PJB posted:Wondering if that bottom left LH turnout can be doubled up to link with a RH turnout that might be added to the return curve to create another reversing loop? Just a thought.
If I understand you correctly, the answer is "no" because the switch is at 4" and the loop is on a grade from 0". Even if they were at the same elevation, the reverse would be in the same direction as the current one and that wouldn't really add much to the operation.
However, if the RH turnout on the right end could be connected to the curve coming out of the current reverse loop, Mark could have an unattended loop2loop run, but again, that section is on a grade, so it's not practical.
Besides, Mark has the ceiling layout in the next room for unattended operation of his larger engines/trains. With this new layout, I believe he's more interested in a prototypical reason to go up to the turntable area, swap engines/trains and return to the valley. I just didn't like the dead-end on the bottom of the design he posted, so I added the reversing loop. 
The way I envision things, if he stages a short train on the siding inside the revering loop, he can pull another train into the loop, stop, pull out the new train to head up the grade, pull the other train around the loop and park it to set up for the next run. Basically, he'd be taking supplies/empty cars up to the turntable and bringing down product. If he does things this way, he can be operating 3 trains at the same time. He'd stage one up top and one in the loop while another is running between the 2 areas.
Here's a view with some color and trains.
