Chūō Line (Rapid)

Early history Most of the route of the Chūō Line (Rapid) was built by the during the Meiji era and entered service in two phases as the Kōbu Line. The first was between Tachikawa and Shinjuku, opening on 11 April 1889. Trains took one hour to travel between those two points and only went as fast as 30 km/h (18.64 mph). The second section between Tachikawa and Hachioji opened later on 11 August. Around the time of opening, there were only four round trips per day, and only one of them traveled the full route between Hachioji and Shinjuku. Additionally, as most of west Tokyo was not yet developed or populated, stations were only located at Nakano, Sakai (now Musashi-Sakai), Kokubunji, and Tachikawa. This was expanded to six round trips with an extension to Iidamachi (near today's Iidabashi) in April 1895. In response to high ridership, the line was electrified in August 1904 between Nakano and Iidamachi, becoming the first rapid electric railway in Tokyo and electric powered De-968 cars were brought into service. Service was extended to Ochanomizu on 31 December 1904. Kōbu Railway was later acquired by Japanese Government Railways (JGR), and was nationalized on 1 October 1906. This allowed the introduction of , a precursor to current rapid service, on 15 September. These trains only stopped at Tōkyō, Kanda, Manseibashi, Ochanomizu, Yotsuya, Shinjuku, and Nakano. Express service only operated during peak hours on weekdays. Post-war After World War II, JGR became Japanese National Railways (JNR). Areas of west Tokyo experienced large population growth during the post-war boom, and in turn resulted in very crowded trains, some operating at 300% above full capacity. JNR 101 Series trains were introduced starting in December 1957 with a prototype unit. Production trains were delivered to Mitaka Depot and entered service a year later. These electric trains had four double-leafed doors per side, featured quicker acceleration, and were 10 cars long, ideally accommodating as much as 1,400 passengers per train. They were colored orange vermillion (officially JNR Vermillion No. 1), which became the trademark color for the Chūō Line and all its future rolling stock. Between Nakano and Tachikawa, these trains operated as a super-express service, only stopping (from east to west) at Mitaka, Kokubunji, and Tachikawa. signed up as a Special Rapid service train for Takao makes a stop at Ogikubo in August 1984. Prototype 201 series trains began operating on 20 August 1979, with full service starting in August 1981, replacing the 101 series cars. By 1987, Japanese National Railways had incurred a large amount of debt – ¥27 million. It was broken up and privatized into seven separate companies within the Japan Railways Group. The Chūō Line (Rapid) and other lines in the Kantō region fell under control of the East Japan Railway Company, or JR East. There were multiple grade crossings along the right-of-way, and as a result of frequent train service, gates were often closed. This led to high levels of traffic congestion, accidents, and a feeling amongst nearby residents of being disconnected from one another. The work along this 9 km (5.59 mi) section was done in phases, two tracks at a time starting in 1999, with trains using the two remaining tracks. Women-only cars were introduced on 5 September 2005, they were offered during various periods in the past, even during the early days of the Chūō Line. Some iterations of this policy also allowed children of any gender to ride in these cars. On Chūō Line (Rapid) trains, this is car number #1, the first car on all trains towards Tōkyō. The policy is only in effect during the height of the morning peak on weekdays. On 26 December 2006, E233 series trains entered service, and remains the current rolling stock on the line. 688 cars were initially ordered to replace the older 201 series trains, which operated until 14 October 2010. The E233s were built with universal design in mind, and JR East surveyed customers to gather further input on features to include such as air purification, and lower luggage racks in women-only cars. In 2016, station numbering was introduced with stations being assigned numbers between JC01 (Tōkyō) and JC24 (Takao). Stations on the Ōme and Itsukaichi lines, where some trains operate as through services, are also identified with JC station codes. , approaching Tachikawa JR East planned to introduce green cars on both the Chūō Line (Rapid) and Ōme Line in spring 2025. To do so, two newly built bilevel green cars would be added to each 10-car and 6-car E233 series EMU set, forming 12-car and 8-car sets respectively. In addition, toilets were also installed in each trainset. JR East announced the introduction of Green Car equipped trains from 13 October 2024 on a trial basis without additional fares. Full deployment (with fares) commenced in early 2025. It was reported in October 2025 that some passengers were using green cars without paying the proper step-up fare. ==Issues==