http://www.brasslocomotive.com/ has an image of each of the prototypes. Just search for "F4" or "F5". All I could see is that there's a clamshell cover on the stack on the 3765 and some plumbing differences. What else?
As far as my SP motive power books can tell me, there isn't much distinguishing the two classes apart. Smoke deflectors and other items were region specific on the SP (Tehapachi vs Donner Pass vs the Roseville district...for example). It seems that aside from some minor tonnage ratings, the F4-F5 were like the AC 10/11/12's not much besides roadnumbers differentiating them. Seems that every time the SP wanted to order new engines, they decided to designate them with a new class number, at least in the case of the AC locomotives.
Great info, thanks. Were the F4 and F5 operating at the same time? What year were they introduced, and how long did they last?
What SP motive power books are you referring to? So many questions. For instance, what's the difference between the cabooses with and without yellow ends? On the accucraft offerings, what constitutes "modern lettering" vs. other. What era constituted modern? I like the old serif font better than the modern san serif.
The F-5 #3765 has the clam shell stack and is modeled as it appeared in the mid 50's after a rebuild.
The F-4 #3680 has the straight stack and is modeled as it looked around the same time.
There are minor detail differences with the hand rails but the big difference is that the running boards along both sides of the locomotives are different between the F-4 and F-5
Both these engines have the 16000 gal tenders. These two models are of these two specific number prototype locomotives. You will find other numbers of 2-10-2's similar but not exactly like these two engines .
The F-4's were built in 1921 and the F-5's were built between 1923 and 1925. They lasted all the way until the end of steam for the SP in 1957. Both engines weighted the same at 397,900 lbs.; both had a tractive effort of 75,150 lbs. The cylinders were 29" dia. and 32" stroke. The drivers are 63" in diameter. They were both built by Baldwin and had 200 lbs. boiler pressure. The 3765 was one of the last 2-10-2's to be shopped by the SP. None of the F-4 or F-5 class 2-10-2's survive today.
Looking at Acc. website looks like there are 4-5 of SP (looks like old style coloring and letting, and same with UP list. Couse tthat's not much help, but I guess I kept more track (?) of SP power than cabooses. UP I know nothing about.
Richard,I really like this new Engine from Accucraft.I talk to Cliff about it and He Said, this was His Baby,He is front it.I had Ask Him if it had a Axle Pump,Because it was not listed.Cliff said it had Both a Hand pump in tender and a Axle Pump.For the Price listed,And What You can get it FOR, I think it is a great BUY,I order one,Sad thing is that it won't get here till Next Summer.Will turn it into a B&O and have the tender with a Coal Load.NOW I ONLY Hope,"THEY HURRY UP WITH THE 1/32 Box Cars".