# USAT SD70MAC experiences article



## Ted Doskaris (Oct 7, 2008)

*USAT SD70MAC experiences article*

*Couplers, railing & assembly installation, curve track operation, & speed mismatches with Aristo-Craft locos*

This is a fairly large article with more than one hundred moderate size pictures that I think would be pushing the limits of acceptance on MLS because of bandwidth concerns and memory space usage.
Given this consideration, the article is hosted for me by Greg Elmassian on his web site that is where my 30 plus "vignettes" have ultimately taken residence - thanks to his generosity. 

The USAT SD70 is my first non Aristo-Craft brand loco, and because I have mostly Aristo products, the article is presented from a perspective of striving for operational compatibility of the SD70 loco with respect to rolling stock equipped with standard Aristo knuckle couplers. (At least that's the basis I started out with, and it grew from there.)

That said, the information presented, including the installation of the SD70's factory supplied detail parts, should be of value for those that are not concerned with just Aristo products.

With plenty of pictures peppered throughout the article, my hope is that a viewer's interest level should be maintained.










Shown below is a list of contents so as to know what is covered.
The link for the article is at the end.

-Ted


*SD70 article list of contents:*

PREFACE

First - some prototype Southern Pacific SD70 information

Now for the USAT SD70 as received in its packaging

Some observations about the USAT SD70

Now for the coupler issues
The Kadee coupler experiment
Coupler mounting considerations
Possible SD70 Kadee couplers
The Kadee #836 issues
The Kadee #831 issues
The Kadee 832 possibility
The chosen solution, Kadee #787s modified as swinging box couplers
The SD70 FRONT coupler
The SD70 REAR coupler on SP road number 9813
The SD70 REAR coupler on SP road number 9812

Installing the pilot end detail parts

Installing the Railings
The side railings
The pilot end railings

Operational results
Coupling the SD70 with Kadees to other Aristo-Craft Locos & Cars having Aristo Knuckle couplers
Coupling SD70s with Kadees to an Aristo-Craft Car having a Kadee body mount coupler
A pair of SD70s with Kadee couplers pulling a test train

Some comparisons

The SD70 loco coupler assembly observations

Comparison of USAT SD70 & Aristo Dash-9 locos for pilot overhang

USAT SD70 Performance

Summary & Conclusions with respect to couplers
The impact of acquiring USAT SD70s and the Aristo couplers
Along came the SD70!


*The SD70 article link is below: *
USAT SD70MAC experiences article


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## aceinspp (Jan 2, 2008)

Ted: As usual a fine write up. Later RJD


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## eheading (Jan 5, 2008)

Very informative and well written write-up, Ted. Thanks for sharing your findings with us in such detail.

Ed


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## NTCGRR (Jan 2, 2008)

Ted 
Your way behind the times. My 4th one has not even been out running yet...


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## Ted Doskaris (Oct 7, 2008)

Sorry Marty - being so late to the show.


It did take a good deal of time to put the article together and implement the mechanics of it all. 
My thinking was to document everything for the future benefit of other folks. 

I could have better spent the time on other things.


-Ted


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## Nicholas Savatgy (Dec 17, 2008)

Ted, Great info and thanks for writting it, it will help a lot of people out......


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## Great Western (Jan 2, 2008)

Hi Ted,

A pleasure to see you around from time to time and many thanks for an interesting report.

By the way I now know why I run nothing larger than an RS3.


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## Engineercub (Oct 18, 2008)

Great article Ted! Very comprehensive and elaborate. I have to say that this is my favorite USA Trains diesel locomotive. These are a real pleasure to run at work as well. One thing about the 70MACs that alot of people have been critical of is the model versus the prototype. Really I think it has got to be difficult trying to decide which 70MAC to base the model on because they are all different. GE locomotives tend to all be exactly the same as if constructed on an assembly line but EMDs have unique features from one locomotive to the next. EMD has always been able to customize just about every part of their locomotives inside and outside. The SD40-2 had TONS of different setups though they are all similar. One of the strangest designs I have come across is when I went to start one, the expansion tank was about 10 feet behind the diesel engine at the start station, and the sump extended further back as well. I would hate to have to pick one to base a model on. EMD changes things alot by carrier request or just tinkering to make the locomotives better. With this in mind, it would cost a heck of alot more money to research and manufacture all the differences between these locomotives by road name and date made, and is understandable why they really can't. Whichever 70MAC the USA's version is based on though I think they did an incredible job. I hope everyone else has as much fun running this thing as I do. I brought mine over to my friend's house and we ran it with his Dash-9 and had a blast. We couldn't stop talking about the lit computer screens in the cab, that is a great touch! 

-Will


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