Go for this plan
Chris,
I've been rough sketching my crazy idea and it's just too crazy...actually, it's trying to fit too much track in the space. And the more I look at this plan the more I like it. I hope you do too. Here it is with the requested modifications. Sorry it took so long to get back to you. I've been pulled more and more out into my garage as it becomes my workshop. The pencil and paper have been set down now for a while unless an urgent and compelling need to sketch arises.
View attachment 34515
As you can see, the areas for 20-22" radius curves have been marked. Adjusting these will take some tweaking, as you will see. I'm leaving that up to you and the software to determine where you will have to give and take in order to make this work. Also, the area over on the right will benefit from moving the spur to the mine further toward the double track 'main' and paralleling the existing track.
Another possibility is one I alluded to earlier, of swapping the coal mine for the gravel pit. You'd need to start the turnout ladder before the track passes under itself to accomplish this. Consider changing the coal MINE into a coal PROCESSING PLANT. Loaded hoppers arrive and the coal is washed and oiled then replaced in the hoppers...not sure if they get cleaned as well...it could be some fun research and could be a bit more plausible for your setting. May only need some minor kitbashing, and it would be a more unique industry, not commonly found on other layouts.
Galen