 | This article needs additional citations for verification. (October 2019) |
| Kosei Line | |
|---|---|
 | |
 Special Rapid Service train (right) and Thunderbird limited express (left) at Hira Station | |
| Overview | |
| Native name | 湖西線 |
| Owner | JR West |
| Locale | Kyoto Prefecture and Shiga Prefecture |
| Termini | |
| Stations | 21 |
| Service | |
| Type | Heavy rail |
| System | Urban Network (Yamashina – Nagahara) |
| Operator(s) | JR West JR Freight |
| History | |
| Opened | July 20, 1974 |
| Technical | |
| Line length | 74.1 km (46.0 miles) |
| Track gauge | 1,067 mm (3 ft 6 in) |
| Electrification | 1,500 V DC, overhead catenary |
| Operating speed | 130 km/h (81 mph) |
| Train protection system | ATS-P and ATS-SW |
The Kosei Line (湖西線, Kosei-sen, lit. 'lake west line') is a commuter rail line in Osaka-Kobe-Kyoto Metropolitan Area, operated by West Japan Railway Company (JR West). The line was completed in 1974 by the former Japanese National Railways (JNR) to provide faster access from the Kansai region to the Hokuriku region. It originates at Yamashina Station in Yamashina-ku, Kyoto and ends at Ōmi-Shiotsu Station in Nagahama, Shiga.
Its name means "the line to the west of the lake," indicating that it approximately parallels the western shore of Biwako. Trains continue from Omi-Shiotsu Station to Tsuruga Station on the Hokuriku Main Line Yamashina to Kyoto Station on the Tōkaidō Main Line for convenient transfer to lines serving the Kansai as well as the Tōkaidō Shinkansen.
In addition to local, Rapid and Special Rapid services, limited express trains such as the Thunderbird, as well as freight trains are frequently operated on the line. Only few of limited express trains stop at Katata or Omi-Imazu and others skip all stations on the line.