Sooo, I'm sure there are applications for this contraption, but you still have to drag your trailer through whatever you dumped! That could get expensive on tires if you are hauling something sharp like crushed chert or some such thing. I've seen grain trailers that are similar, but they drop over a pit. What do you use this for?... It looks like crushed limestone fell out.
I've been hauling 1 1/4" minus crushed basalt. I will show how this trailer functions in a post in the next couple of days.