Background and overview
The Fukushima-Yamagata section of the 1,067mm gauge Ohu line was converted to 1.435mm gauge to enable Shinkansen trains from Yamagata to travel on the Tohoku Shinkansen line through Tokyo. Regional services also continued to be provided on the gauge-converted lines. Thus, JR East developed 719-5000 series suburban AC EMU trains for standard gauge in 1991. 12 two-car sets consisting of a powered end vehicle and a trailer end vehicle were delivered to Yamagata depot in 1991.
Car body
They have 2950mm wide body, incorporating light weight stainless construction. Bodies are unpainted and have an orange and green waistline band running the length of each car below the windows. Cab ends are covered by a Fiber Reinforced Plastics (FRP) panel with a gangway painted in green at the centre. Electrolytic colouring aluminum black plates are fitted above and below windscreens. Left windshield panel is expanded below to have a commanding view of the tracks ahead. A destination roll sign is fitted above the gangway door. They are equipped with 3 stepless double-leaf automatic sliding doors on each side of the vehicles and pairs of drop windows. Door operating equipments, TK111, are fitted above the door header of the sliding doors which can be operated manually by pushing the buttons fitted beside the door. A drop window and two fixed windows on each side of a drop fixed window are fitted between the doors. An air conditioner, AU710A rated at 38,000kcal/h, is fitted on the centre of their roof. Forced draft ventilators are fitted on both side of the air conditioner. Class kumoha719 vehicles have a low roof section where the current collector is fitted to reduce upper structure clearance for current pickup, since a tunnel section of the Senzan line is low. The LED destination indicators are fitted on the body side. End cars are equipped with the automatic jumper coupler to ease rush-up operations.
Bogies
The 719-5000 series are equipped with DT60 bogies on the powered vehicles and TR245 bogies on the trailer featuring bolster-less secondary air suspension, rolled rubber spring journal supporting system, and the Z link traction device. Parallel cardan drive with hollow shaft is applied for power transmission device. The gear ratio is 6.07 to operate at the steep gradient of railways and get the maximum service speed at 110km/h. Motored bogies employ single tread brake device and trailer bogies employ double disk brake device.
Traction unit and ancillary equipments
Four powerful shunt-wound brushed DC traction motors, MT61, with a power output of 130kW and featuring high terminal voltage at 400V, are controlled by the traction control system, CS55B, featuring thyristor phase control and holding brake. They feature field added excitation control to expand the field weakening ratio to 33%. Class kumoha719-5000 vehicle is equipped with the traction transformer, TM22C under their floor. The traction rectifier, RS52A, consists of a pair of the thyristor full bridges and a thyristor/diode hybrid bridge. The thyristor full bridges convert alternating current to direct current while power running and change direct current to alternating current as the external excited inverter while regenerating to control armature current. Thyristor/diode hybrid bridge powered by the current of fourth wiring of the traction transformer controls the field weaking ratio. The minimum field weaking ratio is 30% to realize regenerative brake at high-speed range. Class kumoha719-5000 vehicles are also equipped with a motor-driven reciprocating air compressor, MH1103-C1000D, under their floor and a cross-arm current pickup, PS104 on the roof. They feature the electric commanding brake with regenerative brake and holding brake.
Accommodation
They have a transverse bucket seating bay with 1490mm seating pitch at the centre, two transverse bucket seatings with 845mm seating pitch outer side of a centre bay, and two longitudinal bench seatings outer side of the transverse seating. The air conditioning duct is fitted above the ceiling in order to improve interior design and the outlets of cool air are slit shape. Trailer end vehicles, class Kuha718, are equipped with a Japanese style toilet.
Modification
JR East equipped 6 train sets with the ticket machine, which put the ticket
indicating the boarding station, located beside doorways at the end of
their body, the fare chart seven segment display box located behind the
driver's cab and the fare, for conductor-less operation.
Operations
719-5000 series vehicles were delivered to Yamagata depot and entered revenue services on Ohu line between Fukushima and Yamagata in November 1991. Their services were extended to Shinjyo in December 1999. 719-5000 series are now used on the rural services on Ohu line between Fukushima and Shinjyo. |
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