Japanese railway signals

Japanese railway signals, according to the ministerial decree defining technical standards of railways (鉄道に関する技術上の基準を定める省令, Tetsudō ni kansuru gijutsu jō no kijun wo sadameru shōrei^?), are defined as indicating operational conditions for railway staff driving trains.

Japanese signalling was initially based on British railway signalling, and Japanese railway signalling continues to be based on the UK route signalling system. However, as signalling has advanced to meet the requirements of the system (and due to the influence of the United States), the Japanese signalling system is a mixture of route signalling and American speed signalling.

A main signal (主信号機 shu shingōki) protects a section of track (known as a block). A protected section is in advance of (内方 naihō) the main signal. The section behind the main signal is called 外方 (gaihō). However, under the non-automatic block system a starting signal has no protected section; it only indicates that all turnouts on the route to the mainline are switched correctly. Under the non-automatic block system trains cannot leave a station without an appropriate token, even if the starting signal is clear.

Home, starting and block signals on Japanese railways are usually lights composed of three colors (green, yellow and red). The composition of the lighted colors shows the speed limit of the protected section.

G is a green light, Y is yellow and R red:

If a signal lamp has burnt out, the signal will display its most restrictive aspect. If no lights are showing a signal is to be treated as stop, and may not be passed until a substitute signal is in place. Since the lights are all black, this situation is referred to as a "crow" (カラス, karasu).

Many semaphore signals were formerly used, which were controlled by a hand lever. Few semaphores remain in Japan. On 28 July 2005, the last semaphore signals on the JR lines at Rikuchū-Yagi Station were replaced by colored lights. A few stations are still equipped with semaphore signals on the Tsugaru Railway Line, the Fukushima Rinkai Railway Main Line and the Niigata-Higashi industrial line.

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Wikipedia