Within the general scope defined in Section I of the introduction, ASME B30.11 applies to underhung cranes and monorail systems where load-carrying members, such as end trucks or carriers (trolleys), travel either on the external or internal (see Fig. 9) lower flange of a runway track section, single monorail track, crane bridge girder, or jib boom (see Fig. 1), including all curves, switches, transfer devices, lift and drop sections, and associated equipment. This Volume includes provisions of both power-driven and hand-operated equipment on which the carriers are independently controlled. This equipment is grouped together because of the similarity of construction and because of common considerations which are peculiar to this type of equipment. Systems used for transporting personnel require special considerations and are not included in this Volume. Also excluded from this Volume are conveyor systems, including power and free conveyors.