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Alco FB-1 and B unit for EMD F3/F7/FP7 -- how similar are they?

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Alco FB-1 and B unit for EMD F3/F7/FP7 -- how similar are they?
Posted by crossthedog on Wednesday, January 12, 2022 12:11 PM

"Uh-oh, why is he asking this?"

Well, I am eyeing Bowser's forthcoming F7 A unit in SP&S "red top" livery. The accompanying B unit is apparently not being offered for this road, but I often see dummy or powered SP&S red top B units for Alco's FA-1 offered on eBay, and they look almost identical to the EMD B units for the EMD F series. At least, I have not yet learned to see what must be obvious and glaring differences. Yes, your worst fears are realized; I was asking because it occured to me I could buy an FB-1 to hitch to my wagon, as it were, and was wondering how soon it would be before I started internalizing the seriousness of my crime.

-Matt 

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by wrench567 on Wednesday, January 12, 2022 12:46 PM

  It's your railroad. You can do what you want. But if you're looking at prototype operations you have to think like a railroad operations manager. Most smaller roads didn't bother with cables B units and opted for cab units that didn't need turning. And also standardize on the fewest manufacturers to keep supply chains simpler. I'm not an SP&S modeler. I don't know what or how they ran their locomotives. Larger roads had the need to dieselize quicker and bought from anyone who could deliver and experimented with operating them.

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Posted by doctorwayne on Wednesday, January 12, 2022 12:58 PM

An ALCo FB is about as similar to an EMD B-unit, as an ALCo FA is to an EMD A-unit.

If you're planning to buy the F7 A-unit in that paint scheme, why not buy an undecorated  F7 B-unit, and then paint it to match the A-unit.

I'm not all that familiar with the SP&S, but if they also used ALCos (in that paint scheme) I can't see any reason why you couldn't run an ALCo B-unit with an EMD A-unit.  Some manufacturers' mu-systems were not compatible with EMD's, but ALCo wasn't one of them.

Wayne

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Posted by 7j43k on Wednesday, January 12, 2022 1:13 PM

SP&S had one E7A and 3 F3A's and 4 F7A's.  They had no EMD B units.

These were all used (usually) for passenger service only.  They had steam generators.

 

The SP&S Alco F's were all freight engines.  They had 18 FA-1's, 2 FA-2's, 12 FB-1's and 2 FB-2's.

The Alcos and the EMD's were rarely mixed.  But.  You COULD run an EMD F in freight, as a "that's all we have available and it's just sitting there" solution to a problem.

The usual power for a passenger train was two A's.  

 

Ed

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Posted by cv_acr on Wednesday, January 12, 2022 2:02 PM

crossthedog
Well, I am eyeing Bowser's forthcoming F7 A unit in SP&S "red top" livery. The accompanying B unit is apparently not being offered for this road, but I often see dummy or powered SP&S red top B units for Alco's FA-1 offered on eBay, and they look almost identical to the EMD B units for the EMD F series. At least, I have not yet learned to see what must be obvious and glaring differences.

They are not. Not a single detail is similar, except for the overall impression of a blocky unit with a rounded roof.

However they are *compatible* and can run with each other.

The last poster above me has given good information specific to the SP&S fleet and usage.

If you were trying to model what should be an F7B unit with an FB-1 body, I would recommend against that. But if you want to run a F7A coupled to an FB-1 there's nothing technically wrong with that. Plenty of railroads ran mixed-builder consists.

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Posted by gmpullman on Wednesday, January 12, 2022 2:08 PM

Some photos here:

http://www.rr-fallenflags.org/sps/sps.html

Scroll toward the bottom of the "locomotives" list.

Good Luck, Ed

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Posted by crossthedog on Wednesday, January 12, 2022 5:36 PM

Thanks to every one of you. Great information. I was trying to formulate a response to the first two respondents, but cv_acr really hit it on the head here:

cv_acr
If you were trying to model what should be an F7B unit with an FB-1 body, I would recommend against that. But if you want to run a F7A coupled to an FB-1 there's nothing technically wrong with that. Plenty of railroads ran mixed-builder consists.

Yes, the first is what I was contemplating. I wasn't asking did real railroads ever mix an A from brand Alco with a B from brand EMD (although we see it might have happened historically once or twice in a pinch)... I was really considering PRETENDING (cuz that's a good bit of what model railroading does) that the EMD B model was an Alco B, and specifically asking how long it would be before an educated visitor to my pike blinked and pointed and said "hey! Liar!"

But now I have an answer to both questions and learned a good deal, too. Looking more closely, I see that the Alco had just one porthole in the center, up high, instead of the row of several portholes below the grill. Also, for some reason the truck placement looks somehow different, but I don't know. They both sort of look like (I had to chuckle) "a blocky unit with a rounded roof".

-Matt

 

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by crossthedog on Wednesday, January 12, 2022 5:41 PM

doctorwayne
An ALCo FB is about as similar to an EMD B-unit, as an ALCo FA is to an EMD A-unit.

Smarty pants.

doctorwayne
If you're planning to buy the F7 A-unit in that paint scheme, why not buy an undecorated F7 B-unit, and then paint it to match the A-unit.

I could do that. Maybe. Someday. I'm not well equipped for painting, either tool-wise or skill-wise. How 'bout I send you a B shell and some decals and YOU paint it for me?

-Matt

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by Lastspikemike on Wednesday, January 12, 2022 6:22 PM

I have one of each, both Rapido models. 

The FA B Unit is 1/2" longer, does not have the larger porthole windows and the roof profile is noticeably different. 

If it were me I'd buy two A units and wait for a B Unit to come out, if ever. Or buy the Rapido version if it comes in your road name. Many railroads bought far fewer B units than A's and ran two A's in preference, no need to turn the consist for return trips was a big plus.

Also, the A units were more flexible in use as each unit had full cab controls. The cab units were often consisted with GP or RS hood units in the days when both styles were popular, possibly crews liked the comfort of the cab versions? 

If you're trying to create the look of an FA consist with an A and B then I don't think you'll be happy with the look. Too different, especially the extra length.

If on the other hand you're creating the impression of a railroad suffering from a shortage of matching power then go for it. The CPR mixed MLW (Alco) units with CLC (FM units) on occasion out West in the mountains. Those two types would be more different to each other than EMD and Alco units. The FM power units were known for their good pulling power compared to either EMD or Alco.

Alyth Yard

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Posted by dehusman on Wednesday, January 12, 2022 10:34 PM

crossthedog
They both sort of look like (I had to chuckle) "a blocky unit with a rounded roof".

Its one of those they look the same except for all the details.

The FA has a flatter roof profile.  The FA has one large fan at the end, the EMD has multiple fans along the roof.  The FA has one door in the center, the F&B has two doors, closer to the ends.  They have very different fuel tank shapes.  They have very different truck designs.  They have different grills along the side, with the Alco having a section of vertical shutters and the EMD having grills or "chicken wire".

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by NHTX on Wednesday, January 12, 2022 10:50 PM

     This may not matter to the OP but, era matters in many cases.  Early in the diesel age, when cab units were the rage, railroads like to run them in like, matched sets.   EMD F-units with like EMD F units, ALCo FAs only with other FAs.  When the versatility of the road switcher was realized, things changed.  Suddenly the F-3, F-7 and FA-1 simply became a 1500 HP building block for assembling a power consist.  As long as certain parameters were met, road switchers began to infiltrate these streamlined power blocks, as it was realized that under the hood, it was the same basic machine as occupied the stream-styled carbody.

     It didn't take crews long to discover the utility of the roadswitcher, especially on those trains that did a lot of picking up, and setting out.  A cab unit is a real PITA to switch with, even when modifications were made.  Hence, cab units became "filler" used in building these consists, and hood units could replace unavailable B units otherwise. I have seen many photos of Colorado and Southern SD-9s splicing what would otherwise be an A-B-B-A powerset.  By the end of the F unit's days, on most roads a pure cab unit consist hadn't been seen in years, although Chicago Great Western comes to mind, as having no reservations about coupling six or more A and B units together, to get the needed horsepower, well into the SD-40 days.

     An interesting illustration of why the railroads initially tried to keep like models of the same manufacturer together can be found on the New Haven after they took delivery of their FA/FB-1s and subsequent RS-3s.  Originally, it was figured 4500 HP would be sufficient on their Maybrook NY bound freights.  Car capacities were on the rise, and with only 15 B units but 30 A's, and trains getting much heavier than originally figured, three units were not enough.  Simple fix-add one of the 45 RS-3s to the consist.  Not so fast, Batman!

   Now, it was the RS-3, with its 1600 HP that was taking the beating.  The fly in the ointment came from two factors of 1940s-1950s diesel technology.  The RS-3s were dual service, freight-passenger locomotives, geared for 80 MPH.  The FA/FBs were freight engines geared for a maximum of 65 MPH.  Picture a six foot tall runner, in harness with three five footers.  Not as harmonious or "smooth" as four, five footers or, four six footers.  Not only did the mix of units "fight" amongst themselves coming down hill, the FAs could fry the traction motors of the higher powered RS-3s, lugging up that hill.  Locomotives have a minimum speed at which they can operate, based on their gearing.  This is known as "minimum continuous speed".  When lugging, maximum amperage is fed to the traction motors, causing tremendous heat build-up and, if the blowers can't cool them fast enough, lots of smoke may result.  MCS is directly related to gearing-at least on units with DC motors-this new-fangled AC stuff?   You're on your own!  The higher speed a unit is geared for, the higher its MCS will be.

    In the New Haven's case, the 15 MPH difference in MCS caused more problems than were solved.  What to do?  Go back to ALCo for five more FB-1s!  Nope.  We don't build that model anymore.  They opted for five FB-2s instead.  Just B's, no A's.  And, the FB-2s outlasted the New Haven, going into Penn Central in 1969.

     Points to be taken:  Buy enough B units, when you are in the store.  If you don't, it is OK to run later model B units without rostering the corresponding A's!                  

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Posted by crossthedog on Thursday, January 13, 2022 11:33 AM

Thanks Mike, dehusman, and NHTX for all this info. I would have thought this was a dumb question and I almost didn't post it, but as it turns out, I've learned a lot reading your responses. Mike, I cannot afford two of the F7As coming out from Bowser, but I appreciate you and others pointing out that the prototypes -- especially Spokane Portland and Seattle -- would more likely have had several As back to back than an AB pair. There are also nice photos of SP&S' old F7A crawling along the Columbia as the only power on a local consisting of a boxcar and two or three passenger cars.

Much as I'm an Alco man, I don't much love the look of the FAs. Consequently I have not heretofore given the FBs the time of day. It was just a thought... but one that paid dividends in historical perspective. Thanks all!

-Matt

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by SD70Dude on Saturday, January 15, 2022 12:26 AM

The problems that NHTX mentioned were solely due to the gear ratio difference, not the locomotive types.  New Haven could have re-geared the RS-3s for a lower top speed and achieved the same result.  

For a real-world example of mixed consists, look up some photos of Canadian National's passenger trains in southern Ontario and Quebec during the 1960s.  During that time you could get any mix of passenger-geared units from three different manufacturers, mostly streamlined but GP9s, GMD1s and RS-18s would also run in passenger service on a daily basis.

Here's a A-B-A consist where each unit is from a different manufacturer:

http://www.railpictures.ca/?attachment_id=27522

While the FM/CLC units were gone by 1970, CN and VIA continued to run mixed consists until the MLWs were retired in 1989.

http://www.railpictures.ca/?attachment_id=30720

Greetings from Alberta

-an Articulate Malcontent

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Posted by 7j43k on Saturday, January 15, 2022 8:31 AM

SP&S EMD's F's were geared for 83 MPH.

SP&S Alco F's were geared for 65 MPH.

 

If the EMD was leading, then the engineer could watch it's ampmeter.  The trailing Alcos would not be having a problem.  

Of course, if you're adding the EMD because you need more power, you just gave yourself less power on the Alcos.  At a very rough guess, 22% for each unit.  With only two units, you're ahead with adding the EMD.

 

Ed

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Posted by wjstix on Monday, January 17, 2022 2:54 PM

crossthedog
I wasn't asking did real railroads ever mix an A from brand Alco with a B from brand EMD (although we see it might have happened historically once or twice in a pinch)... I was really considering PRETENDING (cuz that's a good bit of what model railroading does) that the EMD B model was an Alco B, and specifically asking how long it would be before an educated visitor to my pike blinked and pointed and said "hey! Liar!"

I think it's not so much a question of how long until someone noticed one was an EMD engine and one was an Alco, but rather how long until someone knew it was wrong...assuming on the SP&S it was wrong?

EMD and Alco locomotives were completely compatible, and seeing EMD and Alcos mixed together in a consist didn't happen once or twice, it happened every day. It would look perfectly normal to see an EMD F-unit and Alco B-unit together. 

Remember too SP&S was a relatively small, rarely modelled railroad. Even if what you're doing were 'wrong', probably only one of the few experts on the SP&S would know it. 

Stix
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Posted by crossthedog on Monday, January 17, 2022 4:36 PM

wjstix
Remember too SP&S was a relatively small, rarely modelled railroad. Even if what you're doing were 'wrong', probably only one of the few experts on the SP&S would know it.

Except that I just went and blabbed about it, eh? But seriously, I don't expect that many SP&S experts are that interested in visiting my little spur in the garage, so probably this is a nonissue. But as I said before, I learn a ton asking these questions.

-Matt

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by wjstix on Monday, January 24, 2022 3:07 PM

Key point is, if SP&S had both engines (as apparently they did), it isn't wrong to run them together. I think what's confusing you is that some railroads did connect say F3 A&B units with a drawbar and keep them together, but that's not a requirement. By the later 1940's most railroads used couplers on A and B units so they could mix and match with other engines. Alco and EMD engines could m.u. together quite easily, and very often did. 

(addition)

Maybe this will make my point better. Say you had an open house and 100 model railroaders visited your layout. You tell them that the F7A-FB consist is really an F7 A-B  consist. Probably 100 of the 100 would give you a funny look and then point out 'no, the B unit is an Alco' and they'd chuckle about you behind your back. Embarrassed

However, if you ran the F7A unit with FB unit, maybe one person would point out that SP&S rarely if ever did that. The rest would think it looks good, since SP&S did have both kinds of engines, and railroads ran Alcos and EMD engines together literally every day. They'd think very positively about you and what a great modeller you are. Bow

So given the option of doing something 100% wrong (pretending the Alco is an EMD) or something 99% right (running accurate models of real engines together), I'd go with the latter.

Stix

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