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".

 WALTH 5885

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.


This table cross references Pennsy electric locomotives by class, type, sub class, sub class designator, year of introduction, and availability of HO scale models.

Eventually, clicking on minor class number will link to a class-specific page which will include prototype builder data, specifications, unit rosters, and unit photos.

Corrections and additions to this page are welcome. However, please refrain from submitting roster and subclass information for classes whose class detail pages have not yet been created. Thank you.

 PRR X38 Box Car 73863 E18850 BLT 2 42 a x

In HO scale, the X38 box car is available as a resin kit from Funaro & Camerlengo. In addition to the decals in the kits, Mount Vernon Shops offers decals for the series. .

Additional References:

Fischer, Ian, "PRR Class X37 and X38 Box Cars", The Keystone, published by the Pennsylvania Railroad Technical & Historical Society, volume 14 number 4, Winter 1981.

JB X44

The X44 series were 50' post-war steel box cars based on an AAR design.


The X43 series were 40' post-war steel box cars based on an AAR design.

With more than 42,000 cars built for the American railroads and 38,000 for the Canadian roads, the postwar AAR 40' boxcar was one of the most widely used freight cars. Many of these cars saw service into the 1980s. Like their 50' design, the AAR 40' box car was modular in concept and the primary aspects of the design standard were dimensions that must be conformed to. The side panels, ends, and roofs were nothing more than component parts that could be used interchangeably.

The 50 ton postwar AAR 40 foot boc car was on illustration of a standard car in a continuing series of AAR standard designs that began in 1932. THe original 1932 AAR had a standard inside height of 9'11" and the 1937 AAR standard box car had a 10'0" inside height. In October, 1947, the Committee on Car Construction revised the inside height from 10'0" to 10'6" because there had been little demand for the 10'0" height car. Standard features of the postwar AAR 40' box car were as follows:

 X26 518824

The X26 series were 40' World War I composite box cars based on an AAR design.

Due to a variety of door and ladder combinations within subclasses, photographs should be referenced for accurate road numbers. Photos of models cannot be trusted for legitimate road numbers, but photos of completed models are included for illustration purposes.

 30 ribbed single trlr proto1

Trailer Numbering

Early Trailer Numbering

The trailer number was broken into three parts. The first two digits indicated the trailer length. These two digits were followed by an alphabet letter (C, E, or W). The significance of the letter is unknown. The letter was followed by numbers indicating the trailer number. Thus trailer 32E250 is a 32’ trailer numbered 250.


So you know what the PRR called the color of paint you want to apply to your model, your shed in the back yard, etc., but how do you go about selecting an available paint?

Color Models

First, you should have a brief understanding of colors. Different media have different models for describing how they depict colors. Here are just a few of them:

RGB - RGB is the system most people are familiar with. It's used for video and is described by expressing percentages of Red, Green, and Blue.

 Alco RS3ph1a

Alco RS-1, Class AS10s / AS10am / AS10ams / AS10as

The ALCO RS-1 was a 4-axle road switcher diesel-electric locomotive built by Alco-GE between 1941 and 1953 and the American Locomotive Company from 1953 to 1960. The Montreal Locomotive Works built three RS-1s in 1954. This model has the distinction of having the longest production run of any diesel locomotive for the North American market. The RS-1 was in production for 19 years from the first unit Rock Island #748 in March 1941 to the last unit National of Mexico #5663 in March 1960.