JNR Class ED79

Class ED79
JR Hokkaido ED79 19 on a Kaikyo service in 1992
Type and origin Power type Electric Builder Hitachi, Mitsubishi, Toshiba Build date 1986–1990 Total produced 44
Specifications Configuration: ​  • UIC Bo-Bo Gauge 1,067 mm (3 ft 6 in) Bogies DT129 Wheel diameter 1,120 mm (3 ft 8 in) Length 14,300 mm (46 ft 11 in) Width 2,800 mm (9 ft 2 in) (ED79-0/100) 2,800 mm (9 ft 2 in) (ED79-50) Loco weight 68.0 t (ED79-0/100) 67.8 t (ED79-50) Electric system(s) 20 kV AC, 50 Hz Current source Overhead catenary Traction motors MT52C x 4 Safety systems ATC
Performance figures Maximum speed 110 km/h (70 mph) Power output 1,900 kW
Career Operators JR Freight, JR Hokkaido Number in class 0 Delivered 1986 Preserved 0 Disposition All withdrawn

The Class ED79 (ED79形) was a Bo-Bo wheel arrangement AC electric locomotive type operated on passenger and freight services in the north of Japan from 1986, originally by Japanese National Railways (JNR), and later by Hokkaido Railway Company (JR Hokkaido) and Japan Freight Railway Company (JR Freight) until 2016.

21 Class ED79-0 locomotives were converted between 1986 and 1987 at JNR's Omiya, Tsuchizaki, and Naebo Workshops from former Class ED75-700 locomotives to haul both freight and passenger trains through the undersea Seikan Tunnel between the main island of Honshu and the northern island of Hokkaido, which opened in March 1988. The gear ratio was reduced from the 4.44 of the original ED75 locomotives to 3.38, giving a top speed of 110 km/h (70 mph) better suited to express passenger and freight workings. With the privatization of JNR on 1 April 1987, all 21 locomotives were transferred to the ownership of JR Hokkaido.

Daytime Kaikyo services previously hauled by Class ED79 locomotives between Aomori and Hakodate through the Seikan Tunnel were discontinued in 2002, replaced by the Hakucho and Super Hakucho limited express services using electric multiple unit (EMU) trains). In 2006, the Nihonkai sleeping car service no longer ran through the tunnel, and JR Freight also ceased using JR Hokkaido locomotives on freight services, due to the increased availability of Class EH500 locomotives.

By 1 April 2013, nine Class ED79-0 locomotives remained in service, owned by JR Hokkaido and based at Hakodate Depot. These were used to haul the Cassiopeia, Hokutosei, Twilight Express, and Hamanasu overnight services between Aomori and Hakodate via the Seikan Tunnel. All remaining locomotives had been withdrawn by March 2016.