real name on LSC, good for you, did not realize you were you at first ha ha. 

back into the shadows 

Greg


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## Totalwrecker (Feb 26, 2009)

After all the bs I got here, I asked Shad if it were possible to undo my cleverness, he said no, so I defended my self..... big mess there! 
Bob was willing and able to undo the same nickname there. 
I had no idea what an alias would stir up amongst the suspicious.... 

So that was you I bumped into on my way out... lol 

John


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