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Construction is underway at Fukushima Station in Fukushima Prefecture to add approach tracks for Yamagata Shinkansen trains. This article explains the details and significance of the construction, along with photographs from the site.
What are the approach lines to Fukushima Station?
The Yamagata Shinkansen, also known as the "Tsubasa" train, began operation in 1992. Currently, it mainly operates between Tokyo Station and Yamagata Station and Shinjo Station in Yamagata Prefecture.
The "Tsubasa" train runs on the Tohoku Shinkansen tracks between Tokyo Station and Fukushima Station. Many "Tsubasa" trains alsoYamabikorun coupled with The Yamabiko mainly operates between Tokyo Station and Sendai/Morioka Stations.
The Yamabiko (left) and Tsubasa (right) trains, coupled together, traveled from Tokyo Station to Fukushima Station. (Photo by the author: All images below, except for those on Google Maps, were taken or created by the author.)
After the Yamabiko train is detached at Fukushima Station, it continues onto the Ou Main Line and heads towards Yamagata Station or Shinjo Station. "Yamagata Shinkansen" is a general term for the section of the Tohoku Shinkansen between Tokyo Station and Fukushima Station, and the section of the Ou Main Line between Fukushima Station and Yamagata Station or Shinjo Station, and is also a common name for the trains (Tsubasa) that operate on this section.
Please see this article for details on how the Yamagata Shinkansen was born
As already explained, southbound Tsubasa trains bound for Yamagata and Shinjo stop at Fukushima Station on the Tohoku Shinkansen line before continuing onto the Ou Main Line. Northbound Tsubasa trains bound for Tokyo, of course, do the reverse, starting from the Ou Main Line and continuing onto Fukushima Station on the Tohoku Shinkansen line. Trains that are coupled with Yamabiko trains are coupled at Fukushima Station. The track that allows the Tsubasa trains to travel between the Tohoku Shinkansen and Ou Main Line tracksis called the "approach line.
What is the problem with the current approach?
Here is a simple diagram showing the current wiring at Fukushima Station on the Tohoku Shinkansen
Fukushima Station wiring diagram (arrows in the diagram indicate the direction trains can travel)
Platform 11 is an up-track platform, and is designed to allow trains to enter from the Sendai direction, but it is currently not in use
Platform 12 is for upbound trains, and Yamabiko trains that do not connect with Tsubasa at Fukushima Station will stop here
The two tracks between tracks 12 and 13 are for through trains. The Tohoku Shinkansen's "Hayabusa" and the Akita Shinkansen's "Komachi" do not stop at Fukushima Station, so they speed through these tracks.
Platform 13 is for outbound trains, and is also where the Yamabiko, which does not connect with the Tsubasa, stops
And then there's track 14. I'll explain the details later, butboth the "Tsubasa" and the "Yamabiko" (which operates coupled with the "Tsubasa") must stop on this track, both inbound and outbound.
First, the outbound Yamabiko and Tsubasa trains will stop at platform 14 and be uncoupled, allowing the Tsubasa to depart first, passing through the current approach line and descending to the Ou Main Line tracks, heading towards Yamagata
Afterwards, the Yamabiko departs for Sendai
The problem is the train heading up to Tokyo
First, the Yamabiko enters platform 14, crossing over from the up line to the down line
After that, the "Tsubasa" train ascends the approach line from the Ou Main Line and enters platform 14 to connect with the "Yamabiko" train. the approach line only connects to platform 14, the "Tsubasa" can only enter platform 14, and therefore the "Yamabiko" also has to enter platform 14 to wait for the "Tsubasa". Incidentally, the "Yamabiko" train that does not connect with the "Tsubasa" does not need to enter platform 14 and stops at platform 12.
After the "Yamabiko" and "Tsubasa" trains are coupled, the train crosses the down line again to move onto the up line and heads towards Tokyo. In the diagram above, the "Tsubasa" is shown coupled with the "Yamabiko," but some "Tsubasa" trains do not couple with the "Yamabiko." However , as mentioned earlier, the "Tsubasa" can only enter track 14. Therefore,as long as there is an upbound "Tsubasa" running (whether it couples with the Yamabiko or not)will occur
When an inbound "Tsubasa" train operates alone, it crosses the outbound track once. When a "Tsubasa" and a "Yamabiko" train are coupled together, the train crosses the outbound track twice. While an inbound train is crossing the outbound track, it is naturally impossible for an outbound train to pass through Fukushima Station. Therefore, Fukushima Station alone creates a significant constraint on the scheduling of the Tohoku and Yamagata Shinkansen lines.
Furthermore, if the timetable is disrupted, situations will arise whereby passing down trains will have to wait for up trains to cross the down line (it is said that when a high-speed Shinkansen train stops, the journey time will increase by five minutes), or conversely, up trains such as Yamabiko and Tsubasa will have to wait for down trains to pass, or down and up Tsubasa trains will compete for platform 14, further exacerbating the disruption to the timetable
Furthermore, if the train schedule is significantly disrupted, the impact will not be limited to just the Tohoku Shinkansen and Yamagata Shinkansen lines. The tracks between Tokyo Station and Omiya Station on the Tohoku Shinkansen line are also used by Joetsu Shinkansen and Hokuriku Shinkansen trains. This means that if the Tohoku Shinkansen and Yamagata Shinkansen schedules are disrupted, and that disruption is amplified at Fukushima Station, itdisrupt the schedules of Shinkansen trains bound for Niigata, Kanazawa, and Tsurugacould potentially
There's another problem. As explained above, northbound "Yamabiko" trains stop at platform 12 if they are not coupled with "Tsubasa" trains, and at platform 14 if they are coupled with "Tsubasa" trains. When you want to take a northbound "Yamabiko" train from Fukushima Station towards Tokyo, the platform you should go to differs depending on the train. There's probably no disagreement that this is confusing (although it might be commonplace for people who frequently use large stations like Tokyo Station or Shin-Osaka Station...).
Details of the approach line expansion work
Currently, at Fukushima Station, the northbound "Yamabiko" and "Tsubasa" trains have to cross the southbound tracks twice, which is a bottleneck. This two-crossing is necessary because the current approach tracks only connect to platform 14 at Fukushima Station. It should be easy to come up with a solution to this problem.
New approach line for the ascending Tsubasa train
As shown in the diagram above, the current approach line should be used exclusively for southbound "Tsubasa" trains, andon a new approach line connecting to the northbound platform at Fukushima Station for northbound "Tsubasa" trainsshould be carried out
With this track layout, the northbound Yamabiko bound for Tokyo will first stop on the Tokyo side of track 11 to wait for the Tsubasa, and the northbound Tsubasa will enter track 11 at Fukushima Station via the new approach line from the Ou Main Line to couple with the Yamabiko. This Yamabikoto cross the southbound track when entering Fukushima Station.
When the Yamabiko and Tsubasa trains depart from Fukushima Station, they will not cross the southbound tracks. Since northbound trains will no longer cross the southbound tracks at all, the flexibility of timetable scheduling will be greatly improved, and the occurrence of delays escalating at Fukushima Station will also be reduced.
Furthermore, since there is only one existing approach line, it was not possible to have a southbound Tsubasa train depart and a northbound Tsubasa train arrive at Fukushima Station simultaneously. The fact that this will now be possible is a key point. With the completion of the new approach line, the previous constraints will be removed, which may lead to an increase in the number of Tsubasa trains.
Furthermore, the platform number for northbound Yamabiko trains will be platform 11 for trains that will be coupled with Tsubasa trains, and platform 12 for trains that will not be coupled, as before. This eliminates the hassle of having to check which platform the Yamabiko train will stop on before going up to the platform.
, specifically the addition of approach tracks,will contribute to improving the convenience and reliability of the Shinkansen, which runs across a wide area of eastern Japan.
The new approach line took time to realize
The need for a dedicated approach line for northbound Tsubasa trains was apparently recognized within JR East, the company that operates the Shinkansen, at least as early as 2005. However, it was easy to imagine that the construction of a new approach line would be difficult, and it took time to consider the project and wait for advancements in construction technology, which is why it took so long to realize.
As shown in the diagram created by the author, the new approach linemust pass under the Tohoku Shinkansen, then make a sharp curve to reach the elevated platform at Fukushima Station. And although not shown in the diagram, it must take a route that does not interfere with the conventional railway lines running at ground level. Furthermore, to the north of the station (to the right in the diagram) is the Nishimachi Overpass on Fukushima Prefectural Road 310, the Niwasaka-Fukushima Line, which crosses over the conventional railway tracks. The new approach line must cross the Niwasaka-kaido Overpass at a height that does not obstruct automobiles using it.
As a result, the new approach linenot only curved but also has a steep uphill sectionhas become The gradient is 33‰ (per mille), meaning that for every 1km traveled horizontally, the elevation rises by 33m (the angle at which the tangent is 0.033), which is 1.89 degrees. This is quite a steep gradient for a railway, although it may be manageable for a car. However, the uphill "Tsubasa" train has already crossed the Itaya Pass, which has an average gradient of 33‰, between Yonezawa Station and Fukushima Station before arriving at Fukushima Station, so adding another 33‰ uphill section should not be a problem at all.
For more information about the Itaya Pass railway, please see this article
With its sharp curves and steep gradients, the new approach line resembles a junction on an urban expressway. It's best to see it for yourself, so from here on, the explanation will include photos.
Current status of approach line expansion work
The following is an overview of the current status of the approach track expansion work, based on photographs taken by the author on-site in early August 2024. Please note that the photographs were taken from public roads, sidewalks, and platforms. No photographs were taken in areas where public access is restricted.
The new approach line, which branches off from the northbound track of the Ou Main Line, begins to gain altitude towards Fukushima Station after passing the Mikawa level crossing near Fukushima Station (currently only local trains on the Ou Main Line pass through the Mikawa level crossing, but after the new approach line opens, northbound Tsubasa trains will also pass through it).
At the center of this aerial photograph is the Mikawa level crossing. The new approach line extending to Fukushima Station to the southeast is already visible as of September 2024, when this article was written.
The tracks for the new approach line have already been laid, but the overhead lines that supply electricity to the trains have not yet been installed. Presumably, electrical equipment installation will begin soon. The elevated bridge that runs above the new approach line is part of the Tohoku Shinkansen line.
This elevated line is the current approach line
The current approach line slopes gently downwards towards Yamagata
The new approach line steadily gains altitude and passes under the Tohoku Shinkansen viaduct
The train comes closest to the Tohoku Main Line near the Soneda (East) level crossing, which serves the Tohoku Main Line, Fukushima Kotsu Iizaka Line, and Abukuma Express Line. From here, it curves further, approaching the Tohoku Shinkansen tracks that it had previously passed under. The small cream-colored bridge visible in the distance is the section that crosses over the Niwasaka Fukushima Line Nishimachi overpass.
As you can imagine from the name Soneda (East) Crossing, Soneda Station on the Iizaka Line is located right after crossing this crossing
Photographed from the Nishimachi Overpass Bridge, crossing the bridge
And then head to Fukushima Station..
This is the section that connects to the Tohoku Shinkansen tracks (the new approach line is the track on the far right). Currently, a wire mesh gate has been installed.
The tracks continue to platform 11, which is currently a spare platform
At this time (early August), the Yamagata Shinkansen was partially suspended due to the effects of the heavy rain disaster in late July, and the Tsubasa train that was supposed to be bound for Shinjo had a sign indicating an unusual destination: "To Oishida."
Furthermore, on the day I was scheduled to take the Shinkansen from Fukushima Station, the Yamagata Shinkansen was significantly delayed due to a signaling system problem on the Ou Main Line, and this delay spread to the Tohoku Shinkansen, causing chaos. I experienced firsthand the necessity of a new approach line.
summary
Construction of the elevated bridge and tracks for the new approach line is already well underway, and it looks like trains could start running at any moment. However, electrical equipment and other work is still to be done, and thorough test runs will be necessary even after completion. The new approach line is scheduled to open at the end of fiscal year 2026. It is likely that northbound "Tsubasa" trains will start running on this new track from the day of the JR Group's timetable revision in March 2027. This short section of track, only a few hundred meters long, will greatly improve the convenience and operational stability of the Shinkansen in East Japan in the future.
![3106705_l](https://jp.neft.asia/wp-content/uploads/2024/05/3106705_l-150x150.jpg.webp "Why was the Yamagata Shinkansen "Tsubasa" mini-shinkansen created? [Yamagata Prefecture]")
![cb115f1bbd09cb04b9138b7ecd35f6c6.jpg](https://jp.neft.asia/wp-content/uploads/2023/06/cb115f1bbd09cb04b9138b7ecd35f6c6.jpg-150x150.webp "Yamagata Prefecture's "Sokushinbutsu" and Yudonosan's "Reincarnation Belief"")
