JNR Class ED73

The Class ED73 (ED73形) was a Bo-Bo wheel arrangement AC electric locomotive type operated by Japanese National Railways (JNR) in Kyushu, Japan, between 1962 and the 1980s.[1]

Class ED73
The first locomotive delivered, ED73 1, in 1962
Type and origin Power type Electric Builder Toshiba Build date 1962 - 1963 Total produced 22
Specifications Configuration: ​  • UIC Bo-Bo Gauge 1,067 mm (3 ft 6 in) Bogies DT119B Wheel diameter 1,120 mm (3 ft 8 in) Length 14,400 mm (47 ft 3 in) Width 2,805 mm (9 ft 2.4 in) Height 4,260 mm (14 ft 0 in) Loco weight 67.2 t Electric system/s 20 kV AC, 60 Hz Current pickup(s) overhead wire Traction motors MT52
Performance figures Power output 1,900 kW
Career Operators JNR Numbers ED73 1–22, ED73 1001–1022 Locale Kyushu Delivered 1962 First run 1962 Preserved 0

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 for train heating, and was therefore 3 m (9 ft 10 in) shorter than the Bo-2-Bo wheel arrangement Class ED72.[1] The DT119B bogies were also almost identical to those used on the full-production Class ED72 locomotives.[2]

History

A total of 22 locomotives were built by Toshiba between 1962 and 1963.[1] The first locomotives were delivered to Moji Depot in northern Kyushu.[2]

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.[1] The locomotive numbers were painted yellow at this time.[1] In later years, the class was also used on overnight sleeping car services, as these trains did not require steam heating.[1]

The class was withdrawn by the early 1980s.[1] No examples of the class have been preserved.[3]

Classification

Main article: Japan Railways locomotive numbering and 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 85 km/h (55 mph)

References

1. Inoue, Koichi (1999). 国鉄機関車事典: 蒸気・電気・ディーゼル機関車66形式 国鉄機関車辞典 [JNR Locomotive Encyclopedia]. Japan: Sankaido. pp. 140–141. ISBN 978-4-381-10338-3.
2. Tezuka, Kazuyuki (January 1963). 交流電気機関車ED731 [AC electric locomotive ED73 1]. Japan Railfan Magazine (in Japanese). Vol. 3 no. 19. Japan: Koyusha Co., Ltd. p. 14.
3. Sasada, Masahiro (September 2012). 国鉄&JR保存車大全 [JNR & JR Preserved Rolling Stock Complete Guide]. Tokyo, Japan: Ikaros Publications Ltd. p. 126. ISBN 978-4863206175.