The scenic mechanism is a system of scenic bars. The bars are round cross-section tubes attached to the trusses, to which scenographic elements, lighting equipment and scenic draperies are attached. Its movement can be done manually, with counterweights or motorized.
The system of manual bars is light, driven by ropes and pins attached to the sides of the stage. Manual hooks comprised of one or more drums connected to a horizontal axle and an activation lever may be used.
Systems of counterweight bars are used in theaters to alleviate the weight of the scenographic or lighting bars during handling. These are mechanic systems most widely used for lighting.
These bars are hoisted by a suspension system comprised of wire ropes, moto-reducers and pulleys that allow for the movement of the bars.