Here we have added a 4' by 8' extension to the lower left. This layout uses 42" curves and O27 straights. It would serve industries that serve or are served by shipping. Among those to consider are oil or coal producers, such as refineries, mines, etc. Since the extension is a mainline railroad, it would not be restricted to smaller trains. This is like the real world, where portside and industrial pikes cannot be traversed successfully by large mainline locomotives such as the Pacific, Consolidation, Mikado, SD and Dash-9 series, FM Trainmasters and Alco Centuries.
We add a 4' by 6' extension to the lower corner of the 4' b8 8' extension. Open space is delineated by thick black lines. To cover a switch that crosses empty space, a small panel is added (gray-green angle in lower center). O-31 or )-34 curves are used for a siding at the lower center that reaches upward. Every other curve is O-42. This pattern is great for a corner of the room, and leaves everything in reach. You can let the long trains run here, and enjoy the portside activity of the small ones. Again, industries served would have some connection with supplying ships, providing cargo, or taking products sent by ships.