Feeder messenger wire type overhead contact lines are drawing attention recently from the viewpoint of laborsaving for maintenance. Those that use two PH356mm² messenger wires are introduced in Tokyo, and those that use an SB-TACSR730mm² messenger wire are in the Kansai district. Regarding the number of messenger wires, the one-wire system is more advantageous, as it involves a smaller number of parts. As the material for the wire, copper is more advantageous than aluminum, since it does not require connection with different metals. To realize the advantages of the two systems, therefore, we promoted this research to develop a feeder messenger wire type overhead contact line which has only one copper messenger wire.