Oigawa Railway

Japan's most popular railfan destination with steam operations and an Abt rack rail system

A mini train at Ikawa station.	An old logging train in exhibition at Senzu station.

By Hiroshi Naito

The Ikawa Line and Its History:
From Senzu, the Ikawa line starts its route. Although the line uses the same 3'6'' gauge as the Oigawa main line's, the rolling stock in use is much smaller in size than regular 3'6'' trains. The line is even called a forest railway by local people and tourists. The reason for this peculiarity is simple. The line was originally built by the electric power company in 1933 as a 2'6'' narrow gauge line with the main purpose of transporting construction materials for dams and hydroelectric power plants. The line later was transferred to the Forestry Ministry and was utilized as a logging railway followed by extensions along tributary rivers in the depths of the mountain range. The total trackage once accounted for even 50km at its greatest. In 1936, to increase logging transportation capacity by allowing dangerous rafts to be eliminated, the main line was regauged to 3'6''(1,067mm) enabling direct freight train operations through to the Oigawa Railway line from Kanaya to Ikawa. To allow rapid progress and to reduce the reconstruction costs, only the gauge of the track was widened and the tunnels were not expanded in size. Thus, the line's allowable clearance remained smaller and resulted in today's unique feature of the "mini" trains.

After the war, as the projects of developing the Oi river water system restarted, the construction of the Ikawa Dam was begun, and the mini freight trains resumed busy operations. In 1951, the railway was taken over by Chubu Denryoku, the electric power company based in central Japan, which was constructing the Ikawa Dam. In 1958, the next year when the Ikawa Dam was completed, the power company acquired the right to operate the rail service on the line and commenced passenger revenue operations. In 1959, the Oigawa Railway finally took over the entire trackage of the Ikawa line. The construction of two huge dams, Hatanagi #1 and #2, located upstream of the Ikawa Dam, was completed in 1964. The role of transporting construction materials finally ended. Besides, as the improvement of the roads made considerable progress, trucks the most became common mode for log transportation, resulting in a sharp reduction on rail freight demands. Under these circumstances, the railway company moved on to enhancing passenger train service targeting tourists campaigning for a scenic mountain railway going along a breathtaking deep canyon.

Train Ride on Ikawa Line:
I hurried to the Ikawa line track, on which a mini train in its red and cream livery was waiting. Although the passenger facility is separated from the Oigawa main line, the rails are linked to each other through a siding. Almost all the passengers who got off the steam train seemed to change to the mini train. The formation of the mini train was five coaches with motive power provided by a diesel hydraulic engine at the lower end. At the upper end was a car with a driving cab for reverse operations. Push-pull operation using a single engine with a car with driving cab at the opposite end is commonly seen on U.S. and Canadian commuter lines, but this is the only line in Japan that features this mode.

On the siding were some smaller-sized freight cars.	The train slowly wound up along a path faithfully tracing sweeping curves on the slope

The train started rolling almost fully loaded with sightseeing passengers. Fortunately, I could get a railfan seat just behind the cab so that I was easily able to see the way ahead. Shortly after leaving Senzu station, the scenic Oi river came in view right down the track. On the siding just before arriving at the next station, where the line's engine depot was located, were some smaller-sized freight cars. Soon after leaving the loop there, a suspended bridge over the river bed and track came into view on the right. The bridge was in a quite scenic setting connecting to woods on the opposite bank. Soon, the rugged mountain route began with a fairly long tunnel. The train slowly wound up along a path along the densely forested slope of the ravine, faithfully tracing sweeping curves on the slope and passing through small tunnels frequently. The walls inside the tunnels were all bare rocks.

An electric locomotive standing by for banking duties.

Crossing a viaduct over a fairly deep valley and going through a tunnel, the train suddenly emerged into an open space on the riverside. Looking at an electric locomotive on the left standing by for banking duties, the train arrived in a modern looking loop, Abt Ichishiro, with overhead catenaries fully strung. The 1.5km segment from here to the Sessokyo Onsen (Sesso Canyon Hot Spring Spa) is a newly built segment including a rack rail section that gains 90m in elevation between here and the next loop at Nagashima Dam. In 1973, as the construction of the Nagashima Dam started in the valley upstream of the area, certain sections of the original line became likely to sink into the new artificial lake. The Oigawa Railway's solution to maintain the line was to construct a detour partly featuring rack rails with a Abt system. The construction was completed in 1990, and a new rack rail route entered revenue service with newly purchased Abt system electric locomotives to provide assistance. The fleet of is three Type ED90s, which are equipped with two sets of 175kw motors on each. They also use 53kw motors for runs on the flat track.

The train slowly rolled along the steeply grading rack rail track, at its steepest at 9%.

As soon as the train arrived in the home track, an ED90 quietly came in from the siding. Following a hand signal instructed by the conductor, the engine was attached to the lower end of the train. Since the ED90 is regular 3'6'' railway size in height, it looked very tall in contrast to short Ikawa line stock. That unbalanced combination was quite impressive.

With the assistance of the ED90, the train started to roll. The engineer was a young man who seemed to be dedicated to operation of such duties. I realized that the driving cab car was fitted with two sets of control for both a regular diesel engine and an electric locomotive. The train slowly rolled along the steeply grading rack rail track, at its steepest at 9%. With 50kg rails on the heavily laid ballast, riding comfort was very good. After about ten minutes running, the train finished climbing up the incline and completed the rack rail section by reaching the next loop at Nagashima Dam. Like Abt-Ichishiro, this location looked modern with some powered switches and position-light dwarf signals protecting switching operations in the vicinity. Soon the helper was released and went backwards down to a siding.

Soon after leaving Nagashima-Dam, the construction site of the huge Nagashima Dam came into view down at the right. The train was still rolling along the newly constructed track that continued further beyond the construction complex. The train crossed a fairly long viaduct, the Rainbow Bridge, having an intermediate station in the middle. On an elevated terrain beside the station was a rest house, which looked like a log house, looking down at the track on the viaduct. After the lake is filled in, the area is supposed to be scenic with water reflecting the green of the forest on the surface, but under the viaduct was a still just a deep canyon.

The construction site of the Nagashima Dam.	The Oi river was seen far down the track at the bottom of the canyon.

The modern looking segment finally finished. The train began rolling again along the old rugged mountain path on the steep slope of the sharply V shaped canyon. The scenery outside the window resumed dense forest, and the Oi river, which now turned out to be a narrow stream, was seen far down the track at the bottom of the canyon. The train kept on proceeding sometimes stopping at loops where other trains were crossed. The train crossed the highest viaduct on the line, 100m from the river bed. Winding up a lengthy 2.5% grade, the huge concrete wall of the Ikawa Dam came into view on the right and the train reached Ikawa. The 2-hour and 45-minute trip by the mountain railway from Senzu was finally accomplished.

Upstream of the Ikwa Dam is Ikwa Lake, about 10km long from the north to the south. The central area of Ikawa village (actually part of Shizuoka city) is located on the western coast of the lake a further 4km north from the station. At the northern end of the lake is another huge dam, Hatanagi #1 Dam. A bus service is available connecting Hatanagi #1 Dam and Shizuoka city via Ikawa village and Ikawa station, but operations are limited.

Oigawa Railway Ikawa Line Photos