Keikyu Main Line (京急本線): History & Facts

History

The line traces its origins to the Daishi Electric Railway, the predecessor of Keikyu, which was founded in 1898 and operated a pilgrimage railway to Kawasaki Daishi (Heikenji temple). According to Keikyu's corporate chronology, the company's line of about 2 km between Rokugōbashi and Daishi opened on 21 January 1899. With the aim of building a railway linking Tokyo and Yokohama (Keihin), the company renamed itself the Keihin Electric Railway and opened a tramway from southern Tokyo towards the Kawasaki area.

The early build was incremental. On 1 February 1901 the Keihin Electric Railway opened the section between Ōmori-teishajōmae (later Ōmori) and Kawasaki (later Rokugōbashi), laid to 1,435 mm gauge and operated at 600 V DC. In 1904 the line was regauged to the narrower 1,372 mm and extended to Shinagawa, and on 24 December 1905 it was extended from Kawasaki to Kanagawa-teishajōmae (later Keihin Kanagawa). By the end of the Meiji era it had become a major interurban line between Tokyo and Yokohama.

A second company supplied the southern half. The Keihin Electric Railway took a capital stake in the Shōnan Electric Railway, which had been planning a suburban line between Yokohama and Yokosuka and had been hit by the effects of the Great Kantō Earthquake; with Keihin's investment the Shōnan Electric Railway opened, in the Shōwa era, sections corresponding to parts of today's Keikyū Main Line and Keikyū Zushi Line. Its section between Uraga and Koganechō opened in 1930 as a standard-gauge line electrified at 1,500 V DC, and in 1931 the line from Yokohama was extended to connect with it at Koganechō. Because Keihin's line used the 1,372 mm gauge while Shōnan's had been licensed and opened at standard gauge, through-running required regauging one of them; the two companies were joined at Hinodechō in December 1931, after which Keihin's line was converted to standard gauge. Freight services ceased in 1932. The decisive step came on 1 April 1933: the line was extended into the national railway's Shinagawa Station, Takanawa Station closed, Shinagawa Station opened, the section north of Yokohama was regauged from 1,372 mm back to 1,435 mm, and through operation between Shinagawa and Uraga began.

A northbound Keikyū Main Line train crossing the Katabira River bridge on its approach to Yokohama Station.yagi-s · CC BY 2.0 · Wikimedia Commons

War-era consolidation reshaped the operator. The Shōnan Electric Railway merged with the Keihin Electric Railway in 1941, and the following year that company merged into Tokyu (the wartime "Greater Tokyu"). During the Tokyu years the voltage on the whole line was raised to 1,500 V DC, and on 1 June 1948 Keikyu (Keihin Kyūkō Dentetsu) was separated from Tokyu to operate the railway; the line was later renamed the Main Line (Honsen).

In the postwar decades the line was upgraded for higher capacity and speed in a corridor where it competes directly with the parallel JR East Tōkaidō and Keihin-Tōhoku lines; on the Shinagawa–Yokohama section, where the alignment is favourable, trains run at 120 km/h to compete with JR. Today the line is double-tracked except for a three-track section between Koyasu and Kanagawa-shimmachi and a quadruple-tracked section between Kanazawa-bunko and Kanazawa-hakkei. From Sengakuji it through-runs onto the Toei Asakusa Line and, via that line, onto the Keisei and Hokusō networks, so that together with the Keikyū Airport Line it functions as an airport-access railway: it connects to Haneda Airport, while its through-service partner Keisei reaches Narita Airport, linking the two airports. Operational changes in the 2010s and 2020s continued: in October 2012 the section between Heiwajima and Rokugōdote was elevated to remove level crossings and Keikyū Kamata Station was rebuilt as a dual-level junction connecting the Main Line with the Airport Line; from 25 November 2023 all "Airport Express" services were renamed "Express"; and elevation of the Shinagawa-to-Shimbamba section, including a rebuilt Kitashinagawa Station, was under way as of 2023, due for completion in 2029.

There are 50 stations, and the maximum speed is 120 km/h; the track is 1,435 mm gauge with 1,500 V DC overhead electrification. The section from Shinagawa to Uraga is 55.5 km long; with the 1.2 km Sengakuji–Shinagawa section, the line totals 56.7 km. Daily ridership was 1,129,320 in fiscal 2010.

The Keikyu 1000 series "Yellow Happy Train" in its distinctive yellow livery.yagi-s · CC BY 2.0 · Wikimedia Commons

The line has seen several mudslide- and level-crossing-related accidents. On 7 April 1997 the first three cars of a four-car train derailed after colliding with a mudslide between Keikyū Taura and Anjinzuka, injuring people on board. On 24 September 2012 the first three cars of an eight-car train derailed after striking a mudslide between Oppama and Keikyū Taura, with about 700 passengers aboard. According to the Japan Transport Safety Board's accident investigation report, 55 passengers and the driver were injured, and the driver applied the emergency brake while the train was travelling at about 72 km/h. The train was scrapped afterwards. On 5 September 2019 a rapid limited express collided with a truck and derailed at a level crossing between Kanagawa-shimmachi and the station then called Nakakido in Yokohama's Kanagawa Ward; the truck driver was killed and 35 others were injured, and that train too was scrapped.

Stations on this line

50 stations tracked on the map, listed alphabetically. Select any to read its page.

Timeline

1898The Daishi Electric Railway, the predecessor of Keikyu, is founded.
189921 January: according to Keikyu's corporate chronology, the Daishi Electric Railway, Keikyu's predecessor, opens a line of about 2 km between Rokugōbashi and Daishi.
19011 February: the Keihin Electric Railway opens the Ōmori–Kawasaki (later Rokugōbashi) section at 1,435 mm gauge, 600 V DC.
1904The line is regauged to 1,372 mm and extended to Shinagawa.
190524 December: the Kawasaki–Kanagawa section opens, completing the route from Shinagawa to Kanagawa.
1930The Shōnan Electric Railway opens the Uraga–Koganechō section as a standard-gauge line electrified at 1,500 V DC.
1931December: the Keihin and Shōnan lines are joined at Hinodechō; the line from Yokohama is extended to connect at Koganechō.
19331 April: the line is extended into the national railway's Shinagawa Station; Takanawa Station closes; the section north of Yokohama is regauged from 1,372 mm back to 1,435 mm; Shinagawa–Uraga through operation begins.
1941The Shōnan Electric Railway merges with the Keihin Electric Railway.
1942The Keihin Electric Railway merges into Tokyu (the wartime 'Greater Tokyu').
1945The overhead voltage is raised to 1,500 V DC.
19481 June: Keikyu (Keihin Kyūkō Dentetsu) separates from Tokyu to operate the railway; the line is later renamed the Main Line (Honsen).
19977 April: the first three cars of a four-car train derail after hitting a mudslide between Keikyū Taura and Anjinzuka; people on board are injured.
201224 September: an eight-car train's first three cars derail after striking a mudslide between Oppama and Keikyū Taura; 55 passengers and the driver are injured and the train is scrapped. October: Heiwajima–Rokugōdote elevated and Keikyū Kamata rebuilt as a dual-level junction.
20195 September: a rapid limited express collides with a truck and derails at a level crossing between Kanagawa-shimmachi and Nakakido (now Keikyū Higashi-Kanagawa) in Yokohama; the truck driver is killed and 35 others injured; the train is scrapped.
202325 November: all 'Airport Express' services are renamed 'Express'. Elevation of the Shinagawa–Shimbamba section (incl. a rebuilt Kitashinagawa Station) is under way, due for completion in 2029.