[TechTalk]

This is a complicated question. To start, there is no agreed definition of "full monocoque" or "semi-monocoque." Newell uses a combination of welded steel framing from the floor down and rivited aluminum framing above the floor, with the majority of the load carried by a wide steel channel going front to back in the center just under the floor (the top of the chassis). This construction is certainly some form of moncoque, rather than body-on-frame, but a hybrid to be sure. The typical bus shell extends the steel structure above the floor and across the top, with the majority of the load carried in truss like structures running front to back between the windows and the floor. Without question, this is full monocoque. When Mr. Newell designed his structure in about 1970, his goal was for the chassis to be "self supporting," not relying on the coach body, specifically the sidewalls, for support. He wanted to be able to locate doors, windows, furnace vents, etc. (slide-outs!) anywhere required without losing the structural integrity of the vehicle. By the same token, Newell solidly and permanently attaches the body structure to the chassis so that the finished unit has the much of the structural advantage of a monocoque without depending on the walls for strength. Cutting slide-outs into the walls effects the structure of both a Newell and a bus, but not as much with the Newell since the majority of the load is carried by the center channel under the floor. Hence Newell has required only a small amount of structural upgrading to go to four slides, while buses are typically limited to only two slides. We would not agree that the chassis/frame design has been greatly compromised in either case.