Keio Railway



Keio Railway operates an 88,3Km-long commuter railway network in western Tokyo, formed of a main line, the Keio Line, wich connects Shinjuku to Hachioji and Mount Takao (via the Takao Line), the Sagamihara Line, a branch of the Keio Line wich runs to Hashimoto, two short shuttle lines, the Dobutsuen and Kebajo Lines, wich connect the Keio Line to the Tama Zoo and the Tokyo Racecourse and the Inokashira Line, a separate and independent line (using the 1067mm gauge – the rest of the Keio network uses the peculiar 1372mm gauge) that runs diagonally, connecting Kichioji to Shibuya, intersecting half-way with the Keio Line at Medaimae.


Keio has it’s origins in the Nippon Electric Railway, wich was founded in 1905 to operate interurban tramways west of the current area of Shinjuku, wich at the time was still a sparcely built-up area around a Yamanote Line station. The company was renamed in 1906 as the “Musashi Electric Railway” and in 1910 the company was renamed again as the “Keio Electric Tramway”, with “Keio” being a kanji-compound name using the last kanji of “Tokyo” and the middle one of “Hachioji”, the two places the company intended to connect.

The Keio Electric Railway began operating railway services in 1913, on it’s first completed section of railway, between the current stations of Sasazuka and Chofu. Work progressed rather slowly, with the current Keio Line, from Shinjuku to Hachioji being completed in 1923, after the acquisition and re-gauging (from 1067mm to Keio’s 1372mm gauge) of the Gyokunan Electric Railway, wich had built the current Hachioji to Fuchu section of the line. In 1916 the first section of the Sagamihara Line was completed, branching off the Keio Line at Chofu and running to the current station of Keio-Tamagawa.


In 1942, during the second world war, Keio was forcibly merged, by the order of the imperial government, into Tokyu Railway, along with all the other major private railways in the Tokyo area, forming the huge “Dai-Tokyu” conglomerate.

After the war, Dai-Tokyu was broken up into the pre-war private railways, with Keio re-gaining it’s independence in 1947, acquiring in the process the current Inokashira Line, wich had been built in 1933 by a small company, the Teito Electric Railway, and later acquired as a subsidiary of Odakyu Railway. With the acquisition of the new company, Keio changed it’s company name once more, being renamed as the “Keio Teito Electric Railway”.


After the war, thanks to the booming economy during the Japanese economic miracle of the 1960s, Keio was able to modernize it’ fleet and expand it’s network, opening the Kebajo Line (wich connected the Keio Line to Tokyo’s Racecourse) in 1955, the Dobutsuen Line (running to the Tama Zoo) in 1964 and Takao Line (a branch of the Keio line that run to Mount Takao, a popular tourist destination) in 1967 using the right-of-way of an old railway that had been closed during the war.

1963 saw the end of half-a-century of interurban-style operations; the street-running arrangment near Shinjuku was abandoned in favour of a modern underground terminus, the catenary voltage was increased from 600V to 1500V DC, the remaining single-track sections on the Keio Line were double-tracked and modern rolling stock was introduced, marking the completion of Keio’s transition to a full-fledged railway network.

At the same time, the company also made several ventures in other businnesses, acquiring several local bus companies and merging them into the current Keio Bus company and network, wich operates as a feeder for the railway, and also constructing department stores and hotels around it’s stations (primarily the Shinjuku terminus), so as to increase ridership.


The 1970s saw the Keio Line and Sagamihara Line ridership boom as they became the backbones of the Tama New Town urban development project, the largest New Town to be built in Japan, effectively marking the start of Keio Railway’s primary function as a commuter railway, often more so than other Major Private railways. Subway trough-services with the Toei Shinjuku Line began in March 1980, via the Keio New Line, an underground bypass line with two intermediate stops that branched off at Sasazuka and connected to the Toei subway’s Shinjuku Station (directly connecting the Shinjuku Line to Keio’s Shinjuku terminus having been deemed too complex and costly).

The final new section of the Keio network opened in 1990, when the Sagamihara Line was extended westwards, from Keio-Tama-Center to Minami-Osawa to it’s current western terminus of Hashimoto. 


The current company logo was introduced in 1989 and in 1998 the company re-structured itself under the current name of “Keio Railway” (sometimes called “Keio Corporation” in english pubblications) as a constituent company of the “Keio Group”, the conglomerate that encompassed all ventures, such as Keio Bus, Keio Department Stores and Keio Hotels, that the railway had embarked on during it’s history.

Currently, Keio’s main concern is the replacement of level crossings, for wich the Keio Line is infamous for, and the overall increases in capacity of the lines, including moving underground some stations.




The choice of the unusual 1372mm gauge was dictated by the fact that in it’s early years as an interurban tramway Keio railway planned to operate trough-services with the 1372mm Toden tramway network. Such services were discontinued by 1963, when the catenary voltage was raised to 1500v and the Shinjuku terminus relocated underground. A decade later, as part of the initial plans for the Toei Shinjuku Subway Line, the Tokyo Metropolitan Government requested Keio to regauge it’s network to 1435mm (similarily to what had been done two decades earlier by Keisei), as the Shinjuku Line was planned to use standard gauge. Keio refused due to the complex and costly nature of the plan, not to mention the need to close down it’s heavily-utilized lines for several months, in the end forcing Toei to adopt the 1372mm gauge instead. Thus, things came full circle: Toei (as Toden) imposing the 1372mm gauge to Keio in the early 1900s, and in turn, Keio imposing the 1372mm gauge to Toei sixty years later.


Bonus video:

Owning to the extreme congestion on the Keio Line section between Chofu and Shinjuku, due to the lack of passing loops for most platforms, Keio Railway is infamous for it’s “Dango-Unten” (named after the “Dango”, japanese round dumplings that are served piled on a skewer), the habit of drivers to creep as close as permitted by the ATC system to the preceeding train, often stopping about 30 to 50 meters away. Thanks to the ATC system this otherwise risky manouver is completely safe (the ATC mandating an approach at a very limited speed, at wich the emergency brakes are able to stop a train in less than 10 meters if it ever was to pass the signal at danger), however it’s still a sight to behold!




1372mm gauge network

Keio Line, Sagamihara Line and Takao Line

Trough-services with the Toei Shinjuku Line via the Keio New Line and some trough-services also with the Kebajo Line at weekends.






Non-trough service rolling stock












Keio Kebajo Line

Local shuttle service






Keio Doubutsuen Line







1067mm gauge network

Inokashira Line