Degussa airside hoppers

Bowser makes thease cars in N scale and have seen pictures of them in real life. Where do thease cars come from ? Which trains are they on? What is there final destination?

[8D]Around here, western Oregon, these cars are loaded at a rock quarry after being screened to railroad specifications for ballast. A maint of way work train picks up usually 4 or 5 cars and proceeds to a track gang work site. I have also seen them on standby in yard as part of a wreck train consist.

Ooops, my comments above are about the Difco side dump cars. N-scale mag had a scratchbuilding article in the July/August issue. Sorry if I caused confusion !!