After wanting to build a layout for many years, I finally have room for a small shelf layout and I was wondering what the minimum curve size can be used in N scale? The largest locomotive that would be used would either be a Mikado or a Northern, but I would most likely use a locomotive smaller than that. I am mostly interested in some mainline running and have never been interested in a lot of switching although I will have a couple switches on it. The longest the shelf can be is 72 inches, one end could be 24 inches wide, maybe a little more, the other end probably around 18 or 20 inches wide. I have been going through the threads for a while and have learned a lot and gotten some very good ideas. To get some practice at scenery, I will try a couple dioramas first. One will be in HO and I will use the Monogram Big Boy and a couple cars by it, a Tucker and a 1948 Plymouth business coupe, just waiting to get them from eBay. The other will be an old bridge from my home town in southern Minnesota (Red Jacket bridge) which is part wooden trestle and part metal and goes over a river and a road. I have picked up a number of books and quite a few Model Railroader magazines that are also a big help.