The Bopper.
Hard to clean from what I was told.
Hard to Clean??, there is a 10' door on each side of the darn thing to get into it...
Likely not so much 'HARD' to clean... but the fact that they have to clean all the boxcar junk out of it before can be used as a hopper.
I.E. nails, staples, tacks, paper, cardboard, wood, dirt, ect.
Funny thing is.... This concept is done every day with containers for export grain shipments.
~Ian