Plans for the Tsugaru Straits Line
The standard of the Tsugaru Straits Line is type A and the line has been electrified for both up and down tracks.
In order to cater for the future possibility of the Shinkansen using the same
tracks, the line has been designed such that curves have as large a radius
as possible, and slopes are kept to an absolute minimum.
Additionally, the main rail type used is the same as that used for the Shinkansen, the 60 rail.
(Note:Shared sectors are lengths of track which can be used by both the Shinkansen and local lines running in parallel to it.)
|The Hokkaido |
|Minimal curve radius
|Fast rail types for inclines
|Extension of lines
|Extension of tunnels
|Temporary suspension bridges
||Heavy simple catenary
||Heavy compound catenary
||Heavy simple catenary
Subdivision of upgrade work
The upgrade of the Tsugaru Straits Line was divided into three sectors: the sector passing under the Tsugaru Straits through the Seikan Tunnel, and the two sectors connecting onto the Honshu and Hokkaido tunnel entrances, extending through to the existing Nakaoguni and Kikonai stations, respectively. The two connecting sectors comprise tunnels, bridges and embankments, and the JR Morioka branch office is responsible for the Honshu connecting sector, whereas the JR Sapporo branch office is responsible for the Hokkaido connecting sector. The Seikan Tunnel was built by the Seikan Construction Bureau, and the greater part of electrical work has been carried out by the Kanto branch office.
Upgrading the Tsugaru and Esashi Lines
The Tsugaru Line between Aomori and Nakaoguni, and the Esashi Line between Kikonai and Hakodate were both local, unpowered lines. To rectify this situation, JR Hokkaido was given the job of electrifying and reinforcing the tracks to improve the general standard of the lines.
The gauge of the Tsugaru Straits Line
New 60 rails (60kg weight per meter) have been laid in shared sectors where the Shinkansen will run in parallel to the existing line. These are the same rails as are used by the Shinkansen.
The rails used in general sectors, where only the local train will run, are 50 rails.
Tri-rail slab-type tracks
To minimize maintenance, slab-type tracks have been utilized as much as possible for the Tsugaru Straits Line. In order for the Shinkansen and local trains to run on the same tracks, a tri-rail track has been laid over the entire extent of the line, allowing for both standard gauge (1435mm) and narrow gauge (1067mm) trains.
Throughout the Seikan Tunnel, sea water resistant medium Portland cement has been used for the slabs in order that the tracks are not damaged by sea water. The slabs have also been pre-stressed so that they do not crack.
The longest rail in the world
Long rails have been used throughout the line because of the smoother ride they offer and to minimize maintenance. In particular, the signal circuit for the Seikan Tunnel is based on an uninsulated rail circuit which does not require insulated connections, and so rails were welded together to form a single rail 52.570km long, running almost the entire length of the tunnel. This super long rail is the longest single rail in the world.
A short history of the Tsugaru Straits Line
Seikan Tunnel Statistics
||Geological study started.|
||Japan National Railways separated from the Ministry of Transport.|
||Added to planned lines under Railway Construction Act.|
||Japan Railway Construction Corporation established.
Took over research operations from JNR.
||Minister of Transport ordered the basic plan (research).|
||Started to dig an inclined shaft on at Yoshioka, Hokkaido.|
||Tokaido Shinkansen started commercial services.|
||Started to dig an inclined shaft at Tappi, Honshu.|
||Minister of Transportion ordered the basic plan (construction) and construction enabling to operate the Shinkansen.|
||Minister of Transportion approved the construction execution plan.|
||Main construction started.|
||Tohoku Shinkansen started commercial services.|
||Construction execution plan between Nakaoguni and Kikonai approved.|
||Construction of the entrance section of the Seikan Tunnel started.|
||Pilot tunnel completed.
Honshu and Hokkaido connected on land.
||Main tunnel completed in the central section below the channel.
||Rail construction completed.|
Honshu and Hokkaido connected on rails.
||JR Hokkaido established.
Decided to operate the Tsugaru-kaikyo line.
||Commercial services of the Tsugaru-kaikyo line started.|
|Total length of pilot boring
||Distance between Tokyo and Mishima|
|Amount of injected soil
||1.6 times the volume of Kasumigaseki Bldg.|
|Amount of used steel
||Steel for 42 Tokyo Towers|
||5.1 times the volume of Tokyo Dome|
|Amount of used explosive
||Explosive for several hundred times an amount used for Sumidagawa Fireworks Competition|
||Almost similar to the amount of concrete used for Kurobe Dam|
|No. of track slabs
||1.2 times the height of Mt. Fuji if stacked up|
||Distance between Aomori and Kyoto|
|Total No. of workers
||Approx. 1/4 of the working population in Japan|