Background and overview
JR East converted 205‑0 series EMUs—displaced from the Yamanote Line by the introduction of the E231‑500 series—into 205‑3000 series DC commuter electric multiple unit (EMU) trains between 2003 and 2005. These conversions, which included shortening the formations to four‑car sets, were undertaken to replace the aging 103‑3000 and 103‑3500 series operating on the Hachikō Line.
Five four‑car sets—each consisting of two powered vehicles and two trailer vehicles—were converted and allocated to the Kawagoe Depot.
Car body
The carbody of the 205‑3000 series measures 19,500 mm in length and 2,800 mm in width, with a bogie centre distance of 13,800 mm. The structure is primarily composed of stainless steel, except for the bolster beams, the end sections of the centre beam, and selected cross beams, which are fabricated from weather‑resistant steel plate (Steel Plate Atmospheric). The exterior features unpainted bead‑stiffened stainless‑steel panels with waistline and headline bands finished in a combination of navy blue and light blue running the length of each car below and above the windows.
The end cars were converted from Class Saha205‑0 intermediate trailer cars. These conversions included removing the original end structure and the side panels adjacent to the end windows, welding a reinforced front frame to the cut body end, and mounting a non‑gangwayed high‑strength composite structure—consisting of phenol‑resin foam and paper honeycomb covered with fibre‑reinforced plastic panels—onto the reinforced frame. An obstacle deflector is fitted beneath the cab, and the driver’s cab is elevated 300 mm above floor level to improve forward visibility and provide additional protection against obstacles at level crossings. The horizontally curved windscreen, finished in black at the upper portion with ceramic coating, is installed at the cab end. An LED destination display is mounted centrally behind the upper portion of the windscreen. Lighting equipment consists of two high‑intensity discharge (HID) lamps flanking the destination display and two externally mounted taillights.
Each car is equipped with four double‑leaf automatic sliding doors, each 1,300 mm wide. Manual operation is enabled via push‑button controls adjacent to each door. Between the doors, the side panels feature pairs of drop windows measuring 920 mm in width, with additional drop windows provided at each end of the carbody. Door operation is controlled by TK4J units installed beneath the bench seats. A destination rollsign is also mounted on each side of the carbody.
Each car is fitted with a roof‑mounted AU75G air‑conditioning unit rated at 42,000 kcal/h. End vehicles are equipped with four roof‑mounted draught ventilators; Class Moha204‑3000 vehicles feature six, while Class Moha205‑3000 vehicles feature four.
Couplers between married‑pair motored cars use drawbars, while all other connections employ tightlock couplers.
Bogies
The powered bogies are designated as type DT50, while the trailer bogies are classified as type TR235. Both types feature bolsterless secondary air suspension and conical multilayer rubber‑spring journal supports. Traction force is transmitted via the centre pin and multilayer rubber‑spring draw gear. The side beams of the bogie frame are straight in shape, and the bogie transom incorporates seamless pipes to achieve a lightweight and simple construction.
Power transmission utilizes a parallel cardan drive system with a hollow shaft. The gear ratio is 6.07. Corrugated wheels are adopted for reduced weight, and a compound circular wheel profile is employed to minimize lateral forces exerted on the track.
The braking configuration varies by bogie type. Powered bogies are equipped with single‑tread brake rigging, while trailer bogies combine a single‑disc brake device with single‑tread brake rigging to enhance overall braking performance.
Powertrain and ancillary equipment
Series‑wound brushed DC traction motors (MT61), each rated at 120 kW, are employed. The eight traction motors on Class Moha205‑3000 and Class Moha204‑3000 vehicles are controlled by the CS57 armature‑resistance traction control system, which incorporates field‑added excitation control. A naturally ventilated traction‑resistor unit designated as MR159 is used. During the armature‑voltage control stage, armature‑resistance control and series–parallel control are applied. During the field‑weakening stage, the HS52 field‑added excitation system indirectly regulates the field current by controlling the current of the inductive shunt. Forced‑field control provided by the field‑added excitation system enables regenerative braking. At low speeds, regeneration voltage is maintained through series–parallel control, allowing regenerative braking to remain effective down to approximately 20 km/h. If regenerative‑braking performance falls below the required threshold, pneumatic braking is automatically applied to supplement the braking force.
Current collection is handled by a PS21 lozenge‑type pantograph mounted on the roof of Class Moha 205‑3000 vehicles. Class Moha 204‑3000 vehicles are equipped with a brushless motor‑generator unit (DM106) delivering 190 kVA, as well as a motor‑driven air compressor (MH3075‑C2000M), both mounted beneath the floor.
The brake system features an electrically commanded pneumatic braking system with regenerative‑braking capability, resulting in improved brake response. End vehicles are equipped with onboard ATS‑P and ATS‑SN signalling systems mounted beneath the floor.
Accommodation
The passenger saloon of the 205‑3000 series EMU is configured with fully longitudinal seating to maximize capacity and facilitate smooth passenger flow during boarding and alighting. Each bench is fitted with end partition panels to delineate individual seating areas. Hanging straps are installed throughout the passenger compartment to support standing passengers in two parallel rows along the ceiling. The air‑conditioning ductwork is installed above the ceiling to maintain a clean interior profile, with slit‑type vents providing evenly distributed airflow. Illumination is provided by fluorescent fixtures arranged in two parallel rows along the ceiling. Kuha205‑3000 vehicles are equipped with a wheelchair‑accessible space located toward the rear of the passenger compartment.
The control desk is fitted with a single‑handle master controller operated with the left hand.
Modifications
Pantograph replacement
The pantographs of Class Moha205-3000 vehicles were replaced with PS33C single‑arm pantographs between 2004 and 2005.
Operations
The 205‑3000 series EMUs were converted between 2003 and 2005 to replace the aging 103 series EMUs operating on the Hachikō Line and subsequently entered regional services on the line.
The 205‑3000 series continued to operate on regional services on the Hachikō
Line; however, replacement by the E231‑3000 series began in 2017, followed
by the 209‑3500 series in 2018. The 205‑3000 series was completely withdrawn
and scrapped in 2018. |
|
| Technical Data |
| Items |
Data |
| Supply Voltage |
1,500 V DC |
| Service
speed, etc. |
Acceleration:
2.5km/h/s Deceleration: 2.8km/h/s Service speed: 100km/h |
| Length |
19,500 mm |
| Width |
2,800 mm |
| Height |
4,140 mm |
| Bogie |
DT50 (motored) TR235 (trailer) |
| Collector |
PS21 |
| Traction
motor |
MT61 (120kW) |
| Gear ratio |
6.07 |
| Traction system |
Field added
excitation control (CS57) |
| Air conditioner |
AU75G (42,000 kcal/h) |
| Designed
by |
JR East |
|
|
