Integral Design (Bus Bodywork)

Integral design, also called grid frame design, combines extruded profiles in a grid frame. Main ribs circumferentially and supports longitudinally form a stable and highly rigid bodywork structure. Panelling and a number of other partially supporting functional assemblies, such as engine or axle mounts, are integrated within this grid frame. In addition to the main ribs, the floor assembly is inextricably linked with the vehicle body via panelling, reinforcements and mudguards. The chassis (substructure) and the ribbed skeleton structure of the passenger compartment (superstructure) form an inseparable unit as a self-supporting bus bodywork that can absorb all inherent forces. The engine, transmission and axles are connected with the bus bodywork at strengthened key points. Integral design means that all the equipment and layout requirements for the passenger compartment are considered early in the bodywork planning phase. This allows weight savings and a highly stable and safe vehicle structure. The main advantage of high dimensional stability with lower mass has to be weighed against the elaborate production. There is little scope in the event of modifications or repairs to a structure. This can be a disadvantage in some parts of the world. Other means of assembling the bus bodywork are Semi-integral Design, Composite Design (ladder and grid frame) and Ladder Frame Design.