Sometimes I will noticed an article in one of the modeling magazines about B&M cab units. The modeler will include pictures (of both the models and the prototypes) of a roof-mounted radiator tubing section. IIRC, it is usually mounted near the cab of the A units. I've seen them pictured/modeled on EMD F units, and possibly also ALCO FA/B units. Other roads may have also applied similar radiators, but I always see them in B&M articles. They are a lot longer than they are wide... usually a long, thin rectangle with a U-shaped tube sticking out of either end. I've seen them mentioned and modeled, but have never read an explanation as to what function they served. In the prototype world, what exactly was the function of these road-applied radiators? Were they for additional engine radiation, or were they for radiating heat from another mechanical part of the unit?
Hi FA-2, welcome to the Trainboard, we're glad to have you aboard. Now as to your question....I lived trackside to the B&M Fitchburg Division in Hoosick, NY for six years, 1947-1953. During that time I probably saw thousands of FTs, F2s, F3s, and E7s, both from above and from trackside, but try as I might, I can't remember what the rooftops looked like. Initially I would have said they were smooth except for the fans, exhaust ports, and horns. But then I looked at my IM model of a B&M FT and low and behold there was a fixture similar to what you describe, between two fans in front and two in back, and either side of the four exhaust stacks. I have no idea what it was for, so I can't help you there, but I'd be very interested in what you find out.
I am not certain, but from your description of their placement, I believe the features you are seeing might be part of the dynamic brake system. The dynamic brake "spotting features" can be seen from the ground on the roofs of the units in this picture: http://www.northeast.railfan.net/images/bm4200.jpg Just above the portals, surrounding what would be the exhaust stacks, are the long, boxy-looking dynamic brake "housings." Is that what you are seeing on your model, or are they a lot smaller than that? I looked for some pictures of what I was seeing, but have not found any yet. I will post them if I do!
That's what the IM FT model looks like when viewed from below....could easily be a dynamics grid, I wouldn't know. On the other hand, I believe the F3 dynamics were cooled by a fifth fan at a different location on the rooftop from the four radiator fans. So back to your question....I don't remember seeing what you describe, since it's not the structure atop the FT.
Well, I've still not found any pictures online, but I did find a reference to the appliance in question on the following page: http://www.faracresfarm.com/jbvb/rr/bmrr/dieselde.html In the section titled "EMD FT detailing," I found the following: "Most of the FTs received a long, narrow rectangular roof-mounted cooler of some sort at the rear of the fireman's side in the 1950s." Well, still doesn't say what it was for, but at least I know I am not crazy now. :tb-cool:
Rooftop Details of B&M Diesels Just curious if you ever decided what to use for the rooftop detail. I have a number of Genesis F units and am now wondering if I should consider applying this detail. Has anyone else done it and have photos to post ? Mike S in Aiken County
I don't actually model the B&M, I freelance. However, I have gotten some detailing ideas from articles from people who model prototypes, and one I have used for ideas was in the February, 1999, edition of Model Railroading. There is an article in there about the B&M FTs, written by Mark E. Sharp. He says he used 4 pieces of .030 styrene cut to an approx. scale 5'. He glued the pieces lengthwise into 2 pairs, and drilled .033 holes into each end. He connected the two pairs together with a couple of pieces of wire (through the holes), and bent a couple of pieces of wire to go into the two holes at each end of the set of coils. The article has a picture, but I've no way of getting it onto the Internet. :tb-embarrassed: This was one of the details that I didn't carry over to my freelance FT units, but I always wondered what, on the prototype, where they cooling? This article doesn't say, and does not include any prototype photos with the coils in place.
Have you tried your question with the B&M Historical Society....... http://www.network54.com/Forum/43027/
