Loco Designations F, E, P,SD Etc

[scubaterry]

I was wondering if there was a diffinitive source for an explanation for all of the designations I see assigned to Locomotives. I always thought (in my four years of MRRing) that F would mean Freight, P would mean Passenger. obviously that is not the case. I just purchased an FA1/FB1 NYC LL P2K set to be used for Freight hauling. I'm wondering now if that will not be the case. If someone could enlighten me on a source I would appreciate it. Of course my layout is so far from prototypical that this additional boo boo will not matter.
Terry[8)]

[nbrodar]

Different manufacturers use different designations:

EMD Cab Units
E - (6 axle) Passenger
F - (4 axle) Freight although many western roads equiped them for passenger service.
Sub designators
A indicated a cab
B indicated a cabless unit

EMD Hood Units
GP (4 axle)
SD (6 axle)
F (4 or 6 axle) cowl unit
Sub designators
P - passenger unit
H - head end power equipped
B - cabless
M - wide cab
AC - AC traction motors

Alco Cab units
P (6 axles) Passenger
F (4 axles) Freight
Sub designators
A - Cab equipped unit
B - Cabless unit

Alco Hood units
RS (4 axle) Freight and Passenger
RSD (6 axle)
C - Freight (the number following the C indicated # of axles)

GE
B (4 axles) Freight
C (6 axles) Freight
P (4 or 6 axles) Passenger
Sub designators
W - wide cab
H - head end power equipped
AC - AC drive

Freight units sometime pinch hit in passenger service. Displaced passenger units usually ended up in freight service.

Hope this helps.

Nick Brodar

[scubaterry]

Nick - Thanks for all the info. I didn't mean for you to type in all that info. That was a lot of work for you. But it is helpful. So if I have an "F" unit and I count the axles it will tell me if it was for Freight or Pass service? 4 = Fr, 6 = Pass? Is it really that simple? Where could one find additional info on this subject (no don't type it in just point me in the right direction).
Terry

[Darth Santa Fe]

The F-units were used for both freight and passenger service. The most famous ones were the ones used in passenger service, like the Super Chief for example.

[jrbernier]

Terry,

It is not all that simple. E units have 6 axles, but 2 of the are 'idlers' with no traction motors. SD units do have 6 powered axles. The reasone for the 2 'idler' axles on the E series was:

o - Spread weight and keep the total axle loading under 50,000 lbs.

o - Provide a 'long' truck to give improved tracking/smooth ride to the engine crew at
speed(E series units could be delivered with 117 mph gearing).

When EMD released the first 'F'( the FT) in 1939, it had all of it's weight on the powered axles for maximum continuous tractive effort. A high speed 'ride' was not an issue as the design market was for a slower freight engine. That said, many FT's were delivered with a S/G in the 'B' unit and considered 'dual service' units. A 4 unit set of FT's delivered 5400 hp, and were marketed as a competitor to the 5,000-6,000 hp 'Northerns' at the time. Most early freight units were 4 axle units; higher hp 6 axle units capable of providing 'unit replacement' on a 2 for 3 basis started to be delivered in the mid to late 50's. By the 60's, 6 axle freight engines were now on the mainline road freights. Also by the 60's, most engine orders were for freight units. A handful of 'E' units were built in the early 60's. Alco's 'PA' series had been dropped from the catalog years ealier.

Jim

[trainboyH16-44]

The real passenger units of the 40s and 50s were the E units (6 axle) and the PAs (Also 6) The FA and F units were used for both/.
SD= Special Duty
GP=General Purpose
Other all passenger units were the GE P series, and the aforementioned by nbroder P in the title. Any specific questions?
Matthew

[nbrodar]

For more detailed information you might want to check out a copy of Kalmbach's Diesel Locomotives, the First 50 Years.

Nick Brodar

[scubaterry]

All right, clear as mud! I guess I need to do some reading. The question in my mind that started this was the LL P2K FA1/FB1 NYC set that I ordered. Anyway of knowing if it is configured for Freight or Pass service? Or is it not an issue as it could be used for both? Sorry to beat the dead horse here but my inquiring mind wants to know. Thanks for everyones patience. And Nick I will check out the reading.
Terry

[jimrice4449]

The letter designations for EMD units started out as approximating horsepower. The first psgr units were 1800 HP, hence E units. The first frt units (in 4 unit sets were around 4500 HP. The "custom made" A units for the first Rock Island Rockets were 1200 HP, hence TA. As HP increased they kept the letter designations and just changed the numerical, hence E-3 to E-7 were simply upgraded 2000HP units, the E-8 was 2250 HP and the E-9 2400. Ditto for the F-3 (1500 HP per unit) through the 1750 HP F-9. Then we can get into all the cute little variations....no let's not!

[dehusman]

E stood for Eighteen (hundred horsepower) and F stood for Fifteen (hundred horsepower).

SW is Six (hundred horsepower) with a Welded frame. An NW in Nine (hundred horsepower) with a welded frame.

EMD soon realized that that coding wouldn't work so used model designations for service :
BL branchline
GP general purpose
SD special duty
SW switcher
TR transfer

Then they used a curous mix of model designations. First they used a series of semi-sequential models (usually odd numbers) : GP7-9, F3, F5, F7, F9. SD7, SD9. Then they sorta went to horsepower : GP180, GP20. Then, since size matters, they tried to one up the U25b by going to the GP30 (instead of the GP23). After that there was a model series. Series -2 was the nonturbo charged model. Series -1 was a special lower hp version, then the series. Sorta kinda. Maybe.
In the 40 series, the GP38 was the non turbo charged version, GP39 was the turbocharged 12 cylindre version and GP40 was the stock unit.
The GP28 was the non turbo charged unit, but the stock unit was the GP35.

Oh well.

Dave H.

[scubaterry]

Jim/Dave - Well that shed some light on my confusion. Sounds like they had a plan originally but it went south as new models came on line. I appreciate you guys taking the time to explain in such detail. It always impresses me when I see how much knowledge is available on this forum. Thank you to everyone who contributed to my Loco Designation education. I feel just a tiny bit smarter today!
Terry [:)]

[Anonymous]

You know, I see us going over and over and over the basic stuff (like E units and F units, etc) again and again and that tells me that new people are coming along and getting interested and asking the obvious questions as they learn. That means new blood is coming into the hobby and THAT IS GOOD! Welcome in, new folks; and ask all the questions you want.

[nbrodar]

Terry,

The easiest way of knowing if your FA's are equipped for passenger service is to look for the steam generator fittings on the roof. Usually a mushroom shaped cap and a short exuast stack on the roof, near the units rear end. Page 75 of this months (November) MR has some pictures. The last run of P2K FA's I saw, lacked these fittings.

Oh and we don't want to forget. Some GP7 and 9s were equipped for passenger service, but had no special designation.

NIck Brodar

[Anonymous]

QUOTE: Originally posted by scubaterry

The question in my mind that started this was the LL P2K FA1/FB1 NYC set that I ordered. Anyway of knowing if it is configured for Freight or Pass service?

In the real world, the diesel types that could be used for either freight or passenger service usually had different gearing to run at different top speeds. But on the model, the more important issue is the paint scheme. Most railroads painted their units differently for freight or passenger.

I don't know anything about NYC paint schemes, perhaps someone else can enlighten you.

While most railroads that bought ALCOs for passenger service chose PAs, there was another FA version produced (the "FPA") that was intended to operate both freight and passenger. I don't know if any models have ever been produced, but these would have steam generators. There's a note on page 75 of the Nov. MR that tells how to look for modeled suggestions of steam generators.

Jon

[Paul3]

With regards to Alco FA-1/FB-1's in passenger service...

Although FA's were traditionally geared for freight operations, they could occasionally be seen in passenger service, at least on the New Haven. I have seen video of an NH FA/FB set hauling a commuter train in the spring of 1959 on the Old Colony lines. They of course coould not be used for passenger service in the winter due to the lack of steam generators, but in the warm weather that was not a problem.

Did the NYC? Can't say yes, can't say no, but is it possible? Sure, in warm weather anyways. And on not so high speed a train. I don't think you'd ever see them on the 20th Century, but on a commuter job? Why not...

BTW, the Alco designations are not as clear cut as it may appear. Alco's designations were usually "DL-xxx", for "Diesel Locomotive design - number xxx". So, for example, what we railfans call an RS-11 was known to Alco as a DL-701. Some of what we usually call an engine is something that was made up by railfans that has simply caught on. HH660's, for example, stand for "High Hood, 660 Hp". Now, I don't think Alco would have called their 660 Hp switcher a "High Hood" (sounds like a criminal junkie), but railfans did and it stuck.

And we're not even getting into what the actual RR's called them. For example, the New Haven called their FL9's (a 5 axle EMD F-unit), Electric/Diesel-Electric Road-5 (EDER-5) or EDER-5a (depending on the order). This stands for the 5th model of a Diesel-Electric Road unit that had external 3rd rail shoes making it also a straight Electric. Fun, isn't it?

Paul A. Cutler III
*****************
Weather Or No Go New Haven
*****************

[cwclark]

on correction...EMD stands for Electo-Motive Diesel a division of the General Motors corperation.... in other words it's a Chevy locomotive .... : )

[trainboyH16-44]

Lets just say that they would look good in passenger service. If you look it up on aroster, I'm sure you could find out. I couldn't find one in the first couple pagesof googe, but you might want to try
Matthew

[ort007]

This site has a pretty thorough description of each type of locomotive in one convenient location.

http://en.wikipedia.org/wiki/General_Motors_Electro-Motive_Division

You can follow the links to ALCO, FM, Baldwin...

Cheers,
Ort007