First, a couple of definitions:
- Outdoor. Located where exposure to real sunlight, real rain and way overscale wind comes with the territory.
- Garden. Cultivated (or pruned wild) greenery, tended with loving care by a professional or amateur horticulturist.
A garden railway can be ANY scale, but, usually, bigger is better.[8D]
An outdoor railway may or may not be a garden railway. If any encroaching plant life is either accidental (weeds) or nonexistent, it’s still an outdoor layout if exposed to the weather. The deciding factor will be weather resistance, in which, once again, the larger scales have an edge.[sigh]
There have been small scale outdoor/garden railways, including at least one (HO, European prototype, IIRC) at Disney World in Florida and several (OO) in the British Isles, a location not noted for model-friendly weather.[:)]
When I first moved to the dessicated desert I experimented with the idea of building my 1:80 scale empire in my foliage-free back yard. 115 degree temperatures, sunlight strong enough to melt an Athearn BB car, raindrops that impacted like bombs (not often, but definitely possible) and straight line winds that scaled out to orbital speed ran me back indoors in a hurry![#oops]
FWIW, would a modeler running live steam and real internal combustion in 1:4, 1:8 or 1:12 scale have an outdoor railroad, a garden railroad or just a miniature railroad? (Before you jump, remember that there is at least one commercially viable public railroad that runs 1:4 scale model locomotives.)[^]
For that matter, does a modeler who builds a shelf railroad in weatherproof display cases attached to his backyard fence have an indoor railway or an outdoor railway?[:-,]
Chuck (modeling Central Japan in September, 1964 - ind