For an electric locomotive to achieve widespread use, it should be an AC/DC dual mode electric locomotive with enough power and allowable axle load to adapt to any kind of track. To meet such needs, Hitachi, Ltd has developed and manufactured a test version of the ED500 type 4000-kW AC/DC dual mode 4-axle type inverter controlled locomotive. This model was developed based on the EF200 type 6000-kw 6-axle type inverter controlled DC electric locomotive. The ED500 type employs «high adhesion inverter control», which greatly improves traction performance and enables AC/DC dual mode operation. The increase in weight resulting from these improvements is offset by weight reduction in the car body and bogie, so that the allowable axle load is kept at the same level as that of conventional electric locomotives. Many other advanced technologies have been applied to the ED500 such as a contactless main circuit, brushless motors, and an automatic adjustment which greatly reduces maintenance labor requirements. In addition, the ED500 features a high performance bogie and grake system, easy operation, and an information-rich intelligent driver's cab