The Class Kumoha123 consists of four variant groups, all converted from
surplus Class Kumoni143 baggage cars and Class Kumoyuni147 baggage and
RPO cars to provide single-car passenger units for lightly used rural lines.
Kumoha123-1
Background and overview
On the Chūō East Line, the section between Okaya and Shiojiri had long followed a circuitous alignment via Tatsuno on the Iida Line. To shorten intercity journey times, the Enrei Tunnel was constructed, creating a new direct route between Okaya and Shiojiri. As a result, the former Tatsuno alignment was left to handle only local services with modest transport demand.
Meanwhile, the abolition of JNR’s parcel and postal services in November 1986 rendered the Class Kumoni143 baggage cars surplus to requirements. To provide suitable rolling stock for the lightly used rural sections that remained, JNR introduced the double-ended Kumoha123-1 in October 1986, converting one of the redundant baggage cars into an economical single-car passenger unit.
Car body
The car features a narrow steel body measuring 19,500 mm in length and 2,800 mm in width, with a bogie centre distance of 14,000 mm. To reduce overall weight, lightweight shaped steel sections and press-formed beams are employed. The body skin is fabricated from 1.6 mm cold-rolled steel plates, while the roof is formed from 1.2 mm hot-rolled steel plates. The floor structure consists of lightweight resin-coated composite panels, providing improved flame retardancy and dimensional stability.
The cab end adopts a flat-fronted, non-gangwayed design, with a slanted windscreen divided into three panes. The front structure incorporates 4.5 mm-thick front panels, 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. Exterior lighting equipment consists of a longitudinally arranged sealed-beam headlight mounted below the windscreen, with a taillight positioned beneath it. A destination rollsign is installed centrally above the windscreen.
Each side of the car is equipped with two single-leaf automatic sliding doors, each 1,000 mm wide. Door operation is controlled by TK4H units mounted on the door headers, which also permit manual operation. The side panels are fitted with pre-assembled double-hung windows designed to reduce drafts. Between the doors, nine 674 mm double-hung windows and two 673 mm door-pocket windows are provided. On all windows, both the upper and lower sashes slide upward.
Four draught ventilators are mounted on the roof.
The exterior livery consists of a cream body with a narrow green band below the side windows, while the front end is finished in green with a narrow cream band below the windscreens.
Bogies
The bogies, designated DT21C, employ coil springs for the bolster suspension and adopt a pedestal-type journal box support configuration. A parallel cardan drive system with a hollow shaft is used for the power transmission mechanism. The gear ratio is 4.82, providing high acceleration performance across medium- to high-speed ranges. The braking system utilizes single-truck brake rigging with a single-action brake cylinder.
Powertrain and ancillary equipment
Kumoha123-1 is equipped with four MT57A series-wound brushed DC traction motors, each rated at 100 kW. The motors have a terminal voltage of 750 V, enabling single-unit operation, and are controlled by the CS44 motor-driven camshaft control system together with the MR133A forced-draught traction resistor. The system employs armature-resistance control to regulate acceleration and power output, and provides holding-braking and reverse-notching capability.
A MH97A-DM61 motor-generator unit rated at 20 kVA and an MH80A-C1000 motor-driven air compressor are mounted beneath the floor. These units supply electrical power for onboard auxiliary systems and compressed air for braking and door operation.
Current collection is provided by two PS23A lozenge-type pantographs mounted on the roof. The rear pantograph serves as the primary unit, while the forward pantograph is retained as a backup.
Inter-car electrical connections are made using three KE76 multicore jumper couplers for control circuits.
The braking system consists of an electromagnetic straight-air brake supplemented by rheostatic braking, providing effective deceleration performance while reducing mechanical wear.
Accommodation
The passenger saloon of Kumoha123-1 is configured with fully longitudinal seating, designed to maximise capacity and facilitate smooth passenger flow during boarding and alighting. Each bench is fitted with end partition panels to define individual seating areas, and hanging straps are installed throughout the saloon to support standing passengers.
Five electric fans are provided to improve air circulation within the compartment. Illumination is supplied by fluorescent light fixtures arranged in two parallel rows along the ceiling.
Modifications
Installation of equipment for conductor-less operation
In January 1990, the vehicle was modified to support conductor-less operation. The modifications included the installation of ticket vending machines near the doorways, as well as fare chart displays and fare boxes located behind the driver’s cab.
AU712 Air conditioner retrofitting
To accelerate the retrofitting of non-air-conditioned cars inherited from JNR, JR East installed two newly developed low-cost AU712 air-conditioning units (21,000 kcal/h) in 1997, together with an SC28 auxiliary power supply rated at 28 kVA. Both units are mounted on the roof, and the existing ceiling-mounted electric fans were retained.
Operations
In November 1986, Kumoha123-1 was delivered to the Matsumoto Depot for deployment on rural services over the Chūō East Line between Tatsuno and Shiojiri. In March 2013, the unit was displaced by the E127-100 series EMU and subsequently scrapped.
Kumoha123-41to -45
Background and overview
Japanese National Railways (JNR) introduced the Class Kumoha123-40 for use on shuttle services over the Minobu Line, specifically on the sections between Fuji and Nishi-Fuji, and between Kajikazawaguchi and Kofu, during the period from January to March 1987.
To provide economical single-car passenger units suitable for these lightly used services, JNR converted five redundant baggage and RPO cars, all of which were surplus Kumoyuni147 vehicles, into the Kumoha123-40 group.
Car body
The cars feature narrow steel bodies measuring 19,500 mm in length and 2,800 mm in width, with a bogie centre distance of 14,000 mm. To reduce overall weight, lightweight shaped steel sections and press-formed beams are employed. The body skin is fabricated from 1.6 mm cold-rolled steel plates, while the roof is formed from 1.2 mm hot-rolled steel plates. The floor structure consists of lightweight resin-coated composite panels, providing improved flame retardancy and dimensional stability.
The cab end adopts a flat-fronted, non-gangwayed design, with a slanted windscreen divided into three panes. The front structure incorporates 4.5 mm-thick front panels, 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. Exterior lighting equipment consists of a longitudinally arranged sealed-beam headlight mounted below the windscreen, with a taillight positioned beneath it. A destination rollsign is installed centrally above the windscreen.
Each side of the car is equipped with two single-leaf automatic sliding doors, each 1,000 mm wide. Door operation is controlled by TK4H units mounted on the door headers, which also permit manual operation. The side panels are fitted with pre-assembled double-hung windows designed to reduce drafts. Between the doors, seven 1,072 mm double-hung windows are provided. On all windows, both the upper and lower sashes slide upward.
Four draught ventilators are mounted on the roof. To maintain insulation clearance from overhead feeders in the small cross-section tunnels of the Minobu Line, the roof sections at the pantograph mounting position are lowered by 20 mm.
The exterior livery consists of a cream body with a narrow red band below the side windows.
Bogies
The bogies, designated DT21, employ coil springs for the bolster suspension and adopt a pedestal-type journal box support configuration. A parallel cardan drive system with a hollow shaft is used for the power transmission mechanism. The gear ratio is 5.6, providing high acceleration performance across low- to medium-speed ranges. The braking system utilises double-truck brake rigging with a single-action brake cylinder.
Powertrain and ancillary equipment
Class Kumoha123-40 is equipped with four MT46A series-wound brushed DC traction motors, each rated at 100 kW. These motors have a terminal voltage of 375 V and are permanently series-connected, enabling single-unit operation. They are controlled by the CS54A motor-driven camshaft control system together with the MR155 naturally ventilated traction resistor unit. The system employs armature-resistance control to regulate acceleration and power output, and provides holding-braking and reverse-notching capability.
A MH81-DM44 motor-generator unit rated at 5 kVA and an MH80A-C1000 motor-driven air compressor are mounted beneath the floor. These units supply electrical power for onboard auxiliary systems and compressed air for braking and door operation.
Current collection is provided by a PS23A lozenge-type pantograph mounted toward the rear of the roof.
Inter-car electrical connections are made using a KE90 multicore jumper coupler for control circuits.
The braking system consists of an electromagnetic straight-air brake supplemented by rheostatic braking, providing effective deceleration performance while reducing mechanical wear.
Accommodation
The passenger saloon of Class Kumoha123-40 is configured with fully longitudinal seating, designed to maximise capacity and facilitate smooth passenger flow during boarding and alighting. Each bench is fitted with end partition panels to define individual seating areas, and hanging straps are installed throughout the saloon to support standing passengers.
Five electric fans are provided to improve air circulation within the compartment. Illumination is supplied by fluorescent light fixtures arranged in two parallel rows along the ceiling.
Modifications
C-AU711D Air conditioner retrofitting
To accelerate air-conditioning retrofits, JR Central installed two newly developed C-AU711D-G3 roof-mounted air-conditioning units (18,000 kcal/h) together with a C-SC33 auxiliary power supply unit rated at 28 kW on all cars between June 1989 and November 1990. The existing ceiling-mounted electric fans were retained. Following this modification, the cars were reclassified as the -5040 sub-class.
Installation of equipment for conductor-less operation
Between July 1989 and May 1990, the cars were modified to support conductor-less operation. The modifications included the installation of ticket vending machines near the doorways, as well as fare chart displays and fare boxes located behind the driver’s cab.
Font gangway door retrofitting
A gangway door and gangway connection base were installed on the front of the cab of Kumoha123-5045. Following this modification, the car was reclassified as the -5140 sub-class.
Traction motor replacement
The traction motors were upgraded to MT54 units rated at 120 kW. Automatic jumper couplers were also retrofitted to facilitate rapid turn-back operations.
Operations
In March 1987, Class Kumoha123-40 was delivered to the Shizuoka Depot for deployment on shuttle services over the Minobu Line, specifically on the sections between Fuji and Nishi-Fuji, and between Kajikazawaguchi and Kofu.
Kumoha123-5041 was scrapped in 2006. Subsequently, in 2007, the remaining units were displaced by the 313-3000 series and completely withdrawn.
Kumoha123-2 to -4
Background and overview
Japanese National Railways (JNR) introduced three Class Kumoha123-0 cars to provide additional capacity for rural services on the Kabe Line, converting three redundant Class Kumoni143 baggage cars into economical single-car passenger units during the period from February to March 1987.
Car body
The cars feature narrow steel bodies measuring 19,500 mm in length and 2,800 mm in width, with a bogie centre distance of 14,000 mm. To reduce overall weight, lightweight shaped steel sections and press-formed beams are employed. The body skin is fabricated from 1.6 mm cold-rolled steel plates, while the roof is formed from 1.2 mm hot-rolled steel plates. The floor structure consists of lightweight resin-coated composite panels, providing improved flame retardancy and dimensional stability.
The cab end adopts a flat-fronted, non-gangwayed design, with a slanted windscreen divided into three panes. The front structure incorporates 4.5 mm-thick front panels, 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. Exterior lighting equipment consists of a longitudinally arranged sealed-beam headlight mounted below the windscreen, with a taillight positioned beneath it. A destination rollsign is installed centrally above the windscreen.
Each side of the car is equipped with two single-leaf automatic sliding doors, each 1,000 mm wide. Door operation is controlled by TK4H units mounted on the door headers, which also permit manual operation. Five 1,670 mm side windows, consisting of an upper hopper window combined with a large fixed lower window, and two 673 mm door-pocket windows, are provided.
Each car is centrally fitted with a roof-mounted AU75G air-conditioning unit rated at 42,000 kcal/h, with three draught ventilators mounted on the roof. A destination rollsign is mounted on each side.
The exterior livery consists of a cream body with two narrow blue bands at the bottom of the side panels.
Bogies
The bogies, designated DT21C, employ coil springs for the bolster suspension and adopt a pedestal-type journal box support configuration. A parallel cardan drive system with a hollow shaft is used for the power transmission mechanism. The gear ratio is 4.82, providing high acceleration performance across medium- to high-speed ranges. The braking system utilizes single-truck brake rigging with a single-action brake cylinder.
Powertrain and ancillary equipment
Kumoha123-2 to -4 are equipped with four MT57A series-wound brushed DC traction motors, each rated at 100 kW. The motors have a terminal voltage of 750 V, enabling single-unit operation, and are controlled by the CS44 motor-driven camshaft control system together with the MR133A forced-draught traction resistor. The system employs armature-resistance control to regulate acceleration and power output, and provides holding-braking and reverse-notching capability.
A MH94-DM58 motor-generator unit rated at 70 kVA and an MH80A-C1000 motor-driven air compressor are mounted beneath the floor. These units supply electrical power for the air-conditioning unit, onboard auxiliary systems, and compressed air for braking and door operation.
Current collection is provided by a PS16J lozenge-type pantograph mounted toward the front of the roof.
Inter-car electrical connections are made using a KE96 multicore jumper coupler, enabling multiple-unit operation with 105 series EMUs.
The braking system consists of an electromagnetic straight-air brake supplemented by rheostatic braking, providing effective deceleration performance while reducing mechanical wear.
Accommodation
The passenger saloon of Kumoha123-2 to -4 is configured with fully longitudinal bench-type bucket seating, designed to maximise capacity and facilitate smooth passenger flow during boarding and alighting. Each bench is fitted with end partition panels to define individual seating areas, and hanging straps are installed throughout the saloon to support standing passengers. Overhead luggage racks are constructed using pipe-frame structures.
The air-conditioning ductwork is installed above the ceiling to maintain a clean interior profile, with slit-type vents providing distributed airflow. Illumination is provided by fluorescent fixtures arranged in two parallel rows along the ceiling. FRP decorative panels are used for the door frames.
Modifications
Installation of equipment for conductor-less operation
Between September 1991 and January 1992, the cars were modified to support conductor-less operation. The modifications included the installation of ticket vending machines near the doorways, as well as fare-chart displays and fare boxes located behind the driver’s cab.
Gangway retrofitting
Gangways, gangway doors, and gangway-connection bases were retrofitted between November 1993 and March 1994, enabling multiple-unit operation with 105 series EMUs.
A toilet compartment retrofitting
A western-style toilet compartment and the associated floor-mounted sanitary system were retrofitted, located immediately behind the front door.
Operations
In March 1987, Kumoha123-2 to -4 were delivered to the Hiroshima Depot for deployment on shuttle services on the Kabe Line. They were subsequently displaced by 105 series EMUs and, in 1991, were reallocated to the Shimonoseki Depot for operation on rural services on the Ube and Onoda Lines.
The fleet is currently deployed on rural services on the Ube and Onoda Lines.
Kumoha123-5 to -6
Background and overview
Japanese National Railways (JNR) introduced three Kumoha123-0 cars to provide additional capacity for commuter services on the Hagoromo Branch Line of the Hanwa Line, converting two redundant Class Kumoni143 baggage cars into economical single-car passenger units in March 1987. These cars were built with a gangway door on the cab front, enabling multiple-unit operation with 103 series EMUs. They operated as three-car sets, comprising two Kumoha123-0 cars and one Kuha103 car.
Car body
The cars feature narrow steel bodies measuring 19,500 mm in length and 2,800 mm in width, with a bogie centre distance of 14,000 mm. To reduce overall weight, lightweight shaped steel sections and press-formed beams are employed. The body skin is fabricated from 1.6 mm cold-rolled steel plates, while the roof is formed from 1.2 mm hot-rolled steel plates. The floor structure consists of lightweight resin-coated composite panels, providing improved flame retardancy and dimensional stability.
The cab end adopts a flat-fronted, gangwayed design with slanted windscreens. The front structure incorporates 4.5 mm-thick front panels, 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. Exterior lighting equipment consists of a longitudinally arranged sealed-beam headlight mounted below the windscreens, with a taillight positioned beneath it. A destination rollsign is installed centrally above the gangway door.
Each side of the car is equipped with two double-leaf automatic sliding doors, each 1,300 mm wide. For simplified modification, the doors are mounted in the positions originally occupied by the baggage loading/unloading doors. Door operation is controlled by TK4J units mounted beneath the bench seats. Between the doors, a pair of prefabricated double-hung windows measuring 920 mm in width is provided. Behind the front cab, a narrower 674 mm-wide double-hung window is mounted. Toward the rear of the rear door, two pairs of 920 mm double-hung windows are installed.
Each car is centrally fitted with a roof-mounted AU75E air-conditioning unit rated at 42,000 kcal/h, with two draught ventilators mounted on the roof.
The exterior livery consists of a sky-blue body.
Bogies
The bogies, designated DT21, employ coil springs for the bolster suspension and adopt a pedestal-type journal box support configuration. A parallel cardan drive system with a hollow shaft is used for the power transmission mechanism. The gear ratio is 5.6, providing high acceleration performance across low- to medium-speed ranges. The braking system utilises double-truck brake rigging with a single-action brake cylinder.
Powertrain and ancillary equipment
Kumoha123-5 and -6 are equipped with four MT57A series-wound brushed DC traction motors, each rated at 100 kW. The motors have a terminal voltage of 750 V, enabling single-unit operation, and are controlled by the CS44 motor-driven camshaft control system together with the MR133A forced-draught traction resistor. The system employs armature-resistance control to regulate acceleration and power output, and provides holding braking and reverse-notching capability.
An MH94-DM58 motor-generator unit rated at 70 kVA and an MH80A-C1000 motor-driven air compressor are mounted beneath the floor. These units supply electrical power for the air-conditioning unit, onboard auxiliary systems, and compressed air for braking and door operation.
Current collection is provided by a PS16J lozenge-type pantograph mounted toward the rear of the roof.
Inter-car electrical connections are made using KE70, KE5, and KE6 multicore jumper couplers, enabling multiple-unit operation with 103 series EMUs. KE70 is employed for control-signalling wiring, KE5 supplies power to the air-conditioning unit of the Kuha103 car, and KE6 carries the 1,500 V DC high-voltage supply.
The braking system consists of an electromagnetic straight-air brake supplemented by rheostatic braking, providing effective deceleration performance while reducing mechanical wear.
Accommodation
The passenger saloon of Kumoha123-5 and -6 is configured with fully longitudinal bench seating, designed to maximise capacity and facilitate smooth passenger flow during boarding and alighting. Hanging straps are installed throughout the saloon to support standing passengers.
The box-shaped air-conditioning ductwork is installed beneath the ceiling and fitted with rectangular vents. Interior lighting is provided by two rows of ceiling-mounted fluorescent light fixtures, each rated at 40 W.
Modifications
Multicore jumper-coupler modification
After the cars were reassigned to the Okayama Depot, KE96 multicore jumper couplers, enabling multiple-unit operation with 105 series EMUs, were additionally installed, and the KE5 and KE6 couplers were removed in 2001.
Rearrangement of doors and windows and installation of equipment for conductor-less operation
Between September 1991 and January 1992, the cars were modified to support conductor-less operation. The modifications included the installation of ticket vending machines near the doorways, as well as fare-chart displays and fare boxes located behind the driver’s cab.
The doors and windows on the side panels were also rearranged. The rear doors were relocated further toward the rear, and two pairs of double-hung windows were reassigned between the doors.
Operations
In March 1987, Kumoha123-5 and -6 were delivered to the Hineno Depot for deployment on commuter services on the Hagoromo Branch Line of the Hanwa Line.
In 1995, the cars were reallocated to the Okayama Depot to replace the aging Kumoha84 single-unit cars used on shuttle services on the Uno Line. Following their transfer, they were deployed on regional services on the Fukuen, Sanyō, and Akō Lines.
In 2003, the cars were reallocated to the Shimonoseki Depot to replace the aging Kumoha42 cars operating on rural services on the Onoda Line.
The fleet is currently deployed on rural services on the Ube and Onoda Lines. |
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