Scratchbuilding a B&M Milk Car - Part 1 (frame)

#1920 (August 20, 2017)

As part of the MMR program I am currently scratchbuilding some flatcars. But, I am waiting for the decals so I thought I would start on another. Car #4 will be something special. While scrolling through EBay one day looking at B&M slides I saw several for some attractive black boxcars with the intertwined "B" and "M" logo. Further digging revealed they weren't actually boxcars but instead were reefers, and they were designed for milk service and have have heating pipework to run in passenger trains. I liked the clean lines of the cars, the simple paint scheme, the uniqueness of the cars, and the fact that two of them still exist. I knew I wanted to build one.

Built by General American Tank Corporation (GATX), they likely were the last true milk cars ever delivered to an American railroad. Cars #1900-1914 had four plug doors (2 per side) and were built in January 1958. They were insulated and had mechanical refrigeration and were designed to handle bottles of milk. Cars #1915-1934 had two plug doors (1 per side) and were built in December 1957. They were insulated only and were designed for handling milk cans which were covered with crushed ice. Some were used for moving milk from the Bellows Falls Creamery in Vermont to Boston and lasted in service through 1965, when they were converted to company storage cars.

#1920 at RMoNE (May 2018)

Two cars survive today: #1910 (a 4-door car) and #1920 (a 2-door car). They were purchased by the Railroad Museum of New England in 1989 and car #1920 was restored in 1992. Car #1910 still requires restoration. For some additional information on these cars, check out George Dutka's "White River Division" blog which also contains some pictures of them at the end of their working lives. I even planned a trip to the Railroad Museum in New England in 2018 to see this car and photograph it, as it was supposedly on display. However, at the time we were there the exhibits had changed and the car had been moved to an inaccessible place. So, the best I could do was take this picture as we rolled by on the train.

There are several additional sources of information for building models of these cars. Railroad Model Craftsman magazine ran a series of articles in 1986 (February, March, and May) about milk trains in general and the February issue contained several plans including those for both 2-door and 4-door B&M cars. The Boston & Maine Railroad Historical Society's newsletter also contain several articles in their "modeler's notes" section:

- #80 (Sept. 2002) – by Bruce Bowden – “B&M 1900 Series Milk Cars”

- #96 (May 2005) – by Bruce Bowden – “Modeling B&M 1900 Series Milk Cars”

- #101 (March 2006) – by William Keay – “Milk Cars Used on the B&M”

- #103 (July 2006) – by Bruce Bowden – “Modeling B&M 1900-1914 Four Door Milk Cars”

Athearn HO scale #RND84640

For those who don't want to completely scratchbuild the car, there are several options. Brass models in HO Scale were available by Overland Models Inc. (#3065 for the 4-door car, #3066 for the 2-door car). Challenger Imports also did the 2-door model (2070) and there might be others out there too. George Dutka explained on his blog how he converted an HO scale Walthers Express Reefer car into one. Highball Graphics makes decals for these cars (set #F-191) And for those who like how the car looks and don't care that it is the entirely wrong style car, MDC/Roundhouse (#84639, B&M #1923) and Athearn (multiple cars) both released 40' wood reefers in this scheme. But, for me it is scratchbuilding or bust. I like the look of the single doors on each side, so I picked car #1920 to build. 

So, faced with a full Saturday with absolutely nothing to do I got started. I had plans from RMC article mentioned above but they were a bit complicated to understand, especially the underframe. The refrigeration lines and brake rigging seemed a lot more complicated than my previous cars, and I wasn't quite sure where to begin. But, I did note that the floor board spacing exactly matched the O scale Evergreen grooved siding I already had on hand which was very convenient. I used thin 0.020" thick siding, but laminated it to another layer of 0.040" styrene for strength. From this point one, I began the process of slowly adding and layering pieces to replicate the drawings.

Even though I was essentially figuring it out as I went, I had a couple of things to help me. I had my two flatcars which were built following detailed instructions, so I at least had some idea how to measure and cut and fabricate parts together. However, mostly I just would pick a part on the drawing and figure out how to replicate it with the styrene shapes I had. The main longitudinal centerbeam was laid out first from some 0.080" thick styrene (#168). Cross braces are c-channel ((#262), sometimes laminated back-to-back per the drawings. They were cut oversize and trimmed to final length later.

I was a couple of hours in when I noticed that the car floor was beginning to develop a bow, or sway, just from the little I had done. Having had problems with my styrene car parts warping on both the caboose and flatcars I decided right from the start to prevent that from occurring here. So, I flipped the frame over and glued two heavy pieces of styrene along the length of the car, leaving room on the edges for the car sides and along the middle for things such as truck and coupler screws and weights. Once the glue was applied I flipped it upside down and added heavy weights and let it sit for an hour. After that, the floor was perfectly flat again.

The edges of the floor were framed with tiny strips of styrene (#112), each of which was individually cut and attached to fit between the cross braces. The same was done with individual pieces of extremely tiny 1/16" ABS plastic L-angle (#A-2). The edges of the centerbeam was also adorned with more strips of #112 again to match the plans. The ends got pieces of styrene to build up their thickness around the Kadee coupler boxes I glued in. Bolsters were built up but I left some room for height adjustment which will depend on the final trucks I use. To keep track of everything I was doing, I took notes.

Other details such as the "fascia" pieces at the ends of the cross braces and some diagonal bracing were also added per the prototype. I then added the steam heating lines and train brake lines next, using two different sizes of soft copper rod that I had on hand. Because each end of the car always had the heating on the left side and the brake lines on the right, they obviously had to crisscross somewhere. I used the plans to replicate this on the model. As was done elsewhere, each piece of wire was hand cut, filed flat on the ends, and glued into place between the crossbraces. Everything had to be aligned perfectly to give the impression that it was long solid piece of wire (pipe).

The next step for the chassis is to install the brakes. I ordered a commercial brake casting set though some pieces will need to be fabricated to match the prototype.

I find it hard to believe that I already have about eight hours into the car so far, not including any of the research I have done. It is usually an enjoyable process, but things like cutting and fitting tiny pieces of wire take a lot of time to do neatly and correctly. I do feel the MMR program is forcing me (encouraging me?) to learn new skills, which I appreciate.