Loading from an ore bin (pics)

I am looking for information on a rail siding layout typical of what was found along the RGS or D&RGW for ore loading from a storage or mine bin. Now assuming that the structure was similar to the ore bin located at Sawpit on the RGS ( I understand that this single chute loading was for truck loading on this structure but my question is if it was used for railcar loading).

1. My estimate is that this bin would hold the equivalent cubic material to fill two (2) 30 foot D&RGW high side gondolas.

2. If the car for loading is spotted with one end of the car under the chute how much of a grade is required for the loading operator to respot (roll via gravity) the car under the chute via a hand brake release or mechanical assist to complete the loading?

3. Or did the crew picking up the car do the respotting/loading in this type of structure/ siding pickup ?

4. If the car was moved (or not) by the loading operator as in #2 and if the grade on the siding serving the ore bin descended back toward the mainline would a derail have been required (RGS/ D&RGW practice)?

5. If more than one car (in this two cars) are to be loaded from the fully loaded bin again referring back to #2 scenario is this also possible again using gravity and how much of a grade would be required (assume 10 ton cars and 25 tons of payload in each)?

Rod