Signaling in the Tōkyō Area
The Kanto region around metropolitan Tōkyō is home to a number of different railroads, and multiple lines for some of them. The page provides a brief summary of how signals are used on these lines, based on perusal of online sources including mapping applications and uploaded photos and video.
JR East Lines
JR East has the largest collection of railway lines in the region, and the ones that are of most interest for my modeling activities, so this is where I’ve spent most of my time. Like most JR lines, it is signaled for automatic block control of some form.
Most JR East lines in the region are double-track signaled for one-way operation per track. Crossings between tracks are rare, and used only where needed to access sidings or platforms in larger stations. Station platforms often support multiple trains per track, and one line may branch to two (or more) platforms, so station signals can be complex.
Chūō Line (Local and Rapid)
The Chūō line operates west from Tōkyō station, connecting to the Sōbu line (at Ochanomizu station). From Tōkyō to Mitaka (24.1 km) it is a pair of double-track lines (Rapid and Local), with the local line hosting the through-running Chūō-Sōbu service as well as local commuter trains into Tōkyō station from the west. The Rapid line hosts several classes of rapid (express) trains into Tōkyō station from the west. The line has a maximum speed of 130 kph (according to Wikipedia the rapid line is limited to 100 kph). Freight was excluded from the urban portion of the line due to a 1967 accident on the Chūō Rapid line at Shinjuku station, when an oil tanker train derailed and caught fire, although exactly when it was excluded isn’t clear (some other lines may have needed to have been built first).
The only connections to other lines in the urban area are at Ochanomizu (Sōbu line), Nakano (Tokyo Metro Tōzai Line) and Tachikawa (Ōme Line).
Signals consist of two, three and four-lamp heads, but interestingly near Lidabashi station there are a couple of signals with two subordinate lights (see below), and one five-lamp signal with a subordinate three-lamp head. These appear to be due to the presence of multiple double crossovers in the vicinity of the station, allowing trains to move between rapid and local lines. Although this is likely used for passenger trains, or it wouldn’t still exist, an additional possible reason for this track complexity is the nearby former location of the Lidamachi Freight Terminal (just west of Suidōbashi station), which handled unit trains of newsprint in boxcars up to 1999. Today a small set of sidings exists there, apparently for some kind of JR maintenance shop, but the rest of the site has been redeveloped.
The Chūō line was an early user of Centralized Train Control (CTC) and reportedly continues to use it as part of the more complex modern signaling and control system. It’s all done with computers now, but apparently CTC signaling (which I assume means code lines) are still used, at least in some places.
Immediately east of Ochanomizu station the Chūō Rapid and Chūō-Sōbu lines diverge, and to the west before Suidōbashi station three double-crossovers (just like the Kato unit) and one single crossover exist to allow trains from either line to move to any of the four tracks to the west. The Rapid line appears to be signaled for limited “wrong track” running here, and further west has block signals for bi-directional traffic. These are the only examples I’ve found of a JR crossover signaled for high speed (i.e., not shunting) use, although it is unclear what speed applies when crossing. Trains remaining on their line do not need to change tracks, but any local Chūō train to/from Tōkyō station, or any wrong-track Chūō Rapid train would need to cross here. Tunnels are used at both Suidōbashi and Ochanomizu to allow lines in the same direction to be on opposite sides of the same platform at Ochanomizu, despite the rapid line otherwise being south of the local line both east and west of there, presumably this is to facilitate transfers while avoiding having trains cross between tracks.
It appears that some tracks have at least block signals (three-head) for bi-directional running outside of stations. At the crossovers near Ochanomizu two heads are used in the normal direction of travel, with the main route using either a 4 or 5-lamp head (four seems most common), and the diverging route using an offset lower 4-lamp head. In the reverse direction a single 4-lamp head is used, with two subordinate lunar markers left and right to indicate the route. In at least one instance this appears to be a type A head (which can display Restricted Speed) rather than a type B (which cannot).
There are both north and south Shinkansen lines entering the city. All of these are cab signaled, without lineside signals outside of stations.
Sōbu Main Line
The Sōbu Main Line supports both urban local trains and longer-distance suburban commuter trains from Chiba prefecture to the east of Tōkyō. There are connections to two freight lines at Shin-Koiwa, but freight has been excluded from the line for many years. The line connects to the Chūō local line at Ochanomizu.
On the portion of the line though Koto Ward the tracks are divided into Rapid and Local sections, with the Rapid bypassing the last station before the river and going underground to Tōkyō station, while the other continues through Akihabara to connect to the Chūō line at Ochanomizu. Both portions of the line are signaled for unidirectional running using four-lamp “type B” signal heads (green on the bottom lamp), which could potentially display both Less Reduced Speed (yellow over green, both flashing) and Reduced Speed (yellow over green), although from other sources it is likely that only the latter aspect is used by JR East. Block signals are consecutively numbered using white numbers. The first digit may refer to the line, with 1 on Rapid and 2 on Local, although insufficient examples have been found to confirm that.
Crossovers exist just west of Kinshichō due to the stabling tracks there. These do not appear to have high signals protecting them (they may be used only under control of shunting signals), but photographs are uncommon due to the elevated line, so this is uncertain. Unlike the Chūō line, these are unidirectional, not double-crossovers.
Station Home signals appear to be 3-light heads, although one example of type 4B (green on bottom) exists at Kinshichō station.
Between Shin-Koiwa and Kameido station the line is paralleled by the separate single-track Etchūjima Cargo line, formerly a freight line and now used by JR East maintenance trains to access a welded rail assembly facility on the waterfront.
The Yamanote line is a dedicated double-track high-density passenger-train only line circling the city. It has no standard lineside signals, as all trains using it are cab-signaled. However there are dwarf signals in use at crossovers (and probably other switches) that show a green aspect when the switch is set for straight. These are simple one-light (or possibly one-over-one, it’s hard to be sure from photos) signals rather than standard dwarf signals. Since these switches are rarely thrown, no photos revealing the indication for a thrown switch have yet been found.
Yamanote Freight Line
The Yamanote Freight Line is a double-track line that parallels the Yamanote line on the west side of Tōkyō. It is used by both freight and passenger trains of multiple lines, and is signaled for unidirectional running per track.
It has lineside block signals, mostly single-head four-lamp (type uncertain), but also uses two-lamp and three-lamp signals in places. Signal masts are numbered. There do not appear to be high signals at crossovers or sidings, although some may have these; none were observed in those switches that had been photographed, but some shadows appeared near some on mapping-application photography that may have indicated their presence. Some structures were observed at crossovers that may be dwarf signals of the same type used on the adjacent Yamanote line, but none were photographed with enough clarity to be certain.
The special Imperial Platform siding at Harajuku has both crossovers and siding switches to allow trains access from either direction. One of the crossovers is located adjacent to a Yamanote line platform and well photographed. In addition to green dwarf signals (as seen on other lines) there is a tall signal controlling access to the crossover from the far (northbound) track, and through it into the siding switch to the imperial platform. The platform itself has a tall signal controlling access to the main and crossover track. Both southbound signals (platform siding and main) are single-head. the northbound signal, which provides access to the crossover and through it into the siding, has a three-lamp main head and a subordinate head that appears to be blanked out with a white vertical rectangle. There appear to be similar signals at the other end, but these have not been photographed.