RGN (removable gooseneck)

A lowboy whose front detaches into a ramp so equipment can drive straight onto the deck.

An RGN — removable gooseneck — is a lowboy trailer whose gooseneck (the front section that connects to the truck) detaches and lowers to the ground, turning the front of the deck into a ramp. That lets wheeled or tracked equipment drive on and off the front instead of being craned over the side. RGNs are the workhorse of heavy-haul and frequently run oversize.