Hello; That last feed trailer is a sweet idea! Those rotary dump trucks are a cool idea especially for railway use. At 2:08 wicked unstable to dump sideways like that, unless it has side stabilizers. Dumping to the rear has the engines weight as a counter. But I get the design benefits. Yeah what they don't tell you about the rotodump is how many of them end up on their sides beings how they don't have outriggers to stabilize the truck as the bed is going up from the side. In this video some very fancy and expensive equipment out there. Pitty they don't regard their drivers high enough to pay them a reasonable wage. Some of us are getting paid the same as we were in in the mid 90's.