Background and overview
JR East planned to transfer 205‑0 series EMUs—displaced from the Chuo–Sobu Line by the introduction of the E231‑0 series—to the Musashino Line to replace the aging 103 series. However, 205‑0 series trainsets required a powered‑to‑trailer ratio of 6:2 due to the steep gradients on the underground sections of the Keiyo Line, where Musashino Line services also operate. This resulted in an insufficient number of powered vehicles to support the planned transfer of 205‑0 series sets.
To address this issue, JR East introduced a variable‑frequency drive system with enhanced adhesion performance to the 205 series, enabling a 1:1 powered‑to‑trailer ratio. These modified units were classified as the 5000 subseries in 2002.
Four eight‑car sets—each consisting of four powered vehicles and four trailer vehicles—were converted and allocated to the Toyoda Depot.
Car body
The carbody of the 205‑5000 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 orange and brown running the length of each car below and above the windows.
The non‑gangwayed cab ends, which have no gangway door, are framed with decorative FRP panels. 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 flat and slanted windscreens are divided into a wide glass pane on the driver’s side and a narrower pane on the assistant driver’s side. A destination rollsign is mounted centrally behind the upper portion of the wider windscreen, while an operation‑number indicator—displaying the trainset‑level scheduling identifier—is implemented using an LED display located behind the upper portion of the narrower windscreen. End vehicles are equipped with a longitudinally arranged sealed‑beam headlight with a taillight positioned below.
Each car is equipped with four double‑leaf automatic sliding doors, each 1,300 mm wide. 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. Additional equipment includes a destination rollsign 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. Class Moha 204‑5000 vehicles are equipped with four roof‑mounted draught ventilators; end vehicles feature five, while other variants feature six.
Couplers between married‑pair motored cars use drawbars, while all other connections employ tightlock couplers.
Bogies
The powered bogies are designated as type DT70, converted from the DT50D bogie through the replacement of the power‑transmission system with Twin Disc (TD) flexible joints employing deflecting plates made of carbon‑fibre‑reinforced plastic (CFRP). The trailer bogies are classified as type TR235D. Both bogie 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.
The gear ratio is 6.07. Corrugated wheels are adopted to reduce weight, and a compound circular wheel profile is employed to minimise 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
Class Moha205‑5000 vehicles are equipped with a two‑step variable‑frequency drive (VFD) traction system, designated SC71, which controls eight PG (pulse‑generator) sensor-less asynchronous motors (MT74), each rated at 120 kW, including those on Class Moha204‑5000 vehicles. This traction system employs insulated‑gate bipolar transistors (IGBTs).
Current collection is handled by a PS21 lozenge‑type pantograph mounted on the roof of Class Moha205‑5000 vehicles. Class Moha 204‑5000 vehicles are equipped with a brushless motor‑generator unit (DM106) delivering 190 kVA, as well as a motor‑driven air compressor (MH3075A‑C2000M), both mounted beneath the floor.
The brake system features an electrically commanded braking system with regenerative‑braking capability, resulting in improved brake response. End vehicles are equipped with onboard ATS‑P, ATS‑B, and ATS‑S signalling systems mounted beneath the floor.
Accommodation
The passenger saloon of the 205‑5000 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 in two parallel rows along the ceiling to support standing passengers.
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. The master controller employs a lateral‑motion operating handle.
Additional delivery
A total of thirty‑two 205‑0 series EMU trainsets—displaced from the Yamanote Line by the introduction of the E231‑500 series—were converted into 205‑5000 series EMUs. In addition, four eight‑car trainsets of 205‑0 series EMUs retired from the Nambu, Keihin‑Tōhoku, and Musashino lines were also converted into 205‑5000 series sets.
Class Moha204‑5000 vehicles converted from units not originally equipped with a motor‑generator are additionally fitted with an auxiliary power supply unit (SC66B) rated at 210 kVA.
Operations
The 205‑5000 series entered commuter service on the Musashino Line in 2003.
Replacement by E231‑0 series EMUs—displaced from the Chūō–Sōbu Line by
the introduction of the E231‑500 series—began in 2017. The 205‑5000 series
was completely withdrawn and scrapped in 2020. |
|
| Technical Data |
| Items |
Data |
| Supply Voltage |
1,500 V DC |
| Service
speed, etc. |
Acceleration: 2.5 km/h/s Deceleration: 2.8 km/h/s Service speed: 110 km/h |
| Length |
19,500 mm |
| Width |
2,800 mm |
| Height |
4,140 mm |
| Bogie |
DT70 (motored) TR265D (trailer) |
| Collector |
PS21 |
| Traction
motor |
MT74 (120 kW) |
| Gear ratio |
6.07 |
| Traction system |
variable-frequency drive: SC71 |
| Air conditioner |
AU75G (42, 000kcal/h) |
| Designed
by |
JR East |
|
|
