Anyone knowledgeable about fifth wheel construction?

The main lower floor is indeed connected that way, but the nose section that is the bedroom is not. The frame of that section expands out to be almost the width of the trailer but stops just inside the walls. There are no outriggers. In other words, the pin box frame and the two rails on either side that connect it to the main frame are basically the inside wall to wall width. But we could find nothing obvious that connect up there that portion of the frame and the wall structure.