Feeder messenger wire type overhead contact lines have drawn attention recently from the viewpoint of labor-saving for maintenance. A type that uses two PH356mm² messenger wires was introduced into the Tokyo district, while another that uses an SB-TACSR730mm² messenger wire into the Kansai district. In terms of the number of messenger wires, the one-wire type is more useful, as it involves a smaller number of parts. As the material for the wire, copper is better than aluminum, since it does not require connection with different metals. To realize the advantages of the two systems, therefore, we developed a feeder messenger wire type overhead contact line that has only one copper messenger wire.