Pre-production set
Background and overview
On certain commuter lines operated by Japanese National Railways (JNR), the introduction of modern electric multiple unit (EMU) trains was planned to accommodate short station intervals and the requirement for 8-car formations. However, operating the existing 101 series EMUs on these lines would require a high motored-to-trailer car ratio (e.g., 6M2T) to meet performance demands, resulting in increased manufacturing and operating costs.
To reduce costs while maintaining adequate performance, JNR began developing
a new DC commuter EMU designed to operate with a balanced 1:1 motored-to-trailer
ratio (e.g., 4M4T). This led to the construction of the pre-production
103 series, which featured high-output traction motors rated at 110 kW.
These units were optimized for acceleration and deceleration through the
adoption of a higher gear ratio, enabling sufficient performance even with
fewer motored cars.
In 1963, two 4-car pre-production sets were delivered for testing and evaluation.
Car body
The vehicles feature narrow steel bodies measuring 19,500 mm in length and 2,800 mm in width. Lightweight shaped steel and pressed forming beams are employed to reduce overall body weight. Cold-rolled steel plates are used for the body skin and roof panels.
The cab end adopts a gabled, non-gangway design, with a slanted windscreen
divided into three panes. Exterior lighting equipment includes a centrally
mounted headlight above the windscreen and two taillights positioned below.
A destination roll sign is installed above the driver's-side windscreen,
while an operation number indicator—showing trainset-level scheduling identifier—using
a rotary disc is located above the co-driver's side.
Each car is equipped with four double-leaf automatic sliding doors, each 1,300 mm wide. Between the doors, the side panels feature a pair of 920 mm wide double-hung windows, flanked by door pocket windows on both sides of the sash. At each end of the car body, a door pocket window and a double-hung window are provided. Both the upper and lower sashes of the windows slide upward.
Door operation is controlled by TK4D installed beneath the bench seats. Class Moha103 vehicles are fitted with six roof-mounted globe ventilators, while other vehicles are equipped with seven.
Bogies
The powered bogies are designated as DT26C, featuring wheels with a diameter of 910 mm and a wheelbase of 2,300 mm. The trailer bogies are of type TR62X, equipped with 860 mm diameter wheels and a 2,100 mm wheelbase. Both bogie types employ coil springs as bolster springs and adopt a pedestal-type journal support configuration.
A parallel cardan drive system with hollow shaft is used for the power transmission mechanism. The gear ratio is set at 6.53 to achieve high acceleration performance while maintaining a lower motored-to-trailer car ratio.
The braking system utilizes single-truck brake rigging, incorporating a double-action brake cylinder.
Traction unit and ancillary equipments
The pre-production 103 series EMU is equipped with eight MT55 series-wound
brushed DC traction motors, each rated at 110 kW. These motors are controlled
via the CS20 motor-driven camshaft control system and the MR51 forced-draught
traction resistor, both of which are installed on class Moha103 vehicles.
This system employs armature-resistance control to regulate acceleration
and power output. This configuration reflects a conventional yet reliable
traction control architecture widely adopted in Japanese commuter EMUs
of the period.
The class Moha102 vehicles are fitted with a motor-generator unit (MH97-DM61) delivering a power output of 20kVA and a motor-driven air compressor, either the MH113-C2000M or MH114-C2000N, both mounted beneath the floor. These components supply electrical power for onboard systems and compressed air for braking and door operation.
Current collection is handled by a PS16 lozenge-type pantograph, mounted on the roof of the class Moha103 vehicles. For inter-car electrical connections, two KE57 jumper couplers are employed, ensuring reliable transmission of control and auxiliary circuits between vehicles.
The braking system consists of an electromagnetic straight air brake, supplemented by a rheostatic braking function. This combination provides effective deceleration performance while reducing mechanical wear.
Accommodation
The passenger saloon of the pre-production 103 series EMU features a fully longitudinal seating arrangement, optimized for high-capacity commuter service and efficient passenger flow during boarding and alighting.
Electric fans are installed beneath the roof-mounted ventilators to enhance air circulation within the cabin, particularly during peak hours. For illumination, the interior is equipped with two rows of ceiling-mounted fluorescent light fixtures, each rated at 40 watts.
Mass-production sets
Background and overview
In 1964, an 8-car mass production set of the 103 series EMU was delivered to the Ikebukuro depot, marking the transition from prototype evaluation to full-scale fleet introduction.
Car body
The vehicles feature narrow steel bodies measuring 19,500 mm in length and 2,800 mm in width. Lightweight shaped steel and pressed forming beams are employed to reduce overall body weight. Cold-rolled steel plates are used for the body skin, while hot-rolled steel plates are applied for roof panels for cost reduction.
The cab end adopts a gabled, non-gangway design, with a slanted windscreen divided into three panes. Exterior lighting equipment includes a centrally mounted headlight above the windscreen and two taillights positioned below. A destination roll sign is installed above the driver's-side windscreen, while an operation number indicator, utilizing a rotary disc mechanism, is located above the co-driver's side.
Each car is equipped with four double-leaf automatic sliding doors, each 1,300 mm wide. Between the doors, the side panels feature a pair of 920 mm wide double-hung windows, flanked by door pocket windows on both sides of the sash. At each end of the car body, a door pocket window and a double-hung window are provided. Both the upper and lower sashes of the windows slide upward.
Door operation is controlled by TK4D installed beneath the bench seats. Class Moha103 vehicles are fitted with six roof-mounted globe ventilators, while other vehicles are equipped with seven.
Bogies
The powered bogies are designated as DT33, featuring wheels with a diameter of 910 mm and a wheelbase of 2,300 mm. The trailer bogies are of type TR201, equipped with 860 mm diameter wheels and a 2,100 mm wheelbase. Both bogie types employ coil springs as bolster springs and adopt a pedestal-type journal support configuration.
A parallel cardan drive system with hollow shaft is used for the power transmission mechanism. The gear ratio is set at 6.53 to achieve high acceleration performance while maintaining a lower motored-to-trailer car ratio.
The braking system utilizes single-truck brake rigging, incorporating a single-action brake cylinder.
Traction unit and ancillary equipments
The mass-production 103 series EMU is equipped with eight MT55 series-wound
brushed DC traction motors, each rated at 110 kW. These motors are controlled
via the CS20A motor-driven camshaft control system and the MR51 forced-draught
traction resistor, both of which are installed on class Moha103 vehicles.
This system employs armature-resistance control to regulate acceleration
and power output. This configuration reflects a conventional, yet reliable
traction control architecture widely adopted in Japanese commuter EMUs
of the period.
The class Moha102 vehicles are fitted with a motor-generator unit (MH97-DM61) delivering 20kVA and a motor-driven air compressor, the MH113-C2000M, both mounted beneath the floor. These components supply electrical power for onboard systems and compressed air for braking and door operation.
Current collection is handled by a PS16 lozenge-type pantograph, mounted on the roof of the class Moha103 vehicles. For inter-car electrical connections, a KE70 multicore jumper coupler is employed, ensuring stable transmission of control and auxiliary circuits throughout the train formation.
The braking system consists of an electromagnetic straight air brake, supplemented by a rheostatic braking function. This combination provides effective deceleration performance while reducing mechanical wear.
Accommodation
The passenger saloon of the mass-production 103 series EMU features a fully longitudinal seating arrangement, optimized for high-capacity commuter service and efficient passenger flow during boarding and alighting.
Electric fans are installed beneath the roof-mounted ventilators to enhance air circulation within the cabin, particularly during peak hours. For illumination, the interior is equipped with two rows of ceiling-mounted fluorescent light fixtures, each rated at 40 watts.
Additional delivery
In 1970, a new variant known as class Kumoha103 was introduced to support shorter train formations, specifically 3-car and 5-car sets deployed on the Keihin-Tohoku Line. This configuration addressed operational needs for flexible capacity.
Class Kumoha103
The class Kumoha103 is a powered end car equipped with a driving cab at
the front, structurally derived from the class Moha103 powered car. Due
to the presence of the cab section, conventional mounting space for a traction
motor cooling louver at the front end was unavailable. As a design solution,
a louver was relocated above the door pocket window adjacent to the cab,
ensuring adequate ventilation for the traction motors while preserving
the vehicle's frontal layout.
Vehicles manufactured from 1970 onward incorporated improvements to the traction control system, adopting the CS20C motor-driven camshaft controller. This upgraded system introduced a slip detection mechanism to enhance traction stability under low-adhesion conditions, as well as a non-contact short-circuit relay for the camshaft drive motor, improving reliability and reducing maintenance requirements.
In addition, measures were implemented to address pulsating current effects in the air compressor circuit. As part of this refinement, the compressor was reclassified as MH113A-C2000.
Class kuha103-500
The class kuha103-500 class was developed as a trailer end car for use on the Keihin-Tohoku Line, specifically designed for operation at the B end (even-numbered orientation) of the train formation.
To accommodate this directional requirement, JNR introduced the class kuha103-500 in 1971 as a direction-specific jumper-equipped cab car, with jumper couplers installed only on one side of the cab. This configuration restricted the vehicle's operational orientation but simplified wiring and reduced manufacturing complexity.
103-910 series
To mitigate frequent wheel slip, the standard 103 series was fitted with a slip detection system integrated into the traction control. Although this modification yielded partial improvement, it did not offer a fundamental solution. Consequently, JNR developed the experimental 103-910 series in 1967, incorporating the newly designed CS30 traction system. This system employed fine-step resistance control to improve adhesion performance and enhance overall traction reliability.
Vehicles manufactured for the Joban line from 1968 onward are equipped with the TR212 trailer bogie, which incorporates disc brake rigging to reduce braking distance.
Vehicles manufactured from 1969 onward are fitted with the upgraded motor generator, type MH97A-DM61, which features improved bearings and an integrated oiler.
An air-conditioned prototype train set
In 1969, a prototype 10-car train set was constructed to evaluate air conditioning
systems. Each car was equipped with a centrally roof-mounted air conditioner
rated at 42,000 kcal/h. The end cars of Class kuha103 were fitted with
a single MH129-DM88 motor-generator unit, delivering 210 kVA of electrical
power to operate the onboard air conditioning equipment of five cars, including
the car in which the unit was installed.
Three types of air conditioning units-AU73X, AU74X, and AU75X-were tested, along with variations in duct configurations: a single central duct, dual side ducts, and systems with or without electric fans. Additionally, pre-assembled windows were installed to improve thermal insulation and enhance the overall effectiveness of the air conditioning system.
Vehicles manufactured from February 1972 onward incorporated several improvements, including:
- Replacement of the original headlight with dual sealed-beam units,
- Adoption of pre-fabricated double-hung windows,
- Introduction of the upgraded CS20D traction system, featuring a non-contact
current-limiting relay,
- Enhanced bench seating with a lower and deeper profile for improved passenger
comfort.
Further refinements were implemented from September 1972 onward, notably the adoption of the improved MT55A traction motor.
Air-conditioned mass production sets
Background and overview
Although air-conditioned vehicles had already become common in private railway companies, air conditioning systems began to be installed on vehicles manufactured by Japanese National Railways (JNR) from 1973 onward.
Car body
The vehicles feature narrow steel carbodies measuring 19,500 mm in length
and 2,800 mm in width. To reduce overall weight, lightweight shaped steel
and pressed-forming beams are employed. Cold-rolled steel plates are used
for the body skin, while hot-rolled steel plates are applied to the roof
panels for cost efficiency.
The cab end adopts a gabled, non-gangway design with a slanted windscreen divided into three panes. Exterior lighting includes two centrally mounted sealed-beam headlights above the windscreen and two taillights positioned below. A destination rollsign is installed above the driver's-side windscreen, while an operation number indicator-utilizing a rotary disc mechanism-is located above the co-driver's side.
Each car is equipped with four double-leaf automatic sliding doors, each
1,300 mm wide. Between the doors, the side panels feature a pair of 920
mm wide pre-fabricated double-hung windows, flanked by door pocket windows
on both sides of the sash. At each end of the carbody, a door pocket window
and a pre-fabricated double-hung window are provided. Both the upper and
lower sashes of the windows slide upward.
Door operation is controlled by TK4D units installed beneath the bench
seats. Each car is fitted with a centrally roof-mounted AU75A air conditioner
rated at 42,000 kcal/h. Class Mha103 vehicles are equipped with five roof-mounted
globe ventilators, while other variants feature six. A destination rollsign
is mounted on each side near the rear end.
Traction unit and ancillary equipments
The air-conditioned mass-production 103 series EMU is equipped with eight
MT55A series-wound brushed DC traction motors, each rated at 110 kW. These
motors are controlled via the CS20D motor-driven camshaft control system
and the MR51 forced-draught traction resistor, both of which are installed
on class Moha103 vehicles. This system employs armature-resistance control
to regulate acceleration and power output. This configuration reflects
a conventional, yet reliable traction control architecture widely adopted
in Japanese commuter EMUs of the period.
The class Moha102 vehicles are fitted with a motor-generator unit (MH135-DM92) delivering 160kVA and a motor-driven air compressor, the MH113A-C2000M, both mounted beneath the floor. These components supply electrical power for onboard systems and compressed air for braking and door operation.
Current collection is handled by a PS16 lozenge-type pantograph, mounted on the roof of the class Moha103 vehicles. For inter-car electrical connections, a KE70 multicore jumper coupler is employed, ensuring stable transmission of control and auxiliary circuits throughout the train formation.
The braking system consists of an electromagnetic straight air brake, supplemented by a rheostatic braking function. This combination provides effective deceleration performance while reducing mechanical wear.
Additional delivery
From August 1973 onward, vehicles were equipped with an upgraded air conditioning unit, model AU75B. As part of this improvement, the thermostat was relocated from the air conditioning unit itself to the car body.
In anticipation of the planned introduction of the Automatic Train Control (ATC) signaling system on the Yamanote, Akabane, Keihin-Tohoku, and Negishi lines, JNR improved end cars of class kuha103 to accommodate future installation of onboard ATC equipment. This variant incorporated several design changes, including:
- A raised cab floor, elevated by 300 mm
- A narrower-height windscreen, with an additional narrow stainless-steel
band installed below it
- Elimination of the door pocket window adjacent to the cab to provide space
for the ATC equipment compartment
From 1975 onward, vehicles were fitted with an upgraded motor-driven air compressor, model MH113B-C2000M, featuring enhanced protection against snow ingress.
Vehicles manufactured from 1978 onward also included additional modifications. End cars of class kuha103 were equipped with an onboard ATC signaling unit. The traction system was updated with a revised current limit pattern and reclassified as CS20D-G2. Interior fittings were also modified: the piping of overhead luggage racks and the risers of bench seats were changed to unpainted stainless steel.
Some end cars manufactured from 1979 onward were delivered without onboard ATC equipment, while retaining the elevated cab floor. In these units, the door pocket windows adjacent to the cab were reinstated.
From August 1983 onward, vehicles were equipped with an upgraded air conditioning unit, model AU75G. These units also introduced polyurethane resin-based roofing materials.
Modifications
JNR
103-900 Series
The prototype set was reclassified as the -900 subseries in 1964. Subsequently, its traction system was upgraded to type CS20A. The bogies were replaced with DT33 (motored) and TR201 (trailer) types. The jumper coupler was changed from type KE58 to KE70.
Class Saha 103-750
Beginning in 1973, selected saha101 intermediate trailer cars from the 101 series EMUs were converted to the 103 series and reclassified as class saha103-750. The gangway connections and jumper couplers were upgraded.
–Saha 103-751 to 767
Converted from non-air-conditioned saha101-0 cars. Retrofitted with AU75A roof-mounted air conditioners (rated at 42,000 kcal/h) and equipped with a destination rollsign on each side near the rear end.
–Saha 103-768 to 770
Converted from air-conditioned saha101-0 cars. No additional destination rollsigns were installed.
–Saha 103-771 and 772
Converted from air-conditioned saha101-200 cars. No additional destination rollsigns were installed. The existing motor generator and air compressor were removed.
–Saha 103-773 to 776
Converted from non-air-conditioned saha101-0 cars. Retrofitted with AU75A roof-mounted air conditioners (42,000 kcal/h). No additional destination rollsigns were installed.
–Saha 103-777 to 780
Converted from air-conditioned saha101-0 cars. Destination rollsigns were retrofitted on each side near the rear end.
Class kuha103-2000
To compensate for the shortage of end cars following the shortening of train formations on the Hanwa and Kansai lines, selected kuha100 trailer end cars were converted to the 103 series and reclassified as class kuha103-2000 in 1986. Cab equipment, gangway connections, and jumper couplers were upgraded.
Class kuha103-2050
Similarly, kuha101 trailer end cars were converted to the 103 series and reclassified as class kuha103-2050 in 1986. Cab equipment, gangway connections, and jumper couplers were upgraded.
Air conditioner retrofitting
Non-air-conditioned vehicles were retrofitted with AU75B or AU75E roof-mounted air conditioners (rated at 42,000 kcal/h) and destination rollsigns on each side near the rear end. Class Moha102 cars were additionally equipped with MH135-DM92 motor generators (160 kVA output) mounted beneath the floor.
Sealed beam headlight upgrade
Starting in 1979, headlights on non-air-conditioned end cars were upgraded to dual sealed beam units.
Special maintenance programme
To extend service life, JNR initiated a special maintenance programme in 1981. This included the application of polyurethane resin-based roofing materials, repair of damaged body panels and flooring, and replacement of side windows.
ATC equipment implementation
Beginning in 1979, selected Kuha103 end cars that had previously undergone preparatory work for onboard Automatic Train Control (ATC) equipment were fitted with the actual ATC onboard units.
JR East
Class Saha103-800
The transfer of Class Moha103-910 vehicles, equipped with the special CS30 traction system, to other lines posed operational and maintenance challenges due to the system's non-standard specifications.
To resolve these issues, JR East carried out modifications in 1988. The Moha103-910 vehicles were retrofitted by removing the traction motors, transmission units, driving gears, and current collectors. Additional roof ventilators were installed, and the bogies were replaced with TR212 type.
Similarly, Moha102-912 underwent the same modifications: removal of traction motors and transmission units, and bogie replacement with TR212.
In addition, non-air-conditioned Moha102-62 and Moha102-172 received the same modifications as Moha102-912. These vehicles had previously operated in pairs with moha103 intermediate powered cars, which were subsequently replaced by air-conditioned Moha102-911 and Moha102-913, respectively, to maintain operational consistency.
All modified vehicles were reclassified as class saha103-800.
Air conditioner retrofitting
To accelerate the retrofitting of non-air-conditioned vehicles inherited by JR East following the privatization and division of the former JNR, JR East began installing two newly developed, low-cost air conditioning units (model AU712, rated at 21,000 kcal/h) on these vehicles starting in 1988. The AU712 units are powered either by the existing motor generator installed on class Moha102 vehicles or by a roof-mounted auxiliary power supply unit (model SC24) installed on each vehicle, which provides an output of 28 kVA.
Life extension programme
In 1988, JR East launched a life extension programme aimed at extending the service life of its rolling stock by over 20 years. The programme included the replacement of damaged body skirting, side windows, and door surround panels with weather-resistant steel plates after removing the original coating. Polyurethane resin-based roofing materials were also introduced. In addition, interior panels were replaced with new beige-coloured panels.
JR Central
Air conditioner retrofitting
To expedite the retrofitting of non-air-conditioned rolling stock inherited from the former Japanese National Railways (JNR) following its privatization and division, JR Central began installing two newly developed, cost-effective air conditioning units (model C-AU711A, rated at 18,000 kcal/h) on 12 vehicles starting in 1988.
Class Moha102 cars were additionally fitted with an auxiliary power supply unit (model C-SC24), rated at 120 kVA.
Refurbishment programme
In 1988, JR Central launched a refurbishment program that included the following upgrades:
–Adoption of polyurethane resin-based roofing materials
–Replacement of side windows with prefabricated units featuring a downward-sliding upper sash and fixed lower sash
–Installation of bucket-style bench seating
–Replacement of interior panels with white-finished panels
JR West
Air conditioner retrofitting
To accelerate the retrofitting of non-air-conditioned rolling stock inherited from the former Japanese National Railways (JNR) following its privatization and division, JR West began installing three newly developed, cost-effective air conditioning units (model WAU102, rated at 12,000 kcal/h) on 97 vehicles starting in 1988.
Class Kuha103 cars were additionally equipped with an auxiliary power supply unit (model WSC23), rated at 140 kVA.
Bogie replacement
In 1994, Bogies on cars Saha103-777, -778, and -780 were replaced with TR212, replacing the original TR64 bogies.
Class Kuha103-2500
To address the shortage of cab-end cars resulting from shortened train formations on the Yamatoji Line, selected Moha102 motored intermediate cars were converted into trailer end cars in 1988. This involved the addition of a new cab-end structure and reclassification as class Kuha103-2500. The door pocket windows adjacent to the cab were eliminated to expand the driver's compartment. The original DT33 motor bogies were modified to DT33T specification by removing the traction motors, transmission units, and other related components.
Class Kuha103-2550
Similarly, to compensate for the shortage of end cars following train set reductions on the Yamatoji Line, selected Moha103 motored intermediate cars were converted into trailer end cars in 1988. These units were fitted with a newly added cab-end structure and reclassified as class Kuha103-2550. The door pocket windows adjacent to the cab were removed to enlarge the cab space. The traction system, traction resistor unit, and pantograph were also removed. The DT33 motored bogies were converted to DT33T specification through the removal of traction motors, transmission units, and other components.
Class Kumoha103-5000
To shorten the original 7-car formations to 3-car sets following the opening of the electrified Gakken-Toshi Line between Nagao and Kizu, JR West converted selected class Moha103 motored intermediate cars into powered cab-end cars between 1988 and 1989. These converted units were reclassified as class Kumoha103-5000. The conversion included the construction of a new cab-end structure and the installation of automatic coupling and uncoupling equipment.
Kumoha103-5001, however, was converted from an existing class Kumoha103-0 motored end car and modified only through the addition of automatic coupling and uncoupling equipment.
Class Saha102-5000
To shorten the original 7-car formations to 4-car sets following the opening of the electrified Gakken-Toshi Line between Nagao and Kizu, JR West modified selected class Saha103-0 trailer intermediate cars between 1988 and 1989. These cars were not fitted with cab-end structures, but were equipped with automatic coupling and uncoupling equipment as well as a gangway cover. As these sets were not operated independently, cab-end facilities were not required. These modified cars were reclassified as class Saha102-5000.
Class Saha102-0
The introduction of 3-car train sets for operations on the Gakken-Toshi Line between Matsui-Yamate and Kizu resulted in a shortage of transport capacity. To address this, JR West modified class Saha102-5000 cars in 1989 by removing the automatic coupling and uncoupling equipment as well as the gangway covers. The modified cars were inserted into existing 3-car sets operating independently on the same section of the Gakken-Toshi Line, and were reclassified as class Saha102-0.
Class Saha103-2500
To address the shortage of intermediate trailer cars required for extending an existing 3-car set to 4-car formation on the Gakken-Toshi Line between Matsui-Yamate and Kizu, Moha103-232 was retrofitted in 1990. The traction system, traction-resistant structural elements, and current collector were removed, and the DT33 motored bogies were converted to DT33T specification by removing the traction motors, transmission units, and other associated components. The modified vehicle was reclassified as class Saha103-2500. At the same time, three roof-mounted WAU102 air-conditioning units, each rated at 12,000 kcal/h, were installed.
Class Moha102-5000
To address capacity shortages on the Gakken-Toshi Line between Matsui-Yamate and Kizu, Saha103-5000 cars-originally part of 4-car formations not operated independently-were transferred into newly configured 3-car trainsets for use on the section. As a result, the original 4-car sets were shortened to 3-car formations and ceased to operate as independent units. Within these shortened sets, the Moha102 cars came to occupy end positions. In 1989, these Moha102 units were retrofitted with automatic coupling/uncoupling equipment and gangway covers to support flexible operation, and were subsequently reclassified as class Moha102-5000.
Refurbishment programme N/ NA/NB
In addition to special maintenance work aimed at preserving vehicle functionality, Refurbishment Programme N was introduced in 1987 for 103-0 series vehicles to improve outdated interior accommodations and repair body damage. Programme NA was subsequently applied to vehicles that had previously undergone special maintenance, incorporating further accommodation upgrades.
These refurbishment works included several interior improvements: seat upholstery was changed to brown fabric, and wall panels were replaced with ivory-coloured units. From 1990, door pocket windows began to be sealed.
In 1992, Refurbishment Programme NB was launched as a continuation of Programme NA, targeting non-air-conditioned vehicles. It included the retrofit of prefabricated side windows featuring black-coloured sashes.
Life extension programme N40
JR West launched life extension programme N40 with the aim of extending the service life of vehicles to over 40 years from their original construction. The programme included the replacement of damaged body skirting, side windows, and door surround panels; the adoption of polyurethane resin-based roofing materials; and the installation of prefabricated side windows featuring a black-coloured downward-sliding upper sash and black-coloured fixed lower sash.
A total of 180 vehicles underwent this programme between 1992 and 1998.
Refurbishment programme 40N
In 1996, JR West retrofitted a prototype vehicle to evaluate the effectiveness of Refurbishment Programme 40N. While previous life-extension efforts had focused primarily on restoring basic functionality to aging rolling stock, this programme aimed to upgrade onboard accommodation and ancillary equipment to standards comparable with contemporary vehicles
Car body
–Existing pairs of double-hung windows were replaced with aluminum-framed side windows. These featured a two-part upward-sliding upper sash and a large fixed lower sash.
–End windows were converted to fixed-pane units.
–All windows were fitted with heat-absorbing glass.
–Door actuation units were replaced with direct-drive actuators (WTK113 type).
–The rain gutter was integrated into the carbody skin for a cleaner exterior profile.
–Roof-mounted ventilators were removed, and polyurethane resin-based roofing materials were adopted.
Ancillary equipments
The motor-generator set was replaced with an SC927A auxiliary power supply
unit, providing a rated output of 160 kVA.
Accommodation
–The ceiling was flattened to align with the AC ducting, and electric fans were replaced with cross-flow air blowers.
–Fluorescent lighting fixtures were fitted with protective lamp covers.
–Passenger hand straps were installed throughout the vehicle.
–Longitudinal bench seats were constructed using a cantilever design.
–Overhead luggage racks were replaced with pipe-frame structures featuring decorative end caps.
–Floor inspection covers for traction motors were sealed with metal plates.
Mass retrofitting under Programme 40N commenced in 1996. In subsequent production units, the installation of cantilever-type longitudinal seats and cross-flow air blowers was omitted.
Life extension programme N30
In 2002, JR West launched Life Extension Programme N30 as a cost-reduced alternative to the earlier N40 refurbishment programme.
Car body
–Roof-mounted ventilators were removed, and polyurethane resin-based roofing materials were adopted.
–Side windows remained unchanged.
Accommodation
–Passenger hand straps were installed throughout the vehicle.
–Overhead luggage racks were replaced with pipe-frame structures featuring decorative end caps.
–Floor inspection covers for traction motors were sealed with metal plates.
Operations
JNR
The pre-production set of the 103 series EMU was delivered to the Yamanote line in 1963. Mass-production sets followed in 1964, assigned to the Ikebukuro and Shinagawa depots, and by 1969 had fully replaced the 101 series EMUs operating on the Yamanote line. The original 8-car formations were lengthened to 10 cars by inserting an additional powered married pair unit, with the conversion completed in 1971.
In contrast, the 103 series entered revenue service on other lines as follows:
–1965: Keihin-Tohoku line
–1967: Joban Line and Hanwa line
–1969: Osaka Loop Line and Tokaido-Sanyo line
–1973: Chuo Rapid line
–1979: Sobu local line and Katamachi line
–1981: Fukuchiyama line
Following the introduction of air-conditioned units on the Yamanote and Keihin-Tohoku lines, surplus non-air-conditioned vehicles-replaced by newly built air-conditioned stock-were redeployed to replace aging EMUs on other lines:
–1972: Yokohama line (replacing Moha72 series)
–1975: Ome and Itsuka-Ichi lines (replacing older-model EMUs)
–1977: Chuo-West line (replacing Moha70 and Moha72 series)
–1989: Akabane line (replacing 101 series EMUs)
The delivery of the 201 series EMUs to the Chuo rapid line began as replacements for the 103 series. Surplus 103 series units were then used to replace 101 series EMUs on the Sobu local and Nambu lines. Similarly, the 201 series was introduced to the Tokaido-Sanyo lines, displacing 103 series units, which were subsequently transferred to the Hanwa and Kansai lines in 1982-providing increased capacity on the Hanwa line and replacing 101 series units on the Kansai Line.
In 1985, the 205 series EMUs began service on the Yamanote Line, replacing the 103 series. The displaced 103 series units were reassigned to the Sobu Local and Musashino lines, replacing 101 series EMUs, as well as the newly opened Saikyo line.
Following the privatization and breakup of Japanese National Railways in 1987, the 103 series fleet was divided among the new JR companies:
–JR East: 2,223 vehicles
–JR Central: 70 vehicles
–JR West: 894 vehicles
JR East
The replacement of the 103 series EMUs with the 205 series continued through the late 1980s and was completed in 1988. Surplus 103 series vehicles were redeployed to the Yokohama and Musashino Lines to increase capacity. Additionally, they were transferred to the Joban rapid Line to extend train formations from 10 to 15 cars.
Selected 103 series units from the Keihin-Tohoku Line were displaced by newly delivered 205 series EMUs and reassigned to the Keiyo Line in preparation for its opening. The Yokohama Line fleet was replaced with 205 series EMUs in 1989, followed by the Saikyo Line in 1991.
Subsequently, the remaining 103 series units on the Keihin-Tohoku Line began to be replaced by the 209 series EMUs. Surplus 103 series vehicles displaced by the 209 series were then used to replace older 103 series units elsewhere.
In 1998, the 209-500 series EMUs were introduced to the Chuo-Sobu local Line to replace the 201 series. This was followed by the delivery of the E231-0 series in 2000. Surplus 201 series vehicles were transferred to the Keiyo Line to both increase capacity and replace remaining 103 series units.
The E231-0 series was also introduced to the Joban rapid Line in 2002, replacing the 103 series. Around the same time, the E231-500 series began delivery to the Yamanote line, replacing the 205 series. Surplus 205 series vehicles were subsequently redeployed to the Musashino and Nambu lines, replacing the remaining 103 series units. The phase-out of the 103 series on these lines was completed in 2006.
JR Central
JR Central began replacing the 103 series EMUs with the 211-5000 series in 1989. After 1991, the 103 series were relegated to peak-hour operations only. In 1995, they were also introduced into revenue service on the Kansai line. Ultimately, the 103 series were fully replaced by the 313 series and completely retired from service in 1999.
JR West
Following the privatization and breakup of Japanese National Railways in 1987, JR West continued operating 103 series EMUs on the Tokaido-Sanyo, Osaka Loop, Hanwa, Katamachi, Kansai, and Fukuchiyama lines. In 1991, the 207-0 series was introduced on the Gakken-Toshi line to replace 103 series units used on rapid services. Surplus 103 series vehicles displaced by the 207-0 series were subsequently transferred to the Osaka Loop, JR Kobe, JR Kyoto, Hanwa, Yamatoji, and Nara lines, as well as the Shimonoseki area, to replace non-air-conditioned 115 series EMUs.
The replacement of 103 series units on the Gakken-Toshi line was completed by 1996. In contrast, replacement of 103 series units on the JR Kobe and JR Kyoto lines with the 207-1000 series was completed earlier, in 1994. Surplus vehicles displaced by the 207-1000 series were redeployed to the Osaka Loop, Hanwa, and Yamatoji lines, as well as the Hiroshima and Okayama regions.
In the Okayama area, 103 series units were replaced by the 213-0 series. The 213-0 series used on "Marine Liner" rapid services were themselves replaced by the 223-5000 series in 2003. Around the same time, the 207-2000 series was introduced to replace 103 series units on the JR Takarazuka line. Subsequently, 201 series units operating on the Tokaido-Sanyo line began to be replaced by the 321 series. Surplus 201 series vehicles displaced by the 321 series were then used to replace older 103 series units on the Osaka Loop and Yamatoji lines.
On the Sanyo, Kure, and Kabe lines, the 103 series was replaced by the 113 series and 227-0 series EMUs, with full retirement completed in 2015. Around the same time, the 103 and 205 series units on the Hanwa line were completely replaced by the 225-5100 series. Surplus 205 series units displaced by the 225-5100 series were transferred to the Nara line to replace 103 series units.
The 323 series began entering revenue service on the Osaka Loop line in 2016, leading to the full retirement of the 103 series from that line. In 2022, the 221 series units operating on the JR Kobe, JR Kyoto, and Biwako lines were replaced by the 225-100 series. Surplus 221 series units were redeployed to the Yamatoji and Nara lines to replace the remaining 103 series units, which were fully withdrawn from service in 2022. |
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