I have got some F3A, F3B, F7A and F7B. How can i mix and match that engines from point of view of technical capabilities?
Another question is how did NYC mix and match that engines?
I cannot speak to New York Central’s practices, but in general, so long as the gear ratios on the prototypes were the same, there was no problem mixing any F-unit model with any other. On the railroad I model, the Great Northern Railway, F-units were mixed and matched almost indiscriminately. Even FTs eventually wound up being consisted with later models. In fact, as time went on, GN would purchase F7B units to place between former A-A sets of F3As-then renumber the F3 sets to reflect the new 4-unit arrangement. Basically, it all comes down to gear ratios bing the same. GN (and Northern Pacific) even went so far on occasion, to regear older passenger power to freight gear ratios and renumber and re-assign the unit to freight service. Hope this helps.
Many railroads bought F units in two-unit sets, either A-A or more commonly A-B; sometimes with a drawbar between the two and sometimes regular couplers. (FT’s were originally designed to only be available in A-B sets with a drawbar between the two.) Often they bought sets to run together, treating an A-B-B-A set as one locomotive. However, most railroads realized pretty soon that there was an advantage to be able to mix and match engines to get the right horsepower for different situations, so set it up so their A and B units could all be mixed together.
So seeing an A-B-B-A lashup of an F3 A-B set and an F7 A-B set would be normal, but it might also be a mixed bag - F3A-F7B-F3B-F9A for example. Some railroads didn’t put m.u. connections on the nose of their cab F-units (like Soo Line) so A units could only be found at the end. Otherwise other roads would mix A and B units together. NP used to use an A-B-A set of F units on the North Coast Limited in the flatter country of MN-ND-Montana, then add a third A unit for the mountains, so A-A-B-A lashups were common.
F units are essentially interchangeable (except for FT’s which came as semipermanently couple AB sets).
Looking at the F unit pix in Sweetland’s “Lightning Stripes”, F units were mixed interchangeably with GP7’s/GP9’s
Dave H.
More examples from a non NYC RR.
Rio Grande purchased nearly all of there FT’s F3’s F7’s and F9’s in ABBA sets. Only two F7 sets were bought ABA and then later filled out to ABBA sets with 2 extra F9 B units.
Some of Rio Grande’s FT’s were delivered with draw bars and some with couplers between the A and B unit. So not all FT’s were drawbarred together.
Rio Grande ran the F’s mostly in ABBA sets in freight service during the first 10-15 years. A few F’s were ran in AB sets in passenger service or rarely freight. In the late 50’s and early 1960’s, Al Pearlman, who incidentally later ran the NYC, began making up power sets for freight trains on the D&RGW using F7AB-GP7-F7BA sets. They were coined Pearlmen Mallets. By the mid-1960’s as hood units were taking over in numbers, F units were cobbled together in all and any combination to get enough power to get heavier trains over the summits at Tennesee Pass and Soldier Summit. You might see and ABABA set on the front and and ABABBB-GP9 set mid-train. Quite fascinating to watch on the DVD set Rio Grande Odyssey.
As for mixing FT F3 F7 and F9’s, it wasn’t taboo, but as it turns out, mostly it didn’t happen. FT’s were kept together. There were only 3 F3ABBA sets which were used virtually their entire lives for passenger only service. Only during the last year or two of operation could they be seen with F7’s or F9’s. I’ve seen maybe one F3AB-F9B-F3BA set, and in the last 4 months before retirement an F3AB-F7BA set pulling the California Zephyr. F9’s and F7’s were mixed freely.
A lot of railroads found that three FT’s would be “just right” for freight service, but they were originally only available in A-B sets with drawbars (there wasn’t even a door between the A and B units - if you disconnected the two, one end would be open to the elements) and one A-B set didn’t have enough power, and a full A-B+B-A consist had more than needed. Some railroads did make special orders for FT A-B-A sets using a special short B unit (the FTSB) from EMD, but right after WW2 many roads bought F2 or phase 1 F3 A units to make an A-B-A lash-up with one FT A-B set and one F2 or F3. Not sure if NYC did this or not??
I could have sworn that I read somewhere that F3s could not lead F7s or vice versa. This was in regards to Santa Fe running practices. I think it had something to do with MU controls. Maybe somebody could correct me on this or verify this info??
That might have been something specific to Santa Fe units?? Maybe they had some F3’s that didn’t have m.u. connections in the ‘nose’ of the A units so they had to be in front or something?? It wasn’t uncommon that railroads ordered cab F units without m.u. connections in the front, only in the rear to connect to a B unit.
I think you are on to something there. I do believe that it was specifically in regards to an A leading an A. I am going to have to try to dig something up on this.
I checked a couple of books over the weekend at home. I was able to find a pic of a NYC FT A-B set in an A-B-A lash-up with an F7 A unit; I also found a pic of two F7A’s each in a consist with an F3B. Appears NYC was pretty liberal on mix-and-match consisting of F units. Actually, given how many different manufacturers they bought from in their rush to dieselize (Alco, Fairbanks-Morse, Baldwin, GM-EMD and GE) I imagine lash-ups of all kinds of stuff would be possible!! [:)]
Read somewhere that the mu voltage of F7/F9:s would fry a F3/FT:s mu if the F3/FT was not rebuilt to handle the F7/F9:s higher mu steering voltage. Local rebuildings and also a “kit” from the manufacturer alleviated the problem pretty early on. F3/FT:s could however be controlling F7/F9:s since the problem only occured when a F7/F9 was in the lead.
Greetings Hans from Sweden
Reinhard,
I have an New York Central DVD showing footage of a couple of F7s(?) being consisted with some Geeps. (The Geeps are in the inside with the F7s on either end.) It was very strange looking to see, to say the least.
Tom
You are correct about mixing units. It had something to do with the controls and i don’t remember what it was. they were totaly compatible but the F7 had more throttle positions (I think) so when used together the F3 had to be the contorl unit. I have to think about this to come up with the reason.
In the mean time I got the “Enginemen’s Operating Manual Model F7” from EMD.
It says in §330 that FT, F2, F3 and F7 can be mixed as you like.
That follows a list of conditions to be met or to be observed. e.g. same gear ratio, transition indicator of leading F7 does not show correct values for trailing F3 etc.
From point of view of us modell railroaders we can mix and match as we like!
Thank you all so much for your help[:)]
Hi,
I agree with the previous postings, in that as long as the gearing matched up - and the MU connections were ok - then pretty much anything goes. Growing up in Chicago I saw a lot of this in the '50s-'60s with several different roads, and not only with F units, but with GP/SD units too, all mixed together!
Having said that, I really have a hard time having a consist on my ATSF layout that is mixed up, as the asthetics just don’t look right to me. And yet I fully realize - that except perhaps for name trains - the prototype RRs really didn’t care what locos they used, just so long as the power was appropriate. But, IMHO, they just don’t look as nice as the “same unit, same paint scheme” consists.
FWIW…
Mobilman44
I remember what it was now. The F3 engines had a lower amperage traction motor rating then the F7s. So when watching the ammeter when running an F7 if there was an F3 in the consist it could be burning up the traction motors. I suspect that eventually they were all replaced with the newer version but until they were this was a potential problem.
I do recall that this was a problem that was discovered early on in the game, and was “fixed” over time.
I’m not a expert on this, but aren’t B Units simply a locomotive without a cab. If that’s the case, all things being equal as mentioned about gear ratio’s, a B Unit should run with any other locomotive, just like running an SD-40 with a C 40-8. If not, why not?
Ray
Yes that’s not a problem, I’ve seen pics of a GP-F7B lash-up. Well except that some early F units were purchased in A-B sets with a drawbar between the two, so they always had to run together. Most railroads later replaced the drawbars with couplers so the A and B units could be put in separate consists, or one could go to the shops while the other kept running.
BTW it wasn’t unusual to see a long train with engines from two or three different manufacturers m.u.'ed together in the fifties-sixties.
On the prototype, even the gear ratios did not have to match. Since every powered axle had its own independent motor, locomotives of different gear ratios could run together, anf they would synchronize.
What an engineer had to be aware of, though, was the traction motor ratings for the various units so he wouldn’t overload either load or speed ratings (in theory, anyway - I found out that if a chief dispatcher tells you you have all the power you need, he’s the expert and there’s no way an engineer can burn up a traction motor, no matter how much amperage it pulls.
SHABBONA_RR