How can I include a coal tipple in a large city scene, New river mining.
You could kitbash it into a chemical plant. You could also repurpose the building as a gravel aggregate facility. Not too many large cities have active mines in the developed portion of town, but it could fit on an outskirt area.
As for how I would use the space, I agree with the narrow shelves idea for around the room. Depending on what type of railroad you want (urban, suburban, rural, mountain or plains) can dictate what else you do. You could obviously run a skinny peninsula down the middle long ways and put a blob for a return loop. If the wall shelves are 1 foot wide here, and the blob 4 feet wide, you get 2 aisles about 3 feet wide as long as you don't clutter fascia there with controls or projections.
I would also consider a double deck approach around the room with no central peninsula. Leaving a 10 foot, or even 8 foot wide, central area would allow spacious room for operators to move around the room as they operate trains. You will likely get more mainline length from the double deck than you lose from not having the peninsula.
If you plan to focus on an urban or industrial line, you could also skip the skinny peninsula, but have short peninsulas or blobs branch off the shelves in places for industries. They could create a more zigzag style aisle if you make sure they don't have their ends meeting in the middle of the room.
Your shelves along the walls could also vary in width, widening as they approach the middle of the room, and shrinking back to a 12 inch depth near the corners, if you wanted to provide flexibility so the fascia and backdrop are not parallel edges. Doing so would also allow straight track that doesn't parallel the front edge of the layout, which is a very effective design technique that improves foreground scenery, as Bob advocates.
You have plenty of options, so make the most of them.
