Kyle:
If you'll accept a point to point trackplan w/no turning provisions, choose your track system carefully, your engine(s) and rolling stock likewise, I think you can have a superb urban industrial switching layout in that space using the Hi-Rail approach with 3-rail or even 2 rail scale.
A LOT can be done with the urban theme and 17' plus part of those 15'walls in O scale. Given the crowded nature of urban railroading, you'll be justifying tight confines and track density. Win-win. In fact, you can probably do it with 24" to 30" deep benchwork and save a lot of space for "living" in the same room.
Best of luck to 'ya!
Andre
