At the rear of the upper level (the mill area) is a corner formed by a scene block and the apartment wall. I've built this corner up about two inches and populated it with flats and 3D buildings representing various mill shops, delivery points (by road — there is no trackage in this space) and so on. Four house flats at are right, adjacent to one of the three high tension towers positioned in this area (which bring power to the mill). Next to them will eventually be three tenement apartments I'm building from scratch. Those will be at ground level, with their roof tops at a level to that of the lowest house flat's roof (the houses themselves, or the backs of same [since only the rears are represented], are stepped down).
Visible in these four shots are the two tracks that come up to the mill area. One (where the ore cars are in the photos) goes up to serve the blast furnace stock house, where iron ore, coke, and flux (limestone) are stored and then taken as needed from there to the tops of the furnaces by skip cars. This is known as the burden, or charge, for the furnace. Once a blast furnace is "blown in" it never stops, except for periodic maintenance (or some malfunction or emergency). This track is generally known as "the high line" due to it being elevated somewhat above the ground level trackage in the furnace department. On the MonCon Railroad at J&L Steel's Pittsburgh works, this was called the high grade, for some reason. The main running tracks, on the other side of the furnace alley itself, were referred to as the low grade; one supposes this is the explanation. These tracks fronted the Monongahala River. Most high lines in blast furnace departments consist of two tracks, sometimes more. On the MCRR there were four on the high grade, and two additional tracks that went into the stock house itself. Factors of space precluded me from representing more than one high line track, however.
The track to the right leads to the blast furnace itself. It splits on the grade, with one line running up and into the furnace cast house (after having split, itself, into two tracks), and the other running in front of the cast house for slag service and as well to empty the furnace dust catcher. Additionally, this track divides, with one line serving the rear of the #1 electric furnace positioned below. Both of these tracks go off the layout into "infinity" . . . ostensibly to a connection with a Class 1 railroad or to some other part of the plant not represented.
Note: beneath the bridge at this point runs the layout's left side mainline track, at ground level. This is the only track that runs in a "circuit" (offering continuous running).
(In the future I'll post a diagram of the entire "railroad."
Empty ore cars heading downgrade
Upper Level Detail #1
Upper Level Detail #2
Upper Level Detail #3