Here is a one-industry layout that i have drawn to go into a small existing 11x11 ft. bedroom. It is a basic 4x8 design intended to fit in a corner of the room. I had to clip triangles out and other geometric shapes and re-attach them at other places to get what i needed which really ends up making the layout 8 feet 9 inches long. But it is STILL 32 square feet. What I needed most was access to the rear where the un-scenicked fiddle yard is. What I needed (or wanted) next was a little more track capacity. The skewed teardrop shape got me that.
In my mind, the one industry is a sawmill set somewhere in the damp Pacific Northwest, but it could be any industry anywhere and any era too, even in an urban setting. This mill will load an occasional boxcar, many flatcars and several wood chip gons. Speaking of a one industry layout, there is an option for another industry on the proposed spur that trails back towards town off of the chip track if a guy was willing to install a turnout there. Speaking of turnouts... they're expensive! That also brings us to "area A". There are three options for this area indicated by the penciled in dotted lines. I have done the designing already on this and all three options will fit. THEY ARE: 1) build a yard ladder that has a 12 inch engine escape lead... 2) a lateral transfer table (dotted square)... and 3) a sector plate (dotted cone). Those last two options saves on turnouts but does not take away from operations. If you want even less turnouts, we can do away with the run-around at the mill. Of course then, we will have to shove to the mill because of the newly created Ingelnook situation. But then, lets use a caboose for that!
So, with #6 turnouts, my math tells me (HO scale) that there is about 54 inches of clearance room between switches on the runaround track. With that, we could come into town with 5 cars or so and a caboose. The simplest (most boring) way to serve the industry would be to park the train on the outer runaround, start pulling loads from each track, double to the inbound empties and start spotting, then head out of town... NO, NO, NO! We forgot about the self imposed rule! "At no time shall any part of the train enter the off stage area while switching". So much for that long double-over. I will do this instead: stop train between switches on the inner run around. Uncouple and move ahead to retrieve loaded box car (if any) from shed. Run around train and couple to rear (caboose?) Shove ahead and spot empty boxcar at shed (a wise conductor would make sure cars for the shed would have been first out behind locomotive). Run over with engine to pull chip loads and come back to train. Set chip loads, boxcar(s) and caboose to outer run around. Spot empty chip gons (which are still on inside track) over to the loader. Run engine to get loaded flat car(s) and double to empty flat cars which are still sitting on inner run around. Spot them. Return with loaded flats to outer track and rest of train. Then go to coffee or head to staging.
There is not tons of operation here but some. A guy could forget ops and build magnificent scenery or concentrate on structures. This layout could easily be improved with expansion or a different design from the get go. Maybe a shelf? I decided to stick to the constraints of a 4x8 frame of mind just for the challenge. But as it is, would this layout become boring?
