Background and overview
With the opening of the Meishin Expressway between Nagoya and Kobe in 1965
and the Tomei Expressway between Tokyo and Nagoya in 1968, Japanese National
Railways (JNR) faced increasing competition for freight transport from
road haulers. JNR therefore developed the "10000 series" high
seed freight wagons (KoKi10000 and KoKiFu10000 container flat wagons, ReSa10000
and ReMuFu10000 refrigerated wagons, and WaKi10000 bogie vans) capable
of operating at 100 km/h (60 mph). Express freight services formed of these
wagons were introduced on the Tokaido Line and Sanyo Line from October
1966, using Class EF65-500 electric locomotives built in 1965. These locomotives
were designed to be used in pairs hauling 1,000-tonne freight trains, but
as pairs of locomotives drew excessive current from the overhead line,
1,000-tonne freight trains had to be split into 600-tonne and 400-tonne
sections when operating on the Sanyo Line because a pair of banking locomotives
had to be used on the steeply graded "Seno-Hachi" section of
the Sanyo line between Seno and Hachihonmatsu. This led to the need for
a new locomotive design that would be capable of hauling 1,000-tonne trains
singly and JNR began to develop in 1965. Then a prototype locomotive, initially
classified EF90 and numbered EF90 1, was built by Kawasaki Sharyo in 1966.
EF90 was a six-axle, three-bogied (BoBoBo) DC electric locomotive and had
a total power output of 3900 kW (5,230 hp), adopting 6 high power traction
motors, MT56, with a power output of 650kW, and making it the world's most
powerful narrow-gauge locomotive at the time. Its mass was 100.8 tons and
its axle load was 16.8 tons.
Car body
EF90 employed raised driver's cab. Since the height of its body got 160
mm higher than former locomotives, the upper part of the body was slanted
at 12 degrees to keep the body within loading gauge. It adopted tightlock
couplers with pneumatic connecters for high seed freight wagons and coupler
centering devices. A pair of diamond shaped current collectors, PS17, were
fitted on the roof.
Bogies
Bogies having 2800mm wheel base are DT133 for outer and DT134 for centre, employing rubber airbag primary suspension and low centre plate construction for prevention of weight transfer.
Traction unit and auxiliary equipments
Traction motors are controlled by the traction system, CS27, featuring
camshaft contactor vernier control for acceleration and deceleration, and
the camshaft contactor field control system, CS28, for anti-slip control
and axle load compensating. Traction motors are fitted on the trucks by
featuring quill joints, QD10.
Test runnning and operations
EF90 was initially allocated at Suita Depot in November, 1966, and underwent
extensive test running until December. Then it entered the revenue services
on express freight services in January, 1967. It was modified to full-production
vehicles, class EF66-0, in August 1968 and classified into class EF66-900.
Mass-Production vehicles
The full-production standard vehicles, class EF66-0, were delivered from 1968. There are some noticeable differences over a pre-production vehicle. Frames of cab's windscreen were made thinner than before for improvement of the front visibility. Their traction system was changed into CS27A and their field control system was changed into CS28A, employing dust-proof covers. Bogies were changed into DT133A/DT134A, improving their maintainability and the prevention against electrolytic corrosion. Quill joints were changed into QD10A, having improved oil seal.
Improvement
Vehicles built in 1969 differ from earlier EF66-0s in employing CS27B and
CS28B featuring assembled camshaft.
The second batch of class EF66-21 and afterward delivered from 1973 differ
from the first batch of EF66-0 in employing CS27C and CS28C featuring arc-less
vacuum relay. Outer bogies were changed into DT133B employing of which
primary suspension was changed from 3 layered bellows air bag into diaphragm
air bag. Most noticeable difference was the extension of the cab roofs
over the windscreens to reduce the deposition of abrasion dust from the
current collectors on the windscreens. A total of 55 locomotives were built
between 1968 and 1975.
Modification and refurbishment
Some of the first-batch locomotives (EF66 1 to 20) were also subsequently modified with the "sun visor" style cab end roofs from 1974. Current collectors of some of locomotives were changed into cross-arm pantograph, PS22B. Bogies of EF66-901 was modified to full-production bogies, DT133A/DT134A. In 1986, JNR fitted brake pipe decompression accelerator equipment to EF66-901 and EF66 1-39 allocated at Suita depot for a haul of "Super Liner" traveling at 100km/h.
After the splitting of JNR into the new privatized JR companies, JR Freight
equipped EF66-0 locomotives with the electromagnetic command brake in order
to raise the speed of "Super Liner". In 1988, JR freight began
to fit the air conditioners, CU10, on the roof of the cab, in order to
improve the driver's working environment. JR Freight fitted cross arm type
current collectors, PS22B/D, to some of refurbished EF66s. The livery of
refurbished were changed into a two-tone blue livery similar to that carried
by the EF66-100s.
EF66-54 received from JR West was repainted into simplified blue with cream
colour hemline band and cream colour wainscot panel. Only EF66-27 is remained
in original JNR colour.
Operations
EF66-0 entered the express freight services on October, 1968. Then they entered "Freight Liner" using Koki50000 series container flat wagons, hauling 1200-tonne trains at 95km/h, in 1972. They also began to haul semi-express freight services, 1973.
In 1985, EF66-0 locomotives began to haul night trains such as Hayabusa
sleeping car intercity service, because the formation of Hayabusa sleeper
service consisted of 15 cars became too heavier for former EF65-1000 locomotive
to haul at high speed. As result, all sleeper services connection Tokyo
and Kyushu began to be hauled by EF66-0 locomotives, and the journey time
between Tokyo and Shimonoseki was reduce to 20 to 36 minutes.
In 1986, EF66-0 locomotives started to haul 1200-tonne "Super Liner"
services at 100km/h.
After the splitting of JNR into the new privatized JR companies, EF66-0 locomotives had been used on hauling container flat wagons. JR Freight received some newer EF66-0 locomotives from JR West and started to replace superannuated EF66-0s from 1999 to 2002. Then EF66-0 locomotives have gradually been displaced with EF210 locomotives from 2007. Now only EF66 27 in JNR original livery is remained and used. |
|
| Technical Data |
| Items |
Data |
| Supply
Voltage |
1500VDC |
| Service
speed |
115km/h |
| Max power |
3,900kW |
| Length |
18,200mm |
| Width |
2,800mm |
| Total
mass |
100.8t |
| Axles location |
B0-B0-B0 |
| Bogie |
DT133A (1~21 for End), DT133B (22~55 for End), DT134A (Centre) |
| Current
collector |
PS17 |
| Traction
motor |
MT56 |
| Resistance
and vernier controller |
CS27A (1~17),
CS27B (18~21), CS27C (22~55) |
| Field magnet
controller |
CS28A (1~17),
CS28B (18~21), CS28C (22~55) |
| Designed
by |
Japan
National Railways |
|
|
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