Recently I spent a few days with my younger brother, Joe, an avid model railroader. Our Saturday morning entertainment consisted of a twelve-hour period, compressed—thanks to the use of a 4:1 fast clock—into three hours, operating On3 scale model trains; the setting was a 18’ x 27’ room in Dave Adams’ home, with his 1930s-era D&RGW (Denver & Rio Grande Western Railway) Durlin Branch layout. (Less formal version: We ran model electric trains around a big room with a bunch of other model railroaders, who are all really nice guys.). Since I can’t begin to describe how fun this was (and I was prepared to be bored), you should just see for yourself here (brother Joe is playing dispatcher in the next-to-last picture on the third row; nephew Joshua is servicing his engine at a water stop in the next-to-last picture of the first row,) and read for yourself here.
Comprehensive works on play with all types of model railroads and trains are classed in 790.133 Play with toys, where electric trains are mentioned specifically in an including note. However, the literature here is minimal—if you have to be told how to play with a model railroad, you might consider using your time some other way! Indeed, most uses of this number for railroads and trains are either for catalogs (e.g., Gilbert American Flyer Trains: Fun & thrills), multimedia (e.g., Trainz railroad simulator 2004), or the toys themselves (e.g., Stacking train; but note that these toy trains are not the electric variety!).
The “serious” literature on model railways and trains is classed in subdivisions of 625 Engineering of railroads. For example, The model locomotive from scratch is classed at 625.1961 Models of steam locomotives (built with 625.19 Model and miniature railroads and trains, plus 61 from 625.261 Steam locomotives, following instructions at 625.19); it should be noted that 625.19 is a displacement from 625[.100228]. Models and miniatures of a specific kind of special-purpose railroad are drawn off from 625.19 to 625.3-625.6; for example, Scale model electric tramways—and how to model them is classed in 625.60228 Models of surface rail and trolley systems (built with 625.6 Surface rail and trolley systems, plus T1—0228 Models and miniatures).