|Sōbu Main Line|
Sōbu/Yokosuka lines' E217 series EMU
|Track gauge||1067 mm|
|Electrification||1500 V DC|
|Sōbu Main Line|
Sōbu Main Line (総武本線 Sōbu-honsen ) is a Japanese railway line formally between Tokyo and the east coast of Chiba Prefecture, operated by the East Japan Railway Company (JR East). It runs through the cities of Funabashi, Chiba, and Chōshi. Its name derives from the old provinces of the area which it serves: Musashi (武蔵国), Shimousa (下総国) and Kazusa (上総国). Its official line color is yellow.
The character of the line distincts at Chiba. Western urbanized section is informally but commonly called Sōbu Line (総武線 Sōbu sen ) without "Main". Local and Rapid trains west of Chiba to Tokyo area are called another names, mentioned below. The name with "Main" in popular sense refers to the trains operated east of Chiba on the line. Announcements of the operator such as signboards in stations and trains, vocal announcements in trains have this distinction also, with "Main" for eastern rural section, without "Main" for western frequent zone.
Local trains run between Ochanomizu and Chiba Station and are called the Chūō-Sōbu Line (中央・総武線) or Sōbu-Local Line (総武緩行線 Sōbu-Kankō ). Rapid trains are also operated from Tokyo Station to Chiba Station and use different tracks from the local service trains. The rapid trains are called Sōbu Kaisoku Line (総武快速線 Sōbu Kaisoku sen (Sōbu Rapid Line)). For the most part, these trains use the same line, except when they reach Tokyo: Sōbu-Kankō trains continue onto the Chūō Line, while Sōbu-Kaisoku trains continue onto the Yokosuka Line. The following sections describe trains east of Chiba. For details west of Chiba, see relevant articles.
Initially, the line was constructed by a private company, Sōbu Railway (総武鉄道 Sōbu Tetsudō ) (1st). It opened the first service sections, between Ichikawa and Sakura in July 20, 1894, and extended for Tokyo City. On December of the year, Honjo (本所,  present Kinshichō) was opened, and in 1904, on the east bank of Sumida River, Ryōgokubashi (両国橋) (now Ryōgoku) became the terminal of this line. The accesses to the west to Tokyo City were tramways for passengers and ships for freights. From Sahara to the east, this line reached at another terminus, Chōshi in 1897.
The line was nationalized in 1907 under the Railway Nationalization Act, and double-tracked from Ryōgokubashi to Chiba till the next year. Pedecessor of Japan National Railways (JNR) planned to connect with other lines inside Tokyo. In 1932, new passenger line was opened from Ochanomizu to Ryōgoku (with new platform besides the original terminal facility), and frequent service of EMUs commenced. Electrification to Chiba was completed in 1935, and trains has run through from the Chūō line as local since then. But, except a few trains, no rapid service was operated on this line.
On March 10, 1945, Bombing of Tokyo which made casualties estimated at about 70,000 - 100,000 destroyed stations of the line. During the last days of World War II in 1945, the Imperial Japanese Army thought US Army would attempt a landing operation, "Operation Coronet", on the Kujūkuri Beach, and transferred troops on Sōbu Main Line.
Between Chiba and Chōshi, in rural area of Chiba Prefecture, steam traction was used till recently. Fish and soy sauce from the Chōshi were major goods of the line. Because of closeness to Tokyo, JNR did not provide rapid or express trains, such as Limited Expresses from Ryōgoku to Chōshi until 1958. JNR operated tourist trains from Ryōgoku destined to seaside resorts on the coast from the 1950s.
In the 1960s, JNR started the Five-Destination Operation (五方面作戦 Go Hōmen Sakusen ) to hyper increase commuter demand, and it determined that a new rapid line would be constructed from Tokyo Station to Chiba. A new underground line from Tokyo to Kinshichō, and four-tracked section to Tsudanuma were opened in 1972, and the operator began frequent rapid service from Tokyo to Chiba, where four-tracked from Tsudanuma in 1981. The line was succeeded by the East Japan Railway Company (JR East) from 1987. The parallelling Keiyō Line was opened closer to the coast in 1990, first constructed for freight service but later for relieve passengers, however, Sōbu Main Line is still crowded in the mornings.
On the east of Chiba, electrification reached at Chōshi in 1974, and Limited Express Shiosai has been operated from the underground Tokyo Station since 1975. Freight services from Chōshi ceased in 1986, just before the privatalization of JNR, and regular passenger trains stopped using the Ryōgoku terminal platforms in 1988. JR East started new airport train, Narita Express in 1991.
See Sōbu Line (Rapid) for rapid trains.
See Chūō-Sōbu Line for local trains.
For distances, connections and stops of rapid trains, see the route diagram.
|Chiba||千葉||Chūō, Chiba, Chiba|
|Tsuga||都賀||Wakaba, Chiba, Chiba|