... between an F7 and an FP7? I notice on Intermountain's website they are releasing FP7's in HO and F7's in N. With the upcoming N scale Kato Super Chief, which ran with F7 power, it would seem to someone not familiar with these things that the F had whatever it took to run passenger trains. Therefore the first blush answer that the P in FP7 would stand for Passenger doesn't look like the right one.
I believe the FP7 was built puposely to house the steam generator and as such, was about 4 feet longer than an F7. Harold
Harold got it right. But didn't the railroad's go to a different method of steam/electrical generation shortly thereafter, so they didn't need the steam generators at the front end?
Something about the fuel tank, too. I think there might have been a water tank plus a fuel tank under the engine or just a larger fuel tank.
No, steam lasted into the Amtrak era before it was replaced by Head End Power (HEP). Most F units used in passenger service had the steam generators in the "B" units so had to have at least one B in the consist to supply steam. The FP7s could run solo and not require a B unit along to provide steam.
Some longer trains such as the infamous UP "City to Everywhere" required more steam than could be supplied from the front end so additional special steam generator cars were added in the middle or at the end. It could get pretty cold riding in the last car of a long train without them.
Some railroads converted old steam engine tenders. To house a seperate, larger boiler unit for passenger use. Milw, NP, and?? Boxcab E50
Was heating the reason for using steam on passenger trains or was there some other use? If it's only for heat, would a passenger train need a B-unit or FP during the summer? I believe the Southern had some dedicated steam cars (units). In one of my references it appeared to be a converted B-unit. Can't find it right now, so I could've misinterpreted what I saw. Thanks
Santa Fe had a few of them. Southern jerked the guts out and converted old FTBs into steam cars. There is one of those at the museum in Roanoke, VA.
Some railroads like the Santa Fe and Milwaukee Road used steam to run their air conditioning so needed plenty in the summer too. The Santa Fe could leave Chicago running heat and have to switch on the AC in Arizona on the same trip.
I think the original idea was that Fs were for freight (remember, the first F was the FT, which never came equipped for passenger service) and Es were for passenger. Some Fs were made with steam generators in the B-units; I don't believe all. The Super Chief, with F-units, was almost the exception to the rule back then, when passenger trains ran with six-axle engines - Es or Alco PAs. (Incidentally, the Super Chief first ran with an E1A/B set, and a while later with an A-B-A set of FM Erie-Builts! But the A-B-B-A F3s are the engines usually seen in popular depictions, and lasted the longest.) That reminds me: the situation was the same for Alco. FAs were for freight and PAs for passenger... then they made the FPAs with steam generators.
They would if the B units had steam generators. Many model makers put the steam generator vents/stacks on A unit shells anyway. I know I had to shave them off all my Kato F3As to make them correct.
The Rio Grande certainly had passenger F's; they pulled the California Zephyr. It's the CZ and the Super Chief that are responsible for many people thinking of F's aas passenger engines. They are, after all, the most famous diesel-hauled passenger trains.
Back to steam generator cars, WP bought three from GN in 68 and they worked the last couple of years on the CZ. It also tickles my memory that DRGW had some also. I don't remember it pulled by anything but F units but it must have happened once in a while. I have a book with a couple of pictures of converted tenders behind A units.Interesting thread here. I hadn't thought of the steam issue before, I kind of assumed B units were early slugs.
Count the C&O Railway as a road that had FP7's. They were used on both passenger and freight service. Ran in ABA sets in the first years they were on the road. (50's) The second post on this thread nailed the "big picture" difference between the FP7's and F7's. They were also painted the same as the C&O E8's, w/ the gray bottom, enchantment blue body, and yellow nose/trim/stripe. Excuse me if this has already been mentioned above, but the B units (atleast on the C&O) were standard F7 B units. I do not believe that FP7's were made as a "B" unit. Think they were all F7's. I have 3 Atlas FP7's that I painted back in the very early 90's. I love those things. Just like the prototype, I pull passenger or freight hauls w/ those guys. I also have a standing order in w/ the C&O Historical Society for an FP7 ABA set they are having manufactured by Intermountain. I will be glad when that project is done and they start shipping those babies.
Some FP7s have continued on in scenic service. I haven't looked into the history on these units but I would imagine the retain features from the original owner. Verde Canyon Railroad Doesn't this just beg to be modeled? They had offered, or maybe still do, a HO version in their gift shop but I have no details on it.
The FP7's were indeed about 4' longer than a standard F unit. The extra length allowed for addition water in a tank carried in the carbody, and larger fuel tanks, as the boilers burned diesel fuel too. Whether the A units in passenger service were equipped with boilers or not was a railroad by railroad choice. The WP's A's and B's both had boilers. On the D&RGW, a PB unit was rebuilt as a heater car and used on both the Rio Grande Zephyr, and the Ski trains.
In the late 70's I frequently rode Amtrak (Sunset Limited) between Houston, TX and Alpine, TX. I recall one blistering hot August trip with no air conditioning and a closed dining car. The reason we were told was "no steam".
