The light bridge is a peculiar structure used in performing arts settings (concerts, theatre plays, ballets) which allow lifting lights from the stage. Often, acoustic or scenic materials are connected to it. Therefore, it often happens that the base includes an internal box with cables, power sockets and/or signals for assembled materials.
Generally, the light bridge consists in a framework (or, even better: truss), typically made in aluminum and installed on moving supports (winch or hoist) allowing its vertical movement and thus allowing the possibility to install the necessary components on the ground and to then lift them. Normally, the main framework is parallel to the stage and is 10 meters long in average (it rarely exceeds 15 meters). It is usually located near the stage to surround it. It is less frequently located at the end of the stage to surround its background, whenever it is present and to support backlights. Whenever there are several parallel light bridges, they are normally numbered from the most external (towards the public) to the most internal (e.g. first, second, third light bridge)
Due to its limited assembly and removal ease, it is mainly used in open-air events or in events located in places that are not used for shows: theatres and concert halls normally have a lattice surmounting the stage, which is supported by beams and equipped with a light, acoustic and mechanical system.
Light bridges installation is required by assembly and safety regulations.