Baldwin DR 4-4-1500 "Early Shark", Class BF15 / BF15a
The Baldwin DR-4-4-15 was a 1,500-horsepower cab unit-type diesel locomotive built for freight service by the Baldwin Locomotive Works between November 1947 and June 1950. It was produced in two different body types, nicknamed the "Babyface" and "Sharknose" styles by railfans, though Baldwin used the same model number for both. 22 "Babyface" cab-equipped A units were built, along with 11 cabless booster B units; 36 "Sharknose" A units and 36 B units were constructed, making a total for all models of 105 locomotives built.
The ALCO FA was a family of B-B diesel locomotives designed to haul freight trains. The locomotives were built by a partnership of ALCO and General Electric in Schenectady, New York, between January 1946 and May 1959. They were of a cab unit design, and both cab-equipped lead (A unit) FA and cabless booster (B unit) FB models were built. A dual passenger-freight version, the FPA/FPB, was also offered. It was equipped with a steam generator for heating passenger cars.
When planning to model the Pennsy during the post World War II era, there are certain parameters which you may or may not wish to consider when selecting a year (or years) to depict. Among them may be paint schemes, specific models of diesel locomotives, specific models of freight cars, etc.
The graph below illustrates when certain features of the Pennsy came into play, or faded into history.
I consider the following Pennsylvania Railroad model railroads to have a high degree of fidelity to the prototype. They are not freelance, protolance, etc., but depict specific locales on the Pennsy based on historic documentation with a minimum of "modeler's license."
* Indicates a layout on which I have had the opportunity to operate. Those in italics are on my "bucket list" to visit.
Over the years, many lettering "schemes" have graced the sides of the Pennsy's vast fleet of rolling stock used in freight revenue service. This is a brief summary of an article by Brady McGuire which originally appeared in the Summer 1988 (Vol.21 No.2) issue of The Keystone, published by the Pennsylvania Railroad Technical & Historical Society. I highly recommend referring to the original text which contained much more information, prototype photos as examples, and official painting and lettering diagrams.
For modeling purposes, please remember that a particular scheme could be seen well after the period indicated below for the scheme. The period indicated represents what scheme would be applied to a car if painted during the period in question. But many cars, especially gondolas, were rarely repainted. For instance, a Circle Keystone gondola might be seen well into the 1960s...or even today!
Lettering banners and slogans were periodic modifications to lettering schemes which were not tied to a specific scheme but rather to a type of service or concept. For example, "Merchandise Service" or "Buy War Bonds".
In HO scale, the X37, X37A, and X37B box cars are available as resin kits from Funaro & Camerlengo. In addition to the decals in the kits, Mount Vernon Shops offers decals for the series. Kits were once offered by Sunshine Models, now out of business.
Interestingly, the three X37 sub-classes had different interior heights. The X37 was 10'4", the X37A 10'6", and the X37B 10'8".
Bob Johnson's comments, as coordinator of the archives of the PRRT&HS:
a - As built the cars were painted with Tuscan Red body, Metallic Brown roof, Olive trucks and underbody equipment, Black handholds and ironwork (underframe and sill steps), and Gold Leaf lettering edged with a 1/16" Black line. Side lettering included a 6" high "PENNSYLVANIA", 6" car number with figures spaced 1 1/2" apart, 4" high "AMERICAN RAILWAY EXPRESS", and 4" high "REFRIGERATOR". End lettering was 4" high "P.R.R." and car number. Lettering style was the older Block Type with coved letters "P", "S", "R", "C" and "G".
b - On 4-4-1929 "AMERICAN RAILWAY EXPRESS" was changed to "RAILWAY EXPRESS AGENCY, INC." It's possible that the last few cars built received this lettering as built. I haven't seen any photos showing this style.
c - On 10-15-1929 the lettering was simplified to "RAILWAY EXPRESS AGENCY".
d - On 8-14-1930 the end numbers were removed.
e - On 10-21-1930 the side numerals were spaced 2 3/8" apart and the 4" lettering was spaced wider.
f - On 7-9-1936 the lettering was changed from Gold Leaf to Buff Lettering Color, still edged with Black. I believe this is Walthers 5881 (below), "prewar", except I'm not sure about the black edging.