RGN

RGN stands for removable gooseneck. The front section of the trailer detaches from the deck, the deck lowers to the ground, and the front of the well becomes a ramp. Tracked and wheeled equipment drives on under its own power, the gooseneck is reattached, and the load travels in a well as low as a lowboy's.

That removes the crane from the equation. Excavators, crawler cranes, dozers, loaders, and drill rigs load at a mine face, a job site, or a bush landing where no lifting equipment is available, and unload the same way at the other end. It is faster than a crane lift and it is often the only method available at the site.

Capacity is configurable rather than fixed: standard arrangements carry to around 150,000 lbs, and added axle lines spread the load further where the permit allows. Where the piece cannot move itself — a vessel, a transformer, a fabricated assembly — a double-drop or a lowboy craned from above is the more direct answer.