The JNR Class ED73 was a Japanese AC electric locomotive operated by the Japanese National Railways from 1962 to 1982.
History[]
The ED73 was designed specifically for use on the Kagoshima Main Line due to the use of AC electrification on that line. The locomotives were specifically designed for use in Kyushu and were an evolution of the ED72 design.
Twenty-two locomotives were built from 1962 to 1963; Toshiba manufactured both the electrical and mechanical components of the locomotives. Equipped with a steam generator, the locomotives were used on passenger trains which required onboard heating, as well as for pulling Blue Train sleeper trains, freight trains and towing other locomotives. Their axle load prevented them from entering other sections of the line, with operations restricted to north of Kumamoto Station. The locomotives were converted to -1000 series locomotives from 1968 to 1969 (e.g. ED73 1 became ED73 1001 etc.), being fitted with equipment conducive for high-speed services. Their operational area expanded to the Nagasaki Main Line in 1976.
With the electrification of the full Kagoshima Main Line in 1970, the ED75-1000 locomotives were introduced, solving the axle load issue; by the mid-1970s aging of the locomotives becoming noticeable. Their operational area expanded to the Nagasaki Main Line in 1976. Withdrawals began in 1980; all locomotives were withdrawn by 1982. They were replaced by EF70 locomotives in these duties.
No ED73s have been preserved. ED73 1016 (ex-ED73 16) was preserved at Kokura General Rolling Stock Depot for some years after retirement but was scrapped around 2006.
Design[]
The ED73s featured large box-shaped bodies with a slight rake with dual large circular headlights mounted on the top of the cars in two recesses.
Specifications[]
The ED73s used a nose suspension drive system with MT52 traction motors; the use of the nose suspension drive was due to maintenance problems involving the Quill drive, so all locomotives after the earlier EF70 would use the nose suspension drive. This however came at the cost of keeping the rated rotation speed of the traction motors low.
These were the last JNR AC locomotives fitted with mercury rectifiers.
Preservation[]
The following Class ED73 locomotives were preserved in the past but have since been scrapped:
| Number | Manufacturer | Equipment manufacturer | Date manufactured | Date retired | Last location | Notes |
|---|---|---|---|---|---|---|
| ED73 1016 | Toshiba | Toshiba | 1963 | 2 August 1981 | Kokura General Rolling Stock Depot, Kokura, Japan | Ex-ED73 16; scrapped c.2006 due to deterioration |