205-0series
-0 subserires
-500 subserires
-1000subseries(JRW)
-1000subseries(JRE)
-1100 subseries
-3000 subseries
-5000 subseries

Type index

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Yamanote line



Keiyo line


Tokaido line


Hanwa line


Background and overview
In 1985, Japan National Railways (JNR) made a plan to deliver new electric multiple unit (EMU) trains in order to relocate some 103 series EMU used on Yamanote commuter services to Yokohama and Musashino lines to provide additional capacity. Although JNR examined to deliver high-cost 201 series EMU to Yamanote line, it was very difficult to reduce the cost of 201 series much more and budget restraints of JNR prevented the construction of additional 201 series trains. And instead, JNR developed new field added excitation traction control and light weight bolster-less bogies for next generation suburban trains, giving good results. As the result, JNR decided to develop next generation commuter EMU trains, 205 series, applying these new technologies.

Car body
They have 2800mm narrow body. Their body design incorporates stainless steel in order to realize lightweight body, excepting bolster beams, the body end part of centre beam, and some cross beams made of weatherproof steel sheet (Steel Plate Atmospheric). Their bodies are 3.5t lighter than 201 series. Their skin of the bodies features unpainted bead processed stainless sheet. They have the double yellow green waistline and headline bands running the length of each car below and above the windows. The cab end employs glabled shape and raised driver's cab. Windshcreens are asymmetric, and electrolytic colouring aluminum black plate is fitted around windscreens. They are equipped with 4 double-leaf automatic sliding doors and pairs of double-hung unit assembled windows with the upper stage descending and the lower stage rising on each side of the vehicles. Door case windows between the doors and windows located at the end plate of the body are omitted for light weight. Door operating equipments, TK4J, are fitted under the seatings. Traditional roller-binding destination screens are fitted on the body. An air conditioner, AU75G rated at 42,000kcal/h, is fitted on the centre of their roof. Forced ventilators are fitted on the both side of the air conditioner. The end cars are equipped with ATC signaling system under the floor.

Bogies
Their bogies are DT50/TR235 featuring bolster-less secondary air suspension and corn-shaped multilayered rubber spring journal supporting system. Traction device of the bogie is multilayered rubber spring. Side beams of truck frame features straight shaped, and bogie transam features seamless pipes for the light weight and simple construction. Motored bogies employ single tread brake device and trailer bogies employ single disk brake device and single tread brake device. Corrugated wheels are adopted for the light weight and compound circular wheel profile are featured in order to reduce lateral force against tracks.

Traction unit and ancillary equipments
Series-wound brushed DC traction motors, MT61, with a power output of 120kW realize larger torque at low speed and high speed by expanding the field weakening ratio to 35%. The gear ratio is 6.07 to get high traction force at starting. As the result, the acceleration performance and the maximum service speed are same as those of 201 series. Eight traction motors of Moha205 and Moha204 are controlled by the armature-resistance traction control system, CS57, featuring field added excitation control. At the armature voltage control stage, armature resistance control and series-paeallel control are applied. At the field weakening stage, field added excitation system, HS52, indirectly controls the electrical current of field by controlling the electrical current of inductive shunt. Forced field control by HS52 realizes regenerative braking. At low speed range, the voltage of regeneration keeps by applying series-parallel control. So, the regenerative braking is available until 20km/h. If the regenerative brake is not sufficient, additional brake is provided by pneumatic friction brake. Class Moha205 vehicles are equipped with a diamond-shaped current collector, PS21. Class Moha204 vehicles are equipped with a motor generator, DM106, with a power output of 190kVA futuring brush less, for the auxiliary power supply. The brake system is changed into the electric command pneumatic brake from electromagnetic straight pneumatic brake, which was the standard of JNR electric trains, and the brake response has been improved.

Accommodation
Seating is longitudinal throughout. Windshield plates are fitted at the both 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.

Operations of pre-production sets
4 fleets of pre-production type were delivered to Yamanote line and entered the revenue services on the Yamanote line in Mar., 1985.

Mass-Production sets
The first full-production standard set was delivered in 1985. There are some noticeable differences over pre-production set. Side windows are changed into pairs of drop windows. Bogies are changed into DT50D/TR235D featuring double collar sealed roller bearing. 7-car sets were delivered for Tokaido-Sanyo ordinary services from 1986.
After the splitting of the former JNR into the new privatized JR companies in April 1987, JR East, and JR West received 205 series vehicles.
JR East continued to deliver 205 series vehicles to Yamanote line. 205 series built by JR East has difference from those built by JNR in having Luggage rack of 205 series built by JR East is assembled by stainless pipes, although those built by JNR is aluminum wire-netting. After the completement of delivery to Yamanote line, JR East delivered 205 series vehicles to Nambu, Keihin-Tohoku, Sobu, Saikyo, Yokohama, Keiyo, and Musashino lines. The front shape for Keiuo and Musashino lines are different from the others.
In 1990, JR East developed pre-poduction type of intermediate trailer vehicles equipped with 6 double-leaf automatic sliding doors on each side to allow rapid boarding and disembarking during peak periods. Seating is longitudinal seating that were folded up to provide standing room only during the morning peak until 10 a.m. Door operating equipments, TK102, are fitted above the door header of the sliding doors. The luggage rack height is 1,950 mm to be able to stand under the luggage rack. Stanchion poles are fitted at the centre between the doors. An air conditioner is AU717 rated 50,000kcal/h, fitted on the centre of the roof. Bodies are TR241B.
Mass-production type of intermediate trailer vehicles equipped with 6 double-leaf automatic sliding doors on each side, Saha204-0, were deliverd to Yamanote line in 1991. There are some noticeable differences over pre-production set. The luggage rack height is changed into 1,900 mm. A DC-DC converter is fitted in order to supply electrcity for the air conditioner.
In 1994, JR East delivered Saha204-100 vehicles to Yokohama line, allowing rapid boarding and disembarking during peak periods. There are some noticeable differences over Saha204-0. They are equipped with a wheelchair space. A DC-DC converter is discontinued. Bogies are changed into TR246E adopting the bolster-less air suspension, and axle arm type journal box supporting system for the easier maintenance.

Latest operation status
205-0 series used on Yamanote, Soubu, Saikyo, Keiyo, Nambu, and Yokohama lines hae been displaced with E231 series or E233 series.
205-0 series used on Tokaido-Sanyo ordinary services had been displaced with 321 series and relocated to Hanwa line. The refurbishment programme was also commenced, with the same accommodation as 207 series, removing ventilators, and fitting loudspeakers, which a train conductor uses in order to guide passengers waiting at a station. But the vehicles used on Hanwa line were displaced with 225-5000 series and relocated to Nara line linking Kyoto and Nara. Now 205-0 series are used the ordinary services of Musashino and Nara lines.
Technical Data
Items Data
Supply Voltage 1500VDC
Service speed, etc. Acceleration: 2.5km/h/s Deceleration: 2.8km/h/s Service speed: 100km/h
Length 19500mm
Width 2800mm
Height 4140mm
Bogie DT50 (motored) TR235 (trailer) TR241B (saha204)
Collector PS21
Traction motor MT61 (120kW)
Gear ratio 6.07
Traction system Field added excitation control (CS57)
Air conditioner AU75G (42000kcal/h) AU717 (50,000kcal/h)
Designed by Japan National Railways