The was a

Bo-Bo B-B and Bo-Bo are the Association of American Railroads (AAR) and British classifications of wheel arrangement for railway locomotives with four axles in two individual bogies. They are equivalent to the B′B′ and Bo′Bo′ classifications in ...

wheel arrangement In rail transport, a wheel arrangement or wheel configuration is a system of classifying the way in which wheels are distributed under a locomotive. Several notations exist to describe the wheel assemblies of a locomotive by type, position, and c ...

AC electric locomotive type operated by

Japanese National Railways The abbreviated JNR or , was the business entity that operated Japan's national railway network from 1949 to 1987. Network Railways As of June 1, 1949, the date of establishment of JNR, it operated of narrow gauge () railways in all 46 pref ...

(JNR) in Kyushu, Japan, between 1962 and the 1980s.

Design

The Class ED73 design was broadly derived from the Class ED72 locomotives introduced a year earlier, but as the Class ED73 was primarily intended for use on freight services, it did not include a

steam generator A Steam generator is a device used to boil water to create steam. More specifically, it may refer to: *Boiler (steam generator), a closed vessel in which water is heated under pressure *Monotube steam generator *Supercritical steam generator or Ben ...

for train heating, and was therefore shorter than the Bo-2-Bo wheel arrangement Class ED72. The DT119B bogies were also almost identical to those used on the full-production Class ED72 locomotives.

History

A total of 22 locomotives were built by

Toshiba , commonly known as Toshiba and stylized as TOSHIBA, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. Its diversified products and services include power, industrial and social infrastructure systems, ...

between 1962 and 1963. The first locomotives were delivered to Moji Depot in northern Kyushu. In the late 1960s, the entire class was modified with improved braking performance for use on express freight services, and the locomotives were renumbered in the ED73 10xx series. The locomotive numbers were painted yellow at this time. In later years, the class was also used on overnight sleeping car services, as these trains did not require steam heating. The class was withdrawn by the early 1980s. No examples of the class have been preserved.

Classification

The ED73 classification for this locomotive type is explained below. * E: Electric locomotive * D: Four driving axles * 7x: AC locomotive with maximum speed exceeding

References

{{Japanloco Electric locomotives of Japan Bo-Bo locomotives Toshiba locomotives 1067 mm gauge locomotives of Japan Railway locomotives introduced in 1962