The most popular system presently on older bridge cranes is bare, hard drawn, copper wire although it is rarely provided today on new equipment. Local electrician codes prohibit their use except under specific conditions. These systems are installed by a number of hard drawn solid copper or aluminum wires being stretched along the sides of the crane track or under the roof beams and held in place by insulated hangars. This system can only be insulated on straight runs.
For special applications where it is possible to isolate equipment and personnel from electrical lines or when extreme temperatures prevent the use of insulated types of electrification, bare wire can offer an excellent means of bringing power to the equipment. These bare wires do present a very dangerous safety hazard for service personnel working on equipment or where metal bars, ladders, scaffolding or other obstructions may come in contact with the lines.