[MOC] Southern Pacific SD40T-2

[bogieman]

I've recently been making MOC's of several Southern Pacific EMD diesel locomotives, this one is of an SD40T-2 six-axle model built from 1974-1980, a total of 312 built for the SP and a subsidiary (239) and the Rio Grande (73). These differ from a standard SD40-2 in that the cooling system is modified to have the air intake at walkway level and fans below the radiators which improves engine cooling in tunnels where there is significant temperature stratification in the tunnel air. As an engineering co-op student at EMD in 1970, I was tasked to analyze and plot the date from a tunnel test in the Cascade mountains where the SP was having operational difficulty due to locos derating as they overheated in the many tunnels and snow sheds. Here's a picture of a rather dirty one:

The model is reasonably true to scale although the trucks are a bit long making the fuel tank a bit short. Later in life, the units were repainted and given a newer "speed lettering" logo. Decals were provided by Andy at OK Brickworks. The exhaust stack between the dynamic brake fans and inertial filter hatch activates the power switch and is more recessed when in operation. A few parts were not available in Dark Bluish Gray so were painted with automotive interior vinyl spray paint - specifically, the vertical dampers at the truck middle axles and the gear racks used to make the dynamic brake grilles.

The 3-18650 Li-ion batteries drive an MRC Loco Genie wireless DCC receiver/controller that powers the two L-motors, one driving each truck, and the lights and sound effects.

The trucks have two powered axles. I left the wheels off the middle axle wheels to negotiate R40 curves, they can't really be seen anyway. In the interest of full disclosure, I did have to modify the 3x3 curved plates making up the end transom curve to clear the wheels. The trucks are simple but I think capture the HT-C design with the exception of the distinctive core holes.

Later in their life, the units got ditch lights added. The lights I used came from Amazon and are pre-wired surface-mount 0805 LEDs. The wires are like thread and so fit between bricks with no drilling required. Although not prototypical, I set the ditch lights to alternately flash as the Loco Genie supports it and I like the look. Note the SP GP60 in the background.

Here's video of the loco in action:

Dave

Edited March 31, 2021 by bogieman
fix grammar, add re painting parts

[caiman0637]

It's so beautiful... 

Edited March 31, 2021 by caiman0637

[Vilhelm22]

10 minutes ago, caiman0637 said:

It's so beautiful... 

Seconded.  It looks like a scale model train rather than a LEGO model.....

[Murdoch17]

1 hour ago, Vilhelm22 said:

Seconded.  It looks like a scale model train rather than a LEGO model.....

Thirded! It really looks good!  What's the second SP loco behind it in a couple pics?

EDIT:  reread the text. it's a GP60

Edited March 31, 2021 by Murdoch17

[CMF-1138]

Wow! What a remarkable level of detail, and such an amazing layout in the video! I really like your solution of omitting the middle axle wheels to allow it to run on R40 curves since they are hidden behind the trucks.

[Feuer Zug]

Beautiful. It's hard to tell it's LEGO with the excellent SNOT work.

[bogieman]

Thanks all for the positive comments!

Dave

[zephyr1934]

Another amazing build, great work!

[1963maniac]

Looks Great!! Would like to know how are you powering this loco?

On your Southern Pacific EMD MP15AC you used a little bit different batteries. 

 

Edited April 1, 2021 by 1963maniac

[bogieman]

7 hours ago, 1963maniac said:

Looks Great!! Would like to know how are you powering this loco?

On your Southern Pacific EMD MP15AC you used a little bit different batteries. 

 

Thanks! On the MP15AC, I had a more limited space for the batteries so used 2 smaller 18350 batteries. The Loco Genie seems to operate fine on that loco with Lego train motors but here I need the higher voltage of 3 batteries to get a reasonable speed with the L motors, even with them geared up. The 18650 batteries fit fine under the engine hood so I used them for the greater capacify. Here's some pictures of the internals showing the motors front and rear:

 

This is the Loco Genie system including a 25mm speaker. It's designed to plug into a standard DCC socket but it's easy enough to cut the plug off and wire it into a Lego model although I sacrificed a PF extension cable so I didn't have to modify the motor plugs. It's programmed via the remote. With the remote included, it's still cheaper than just a PU hub. I've got 4 diesels and 2 steam locos so far using this system.

[zephyr1934]

15 hours ago, bogieman said:

Here's some pictures of the internals showing the motors front and rear:

That's some insane packing you've done with all of the electronics

[Murtin]

Wow. Love the build, the details and all the added functionalities! Watching (and hearing) that diesel powerhouse haul the train is so immersive

[Pdaitabird]

This is beautiful! (and I don't even care for diesels)! I thought it was an O-scale model at first - the detailing is that good!

[ivanlan9]

There's a prototype one of these at Ogden Union Station; you can climb on it if you want.  Doesn't run, but looks really, really good.  As does your model.  Very, very nice indeed.  You make me very jealous with your layout:  if only I had that kind of space available!

Metta,

Ivan

[bogieman]

17 minutes ago, ivanlan9 said:

There's a prototype one of these at Ogden Union Station; you can climb on it if you want.  Doesn't run, but looks really, really good.  As does your model.  Very, very nice indeed.  You make me very jealous with your layout:  if only I had that kind of space available!

Metta,

Ivan

Thanks Ivan! During my 47 years at EMD engineering I climbed on a lot of these and others. Fortunately, we have a house with a full basement that I have taken over, with my wife's blessing, for the Legos and my machine shop.

Dave

[Modeltrainman]

@bogieman, beautifully done, Dave!