Mark:
I've got an awesome idea for you to consider! I've been drawing on my C.A.D. for hours (my birthday gift to you. :-)) today for you. Things keep falling into place. too bad I didn't charge, I could retire! :-)
The main line run is over sixty feet of non-repeating, non-circling-main and travels along sharp curves with steep grades. It mimics the actual run! I was reading about the real "Big Run" today and read that the curves were so sharp that they had many derailments. Your curves will certainly be a prototypical correct "model" for that canyon. You should as part of your operating plan have RESTRICTED SPEEDS throughout the canyon. No more than 15 MPH. That will be prototypical and make your run feel even longer.
In addition, your track is on 3 levels! This is going to be really cool! The train may be passing through the same wall area twice or three times, but all on distinct different levels. A canyon is PERFECT for distracting viewers that the train is in the same generally vicinity.
I hope that you have some skill with bench-work and backdrop construction. I'm giving you an advanced prototypical track arrangement that will require flex track and the need for ensuring spacing between lines thru the passing siding and several clearance issues. There are 4 places where the main passes over or under itself on its long and winding road.
The best part of my plan is I've left your doors both unobstructed. You may simply walk up to and in or out either one. Life is good.
After receiving your measurements, and getting your blessing, I may want to put some layout in front of the sliding glass door section that does NOT move. Maybe and maybe not--it's entirely up to you.
The "ends" of your line (Blackwater Canyon Line), are the town of Davis (elevation 3100 feet with 600 and some odd people) and the town of Hendricks (elevation 1700 and having 250 people.) The canyon is "between" those two points. YES! Even on YOUR LINE, Davis is higher up than Hendricks at 60 inches and Hendricks at 41 inches. Your grade is 6%, which is steep but ideal for the look you are attempting to capture and allows for between 60 to 70 feet of running without circling.
Currently, I don't have these "ends" drawn, because I could put reverse loops at both ends which would allow a train to run unattended; (My "ceaseless" pattern) so that you could operate the other making it more challenging passing through the canyon. You will have one long passing siding between Davis and Hendricks allowing "opposing" trains to pass by one another.
Because of your room size, and because reversing loops take up a lot of space and aren't that interesting--limit scenic possibilities, I think you should consider a WYE configuration at Hendricks and a small (24 inch) turntable at Davis. Both these configurations are interesting to operate/control vs. just looking at a train run on a turn-around loop. You would stop, switch consists, drop off, pick up, and have some staging drawers near by.
However, I understand that at times it's more convenient to have the reversing loop arrangement. It's up to you.
I will post the main line run tonight for you to observe. It will probably require a phone conversation between us so that you may gain a clear understanding.
You will be able to see my color coded lines and markings on the drawing and trace the main line path. However, you will need a verbal explanation of what I envision as scenery and an operational scheme for this line. This is going to be fun to operate! Two or three people could operate this system at one time.
This DESIGN PROCESS theme theme will require you to investigate more details for your future acquisitions. Also, regardless of what you decide, PREPARE THAT ROOM FOR A LAYOUT COMPLETELY before you start construction.
I think your ceiling is painted already. I would do a very light blue if it isn't. But, the BIGGEST thing I'd do is settle on a track arrangement and then install overhead spotlights that may be controlled by separate dimmer switches so you may set your lighting any way you wish easily.
I know that Im throwing a ton at you at once, but I put the layout higher to get better spacing between the points where needed while leaving that baseboard heater unobstructed. Heat is good. :-) Fire is bad! I hope that you are taking notes. :-) I wish that I lived closer, because this will be a great project.
