Tōkaidō Main Line


The Tōkaidō Main Line is one of the most important railway corridors in Japan, connecting the major cities of Tokyo and Kobe via Shizuoka, Nagoya, Kyoto and Osaka. The line, with termini at Tokyo and Kobe stations, is long, not counting its many freight feeder lines around the major cities. The high-speed Tōkaidō Shinkansen largely parallels the line.
The term "Tōkaidō Main Line" is largely a holdover from pre-Shinkansen days; now various portions of the line have different names which are officially used by JR East, JR Central, and JR West. Today, the only daily passenger train that travels the entire length of the line is the combined Sunrise Izumo/Sunrise Seto service which runs overnight. During the day, longer intercity trips using the line require several transfers along the way.
The Tokaido Main Line is owned and operated by three Japan Railways Group companies:

Completion and early days, 1872–1913

The Tōkaidō route takes its name from the ancient road connecting the Kansai region with the Kantō region through the Tōkai region. Its name meant "Tōkai road", or the road running through Tōkai. The Tōkaidō Line does not follow the old road exactly, since the latter diverges at Nagoya toward the Mie Prefecture coastline; to follow it by train, the Kansai Main Line and Kusatsu Line would have to be followed from Nagoya to Kusatsu. Japan's largest population centers are all along this route: Tokyo, Yokohama, Nagoya, Kyoto, Osaka, and Kobe. Since construction of the line, these centers have since grown to occupy an ever more dominant role in the country's government, financial, manufacturing, and cultural life.
Historically, one of the first priorities of Japanese railway planners was to build a line from Tokyo to the Kansai region, either following the Tokaido route or the northern Nakasendō route. This decision remained unresolved as regional needs were addressed. The first railway in Japan was the line from Shimbashi to Sakuragicho in Yokohama, which opened in 1872; another segment of today's Tokaido Main Line, between Kyoto and Kobe, opened in 1877.
In 1883, the government decided to use the Nakasendō route, and construction of several segments commenced. Railways were opened between Ogaki and Nagahama and between Nagoya and Kisogawa in line with the Nakasendo plan. However, by 1886, it was clear that the Tokaido route would be more practical, and so the Nakasendo plan was abandoned.
File:9850 9856 in the Railway Museum.jpg|thumb|JGR Class 9850 Mallet locomotives were used as bank engines on the mountainous Gotemba stretch of the line; this example is preserved at the Railway Museum.
The lines between Kisogawa and Ogaki, Yokohama and Kozu, and Hamamatsu and Obu were completed in 1887, and the first line from Tokyo to Kobe was completed in 1889, when Kozu and Hamamatsu were connected through the present-day Gotemba Line corridor. The final segments were completed between Kasumigahara and Otsu. At the time, there was one Tokyo–Kobe train in each direction per day, taking over 20 hours each way. The "Tokaido Line" name was formally adopted in 1895. In October 1895, following the Sino-Japanese War, through service to the Sanyo Railway began.
Express service between Tokyo and Kobe began in 1896, sleeper service in 1900, and dining car service in 1901. In 1906, all privately run main lines were nationalized under the newly created Japanese Government Railways, which at the time had a network of just over of track.

Capacity expansion and route changes, 1914–1945

On 20 December 1914, Tokyo Station opened and succeeded Shimbashi Station as the Tokyo-side terminus of the line. On the same day, an electrified commuter line was inaugurated along the section between Tokyo Station and today’s Yokohama Station, which is now part of the Keihin–Tōhoku Line. Automatic couplers were introduced on all freight wagons in 1926. In 1930, the first Tsubame express was introduced, reducing the Tokyo - Kobe travel-time to nine hours - a significant reduction from the twenty hours required in 1889 and fifteen in 1903.File:Tokaido Main Line EF552 Limited Express 1 Train 'Fuji' Shinagawa - Oimachi 1936-08-04.jpg|thumb|JNR Class EF55 hauling the Fuji near Shinagawa, 4 August 1936
By the start of the Taishō era, route changes on several stretches of the line were deemed necessary to accommodate growing demand. The route bypassing Osakayama, in use since 1878, was closed when the current, less steep route with two long tunnels was completed on 25 September 1919. The mountainous Gotemba stretch required an even larger-scale route change, culminating in the completion of the Tanna Tunnel in 1934 after 15 years of construction. The new route through the tunnel is 11.2 kilometres long, compared to the old Gotemba route, which took a 60.2-kilometre detour around the Tanna Basin. With the opening of the tunnel, the section between Tokyo and Numazu was fully electrified, as steam locomotives were unable to operate through the long tunnel safely.
File:JGR Moha52 firstmodel.jpg|thumb|52 Series EMUs were used for commuter services between Kyoto and Kobe following the electrification of the section.
Electrification also progressed on the other end of the line around the same time, in 1934. Commuter rapid services between Kyoto and Kobe, using 52 Series streamliner EMUs, began in 1937. However, further electrification of the line was overshadowed by the Second World War and did not resume until after the war. For security reasons, the army preferred to keep the middle portion of the line unelectrified, as unelectrified tracks were much easier to repair in the event of an enemy attack.
During the war, the line's focus shifted towards freight services. Express services were significantly reduced, and sleepers and restaurant cars were withdrawn from service in 1944. JNR Class D52 locomotives were introduced for wartime freight transport, but their poor manufacturing quality led to several boiler explosion accidents.

As the main transport artery of postwar Japan, 1945–1964

In the immediate aftermath of the war, almost all surviving express train carriages were requisitioned by the Allied Occupation Forces. Services such as the Allied Limited, Dixie Limited, and the BCOF Train operated on the Tōkaidō Line. Express trains for Japanese nationals resumed in April 1947, with sleeper services following in July 1948.
In 1949, the Limited Express Heiwa, a successor to the pre-war Tsubame service, and the sleeper express Ginga both began operating between Tokyo and Osaka. In January 1950, Heiwa was renamed Tsubame. Makeshift D52 freight locomotives were converted into C62 express locomotives, the largest and fastest steam engines in Japan's rail history, to haul these services. One of the C62s, C62 17, holds the narrow-gauge steam world speed record, which was achieved on the Tokaido line near Nagoya on 15 December 1954, and is preserved at the SCMaglev and Railway Park.
On 19 November 1956, the line was fully electrified. The Tokyo–Osaka express trains, Tsubame and Hato, began to be hauled by JNR EF58 locomotives for the entire length of the route, reducing travel time from 8 hours to 7 hours and 30 minutes. With no concerns about smoke polluting the carriages, these trains were painted light green and nicknamed Aodaishō.
On 1 October 1958, the Kodama, the first limited express service operated by EMUs rather than locomotive-hauled carriages, commenced. This service further reduced travel time to 6 hours and 50 minutes. The Series 151 EMUs marked a significant milestone in railway technology, as EMUs were previously considered unsuitable for high-speed and long-distance services due to issues like noise, vibration, and cost. Since then, all non-sleeper express rolling stock, including the Shinkansen, has been designed as EMUs. On the same day, the Asakaze sleeper express entered service with the newly built Series 20 carriages. These carriages were fully air-conditioned and nicknamed the 'hotel on the rail'. Because these sleeper carriages and their successors were painted blue, sleeper trains in Japan came to be known as Blue Trains.

After the opening of the Tōkaidō Shinkansen, 1964–1987

The capacity constraints on the Tokaido Main Line had been clear prior to World War II, and work started on a new standard gauge "bullet train" line in 1959. Intercity passenger traffic between Tokyo, Nagoya and Osaka largely transferred to the Tōkaidō Shinkansen after it was completed in 1964. Since then, the Tokaido Main Line has been used as a commuter and freight line, serving a very small number of long-distance passenger trains.

Privatisation, 1987–present

Following the Hanshin earthquake on 17 January 1995, the line was shut down between Takatsuki and Kobe, with certain segments remaining impassable until 1 April of that year.
On 20 August 2016, station numbering was introduced, with stations between Tokyo and Ōfuna assigned station numbers of JT01 to JT07. Numbers increase towards in the southbound direction towards Ōfuna. Station numbers would be assigned to stations beyond Ōfuna as far as Atami in 2018.
On the evening of 5 August 2023, a JR East Tokaido Line service struck a utility pole near and lost power, resulting in a suspension of service. Four people, including the driver, sustained minor injuries. Service was restored on the morning of 6 August 2023.

Basic data

  • Total distance:
  • *East Japan Railway Company
  • **Tokyo - Atami:
  • **Shinagawa - Shin-Kawasaki - Tsurumi:
  • **Hamamatsuchō - Tokyo Freight Terminal - Kawasaki Freight Terminal - Hama-Kawasaki:
  • **Tsurumi - Hatchō-Nawate:
  • **Tsurumi - Higashi-Takashima - Sakuragichō:
  • **Tsurumi - Yokohama-Hazawa - Higashi-Totsuka:
  • *Central Japan Railway Company
  • **Atami - Maibara:
  • **Ōgaki - Mino-Akasaka:
  • **Ōgaki - - Sekigahara:
  • *West Japan Railway Company
  • **Maibara - Kōbe:
  • **Kyōto Freight Terminal - Tambaguchi:
  • **Suita - - Amagasaki:
  • **Suita - Umeda - Fukushima:
  • *Japan Freight Railway Company
  • **Sannō Signal - Nagoya-Minato:
  • **Suita Signal - Osaka Freight Terminal:
  • *Japan Freight Railway Company
  • **Shinagawa - Atami:
  • **Shinagawa - Shin-Tsurumi Signal:
  • **Tokyo Freight Terminal - Hama-Kawasaki:
  • **Tsurumi - Yokohama-Hazawa - Higashi-Totsuka:
  • **Tsurumi - Hatchō-Nawate:
  • **Tsurumi - Shinkō - Sakuragichō:
  • **Atami - Maibara:
  • **Minami-Arao Signal - Sekigahara:
  • **Minami-Arao Signal - Mino-Akasaka:
  • **Maibara - Kōbe:
  • **Kyōto Freight Terminal - Tambaguchi:
  • **Suita - Umeda - Fukushima:
  • Gauge: Narrow gauge railway
  • Stations:
  • * Passenger: 166
  • ** JR East: 34
  • ** JR Central: 82
  • ** JR West: 50
  • * Freight only: 14
  • Tracks:
  • * Four or more
  • ** Tokyo - Odawara:
  • ** Nagoya - Inazawa:
  • ** Kusatsu - Kōbe:
  • * Two
  • ** Odawara - Nagoya
  • ** Inazawa - Kusatsu
  • ** Shinagawa - Shin-Kawasaki - Tsurumi
  • ** Hamamatsuchō - Tokyo Freight Terminal - Kawasaki Freight Terminal - Hama-Kawasaki
  • ** Tsurumi - Hatchō-Nawate
  • ** Tsurumi - Higashi-Takashima
  • ** Tsurumi - Yokohama-Hazawa - Higashi-Totsuka
  • ** Suita - Umeda
  • ** Suita - - Amagasaki
  • * Single-track: All other sections
  • Electrification: 1,500 V DC
  • Railway signalling: Automatic Train Control
  • Maximum speed:
  • *Tokyo - Ōfuna, Odawara - Toyohashi:
  • *Ōfuna - Odawara, Toyohashi - Maibara:
  • *Minami-Arao Signal - Tarui - Sekigahara, Minami-Arao Signal - Mino-Akasaka:
  • *Maibara - Kōbe: