I want to start a new HO layout themed in the '30's or 40's and "backwoods" type branch line setting using the side tank porter 0-6-0 in a logging and/or mining type scene. But this new layout would have limited space (32" width) requiring 15" radius curves at two ends. Does anyone know if the 0-6-0 porter side tank will consistently and safely negotiate 15" radius curves? I know is states "runs best on 18" radius" but that is usually stated as a most preferred radius for any locomotive. I really don't want to order 2 of the unlettered 0-6-0's only to find out they are constantly derailing on 15" radius. Anyone have any first hand experience with them operating on anything less than 18" radius?  And yes, I know if they do operate on 15" radius that I would be limited to short rolling stock, 40' and less with 4 or 5 car trains, and slow speeds. That is exactly what I want.   Thanks.   Jerry