Background and overview
Rural services in Akita region operated by the locomotive-hauled trains consisted of only 2 to 3 vehicles excepting rush hours was very insufficient caused by locomotive reattachment to the opposite end of the train at the terminal stations, or coupling/uncoupling of the train-set change to fit transport need to name a few. Locomotives and passenger cars used on rural services were also superannuated. So, JR East decided to develop AC electric multiple unit (EMU) trains, 701 series in order to displace locomotive-hauled trains. Thirteen 3-car sets consisting of one motored vehicle and two trailer vehicles, and twenty-five 2-car sets consisting of one motored vehicle and one trailer vehicle were delivered in 1993.
Car body
They have 2870mm narrow body. Their body construction is that the pressed
stainless sheet and the outside sheet are combined together and those sheets
themselves keep the strength. Bodies are unpainted and have the magenta
waistline band running the length of each car below the side windows. Light
and dark magenta bands are also fitted below the windscreens. The end vehicles
are equipped with a gangway door and featured low front cab style. They
are equipped with three 1300mm wide double-leaf automatic stepped doors
on each side of the vehicles. Door operating equipments, TK113C, are fitted
above the door header of the sliding doors which can be operated manually
by pushing the buttons fitted beside the door. Horizontal band of 4 set
windows including 2 double-hung side windows having 960mm height are fitted
between the doors, and fixed windows are fitted at the end of the vehicle.
Heat absorbent glass is employed for all windows in order to eliminate
blinds. Traditional roller-binding destination screens and loudspeakers,
providing guidance broadcast for passengers waiting at a station, are fitted
on each side of the body. An air conditioner, AU710A rated at 38,000kcal/h,
is fitted on the centre of their roof. No ventilators are fitted on the
roof. End cars are equipped with the automatic jumper coupler to ease rush-up
operations.
Bogies
The 701 series are equipped with DT61A bogies on the powered vehicles and TR246A bogies on the trailers, featuring bolster-less secondary air suspension and axle arm type journal box supporting system. Their bogies employ the single link traction device. Their bogie employing bow-shaped bogie frame to lower the fitting position of bolster suspension realizes to lower the floor level. Motored bogies employ single tread brake device and trailer bogies employ both single disk brake device and single tread brake device.
Traction unit and ancillary equipments
Their traction system, CI1, consisting of a converter employing thyristor
and diode to get constant voltage electric current from the secondary current
of traction transformer output and a Variable Frequency Drive (VFD) employing
power transistor controls 4 AC asynchronous traction motors, MT65, with
a power output of 125kW. Their traction transformer features shell and
forced oil cooling type. This transformer's primary voltage is 20kV, secondary
is 825V, and third is 388V. Their gear ratio is 7.07 to realize the maximum
service speed at 110km/h and the acceleration at 2.1km/h/s. Twin Disc (TD)
flexible joint employing deflecting plates made of carbon-fiber reinforced
plastic (CFRP) is applied for power transmission device. They employ the
electric commanding brake with rheostatic brake. Class kumoha701 vehicles
are equipped with a motor generator, MH1083-DM107A, under the floor. They
are also equipped with a crossed arm current pickup, PS104, and a traction
resistor unit, MR102, for rheostatic brake on the roof. Class kuha700 vehicles
are equipped with a motor driven air compressor, MH1112-C1600MF.
Accommodation
Passenger accommodation feature longitudinal bucket bench seating throughout with wind protection panel at the end of 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. Their motorman's cab to fitted to the left side of the body is small for conductor-less operation. 2-car sets are equipped with the ticket machines, which put the ticket indicating the boarding station, located beside doorways, a fare LED display and the fare box located behind the motorman's cab. These equipments are prepared for 3-car sets. A 1200 wide double leaf sliding door is fitted at the gangway connection to ease the movement between vehicles in conductor-less operation. Trailer end vehicles, class kuha700, are equipped with a western style toilet with a chemical holding tank. A wheel chair space is located across the aisle from the toilet.
A LED display for providing passenger information, and a door chime are
fitted above the door header of the sliding doors.
Operations
701 series entered rural revenue services of Ohu, and Uetsu lines around Akita region.
Modification and refurbishment
The accommodation of class kuha700 vehicles of -36 to -38 was remodeled in 2000. The seating accommodation of them were changed into the mixture of longitudinal bench seating and additional 4 transverse bucket seating bays. Their current pickup was changed into the single-arm type current pickup, PS106A. This current pickup was subsequently changed into the single-arm type current pickup, PS109. The current pickup of class kumoha701 vehicles excepting kumoha701-36 to -38 was changed into the single-arm type current pickup, PS109.
JR East replaced their traction system, IC1, into new traction system,
IC19, consisting of a 3-level converter employing Insulated Gate Bipolar
Transistor (IGBT) and a 2 level Variable-frequency drive (VFD) employing
IGBT. This traction system employs dual system and controls 4 asynchronous
traction motors on truck basis. In case of the traction system failure,
one failure unit can be cut off to continue travelling. Their traction
transformer was changed into TM32A adopting the protection against harmonic
current. Their brake system was changed into the electric commanding brake
with regenerative brake caused by introducing new traction system, and
their traction resistor unit was removed. Their roller-binding destination
indicators were changed into the LED destination indicators.
Withdrawal and present operation
One 3-car set completely dmanaged from the collision accident at the level
crossing in 2016 was scraped in 2020. Surplus two trailer intermediate
vehicles, class saha701, by shorten 3-car sets were also withdrawn.
Latest operation status
701 series are now used on the rural services of Ohu line between Shinjyo and Aomori, Uetsu line between Tsuruoka and Akita, and Tsugaru line. |
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