Tokyo Metro plans to extend the Namboku Line and Yukaracho Line

[TokyoImperialPalace]

https://asia.nikkei.com/Business/Transportation/Tokyo-plans-to-extend-subway-network-eyeing-return-of-tourists

 

The Namboku Line will be extended towards Shinagawa Station in anticipation of increased footfall after the Chuo Shinkansen opens. My view is that extending the Namboku  Line from its current terminus at Meguro, for which the line heads south-westand away from Shinagawa, will result in an illogical near-180 degree turn north-east towards Shinagawa, so considering that the Namboku Line and Mita Line both share tracks between Shirokane-takanawa and Meguro, I suspect that the extension will be from the existing terminating tracks at Shirokane-nakanawa (some trains terminate while most continue to Meguro) continuing due south-west towards Shinagawa (which is a more sensible routing), and that Mita and Namboku will be segregated with Tokyu Meguro Line trains only operating through services onto the Mita Line. I still wonder what through-trains could the Namboku Line connect onto after Shinagawa? 

 

The Yukaracho Line will also be extended towards the Skytree.

Edited December 21, 2021 by TokyoImperialPalace
east and west the wrong way round

[Socimi]

I find this rather interesting news, as 've regarded the Tokyo Subway (as a whole, both the Tokyo Metro and Toei Lines) has having reached "maturity" with the opening of the last section of the Fukutoshin Line (the connection to the Tokyu Toyoko Line) in 2013. In other words, in my opinion the Tokyo Subway has built all the extension and lines that were absolutely necessary to build; there are little to no areas within the 23 special wards of Tokyo that aren't well served by the Subway (and absolutely no wards poorly served by railways and other pubblic transport means), so these two extensions have come to me as a bit of a surprise.

I'll be discussing both.

 

Yurakucho Line branch to Sumiyoshi

 

Map elaborated from Urbanrail.net

 

This branch was actually tought out a long time ago, under the planning name of "Line No.14" or the project name of "Tokyo Direct Railway" (東京直結鉄道) as a separated tangential line connecting Sumiyoshi to Toyocho, for wich platforms (allwoing for cross-platform interchange) and tracks were already predisposed at both terminus stations.

 

Currently, the two platforms at Toyosu sit unused (tracks having never been laid) while the two at Sumiyoshi are used as storage tracks for out-of-service trains.

Eventually the concept resurfaced recently, being changed into a branch of Line No.8 (the Yurakucho Line). This extension was also related to the proposals to extend the Hanzomon Line towards Matsudo or Noda.

 

Here's a 2016 brochure detailing the extension plans for Line No.8

 

https://www.city.yashio.lg.jp/kurashi/kotsu/tetsudo/chikatetsu.files/201610.pdf

 

It also seem to hint that the "Tokyo Direct Railway" project could be carried out not as a subway line but rather as a "Rapid Railway", (therefore roughly in the same style as the Saitama or Toyo Rapid Railways).

 

While this project is surely interesting, i have a few doubts over it's practical "carrying-out". The article isn't entirely clear about it, but as it's stated that the new extension will be beneficial towards "those travelling to central Tokyo", i suspect that this branch will not be operated as a "separate one" (such as with the Marunouchi Line Honancho Branch) but with trough-services to the "mainline". This will mean necessarily to split southbound services in two, with roughly half of the trains going to Shin-Kiba and the other to Sumiyoshi. However this doesn't appear to be a problem in regards to capacity.

 

The other thing i'm more dubious about is the "improved access to the Tokyo Skytree" part: Will it mean that the Yurakucho Line will also be extended to Oshiage (an expensive option that means paralleling the existing Hanzomon Line)? Trough-Services with the Hanzomon Line to Oshiage (impractical option, too much traffic)? Just the cross-platform interchange at Sumiyoshi? (seems the most plausible option, but will mean having Yurakucho Line trains dumping all their passenger on already nearly-full Hanzomon Line trains).

 

Anyway, as the current plans stand, the new "Sumiyoshi Branch" of the Yurakucho Line will have surely an interchange station with the Tozai Line at Toyocho, and i suspect also an interchange with the JR Keiyo Line at Shiomi. There's plenty of space for intermediate stops as well, atleast one between Toyosu and Shiomi, one between Shiomi and Toyocho, and a couple between Toyocho and Sumiyoshi.

 

Another article detailing the Yurakucho Line extension:

https://urbanlife.tokyo/post/39167/

 

 

 

 

 

Next post will be about the Namboku Line extension to Shinagawa

Edited December 19, 2021 by Socimi

[railsquid]

6 hours ago, Socimi said:

IThe other thing i'm more dubious about is the "improved access to the Tokyo Skytree" part: Will it mean that the Yurakucho Line will also be extended to Oshiage (an expensive option that means paralleling the existing Hanzomon Line)? Trough-Services with the Hanzomon Line to Oshiage (impractical option, too much traffic)? Just the cross-platform interchange at Sumiyoshi? (seems the most plausible option, but will mean having Yurakucho Line trains dumping all their passenger on already nearly-full Hanzomon Line trains).

 

I believe the intent is to implement through-running onto the existing Hanzomon Line, as some capacity is available on that section (source e.g. here: "一方、住吉から押上方面のダイヤは多少の余裕があるため、豊洲―押上間の半蔵門線直通は実現するかもしれない。"

 

6 hours ago, Socimi said:

I find this rather interesting news, as 've regarded the Tokyo Subway (as a whole, both the Tokyo Metro and Toei Lines) has having reached "maturity" with the opening of the last section of the Fukutoshin Line (the connection to the Tokyu Toyoko Line) in 2013. In other words, in my opinion the Tokyo Subway has built all the extension and lines that were absolutely necessary to build; there are little to no areas within the 23 special wards of Tokyo that aren't well served by the Subway (and absolutely no wards poorly served by railways and other pubblic transport means), so these two extensions have come to me as a bit of a surprise.

 

The Tokyo public transport network's dirty secret (and one they never show on all those documentaries on "wow look how clean and efficient the trains are!1!! And crowded LOL!!!!" is that east and west of the Yamanote Line, there's not much in the way of useful north-south links, so more often than not you're forced head towards the centre, trundle around the Yamanote Line, and head back out. The Yurakucho Line plan will provide such a link on the eastern side, relatively cheaply by filling in a missing section.

 

On the western side there are vague plans to build something under the Kannana and/or Kanpachi ring roads, but nothing more (much to my personal inconvenience).

[railsquid]

1 hour ago, railsquid said:

On the western side there are vague plans to build something under the Kannana and/or Kanpachi ring roads, but nothing more (much to my personal inconvenience).

 

Actually the plans (which are still very much stuck at the "would like to have" stage) are for the "8-Liner" (Japanese wiki; "official" site) under Kanpachi in the west and "Metro Seven" under Kannana (Japanese wiki; Edogawa-ku project page) in the east, connecting at Akabane.

[Socimi]

On 12/20/2021 at 12:50 AM, railsquid said:

The Tokyo public transport network's dirty secret (and one they never show on all those documentaries on "wow look how clean and efficient the trains are!1!! And crowded LOL!!!!" is that east and west of the Yamanote Line, there's not much in the way of useful north-south links, so more often than not you're forced head towards the centre, trundle around the Yamanote Line, and head back out. The Yurakucho Line plan will provide such a link on the eastern side, relatively cheaply by filling in a missing section.

True, the eastern side of the Yamanote isn't really provided with lots of north-south links, but i've always tought that the Toei Oedo Line did, atleast partially, solve the issue of having to go to central Tokyo, use the Yamanote Line and head back out, especially in Koto and Sumida wards.

 

Having said that, a connection between Toyosu and Sumiyoshi via Toyocho (or something equivalent nearby) has always made a good deal of sense, however i'd always expected it to be carried out as an intermediate-capacity AGT system - it's an almost natural extension for the already very tourist-oriented Yurikamome. Another side option may have been the implementation of Tsurumi Line-style services (or even a conversion to Light Rail, or doubling as an AGT) on the Etchujima Freight Line, and maybe even beyond towards Toyosu, re-using old Tokyo Port Authority Railways right-of-way.

 

However, the option of Line No.14 as a full-size subway line is still appropriate, as is it's eventual integration into the Yurakucho Line. The only criticism i have would be the trough-services with the Hanzomon Line. If it'll come out as something similar to the Mita - Namboku Line joint section, i don't think there won't be any particular problems.

 

Speaking of the Namboku Line, here's part 2:

 

Namboku Line to Shinagawa

 

 

 

Unlike the Yurakucho Line extension to Sumiyoshi (there had been many plans in the area for a long time), this one caught me entirely by surprise.

 

This time, there are two possibilities:

The first as stated by @TokyoImperialPalace would be to extend the Namboku Line from Meguro, have it turn 180°, parallel the Yamanote Line to Gotanda (ideally with an interchange to the Asakusa Line) and then head eastwards to Shinagawa.

The other option, wich i would be more supportive of, would be to extend the Namboku Line directly southwards from Azabu-Juban, have an interchange station at Sengakuji (again, on the Asakusa Line, but this time with both Nishi-Magone-bound trains and Keikyu-trough-services) and then continue paralleling the Keikyu Main Line to Shinagawa. The Namboku-Mita Line currently shared section between Shirokane-Takanawa and Meguro would be handed over to the Toei Subway, becoming fully part of the Mita Line, altough Namboku Line trough-services with the Meguro Line could be also retained by preserving the current connecting tracks north of Shirokane-Takanawa.

 

Taking the Namboku Line to Shinagawa isn't however a partiuclar "out-of-the-blue" idea - Shinagawa is currently the largest JR station in Tokyo without an interchange to the subway network (neither Tokyo Metro nor Toei - while it's true Asakusa Line trains get to Shinagawa, they do only as trough-services with Keikyu), and the Namboku Line would provide a good overall relief to the Yamanote Line, particularily for those heading west of the Imperial Palace.

 

In any case, as  @TokyoImperialPalace  pointed out, there won't be any trough-services possibilities for the Namboku Line at Shinagawa. The only thing would be the Tokyu Oimachi Line at Oimachi, some 2600m (paralleling the Tokaido and Keihin-Tohoku Lines) to the south, and even here, it would require the demolition and replacment of the current elevated Tokyu station.

 

 

[railsquid]

2 hours ago, Socimi said:

 

Namboku Line to Shinagawa

 

 

 

Unlike the Yurakucho Line extension to Sumiyoshi (there had been many plans in the area for a long time), this one caught me entirely by surprise.

 

This time, there are two possibilities:

The first as stated by @TokyoImperialPalace would be to extend the Namboku Line from Meguro, have it turn 180°, parallel the Yamanote Line to Gotanda (ideally with an interchange to the Asakusa Line) and then head eastwards to Shinagawa.

The other option, wich i would be more supportive of, would be to extend the Namboku Line directly southwards from Azabu-Juban, have an interchange station at Sengakuji (again, on the Asakusa Line, but this time with both Nishi-Magone-bound trains and Keikyu-trough-services) and then continue paralleling the Keikyu Main Line to Shinagawa. The Namboku-Mita Line currently shared section between Shirokane-Takanawa and Meguro would be handed over to the Toei Subway, becoming fully part of the Mita Line, altough Namboku Line trough-services with the Meguro Line could be also retained by preserving the current connecting tracks north of Shirokane-Takanawa.

 

Taking the Namboku Line to Shinagawa isn't however a partiuclar "out-of-the-blue" idea - Shinagawa is currently the largest JR station in Tokyo without an interchange to the subway network (neither Tokyo Metro nor Toei - while it's true Asakusa Line trains get to Shinagawa, they do only as trough-services with Keikyu), and the Namboku Line would provide a good overall relief to the Yamanote Line, particularily for those heading west of the Imperial Palace.

 

 

FWIW this plan has been around since 2015 (see e.g. here). The proposal is a one-station ca. 2.5km extension from Shirokane-Takanawa to Shinagawa, starting from the existing turnback sidings west of Shirokane-Takanawa (see current track plan e.g. here), with no plans to extend it further.

 

I haven't investigated further, but I assume it would just be a case of basically extending whatever services currently terminate at Shirokane-Takanawa one station to Shinagawa; the first link cited says it will be a mixture of Nanboku and Mita line trains.

 

The main motivation for this is the Chūō Shinkansen, which will terminate at Shinagawa. I suspect the redevelopment around the new Takanawa Gateway station will create demand too.

[TokyoImperialPalace]

I also presumed that they would extend from the existing terminating infrastructure at Shirokane-Takanawa, because looking at a geographic map the north-easterly route from Meguro to Shinagawa is illogical for a train service that has just arrived from a north-easterly direction (and similarly it would be cumbersome to take the Oimachi Line (east-west line) all the way to its eastern terminus just to go [north-]westerly into the central areas of Tokyo, though I doubt it would be any worse that the Oedo Line, nevertheless I agree that the Oimachi Line is the only easy possibility for through-services). @railsquidBut surely they would have mentioned Mita line trains in the announcement as well if they were going to allow through-service with that line? This proposal is a Tokyo Metro only project as well. So it feels as if they are going to try and segregate the two lines in anticipation of heavier passenger flows in the future (such as from the Sosetsu through services on the Toyku Toyoko Line) and the sheer complexity of timetabling such a complex Tokyu Toyoko Line with so many through services.

 

In terms of the through-services onwards at Shinagawa, one possibility might be the Tokyu Ikegami Line from Gotanda (presumably the line can merge south of Gotanda providing enough southwards distance for the Namboku Line from Shinagawa), but trains on the line are only three carriages long and I not sure how feasible it is to extend those platforms easily.

 

On a side note about future development of the underground system, I think there are several corridors that could be built even in central Tokyo. The Seibu Shinjuku Line is in desperate need of a through service for example (as are some in north-east Tokyo as well) and suburban commuters are the king. I also agree there needs to be another Yamanote Line built to the west of the current one.

Edited December 21, 2021 by TokyoImperialPalace

[railsquid]

8 hours ago, TokyoImperialPalace said:

. @railsquidBut surely they would have mentioned Mita line trains in the announcement as well if they were going to allow through-service with that line? This proposal is a Tokyo Metro only project as well. So it feels as if they are going to try and segregate the two lines in anticipation of heavier passenger flows in the future (such as from the Sosetsu through services on the Toyku Toyoko Line) and the sheer complexity of timetabling such a complex Tokyu Toyoko Line with so many through services.

 

The article you linked to is an English-language article, I find quite often they are not a particularly reliable source and omit a lot of detail. The article I linked says:

 

Quote

新線の運行頻度は全時間帯で毎時12本と想定しています。全ての列車が東京メトロ南北線（麻布十番方面）または都営地下鉄三田線（三田方面）と直通運転します。

 

i.e. 12 trains an hour are planned on the new line, all trains will run onto the Nanboku and Mita lines. Which I presume (haven't checked) will be pretty much an extension by one station of all the trains which currently terminate at Shirokane-Takanawa.

 

The physical infrastructure will be built as part of the Nanboku line, but that's no hindrance to through-running.

 

8 hours ago, TokyoImperialPalace said:

In terms of the through-services onwards at Shinagawa, one possibility might be the Tokyu Ikegami Line from Gotanda (presumably the line can merge south of Gotanda providing enough southwards distance for the Namboku Line from Shinagawa), but trains on the line are only three carriages long and I not sure how feasible it is to extend those platforms easily.

 

But no-one's talking about extending it, and there's no imperative to do so even though you can draw lines on a map linking two lines, it doesn't mean it will make sense.

 

[TokyoImperialPalace]

It seems that it was Nikkei that was the first to break the story according to this forum post and the Japanese version of the article doesn't say anything about through-services from the Toei Mita Line. Asahi Shinbun also seems to reiterate the same story omitting anything about the Mita Line. A transport blog also shares a map and article indicating that the line will be a one-stop extension of the Namboku Line.

 

This blog post might be an interesting read in terms of why the two lines should be segregated; he points out that people from Shinagawa are unlikely to use the Mita Line since it mostly parallels a corridor better served by the JR routes. The following couple of links are also articles on the topic that might be on interest to someone here:

 

 

https://www.yomiuri.co.jp/economy/20210716-OYT1T50008/

https://tetsudo-ch.com/11648342.html/3

 

[TokyoImperialPalace]

The story is doing the rounds on the news again recently as Tokyo Metro has applied for the license on Friday to construct the project by the 2030s.

 

https://www.jiji.com/jc/article?k=000000883.000020053&g=prt

 

Namboku Line Extension

Between Shinagawa and Shirokane Takanawa
2.5km
131 billion yen
Stops at Shinagawa and Shirokane Takanawa
Opening in the middle of the 2030s

 

Yurakucho Line Extension

Between Toyosu and Sumiyoshi station
4.8km
269 billion yen
Stops at Toyosu, Toyocho, Sumiyoshi
Opening in the middle of the 2030s

Edited January 30, 2022 by TokyoImperialPalace