Question about JR East Bi-level Green Car Trains

[YamanoteRider95]

Hi, I'm new to the forums, so I'm not sure whether this is the correct place to post.

 

My question is: Why trains with the bi-level green cars usually split into 10+5 or 11+4 car formations, for example the yokosuka line and the tokaido main line. Do they split off at a certain station and then go different directions?

[bikkuri bahn]

I don't know much about the Yokosuka Line, but on the Tokaido Line, full 15 car formations are overkill given passenger demand west of Atami, so for up trains, the additional cars are added at Atami, Kozu, or Hitatsuka to add capacity.  No branching is involved.

[Sacto1985]

I believe the full 15-car E231-1000 trainsets normally operate on the Tokaidō Main Line from Tokyo to Atami Stations (Atami is the west end of JR East operations on the Tokaidō Main Line), especially now that the city of Atami itself has transformed from a resort to a bedroom community for the Tokyo area. There are a small number of E231-1000's that travel as far west as Numazu, especially now that the joint JR East/Odakyu service from Shinjuku Station to Numazu via the Gotenba line has ended.

[YamanoteRider95]

bikkuri bahn, when u say up, you mean towards tokyo?

 

Sacto1985, are the trains that go to Numazu in 15 car formations?

 

So in short, 15 cars from atami to tokyo, but then the 4 car trains usually only serve west of atami?

[katoftw]

15 cars between atami and tokyo, 10 cars west of atami.

[bikkuri bahn]

bikkuri bahn, when u say up, you mean towards tokyo?

 

Yes, up ("nobori") is in the direction of the main terminal/capital city, going away is down ("kudari").  Railways in Great Britain use the same system in relation to London- likely the Japanese practice partly comes from that, though similar practices predates the introduction of railways in Japan, such as place names given in relation to their distance from the old imperial capital of Kyoto- Bizen (closer to Kyoto) and Bingo (farther from Kyoto).

[bikkuri bahn]

Regarding the Yokusuka Line. checking wikipedia, it turns out stations south of Zushi don't have long enough platforms to handle 15 car length trains, so adding/cutting off of consists occurs at Zushi.  I recall as a child wondering why some down Yokosuka Line trains were diagrammed to end at Zushi (to me a minor station), perhaps this is the reason.

[YamanoteRider95]

uh, then what happens to the 4/5 car formations?

[kvp]

Dependig on the setup of the line, they can be:

-laid down until their other half returns

-run along another branch

-run with a higher frequency (if the sets are divided roughly equally)

-connected up to the other half of a set that goes the other way (this would mean less extension set are required than base sets)

[E6系]

Hello,

 

I will check my books over the weekend.  Perhaps it is mentioned in the consist tables.