Sounds really interesting and i love the concept. Ive done alot of skulking round old Collieries and loading points in the past few years and you really get a feeling for the place. Lounge disposal point is down by me which is a similar concept to what your building and the tracks all still in situe just sadly nothing else but wasteland.
Regarding loaded wagons appearing out the other side... coal that missed could end up on the wagons rather than in them and fall off elsewhere on your layout slowly building up and then perhaps fouling tracks. Obviously regular sucking up may help but have you considered dropping fully made up loads into the wagons instead of pouring it in? A simple easily removable load could just be popped in as it passes through the loading point and stop any worrying about overspill. Just a thought like although your idea sounds more fun!
Cheers and good luck! Scott.
hello, i have been lookin at your thread and im very impressed, i would be very interested in buying your trees, how much would you charge for the one in the picture?