Background and overview
In 2006, JR Hokkaido chose not to replace the aging Kiha183 series DMUs
used on "Tokachi" intercity services with the high-performance
but high-cost Kiha283 series tilting DMUs. Instead, they introduced the
more cost-effective Kiha261 series tilting DMUs.
For this deployment, JR Hokkaido developed the Kiha261-1000 series, incorporating substantial improvements over the earlier Kiha261-0 series. These included a redesigned carbody based on the 789-0 series EMU and enhanced trainset flexibility. The Kiha261-1000 series adopts a married-pair configuration consisting of an end car and an intermediate car, with the option to insert an additional intermediate car (Class Kiha260-1300) during peak seasons.
Five Class Kiha260-1300 vehicles and two vehicles of other classes were delivered as part of the first and second production batches.
Car body
The carbody of the KiHa261-1000 series measures 20,800 mm in length and 2,804 mm in width, with a bogie centre distance of 14,400 mm. It shares the same cross-sectional profile as the 789-0 series EMU. The structure is primarily composed of lightweight stainless steel, except for the bolster beams, end sections of the centre beam, and selected cross members, which are fabricated from corrosion-resistant steel plate.
Externally, the Kiha261-1000 series differs noticeably from the earlier
Kiha261-0 series by adopting bead-less exterior panels for a smoother appearance
and a body height reduced by 30 mm. The cab ends, which include a gangway
door and a high-mounted driver's cab for improved protection against level-crossing
obstacles, are constructed from 3.2 mm thick steel plate painted in cobalt
blue, with "Tilt261 Active Air Suspension Syste" logos applied.
A built-in classification headboard is mounted on the gangway, flanked by longitudinally arranged sealed beam headlights and high-intensity discharge (HID) lamps on each side. Additional HID lamps are installed above the windscreen, with tail lamps positioned behind it. When the front gangway is used for public access during rush-up operations, an adapter for bellows connectors is applied.
Each car is equipped with a 930 mm wide single-leaf sliding door, fitted with pneumatic cylinders that press the door against the frame to prevent ice intrusion. Side windows include small fixed double-glazing units for each first-class seat and wide fixed double-glazing windows aligned with two standard-class seating bays. All side windows are reinforced with polycarbonate framing to prevent windowpane breakage.
Class Kiha260-1100 vehicles are equipped with a hinged door for the conductor's
room. Three-colour LED destination displays (red, green, orange) are mounted
on the carbody sides. Roof-mounted air-conditioning units (type N-AU201B)
using R407C refrigerant supply fresh air to the passenger compartment via
integrated electric fans, eliminating the need for conventional roof ventilators.
Class Kiha260-200 vehicles are additionally equipped with a roof-mounted
antenna for public telephone service.
Bogies
The Kiha261-1000 series is equipped with powered bogies designated N-DT261A.
These bogies incorporate a pneumatic tilting system, bolster-less secondary
air suspension, a trailing arm-type journal box support system, a single-link
traction gear, and yaw dampers to ensure smooth ride characteristics even
at speeds up to 130 km/h.
The wheel diameter is reduced to 810 mm to lower the vehicle's centre of
gravity. Compared to the bogies used on the Kiha261-0 series, the N-DT261A
bogies feature a journal shaft with a 10 mm larger diameter.
Tilting control is achieved through an inclination control system using gyroscopes and accelerometers mounted at both ends of the train, combined with a leader-follower control logic that defines a unified "tilting curve" for the entire formation. This system enables curve negotiation at speeds up to 25 km/h faster than conventional limits, with a maximum tilt angle of 2 degrees.
All bogies are equipped with double-tread brake rigging.
Traction unit and ancillary equipments
TEach vehicle is powered by two diesel engines (N-DMF13HZJ), each rated
at 460 PS and equipped with an intercooler to enhance power output. Power
is transmitted via a hydraulic transmission unit (N-DW14A), which features
natural air cooling and a four-stage direct-coupled range, enabling a maximum
service speed of 130 km/h and high gradient performance.
The vehicles are equipped with two generators (N-DM283G3) that supply electricity to the ancillary power system (N-INV261), and two air compressors (C1000H) that are hydraulically driven by the prime movers, eliminating the need for belt drive mechanisms.
The braking system is electrically commanded and includes a jake brake
function..
Accommodation
All seats are adjustable reclining types. First-class vehicles feature 1+2 abreast seating with a pitch of 1,145 mm, while standard-class vehicles have 2+2 seating with a pitch of 960 mm. First-class seats are upholstered in navy leather and equipped with hand-grabs, a power outlet beneath the windowsill, and a reading light mounted under the luggage rack.
The door between the vestibule and passenger saloon is automatic, activated by a photo sensor. An LED passenger information display is installed above this door. Cabin lighting consists of alternating fluorescent and halogen lamps.
Class Kiro261-1100 vehicles are equipped with a catering room, a multipurpose room, and a baggage compartment. Class Kiha260 vehicles are fitted with western-style toilets and flush urinals, both featuring chemical holding tanks. The toilet in Class Kiha260-1100 is designed for universal access.
Class Kiha261-1100 vehicles include a conductor's room, Class Kiha260-1200
vehicles include a telephone room, and Class Kiha260-1300 vehicles include
a baggage room. The conductor's room in Class Kiha260-1100 and the telephone
room in Class Kiha260-1200 are provisioned for installation of a shunting
control position.
Additional delivery
3rd Batch (2009)
Eight additional vehicles incorporating minor improvements were delivered to replace the aging Kih183 series DMUs used on "Tokachi" intercity services. In Class Kih260-1200 and Kih260-1300 vehicles built from this batch onward, one seating bay was removed to accommodate an additional washroom and baggage compartment. The telephone room was repurposed as a crew-only space. Reserved reclining seats were upgraded with wider cushions and larger seatbacks.
4th Batch (2011)
JR Hokkaido delivered six additional vehicles with minor modifications
to compensate for the loss of Kiha283 series DMUs damaged by fire and derailment
on the Sekisho Line on 27 May 2011. Halogen cabin lighting was replaced
with compact fluorescent lamps.
5th Batch (Post–Hokkaido Shinkansen Opening)
Twenty-eight vehicles were delivered to increase capacity on "Super
Hokuto" intercity services following the opening of the Hokkaido Shinkansen
to Hakodate. Vehicles built from this batch onward were no longer equipped
with the tilting control system, and cab-side logos were changed to "HET261
Hokkaido Express Train" The air compressor was changed to type C600A
due to reduced air consumption, and the prime mover was updated to type
N-DMF13HZL. The three-colour (red, green, orange) LED destination displays
were replaced with colour-selectable LED units. All standard-class reclining
seats were upgraded, and all fluorescent lighting was replaced with LED
fixtures.
6th Batch (2015)
Following the cancellation of the next-generation Kiha285 series DMU project—which marked a strategic shift from speed-focused development to prioritizing safety and maintenance efficiency through fleet standardization—32 additional Kiha261 series vehicles were delivered to replace aging DMUs. Vehicles built from this batch onward featured several notable changes: a new livery with white front ends (symbolizing snow), yellow gangway doors (symbolizing rape blossoms), and a purple bodyside stripe (symbolizing lavender lilac). A spare windscreen wiper was added, and the built-in classification headboard was replaced with a full-colour LED display.
7th Batch (2018)
Sixty-seven vehicles were delivered to fully replace the remaining Kiha183
series units, as well as early batches of Kiha281 and Kiha283 series vehicles.
Vehicles built from this batch onward introduced laser welding in carbody
construction. HID headlights were replaced with LED lamps. Provisions for
bellows connectors and shunting control positions were discontinued. The
air suspension's shunting control valve was integrated into the bogie,
which was reclassified as N-DT261B. First-class seats were upgraded to
include built-in power outlets and reading lights. An additional baggage
rack was installed in the standard-class cabin, and the LED passenger information
display was replaced with a colour-selectable LED unit.
Modifications
Vehicles from the 1st through 4th production batches were modified between
2015 and 2018 to conform to the specifications of the 5th batch. As part
of these upgrades, the tilting control system was removed, and cab-side
logos were changed to "HET261 Hokkaido Express Train." The air
compressor was replaced with type C600A due to reduced air consumption,
and the prime mover was updated to type N-DMF13HZL. The original three-colour
(red, green, orange) LED destination displays were replaced with colour-selectable
LED units. All standard-class reclining seats were upgraded, and fluorescent
cabin lighting was replaced with LED fixtures.
Between 2015 and 2019, the new livery introduced with the 6th batch—featuring white front ends, yellow gangway doors, and a purple bodyside stripe—was progressively applied to vehicles from the 1st through 5th batches.
From 2018, an additional baggage rack was installed in the standard-class cabins of vehicles from the 1st through 6th batches.
Operations
Kiha261-1000 series trains were introduced on "Super Tokachi"
intercity services linking Sapporo and Obihiro in October 2007. By 2013,
all Kiha283 series trains previously used on "Super Tokachi"
were fully replaced by Kiha261-1000 series units.
In 2016, Kiha261-1000 series trains were also introduced on "Super
Hokuto" intercity services in conjunction with the opening of the
Hokkaido Shinkansen. Additional units were delivered to replace the aging
Kiha183 series trains formerly used on "Hokuto" services. In
2019, some Kiha281 series trains operating on "Super Hokuto"
were also replaced by Kiha261-1000 series vehicles.
On "Ozora" intercity services, partial replacement of Kiha283
series trains with Kiha261-1000 series units began in 2020. By 2022, all
remaining Kiha283 series trains used on "Ozora" services and
all remaining Kiha281 series trains used on "Hokuto" services
had been fully withdrawn and replaced by additional Kiha261 series vehicles. |
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