Mobile support structure for assembling a fuselage section, and procedure for assembling such a section

A support structure for assembling a fuselage section, the support structure comprising a chassis, and a core mounted to rotate relative to the chassis about an axis of rotation of the core, the core comprising fasteners for holding longitudinal fuselage portions around the core, with a view to assembling them to form the fuselage section, and wherein the support structure includes one or more movement elements on the chassis, in order to allow the movement of the support structure, wherein it also includes, incorporated into the core, a first work platform allowing operators to move around inside the core, when the first platform is oriented horizontally upwards, wherein it includes, incorporated into the core, a second work platform allowing operators to move around inside the core, when the second platform is oriented horizontally upwards and when the core is oriented differently from the angular position in which the first work platform is oriented horizontally upwards.