Semi-Integral Design (Bus Bodywork)

So-called semi-integral design involves two large assemblies initially being produced separately and then later connected. The high-strength base section (substructure) already contains supporting elements, such as engine mounts and longitudinal and cross members. Large parts of the base section, especially between the axles. are mostly built using grid technology. The wheel arches are also partly fitted. Solely the substructure is often deemed self-supporting, but it only forms a load-bearing and stable unit in fixed association with the superstructure. The ribbed skeleton of the passenger compartment (superstructure) with its roof is produced in a similar way to integral design, in grid technology with panelling. Super- and substructure are then screwed or bonded together. Panelling, reinforcements, central pillars and mudguards connect the base section with the superstructure. Semi-integral design also creates an inseparable bodywork unit. The superstructure is an inherent part of the entire bus bodywork. That is why it is also referred to as a mutually load-bearing design. Other means of assembling the bus bodywork are integral design, composite design (ladder and grid frame) and ladder frame design.