I see used horse trailers for sale for reasonable prices. I would suppose they lack tie down points and the floor loading would not be that high. But then a horse only has four small point loads holding up a good weight so maybe??? Are they a stronger floor then a utility trailer or about the same?
Bill D.
There are many different specs and types of horse trailers, hard to generalize.
Problem with older horse trailers you can get substantial corrosion on the underside through floor members / angle iron / aluminum. That's something that horse owners (back in the day) had to check so a horse does not put a foot through a floor while travelling. [That can be pretty fatal to a horse.].
A larger warmblood weighs about 1200 lbs...
Two to three horse trailer I would not put anymore than about 4000 to 6000 lbs for a machine tool like a lathe and then you have to figure out how to spread the load.
The kind of flat bed trailers that you pull (goose neck or otherwise) that you can load an actual medium sized tractor with large wooden planks/ floor boards are much stronger.
A lot of horse trailers are designed to be as light as possible so they can be pulled by something like an F250 or F 350 or even F150. Even from 2 horse, to slant trailers where you can move 5 horses or more.
Also if you have to winch in a heavy piece of equipment of the order of 10,000 to 14,000 lbs + up a ramp I would not count on the structure of the horse trailer for that.
Older heavier steel horse trailer might be worth a look / re-hack / repurpose, most modern horse trailer use Aluminum.