The Class ED500 was a single Bo-Bowheel arrangement dual voltage AC/DC electric locomotive built experimentally by Hitachi in Japan in 1992.[1] The design was derived from the DC Bo-Bo-Bo wheel arrangement Class EF200 also built by Hitachi, and was intended to replace Class ED75 locomotives on Tohoku Main Line freight services. The locomotive was loaned to JR Freight for testing until 1994,[1] but the design was not selected for full production due to problems with restarting a single Bo-Bo wheel arrangement locomotive on the 25‰, 2.5%, gradients of the Tohoku Main Line and in the Seikan Tunnel.[2] The Class EH500 articulated Bo-Bo+Bo-Bo design was ultimately chosen instead.