Dynamometer Car - The Whistle Post

Absnut · #1 (**permalink**) 10-12-2007, 01:05 AM

I've long thought I would like to have one of these since I first saw a picture of it. They don't make one in N scale and the Bangor and Aroostook's is rather different. So, I figured if I could build a Schnabel,I should be able to do a dynamometer car. After workingon it for three days (took me half a day to do the grabs!), I have a dynamometer to test my locos. I started with the frame from an MDC express reefer (cutting 3' from each end) and used Evergreen V-groove siding and strips, MT Andrews trucks, and bits and pieces from my parts/junque box. Some day, I hope to find suitable B&A decals for it. If not, I'll just have to letter it for my own road. It can use a little touching up in places but, after three days of work, I need to rest a while!

Dick

Trainman1965 · #2 (**permalink**) 10-12-2007, 05:25 AM

Dick that is looking good. Now i am still green to the hobbie so please tell me what the dynamometer car is used for.

Absnut · #3 (**permalink**) 10-12-2007, 09:20 AM

TM,

In the early to mid 20th century, most railroads seemed to own a dynamometer car. It was used to test/monitor/measure locomotive performance, drawbar pull, etc. It was usually cut into a train right behind the tender or loco, in the case of diesels.

Trainman1965 · #4 (**permalink**) 10-12-2007, 09:48 AM

Humm Ok i see. So this was a way to see if the steamer was doing it's job are needed a rebuild.

Absnut · #5 (**permalink**) 10-12-2007, 10:50 AM

I would presume so as well as test out new equipment.

ak-milw · #6 (**permalink**) 10-13-2007, 09:56 PM

TallDude · #7 (**permalink**) 10-14-2007, 02:41 PM

Nice car!! I love to see people model equipment you dont see everyday on the tracks.

Absnut · #8 (**permalink**) 10-14-2007, 03:39 PM

Thanks, gents. It is nice to have equipment that is not "the usual"!

Boss Boomer · #9 (**permalink**) 01-23-2008, 12:04 PM

Old thread, I know, but I just learned more about the dynamometer car from reading a book by Kip Farrington. Kip was a popular writer around WW 2, and after, writing about railroad subjects.

The dynamometer car was a mobile testing laboratory for the railroads. They would attach the car to new locos to thoroughly test the engine under differing conditions to determine how much horsepower, how much real "umph" a loco had to pull trains. They would test the engine over and over until the railroad scientists could make a chart or graph showing exactly how much speed, horsepower, and fuel economy a loco had. Then, once they had that chart, they could always match the proper sized loco with the rating tonnage of the train that had to move from one part of the railroad to another, taking into account the grades the train would operate over.

In this way, the railroad would NOT apply too much or too little engine to pull a train--fuel economy being an important part of that consideration, but also efficiency. It would waste time and tie up the track if a train stalled on a grade, for instance, for having not enough power to go "up the hill."