JNR Class ED45

"JNR Class ED45" is a term used to refer to a set of three Japanese AC electric locomotives operated by the Japanese National Railways from 1955 to 1970.
==History==
The term "Class ED45" is used to refer to three similar prototype electric locomotive designed to test out a section of the Senzan Line experimentally converted to feature AC power lines in 1955.
The first locomotive, ED45 1, was completed on 28 September 1955 by Shin-Mitsubishi Jukōgyō, the second locomotive, ED45 2, was completed by Toshiba on 21 December 1956 and the third locomotive was completed by Hitachi in February 1957. All three locomotives featured different specifications and control equipment, with both all locomotives having their equipment regularly changed out for testing purposes. The locomotives were reclassified as Class ED91 locomotives in 1961, with all three reclassified as such; the locomotives received no changes to their numbers. All locomotives were withdrawn by 1970.
No ED45s have been preserved. ED91 11 and ED91 21 (ex-ED45 11 and ED45 21) were preserved in the past but both have since been scrapped.
==Design==
The ED45s generally featured a large box-shaped body with large headlights mounted on the roof.
ED45 1 adopted the same body style as used by Mitsubishi's other electric locomotives for private railways, such as Odakyu's Class DeKi 1041 and Oigawa Railway's Class E10 locomotives. ED45 11 featured an "angular style" based on that of Tobu's Class ED5000 locomotives. ED45 21 adopted the same body style as used by Hitachi's other electric locomotives for private railways, such as the Osaka Cement Class IBuKi 500 locomotives.
==Specifications==
Each of the three locomotives featured different specifications, so these will be detailed in three different sections.
ED45 1 was manufactured with a Quill drive system and MT903 traction motors. It used an air-cooled oil-feeding transformer and water-cooled mercury rectifiers along with a tap changer drive used to drive the DC motors. This system was found to be prone to malfunctioning when there were vibrations and was time consuming to repair due to the water-cooling systems. The locomotive's silicon rectifiers were replaced with silicon diodes in 1959 and phase control was lost as a result.
ED45 11 was manufactured with a nose suspension drive system and MT902A traction motors. Using data obtained from ED45 1, ED45 11 was manufactured with air-cooled rectifiers and a transformer with no need for an oil feed. A motor generator was added to the locomotive, as well as some DC current equipment to develop dual-current locomotives. Measures for fire protection were also added to the locomotives. The nose suspension drive system was based on EH10 15. A Toshiba-manufactured ignitron was used, but this was replaced due to poor performance.
ED45 21, designated as a "technology demonstrator" by Hitachi, was fitted with a Quill drive system and MT904 traction motors. It was manufactured with the Excitron mercury rectifier system, meant to be compared to Toshiba's ignitron system. Unlike the other locomotives, ED45 21 was fitted with a high voltage tap changer drive used to drive the DC motors, along with a field weakening device. The Excitron system was replaced with a silicon rectifier in 1959 due to poor performance.
==Preservation==
The following Class ED45 locomotives were preserved in the past but have since been scrapped:
Number 	Manufacturer	Equipment manufacturer	Date manufactured	Date retired 	Last location 	Notes
ED91 11	Toshiba 	Toshiba 	21 December 1956 	31 March 1970	Morigō Children's Park, Miyagi, Japan 	Displayed outdoors; scrapped June 2022 along with C58 354
ED91 21	Hitachi 	Hitachi 	28 March 1957 	31 March 1970	Sendai General Shinkansen Depot, Sendai, Japan	Displayed outdoors; scrapped September 2019 with a number of other preserved locomotives
==Gallery==
File:ED91-21.jpg
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Category:Electric locomotives
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Category:Narrow-gauge locomotives
Category:Hitachi locomotives
Category:Mitsubishi locomotives
Category:Toshiba locomotives
Category:Japanese locomotives
Category:Scrapped electric locomotives