It’s a trailer toad.
It puts 0 weight on your tow hitch.
Used to be a version for old airstream called “slimp dolly”.
It’s a dolly that takes the weight of the hitch off the tow vehicle. Usually used if the tongue weight would end up overloading your tow vehicle. If you have a travel trailer of much size at all and you fill your cab with people and your bed with stuff you’re probably overloaded in a half ton truck. This would move the weight of the trailer to a separate axle so the weight isn’t carried by the truck.
Now, I’m not sure how well the rig would back up with it on there (you could just drop that dolly and hook it to the tow vehicle, the weight won’t matter if you’re backing into a space). And when I looked into them, the weight of that dolly is usually enough that it plus the trailer plus whatever is in the truck will often put you right over a GCWR of the truck. It’s really just what you buy when you SHOULD have bought a bigger truck.
It’s called the Trailer Toad. Controversial in some circles.
https://www.youtube.com/watch?v=ycTT1wwsQQU&t=1s
Its obviously not for a 5th wheel.
My guess is the tongue weight of the trailer is too much for the truck so they’re using this dolly between the truck and trailer.
You really should just ask them. I’ve never seen anything like this before and am curious if it’s something they created themselves.
So you can use your Tesla to pull a 16k fifth wheel lol
So the camper is not a fifth-wheel. The device in question has 3 tires, the third tire is sideways on the top.
Sorry about the photo, I don’t want to walk to someone’s camp while they are just getting here, so I zoomed in from my camp.
Could it be a converter dolly? In commercial trucking these are used to make semi-trailers act like full trailers, which don’t share any of their weight (except the draw bar) with the tow vehicle.
The same principle can be applied to RV type trailers if the tongue weight is too high for the TV, you’d add the dolly to take the weight instead. It is unusual but not unknown, IIRC this is shown in the classic film The Long Long Trailer (required viewing for every RVer IMO).
