Completed four-track section between Denenchofu and Tamagawa. A Tokyu series 3000 is emerging from half-underground Denenchofu station. Subway through trains use inner two tracks.

By Hiroshi Naito

This must be the hottest news in this decade as to the Tokyo rail transit network.

The Eidan Subway's Nanboku (North-south) line inaugurated its final stage of line extension between Tameike-Sannou and Meguro, 5.2 km, September 26th, achieving linkage to the Tokyu Electric Railway's Meguro Line. At the same time, Tokyo Municipal Subway's (Toei Subway) Mita Line southern extension was completed to Shirokane-Takanwa on thr route of the Nanboku Line's extended segment, accomplishing another connection to the Tokyu Meguro Line with trackage rights over the Nanboku Line to Meguro under a class II operation license. With the linkage at Meguro, the three operators, Eidan Subway, Toei Subway and Tokyu Electric Railway, commenced through operation between Musashi-Kosugi on the Toyku Toyoko Line and Akabane-Iwabuchi, and between Musashi-Kosugi and Nishi-Takashimadaira, (respectively the northern ends of the Nanboku Line and the Mita Line).

As well as the Meguro Line reconstruction, the Toyoko Line's Denenchofu to Tamagawa and further to Musashi-Kosugi segment has been upgraded to a four-track line to accommodate through subway trains. Now, the Toyoko Line trains and the subway through trains are busily running on this section paralleling each other using respective dedicated double tracks.

The fleet for the new subway through operation via the Meguro Line consists of Tokyu series 3000, Eidan series 9000 and Toei series 6300, which are all 6-car 20 m class train sets. The Tokyu series 3000 was specially developed for the new service, as opposed to the former Mekama Line fleet of 4-car 18 m class series 7200 and 7400. The new Tamagawa Line operates with 3-car series 7700, being shrunk from the former 4-car operation. With the withdrawal of the series 7200 and 7400, most of which are expected to be sold to other private railways, 18 m class stock has completely disappeared from the Tokyu fleet.

A new feature applied to the subway Mita Line and Tokyu Meguro Line is platform doors that protect passengers on the platforms and thus allow safe one-man operation. These three lines now operate without a guard (or a conductor) on board (the Nanboku Line was originally fitted with platform screens and doors). Unlike platform screen doors common on fully automated driverless railways, the doors are short in height, about 1300 mm, which is advantageous to the passengers as to reduce feelings of claustrophobia. Another feature supporting safe one-man operation is train-borne platform CCTV display monitors installed in the cab to provide the train driver with clear vision over platforms. At each station stop, visually ensuring passengers safety on the platform by means of the display monitors, the train driver manually opens and closes the train doors by pressing the button mounted on the control. The platform doors simultaneously operate in response to the train driver command conveyed through a train to a wayside communication device (transponder).

As well as the track upgrading, the Meguro Line was resignaled with a cab-signaled ATC system. Also added to the trains in the through service fleet is an automatic station stop controller to ensure accurate stopping at each station to fulfill correspondence between train doors and platform doors. Train drivers manually operate a train, but do not have to worry about braking for station stops at each station, as the transponders mentioned above also function as part of the automatic station stop control system, with some ground devices installed in the approach to the station platform and in the track at the platform, acting as the stopping target makers.

The commencement of the new through service between Tokyu and the two subway lines has caused a great impact on the passenger traffic flow from the areas along the Toyoko Line, mostly in Kawasaki and Yokohama cities west of Tokyo, towards the center of downtown Tokyo, thus easing passenger congestion on the Toyoko Line traffic to Shibuya/Tokyo. The Toyoko Line's reconstruction work to upgrade the current double track to four-track still continues westwards up to Hiyoshi, about 2.8 km west of Musashi-Kosugi, expecting to extend the new subway through operation. With a new subway line under construction in Yokohama, to which the Toyoko Line is to be connected at Yokohama station in three years, the circumstances of the Tokyu Toyoko Line, one of the busiest commuter lines in the Tokyo and Yokohama area, are greatly evolving.

Completed four-track section between Tamagawa and Shin-Mariko. Toyoko Line trains run along the outer tracks. On the left is a Shibuya-bound 8000 series train, with an Eidan Hibiya Line through train on the right.	Tokyu series 3000 in subway through service at Denenchofu. This equipment was newly developed for this service.	Tightly arranged passenger protection doors at the edge of the platform, at Denenchofu. The doors operate in conjunction with the train doors in accordance with the train driver's manual command. Transpoder ground devices are seen on the tracks.
A sight of a a platform at Denenchofu. The overhead passenger information board is indicating that the departing train is destined for Akabane-Iwabuchi, the end of the Eidan Subway Nanboku Line.	Reconstruction is still ongoing along the Meguro Line. This section is to be transformed underground, at a point west of Nishi-Koyama.	Most parts of the Meguro Line run along densly popurated areas. The train, Toei series 6300 from the Mita Line, is approaching Musashi-Koyama station.
Musashi-Koyama station is currently in service with a temporary on-bridge structure. The train is Eidan series 9000 from the Nanboku Line. This is a typical sight around a private railway station in a densely populated area in Tokyo.	A sight of a Shirokane-Takanawa platform on the Nanboku Line. The line protects platform passengers with full-height screens and doors for one-man operation.	Ex-Tokyu 7200 series rolling stock transferred from the Tokyu Mekama Line, at Takashi on the Toyohashi Railway, a short private line located in the eastern part of Aichi prefecture.

All photos were taken by the author in October 2000.