Marunouchi Line

Marunouchi Line
Marunouchi Line 2000 series trains at Yotsuya Station
Overview
Other nameLine 4 / M (Main line) / Mb (Branch line)
Native name丸ノ内線
OwnerTokyo Metro
Line number4
LocaleTokyo
Termini
Stations28 (including branch line)
Color on map     Scarlet
Service
TypeRapid transit
SystemTokyo subway
Depot(s)Koishikawa, Nakano
Rolling stock2000 series
Daily ridership1,159,898 (2017)
History
OpenedJanuary 20, 1954 (1954-01-20)
Last extension1962
Technical
Line length27.4 km (17.0 mi) (Main line)
3.2 km (2.0 mi) (Branch Line)
Number of tracks2
Track gauge1,435 mm (4 ft 8+12 in) standard gauge
Minimum radius140 m (460 ft) (Main line: Near Ginza)
125 m (410 ft) (Branch Line)
ElectrificationThird rail600 V DC
Operating speed75 km/h (47 mph) (Main line)
65 km/h (40 mph) (Branch line)
Signalling
Maximum incline3.5%
Route map

0.0
M-01 Ogikubo
JCJB
1.5
M-02 Minami-Asagaya
2.7
M-03 Shin-Kōenji
3.6
M-04 Higashi-Kōenji
4.6
M-05 Shin-Nakano
0.0
Mb-03 Hōnanchō
Nakano Depot
1.3
Mb-04 Nakano-fujimichō
1.9
Mb-05 Nakano-shimbashi
5.7
3.2
M-06 Nakano-sakaue
6.8
M-07 Nishi-Shinjuku
JBJY
JCJSJA
7.6
M-08 Shinjuku
7.9
M-09 Shinjuku-sanchōme
FS
8.6
M-10 Shinjuku-gyoenmae
9.5
M-11 Yotsuya-sanchōme
N
10.5
M-12 Yotsuya
NYZ
11.8
M-13 Akasaka-mitsuke
N
12.7
M-14 Kokkai-gijidōmae
13.4
M-15 Kasumigaseki
C
Tōkaidō Line
Shinkansen
G
14.4
M-16 Ginza
Y
15.5
M-17 Tokyo
T
16.1
M-18 Ōtemachi
I
17.0
M-19 Awajichō
S
C
JC/JB
17.8
M-20 Ochanomizu
18.6
M-21 Hongō-Sanchōme
Kasuga: E/I
Ōedo,
Mita lines
19.4
M-22 Kōrakuen
Koishikawa Depot
21.2
M-23 Myōgadani
22.4
M-24 Shin-Ōtsuka
F
JA/JS/Y
24.2
M-25 Ikebukuro

The Marunouchi Line (丸ノ内線, Marunouchi-sen) is a subway line in Tokyo, Japan, operated by Tokyo Metro. The line runs in a U-shape between Ogikubo Station in Suginami and Ikebukuro Station in Toshima, with a branch line between Nakano-Sakaue Station and Hōnanchō Station. The official name is Line 4 Marunouchi Line (4号線丸ノ内線, Yon-gō-sen Marunouchi-sen).

The Marunouchi Line was the fourth subway line constructed in Japan, following the Osaka Municipal Subway Yotsubashi Line.

Its design is similar to that of the Ginza Line, the oldest subway line in Tokyo. Both lines are standard gauge and use third rail power, unlike subsequent Tokyo subway lines which use overhead wires and are mostly narrow gauge to accommodate through services with other railway lines.

The line was named after the Marunouchi business district in Chiyoda, Tokyo, under which it passes. On maps, diagrams and signboards, the line is shown using the color red, and its stations are given numbers using the letters "M" for the main line and "Mb" for the branch line.