Hello everyone.
I'm new around here, and generally speaking, new to N-scale model railroading. I've got a couple of trains running but that's about it. Anyway, I wanted to ask and find out if it's possible to run different trains from different manufacturers on the same type of track.
The tracks that I use are Kato Unitracks, and all the trains I have are manufacturered by Kato. But Atlas seems to make more ALCo locomotives, and Broadway Ltd. has the Baldwin Centipede diesel locomotive, which I really want to see run. Is it possible for Atlas and possibly Broadway trains to use Kato's Unitrack, or are the locomotives and rolling stock incompatible with the rails and power supply? (I know it's a pretty dumb question, but I don't want to risk having to buy and maintain 2 different kinds of track for the trains.)
Railroad historian and nutcase
Novice Model Railroader
Short answer. Yes, you can.
I tried to sell my two cents worth, but no one would give me a plug nickel for it.
I don't have a leg to stand on.
Slightly longer answer.
N scale track is 9mm between the insides of the railheads, aka gauge. ANYTHING that has wheels of appropriate size will run on 9mm gauge track. This includes all North American prototype N scale models regardless of manufacturer, and also includes HO scale models of 30 inch gauge prototypes.
Kato Unitrack is a quality product, but more experienced modelers find it limiting for a variety of reasons. Other manufacturers produce a wide variety of track products. Connecting them end-to-end with Unitrack requires some inventiveness, but it can be done. Later, as you get more deeply involved with the civil engineering aspects of railroad construction you might wish to go to products that allow you to lay spiral approaches to curves, or gentle transitions between level and gradient track. There is a learning curve involved, but you don't have to climb it any faster than your personal comfort allows - it's a movement from good to better, not a go/no go situation.
To reiterate, anything that's advertised as N scale will run on Kato 9mm gauge Unitrack. The only problem will be using wide enough curves to allow running long, stiff motive power and cars. Some of the acknowledged N-scale experts might have more specific information on how wide a radius would be needed to run the rolling stock you desire.
My own use of 9mm gauge involves tiny locomotives (aka 'critters') and equally miniscule rolling stock, Japanese prototype in HO scale.
Chuck (Modeling Central Japan in Septembe, 1964 - in 1:80 'twice N' scale)
Another thing to consider is couplers. Needed to connect your cars together into trains and to your locomotives. See this discussion http://www.nscaledivision.com/information_on_couplers.htm
Note that with the excerption of the Rapido, all the couplers available on American prototype models are knuckle types which can be coupled together. Although some work better together than others. If you are just running trains this usually will work fine, but for switching operations it is best to standardize on one type, but not absolutly necessary.
MicroTrains couplers are the most popular and with very few exceptions can be easilly fitted to any loco or car. https://www.micro-trains.com/ They have "conversions" to fit most locos.