Background and overview
Increasing commuter demand in the Sendai area led to prolonged boarding and alighting times, as well as severe crowding around the vestibules of locomotive-hauled passenger coaches. As a countermeasure to these issues, Japanese National Railways developed the 417 series AC/DC dual-voltage suburban electric multiple units (EMUs) in 1977.
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Car body
The vehicles feature wide steel carbodies measuring 19,500 mm in length and 2,900 mm in width, with a bogie centre distance of 13,800 mm. To reduce overall weight, lightweight shaped steel sections and press-formed beams are employed.
The cab end is gangway-equipped, incorporating a gangway door, curved front windscreens, and a driver’s cab elevated 300 mm above the floor level. This raised position, combined with the curved windscreens, improves forward visibility and provides additional protection against obstacles at level crossings.
Exterior lighting consists of two sealed-beam headlights positioned on either side of the gangway and two taillights mounted below. A destination rollsign is installed above the gangway door.
Each car is equipped with two double-leaf automatic stepped sliding doors, each 1,300 mm wide. Between the doors, the side panels feature four pre-fabricated double-hung windows (1,082 mm wide) and two door pocket windows (723 mm wide). At each end of the carbody, additional double-hung windows and door pocket windows are provided. On the cab side only, immediately behind the driver’s compartment, a narrower double-hung window (522 mm wide) and a door pocket window (723 mm wide) are installed. Both the upper and lower sashes of the windows slide upward.
In addition, powered vehicles are fitted with louvers for the snow separator, designed to remove airborne snow from the intake for cooling the traction motors on each side of the body. Door operation is controlled by TK8A units mounted on the door headers, which also allow manual operation.
Roof-mounted draught ventilators are provided as follows: six on end cars and four on intermediate cars. Each vehicle is equipped with a roof opening covered by a plate, allowing for future installation of an air conditioner at the centre of the roof. Class Moha416 vehicles have a low-roof section where the pantograph and high-voltage equipment are installed to maintain insulation clearance from the extra-high-voltage feeder. A destination rollsign is also mounted on each side of the carbody.
The exterior livery is reddish-brown with a wide cream band below the windscreens.
Bogies
The powered bogies are designated DT32F, while the trailer bogies are TR69J. Both types feature diaphragm air springs for the secondary suspension, the top of which is slanted in lateral direction, and pedestal type journal support configuration. Their secondary airbag suspension is not mounted to their body directly but mounted in the bogie unit.
A parallel cardan drive system with hollow shaft is used for the power transmission mechanism. The gear ratio is set at 4.82 to achieve high acceleration performance while maintaining a lower motored-to-trailer car ratio.
The braking system on powered bogies utilizes single-truck brake rigging with a single-action brake cylinder, whereas trailer bogies equipped with disc brake rigging.
Power train and ancillary equipment
The 417 series EMUs employ a married-pair configuration and are equipped with eight MT54E series-wound brushed DC traction motors, each rated at 120 kW. These motors are controlled via the CS43A motor-driven camshaft control system and the MR136 forced-draught traction resistor, both installed on Class Kumoha417 vehicles. The system utilizes armature-resistance control to regulate acceleration and power output.
Class Moha416 vehicles are fitted with a TM20 traction transformer, which uses silicone oil for electrical insulation, and an RS45B traction rectifier, both mounted beneath the floor. Current collection is handled by a PS16H lozenge-type pantograph via a CB103A air-blast circuit breaker mounted on the roof of the Moha416 vehicles.
Class Kuha416 vehicles are equipped with a motor-generator unit (MH135-DM92) delivering 160 kVA, and a motor-driven air compressor (MH113B-C2000M), both mounted beneath the floor. These components supply electrical power for onboard systems and compressed air for braking and door operation. End cars are also equipped with an overhead line voltage detector mounted on the cab roof. Unpressurized air-blast circuit breaker system is employed to prevent accidental entry into AC-electrified sections.
The braking system consists of an electromagnetic straight air brake, supplemented by rheostatic braking on the motored axles, providing effective deceleration and thermal dissipation during extended braking cycles. A holding brake is also provided.
Accommodation
Passenger accommodation consists of a combination of four transverse four-person seating bays on each side, arranged with a seating pitch of 1,490 mm. The areas adjacent to the doors and the end sections of the saloon are equipped with longitudinal bench-type seating. Each bench is fitted with glass end partition panels to reduce cold air intrusion. The backrests of the transverse seating bays are equipped with hand-grabs, and straps are installed above the longitudinal seating for standing passengers.
Seven electric fans are installed to enhance air circulation within the cabin. For illumination, the interior is fitted with two rows of ceiling-mounted fluorescent light fixtures, each rated at 40 watts.
Class Kuha416 vehicles are equipped with a Japanese-style toilet employing a chemical holding tank.
Modifications
Air Conditioner Installation
Beginning in 1988, JR East retrofitted the vehicles with roof-mounted air conditioning units (type AU75G).
Door Operation Button Installation
In 1996, JR East began installing door operation buttons to allow manual opening and closing of the doors from both inside and outside the vehicle.
Livery modification
Starting in 1990, the exterior livery was updated to a white base coat with a green waistline band located below the windows.
Operations
The 417 series entered revenue service in 1978, operating on rapid and regional services along the Tohoku Line between Kuroiso and Ichinoseki.
Following the privatization and division of Japanese National Railways in 1987, all fifteen vehicles were inherited by JR East.
However, they were gradually displaced by the E721 series and fully withdrawn from service in 2007. |
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| Technical Data |
| Items |
Data |
| Supply
Voltage |
1,500 V DC, 20,000 V AC, 50/60 Hz |
| Service
speed, etc. |
Service speed: 100 km/h |
| Length |
19,500 mm |
| Width |
2,900 mm |
| Height |
3,654 mm |
| Bogie |
DT32F (motored) TR69J (trailer) |
| Collector |
PS16H |
| Traction
motor |
MT54E (120 kW) |
| Gear
ratio |
4.82 |
| Transformer |
TM20 |
| Rectifier |
RS45B |
| Traction system |
Armature-resistance control: (CS43A) |
| Air
conditioner |
AU75E (42,000 kcal/h) |
| Designed
by |
Japanese National Railways |
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