Background and overview
Following the privatization of Japanese National Railways (JNR) in 1987, JR Shikoku faced financial constraints due to its limited business foundation. To support stable operations under these conditions, JNR developed the class Kiha54-0 as a cost-effective diesel multiple unit (DMU) designed for low construction and operating costs. The class Kiha54-0 consists of double-ended single-car units, with a total of twelve vehicles manufactured.
Car body
The carbody measures 21,300 mm in length and 2,920 mm in width, with a
bogie centre distance of 14,400 mm to achieve weight reduction. 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-processed stainless panels with a
vermilion diagonal stripe.
The cab end includes a gangway and is framed with decorative FRP panels. A low-profile driver's cab is adopted to accommodate future conductor-less operation. Flat windscreens are used to reduce manufacturing costs. Above the driver's windscreen, a destination rollsign is installed, while a separate window above the co-driver's windscreen displays conductor-less operation status. Two sealed-beam headlights are mounted above the gangway door, and taillights are positioned below the windscreens.
Each side of the vehicle is equipped with two 900 mm-wide automatic folding stepped doors, utilizing bus-type door operating mechanisms. Between the doors, 1,080 mm-wide double-hung pre-fabricated side windows are installed, with fixed upper sashes and vertically sliding lower sashes. Climate control is provided by two AU26 air conditioning units, each rated at 16,000 kcal/h and driven by the prime movers. These are mounted beneath the floor, while two indoor units and three roof-mounted ventilation fans-originally developed for bus applications-are installed overhead. Exhaust pipes from the prime movers are routed through the cab interior. Vehicles are coupled using tight-lock automatic couplers with RD13 rubber draft gear.
Bogies
The vehicles are fitted with DT22A or DT22C bogies, repurposed from decommissioned DMUs. These bogies feature swing hanger suspension, coil springs as bolster springs, and pedestal-type journal support systems. The gear ratio of powered bogies is 2.976. Braking is provided via single-tread brake rigging.
Traction unit and ancillary equipments
Each vehicle is powered by two DMF13HS four-cycle straight-six diesel engines mounted beneath the floor, each rated at 250 PS. These engines incorporate turbochargers driven by exhaust gas flow, direct fuel injection, and fuel control systems to optimize fuel efficiency. The engines are horizontally mounted to the carbody using rubber mounts.
Power transmission is handled by two hydraulic transmissions—TC2A or DF115A—reused from retired DMUs. These units were upgraded with improved torque converters and clutches to accommodate the increased engine output. The TC2A transmission also received modifications to the hydraulic/direct drive stage changeover servo piston position to prevent interference with the engine gear case.
Compressed air is supplied by two C400 air compressors, each driven by a prime mover. The braking system consists of a DA1A automatic air brake, supplemented by a straight air reserve brake.
Accommodation
The interior features longitudinal bucket-style bench seating throughout the passenger compartment. Armrests are provided at every fifth seat, with partition armrests installed at both ends of each bench. Lighting is provided by two rows of fluorescent fixtures. Heating is achieved via a water-based system. Air conditioning ducts are installed above the ceiling, with slit-shaped vents used to improve airflow and interior aesthetics.
The cab is designed as a compartment type located on the left side of the vehicle, in preparation for future conductor-less operation. No toilet facilities are provided.
Modifications
In 1987, the exterior livery was updated to a white base coat with light blue accents, reflecting JR Shikoku's corporate colour scheme. In 1988, the vehicles were modified to support conductor-less operation. These 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 cabs.
Operations
The class Kiha54-0 was initially allocated to Matsuyama Depot and entered service on the Yosan, Dosan, Uchiko, and Yodo Lines. Vehicles operating on the Dosan Line were subsequently replaced by the newer class Kiha1000 DMUs. As of the present, the Kiha54-0 series to operate on rural services along the Yosan, Uchiko, and Yodo Lines. |
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