ELECTRIC LOCOMOTIVE E 321 012

This locomotive was designed for experiments with continuous current rail lines between Milan and Varese, where a special three-rail track was built. The third rail was laid to the side of the track, providing 650 V of current to the engine, collected through lateral skids. The line was converted, with overhead electrical lines connected to the grid, only after World War II. Today the third rail system, created in the United States, is still used in some subway lines. This system is undesirable on surface routes, however, as it raises the risk of short circuit in the case of flooding or objects falling onto the track.