The was a Bo-Bo wheel arrangement Alternating current, AC electric locomotive type operated by Japanese National Railways (JNR) in Japan between 1962 and the 1980s.

Design

The Class ED74 was developed as a four-axle version of the six-axle (Bo-Bo-Bo) Class EF70 electric locomotives introduced a year earlier on the Hokuriku Main Line, and was intended for use on services north of where the gradients were easier.

History

A total of six locomotives were built by Mitsubishi in 1962, coinciding with the electrification of the Hokuriku Main Line between Fukui and . The six locomotives were delivered to Tsuruga Station, Tsuruga Depot. Displaced by the arrival of Class EF81 multi-voltage AC/DC electric locomotives, the Class EF74 locomotives were transferred to Kyushu in October 1968 for use on the recently electrified Nippo Main Line. To enable use alongside the six axle (Bo-2-Bo) Class ED76 AC locomotives, a dead weight of 1.4 t was added to increase the axle load from 16.25 t to 16.8 t. As the Class EF74 locomotives did not have steam generators and were unable to provide train heating for passenger services, they were mostly used on freight services between and , as well as on overnight sleeping car services that did not require a separate heating supply from the locomotive. Despite electrification south to in 1974, the Class EF74 locomotives were not allowed south of Oita due to their axle load, and were subsequently replaced by an additional build of Class ED76 locomotives. The entire class was withdrawn by 1982.

Classification

The ED74 classification for this locomotive type is explained below. * E: Electric locomotive * D: Four driving axles * 7x: AC locomotive with maximum speed exceeding

References

{{Jnrelec Electric locomotives of Japan Bo-Bo locomotives Mitsubishi locomotives 1067 mm gauge locomotives of Japan Railway locomotives introduced in 1962