Like someone else said unless you go gooseneck or just haul mulch I don't see what a bumper pull 7x14 is good for.
I'm pretty sure coal doesn't weigh anywhere near what sand/gravel or dirt does. I realize the 7x14's have 2 7k axles but your still in the same boat. The volume of the box is more than it can hold in heavy dense material. For firewood or coal yes and even mulch or for yard materials. Bri-mar makes a good trailer but I would put them a notch below Moritz IMO. Do they use the scissors lift. I've only been told this, never seen it first hand, that without a scissors some dumps have trouble lifting heavy loads.
My Brimar is a tandem dually and while there are some things that I do not care for, the lifting capability is not one of them. I have done some on site work where I could dump material that was so heavy that I had to put my dually in low range to get started. I don't know if this is relative to the smaller models or not. Do your homework no matter the brand.I'm pretty sure coal doesn't weigh anywhere near what sand/gravel or dirt does. I realize the 7x14's have 2 7k axles but your still in the same boat. The volume of the box is more than it can hold in heavy dense material. For firewood or coal yes and even mulch or for yard materials. Bri-mar makes a good trailer but I would put them a notch below Moritz IMO. Do they use the scissors lift. I've only been told this, never seen it first hand, that without a scissors some dumps have trouble lifting heavy loads.