Would it be unrealistic to run an EMD F3/A unit with a EMD F7/B unit? I believe both the F3 and F7 were 1500hp and some of the modifications made to the F7 were “under the hood” but was this done or could it be done in the real world.
Still learning much about this great hobby!
Thanks,
To my knowledge, EMD units all work together, electrically. Braking systems are different, but M/Uing units electrically doesnt seem to be too much problem. Im sure mating an F unit to a brand new AC loco might be a problem. But certainly any of the F series would work together no problem.
I am sure if you search enough, eventually you will come across a picture showing and F3 mated to and F7. Ive seen SOO mate SD40s with FB units. 20 years difference, but there they were.
BTW, the changes in the F7 from the F3 were alot more than under the hood. Alot of external changes were made aswell. The easiest to spot is look at the radiator fans of an F3 compared to an F7. Tall vs small. The grilles are different too.
Classic Trains just put out an issue covering the F series. And i must say it was extremely impressive!
PM Railfan
Back in the day, when they where all relatively new, the railroads that had them mixed F3’s and F7’s without any thought at all.
While the F7 was the newer, improved version, they all worked together just fine and it was very common on roads like the B&O or the ATSF to see F7’s and F3’s mixed together.
Sheldon
There are no major issues to stop any one unit from running with any other unit in an M.U. lashup. This may not apply to some early units before M.U. connections were standardized, as some builders had different ones - I can think of Baldwin off the top of my head.
Think of it as if you were a locomotive, pulling a string of (very light) cars with a rope. Add a really burly guy onto the rop, and you’ll be able to pull it a lot faster but there won’t be any issues because of your size difference. If you have a strong guy who can run really fast, you’ll just have to be dragged along for the ride, but that’s a gearing issue more than anything and there were runs designed for engines geared to passenger speeds that lower geared engines weren’t employed on.
As far as I know, the main issue for M.U.ing different locomotives (at least today) is wheelslip. With some engines having a better grip on the rails through basic design or computerized wheelslip systems, an engineer may be in a locomotive that’s gripping the rails where another unit is spinning out.
It was common for railroads to inter-mix F7’s and F3’s along with other locomotive models, too.
Don’t forget the Western Pacific they ran F3/7 A&B units together running the California Zephyr. It was very rare to see an complete F3 or F7 set.
'Way back when, MR had a letter to the editor with the heading,
“Diesel Amaze You,” noting that railroads were running all sorts of engine consists of EMD locos. I lived in Waukesha, WI, as a kid and saw all sorts of combinations on the three roads that criss-crossed the city, Soo Line, CNW, and MILW. Of the “First Generation” I saw F3s, F7s, and Geeps in such “lash-ups (a model RR term)” of F3s and F7s, which only a modeler or railfan would know, because the units look so similar. You might see an A-B-A; A-B-B; A-B-A-A; A-B-RS (road switcher)-A; RS-B-RS—anything yiou can imagine, and then some! Motive power superintendants grabbed anything they had on the ready tracks to make up the necessary power—and they didn’t care how it looked! General Motors and ALCO used the same pneumatic transition controls, as well as electrical hookups, so they could be MUed, but Baldwin diesels used different switching arrangements and couldn’t be MUed with either of the others. (Several roads later replaced the Baldwin switching units with the Pneumatic boxes so they could MU them with the others.) I’m not sure about GE diesel locos, but maybe there’s an Old-Timer in the Forum who can tell us.
BTW, after I closed my HO model RR shop, a retired Soo Line engineer had me build models of his three favorite steam locos, a Mikado, a Pacific, and the first loco he fired as a rookie fireman, a dandy little 0-6-0 with a Belpaire Firebox and a a “square” tender instead of a sloped back job. I also built him a passenger train of Athearn heavyweights and F7 AA set all in the old maroon and gold livery. I always liked the looks of the EMD stuff—I kinda think of F3s, F7s, and Geeps as “Honorary Steam Locos”—and would still like to get my hands on an O scale model of an All-Nation F7A and B set. I also loved the ALCO flat-nosed F units and those greyhound-looking PA
Iirc there was a difference in the traction motors and if coupled an f3 had to lead to prevent burning out the traction motors on long pulls on the f3s as f7s were capable of higher longer sustained red line running.
Thanks for the informative responses, I appreciate it!
Hi,
Like a lot of MRs, I much prefer running my F and E units in matching consists and in “proper” order (i.e. AA, ABA, ABBA, ABBBA). At first, the prototypes tended to do this too, especially on name / important trains - be it passenger or freight.
But by the mid '50s it got to the point that whatever unit was most easily available and appropriate was used, in whatever order they fell in. The only criteria (other than mechanical matching - electrics, gear ratios, etc.) was of course that a A type unit led the way.
Short answer, no it is not unrealistic.
In the early days of F units, they did tend to be run together as they were purchased in sets of F3ABBA, AB, ABA etc, same for F7’s. But as time went by, the “building block” concept of putting together power sets became more and more common. By the 1960’s, it was very common for RR’s to run mixed sets of F7’s of various types.
Of course it’s your model RR so you don’t even have to follow what the prototype did, but if you are trying to follow them, do a little research and find out what they did. Time frame matters somewhat, as I alluded to above. The D&RGW did mix up their F sets, mostly in the 1960’s. They even ran GP7’s and GP9’s in the middle of an ABBA set and called it the Pearlman Mallet, named after Alfred E Pearlman who was running operations for a while before heading back east.
Here are a few examples of mixed vintage F units:
http://www.rr-fallenflags.org/bo/bo4404.jpg
http://www.rr-fallenflags.org/bo/bo4463ads.jpg
And here are some runnig with some ALCO units:
http://www.rr-fallenflags.org/bo/bo4517.jpg
http://www.rr-fallenflags.org/bo/bo4555.jpg
Sheldon
The MoPac had a branchline through north Omaha and I can remember many a time being stopped at the grade crossing on California St. and seeing just about every kind of AB lash up you can imagine. Of course there was an A unit in front but after that it seemed like it was anything goes. You might see an AABA and the trailing A units might be pointed in either direction. Back then I knew nothing about differences between FTs, F3s, and F7s. They were all just diesels to me.
Some roads ran F units with Gp 7s and 9s, or Alco RS 3s and 4s.
Hey, I forgot: I know of two documented cases of B units pulling trains! One of the western roads had a B unit specially modified—headlight and windshield wiper on the engineer’s window, etc.—that came into Sterling, CO, as part of a regular consist on a longer train (passenger), then left town on its own, pulling a few cars from the original train. I can’t remember if it was the Clinchfield or the B&O who had a B unit with a windshield and headlight stationed at a yard somewhere in a coal country yard in the mountains of VA-WV. All B units had rudimentary throttle and brake controls next to the door in one end—I presume the hostlers looked out through the open door to move the unit around the engine yard, but those two were outfitted for mainline running. The Colorado unit even had a streamlined fairing around the headlight and special paint job!
Deano
Rock Island AB-6:
http://en.wikipedia.org/wiki/EMC_AB6
You’re talking about the Haysi Railroad I think. They were a shortline serving a coal mine and used an ex-Clinchfield F7B as their sole power.
http://www.rrpicturearchives.net/showPicture.aspx?id=1443619
Rock Island Railroad’s Rocky Mountain Rocket passenger train had an unique EMD AB6 locomotive http://www.american-rails.com/rocky-mountain-rocket.html (scroll down for photo) Two were built by Electro Motive from E6B 's.
The train ran from Chicago IL to Lemon CO where it was split with the main section going to Denver. The other section went to Colorado Springs behind an AB6.
Then I would assume an F9A-F3B-F3A would be OK?
Several years ago a friend told me the CB&Q bought FT ABBA sets in the WWII years and found that they had more power (5400 h.p.) than needed. On the other hand, two unit sets (2700 h.p.) weren’t enough. They decided three unit sets would be best for their purposes. Problem was, the B units had couplers between them; but the A units were connected to their B mates with drawbars, so breaking them into 3 unit sets was a problem. The solution was to buy a bunch of new F3A units shortly after the war, one F3A for each FT A-B set. This gave them an FTA, 1350 h.p.; an FTB, 1350 h.p.; and an F3A, 1500 h.p., giving them 4200 h.p. per set. I don’t know how long they ran like this before these sets were broken up.
Maybe Garry can confirm this.
Tom
Thanks, Chris, Since I lost 112 years of model RR/prototype magazines, I have no way to find much of anything these days. All I have left are MR bound volumes from 1945 through 1961 and a couple of years or so of loose copies (complete years) and specific individual issues of immediate interest to me. I somehow connected that RI modified B unit with Sterling, probably because of that very expensive, very complete kit to build the Sterling roundhouse, but the instant I saw “Limon,” I saw the light flash. (I had a cousin, a long-haul trucker, living in Limon, forty years ago.)
And Haysi it is, too. It was mentioned in a sidebar in MR’s Clinchfield railroad project. Thanks again.
Deano