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What It Means For Diesals and Freight

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What It Means For Diesals and Freight
Posted by wrawroacx on Sunday, September 28, 2008 12:29 PM
What does SD stand for like SD40-2? What does the AH stand for in ES44AH? What does GP stand for like GP38? What does -2 mean like SD40-2? What does DD40X stand for? What does the F stand for in F7 or F3? What does E stand for in E8? What does MAC stand for like SD80MAC? What does U-Boat stand for? What does TTX stand for? What does DTTX stand for?
Tom My Videos - http://www.youtube.com/user/MrWrawroacx
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Posted by silicon212 on Sunday, September 28, 2008 1:05 PM

All good questions.  I can't answer all of them, but I can answer a few.

GP = General Purpose, a unit that 'could do it all', from switching to road service - hence, 'road switcher'.

SD = Special Duty.  This is a 6-axle version of the 4-axle GP.  The first ones had weights close to the GP series, but had an extra 2 axles to distribute the weight better, enabling the units to be used on track structure that couldn't support the axle loading of the GP.  Later, EMD took advantage of the TE (tractive effort) supplied by the SD by making the unit heavier.

Dash Two (-2) is a revision that was made during the production run of the 40 series, involving simplifying the electrical system and other improvements that were all introduced and later included in the Dash Two series.  The -2s came out in 1972 (the 40 series began in 1965).

An E-unit was an explicitly designed passenger unit, 6 axle with 4 powered axles (A1A-A1A arrangement), and two prime movers (diesel engines).  The F-unit was a 4 axle version with all powered axles, and one prime mover.  The F could be used for passenger or freight duty.  It's an advancement of the FT - the first diesel electric produced by EMC and later EMD (after GM bought the company and integrated it with Winton Engine).

MAC stands for Modified, AC traction (modified in this use is EMD speak for wide nose comfort/safety cab).

TTX is the name of a company that was previously known as Trailer Train.  The "X" is used at the end of AAR road designations for privately owned/non railroad owned freight cars.  So, Trailer Train's road designations were along the lines of ETTX, ATTX, DTTX etc.  They changed their name to TTX sometime around '93-'94.

U-boat is a railfan designation for GEs first generation of diesel electric locomotives, due to the fact that GE designated these as the 'Universal Series', i.e. U33C would be a 3,300HP 6-axle Universal Series unit, U23B would be a 2,300HP 4-axle etc.  GE used the U designation through the early-mid 70s, when they began using the recent convention of Dash series i.e. Dash 7 would be a unit designed in the '70s, Dash 8 would be a unit designed in the '80s and Dash 9 would be a unit designed in the '90s.  Now, GE uses the ES designation for Evolution Series.  ES44AC, ES40DC, ES44AH - the AH is a designation that CSX uses for units that have a special computer control software installed for adhesion control similar to UPs Controlled Tractive Effort software (i.e. C44ACCTE, C45ACCTE etc).  Are you confused yet?

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Posted by Matt Van Hattem on Sunday, September 28, 2008 1:13 PM

Thanks for the detailed response!

If you're curious about other initials, check out our listing on the Trains Magazine Web site in the ABCs of Railroading section.

This link is for diesel locomotives:

http://www.trains.com/trn/default.aspx?c=a&id=207

There's another section for railroad reporting marks that covers initials you see on the sides of freight cars.

Hope this helps! And thanks for posting.

Matt Van Hattem

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Posted by wrawroacx on Sunday, September 28, 2008 3:59 PM
Thanks, that really helps out now.
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Posted by Deggesty on Sunday, September 28, 2008 10:06 PM

Here is an answer to part of wrawroacx@windstream.net's question. The DD40X was the UP's Centennial locomotive (no other road owned any). The first units went into service in 1969, UP's centennial year. This was the largest diesel-electric locomotive ever built; it was so long that EMD could not build the frame. It had two 4 axle trucks, with every axle powered--hence the DD designation. "X" indicated that it was experimental. It had not one, but two 3300 horsepower 647 engines. All have been retired.

In the Trains article about this engine, I believe that it was David P. Morgan who said that if you looked inside, you would find a large number of men from EMD pedaling as hard as they could.

I wish I had been able to get a picture of one that I saw going through Lava Hot Springs, Idaho, back in the eighties.

You can put "Centennial Locomotive" into your search engine, and get more information.

Johnny

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Posted by challenger3980 on Monday, September 29, 2008 6:04 AM

DDA40X #6936, While not still in regular REVENUE service, is part of Union Pacific's Heritage Fleet, along with the 844, 3985 and the ABA E-9 set. The 6936 is commonly used for Business trains transporting UP Brass around the system. The 6936, has not been "Retired" but it is in Special Service use.

Doug

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Posted by wrawroacx on Monday, September 29, 2008 7:31 AM
 Deggesty wrote:

Here is an answer to part of wrawroacx@windstream.net's question. The DD40X was the UP's Centennial locomotive (no other road owned any). The first units went into service in 1969, UP's centennial year. This was the largest diesel-electric locomotive ever built; it was so long that EMD could not build the frame. It had two 4 axle trucks, with every axle powered--hence the DD designation. "X" indicated that it was experimental. It had not one, but two 3300 horsepower 647 engines. All have been retired.

In the Trains article about this engine, I believe that it was David P. Morgan who said that if you looked inside, you would find a large number of men from EMD pedaling as hard as they could.

I wish I had been able to get a picture of one that I saw going through Lava Hot Springs, Idaho, back in the eighties.

You can put "Centennial Locomotive" into your search engine, and get more information.

Please don't put my screen name on because I don't like that. Anybody please don't put my name down, put your comment in mine in quote, by pressing the quote button obove if you want to qoute somebody or me. Nobody ever do this again.

Tom My Videos - http://www.youtube.com/user/MrWrawroacx
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Posted by dehusman on Monday, September 29, 2008 10:27 AM

Please don't put my screen name on because I don't like that. Anybody please don't put my name down, put your comment in mine in quote, by pressing the quote button obove if you want to qoute somebody or me. Nobody ever do this again.
What difference does it make?  The way you set up your account your e-mail address appears on every post you make as your name.

Dave H.

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Posted by eolafan on Monday, September 29, 2008 10:35 AM
Well, aren't YOU so very special!
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Posted by zardoz on Monday, September 29, 2008 11:47 AM
 dehusman wrote:

Please don't put my screen name on because I don't like that. Anybody please don't put my name down, put your comment in mine in quote, by pressing the quote button obove if you want to qoute somebody or me. Nobody ever do this again.
What difference does it make?  The way you set up your account your e-mail address appears on every post you make as your name.

Dave H.

You'd think he would notice after 20-30 posts.

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Posted by eolafan on Monday, September 29, 2008 12:00 PM
 zardoz wrote:
 dehusman wrote:

Please don't put my screen name on because I don't like that. Anybody please don't put my name down, put your comment in mine in quote, by pressing the quote button obove if you want to qoute somebody or me. Nobody ever do this again.
What difference does it make?  The way you set up your account your e-mail address appears on every post you make as your name.

Dave H.

You'd think he would notice after 20-30 posts.

Like I said before, he is VERY special indeed!

Eolafan (a.k.a. Jim)
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Posted by Murphy Siding on Monday, September 29, 2008 1:00 PM

     Mr. Original poster, who wished that we not use his name:  Because your screen name has a symbol in it (@) it is impossible to use the quote button.  This same issue comes up, when I try to quote the forum user with the name Awesome!, because of the (!) in his name.  I would get a note that says:Non matching quote blocks in post  Because of that, another poster used your screen name.  Since your screen name has an E-mail address in it, the system lights it up in blue, and makes it a link.

      It might be wise, at this point, to change your screen name to something a little more system friendly.  I'm just trying to help.Smile [:)]

Thanks to Chris / CopCarSS for my avatar.

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Posted by BaltACD on Monday, September 29, 2008 3:26 PM

What does the F stand for in F7 or F3? What does E stand for in E8?

The EMD naming conventions began with the E unit -  The orignial 'streamlined' passenger engines built for the B&O were designated EA's by EMD - the E standing for Eighteen, as in Eighteen Hundred Horsepower.  The Santa Fe's subsequent passenger engines were designated EB's - the next series of engines were designated E3's, then E4's.  The CB&Q engines which had stainless steel fluted sheeting to match their Zephyrs were E5's.  The E6's were in reality the first series produced engines that were sold to a varitey of roads, with production being stunted account WWII.  The E6's were rated at 2000HP. The E7's were the largest selling of the passenger engines as the were the product available at the end of WWII when all the railroads began to dieselize their fleets in earnest and were also rated at 2000HP.  The E8's had many improvements over the E7's and were rated at 2250HP.  The E9's were the last of the series produced passenger engines and were rated at 2400HP.

On the freight side of the game, the orignal demonstrators of 1939 were designate FT models, with the F for Freight and the T being for Thirteen as in 1300HP (engines were actually rated at 1350HP per individual unit).  The FT was the only model sold until the end of WWII and the railroads that were permitted to purchase it and the numbers they were allowed to purchase with controlled by the War Production Board during the war years.  The first post war engine was designated the F2 and had detail improvements over the FT and very few were sold.  The F3 was the the main post war engine sold and was rated at 1500HP.  When the F7's began production in the late 40's they had many electrical improvements over the F3's and were also rated at 1500HP per unit, GP7 production was taking place concurrently with the production of F7's.  There never was an F8, with the next production model being the F9 which was rated at 1750HP, the same HP as the GP9's which were being produced concurrently with the F9's.  

There is a books available that explain both the E and F series of EMD engines in detail.  

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Posted by wrawroacx on Monday, September 29, 2008 6:15 PM

 eolafan wrote:
Well, aren't YOU so very special!

What do you mean by that, I'm going to change my screen name to wrawroacx.

Tom My Videos - http://www.youtube.com/user/MrWrawroacx
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Posted by wrawroacx on Monday, September 29, 2008 6:16 PM
 Murphy Siding wrote:

     Mr. Original poster, who wished that we not use his name:  Because your screen name has a symbol in it (@) it is impossible to use the quote button.  This same issue comes up, when I try to quote the forum user with the name Awesome!, because of the (!) in his name.  I would get a note that says:Non matching quote blocks in post  Because of that, another poster used your screen name.  Since your screen name has an E-mail address in it, the system lights it up in blue, and makes it a link.

      It might be wise, at this point, to change your screen name to something a little more system friendly.  I'm just trying to help.Smile [:)]

I'm changing my screenname to wrawroacx.

Tom My Videos - http://www.youtube.com/user/MrWrawroacx
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Posted by Deggesty on Monday, September 29, 2008 8:30 PM
 BaltACD wrote:

What does the F stand for in F7 or F3? What does E stand for in E8?

The EMD naming conventions began with the E unit -  The orignial 'streamlined' passenger engines built for the B&O were designated EA's by EMD - the E standing for Eighteen, as in Eighteen Hundred Horsepower.  The Santa Fe's subsequent passenger engines were designated EB's - the next series of engines were designated E3's, then E4's.  The CB&Q engines which had stainless steel fluted sheeting to match their Zephyrs were E5's.  The E6's were in reality the first series produced engines that were sold to a varitey of roads, with production being stunted account WWII.  The E6's were rated at 2000HP. The E7's were the largest selling of the passenger engines as the were the product available at the end of WWII when all the railroads began to dieselize their fleets in earnest and were also rated at 2000HP.  The E8's had many improvements over the E7's and were rated at 2250HP.  The E9's were the last of the series produced passenger engines and were rated at 2400HP.

On the freight side of the game, the orignal demonstrators of 1939 were designate FT models, with the F for Freight and the T being for Thirteen as in 1300HP (engines were actually rated at 1350HP per individual unit).  The FT was the only model sold until the end of WWII and the railroads that were permitted to purchase it and the numbers they were allowed to purchase with controlled by the War Production Board during the war years.  The first post war engine was designated the F2 and had detail improvements over the FT and very few were sold.  The F3 was the the main post war engine sold and was rated at 1500HP.  When the F7's began production in the late 40's they had many electrical improvements over the F3's and were also rated at 1500HP per unit, GP7 production was taking place concurrently with the production of F7's.  There never was an F8, with the next production model being the F9 which was rated at 1750HP, the same HP as the GP9's which were being produced concurrently with the F9's.  

There is a books available that explain both the E and F series of EMD engines in detail.  

Thanks, BaltACD, for explaining the "E." I had wondered about this for more than fifty years. I saw the explanation recently, but I had forgotten it and also I had forgotten where I put the article with the explanation.

Incidentally, there was a model designated "E2," which the Seaboard bought. If I could find my original Diesel Spotters Guide, I could check on the details of the E2.

Johnny

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Posted by CShaveRR on Monday, September 29, 2008 8:45 PM

Slightly incorrect description of who operated which E-unit models.

The EA and EB were both B&O.

Santa Fe had the E1 units.

The E2s were owned jointly by UP, SP, and CNW. for use on UP's Overland Route trains (and also the trains from Chicago to LA).

E3s were a fairly widely-circulated model.

E4s were owned exclusively by Seaboard Air Line.

E5s were operated exclusively by the CB&Q and its subsidiaries.

Subsequent models (E6, E7, E8, and E9) were bought by multiple purchasers.

Carl

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Posted by Transr on Sunday, December 21, 2014 7:52 AM

The link is no longer valid - is there an updated link?

Question at hand - What did the "F" stand for in "FT" or even "F7" - officially?
I've read F for Freight, F for "Fourteen Hundred HP (1,350 rounded up).  It would seem if E was for Eighteen Hundred HP, and then the F unit was built, would they not continue the pattern?  After all, N was for 900 HP and S was for 600 HP.

For the T in FT, below it is suggested it stood for Thirteen Hundred HP but I've heard also, Twentyseven Hundred HP (an AB set).  And then there is T for Twin, again suggesting the units were to be ran in pairs.

Thanks!

 

/Mitch

Matt Van Hattem

Thanks for the detailed response!

If you're curious about other initials, check out our listing on the Trains Magazine Web site in the ABCs of Railroading section.

This link is for diesel locomotives:

http://www.trains.com/trn/default.aspx?c=a&id=207

There's another section for railroad reporting marks that covers initials you see on the sides of freight cars.

Hope this helps! And thanks for posting.

Matt Van Hattem

Senior Editor

 

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Posted by Paul_D_North_Jr on Sunday, December 21, 2014 10:08 AM

"Locomotive Model Abbreviations - Deciphering an Alphabet Soup":

 http://trn.trains.com/railroads/abcs-of-railroading/2006/05/locomotive-model-abbreviations 

 

http://trn.trains.com/railroads/abcs-of-railroading/2006/05/understanding-railroad-reporting-marks 

Whole list of topics:

http://trn.trains.com/railroads/abcs-of-railroading 

- Paul North. 

P.S. - What I think of this new Forum software remains unprintable here !  The above was way too hard to accomplish, and I still don't like the formatting result. - PDN. 

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Posted by Wizlish on Sunday, December 21, 2014 10:28 AM

Can we have the link to "ABCs of Railroading" put into one or more of the fancy site menus, or at least made a 'sticky' somewhere? 

There are many things that can be added to this feature, too (not least among them, having the topics actually list in alphabetical order).  If I were doing a feature like this, I'd put cross-referencing in the topic list, too.

Thanks, Paul, for finding a link that worked.  (I didn't succeed at finding it, so I appreciate how hard it must have been...)

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Posted by Paul_D_North_Jr on Sunday, December 21, 2014 11:37 AM

The link - and the list - can be found by "mousing over" /clicking on/ under "RAILROADS" in the black bar at the top of the page;

then over at the right-most column, under "FEATURES",

the bottom one is "ABC's of Railroading".  

Not intuitive, but find-able with a little looking.  Still, it really should be instead under "Resources" in the tiny little font at the upper right corner . . . 

But the part that really annoyed me was trying to get rid of the headline's large size font and the bold text - it's 'locked' somehow, so all I could do was re-type it into a more normal format and then delete the big stuff.

It's just as bad when I quote from the "Magazine Index" results - too much of that "table" formatting comes through, and is practically impossible to edit out to avoid a lot of double-spacing and single-spaces between lines where they aren't wanted - perversely, each is where the other one is wanted !

- Paul North.      

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Posted by Paul of Covington on Sunday, December 21, 2014 1:34 PM
Having worked in the hardware end of computers for 30 years, for at least 29 years I kept saying to myself, "Programmers think weird."

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