Japan National Railways (JNR) was supposed to deliver the suburban DC electric
multiple unit (EMU) trains to the Tohoku line and the Takasaki line, JNR
delivered 111 series suburban DC EMU trains to the Tokaido line in 1962.
There are some steeply graded routes in the Takasaki line and the district
on the Tohoku line and Takasaki line is cold and snowy. So, JNR developed
115 series suburban DC EMU train type in 1968.
They have 2900mm wide body. Their body design incorporates lightweight
shaped steel and pressed forming beam to realize a light weight body. Double-hang
windows and 3 double-leaf doors on each side of the vehicles are adopted.
Door operating equipment is TK8, which can open/close manually to prevent
the passenger's room from being cold in winter. Forced ventilators are
fitted on the roof. 115-0 series are not equipped with air-conditioning.
There is a motored end car, Kumoha115, in order to make 3-car formations.
Standard bogies DT21/TR62 for commuter EMU vehicles are adopted. Trailer
bogies employ disc brakes to realize the good brake performance.
Eight more powerful series-wound brushed DC traction motors, MT54, rated
at 120 kW are controlled by armature-resistance traction control system,
CS15A, featuring holding brake. The gear ratio is 4.82. Type Moha114 vehicles
are equipped with a diamond-shaped current collector, PS16. 115-0 series
adopt electromagnetic straight air brake. The rheostatic brake is available.
Seating is arranged as mixture of longitudinal bench seating and transverse
seating bays with 1420mm seating pitch. Trailer end cars, Kuha115, and
trailer intermediate cars, Saha115, have a Japanese style toilet. These
cars are not air-conditioned.
Vehicles built from 1965 differ from earlier 115 series in having improved
traction system, CS15B. Their traction system of Vehicles built from 1966
was changed into CS15C featuring contact-less. Vehicles built from 1968
differ from earlier 115 series in having a traction system, CS15E, featuring
load responding function, improved airtight traction motors, MT54B, and
stainless double-leaf doors.
JNR began to fit AU75 air-conditioner. Although JR companies continued
this reconstruction after the splitting of JNR into the new privatized
JR companies in April 1987, JR companies developed the new air conditioners
reduced the initial cost, and fitted them.
115 series have been used on ordinary services of Shinetsu, Joetsu, Chuo, and Sanyo lines besides Tohoku and Takasaki lines, but are gradually withdrawing by the replacement to 211 series, E231 series, E129 series and 227 series. Remaining 115-0 series were withdrawn in 2018. |
|
