>>102055377 1/4 or 7 1/2 is the gauge. They're usually either 1 1/2 inches to the foot for standard gauge, and 2 1/2 inches to the foot for narrow gauge. There are factory built models, but a lot of people will build locomotives and rolling stock from kits or even scratch build using components that are pre made thinke wheel and truck sets. Something like a battery powered electric box cab locomotive will cost about $2000 while somethingblike this live steam 2-8-4 will run north of $50,000 used. Of course there's a lot between those, like diesel hydraulic locomotives or smaller live steam locomotives.
