Dosan Line

Dosan Line
Nanpū2000 series DMU at Sanuki-Saida Station
Overview
Status	In operation
Owner	JR Shikoku
Locale	Kagawa,Tokushima,KōchiPrefectures
Termini	Tadotsu Kubokawa
Stations	61
Service
Type	Heavy rail
History
Opened	23 May 1889(1889-05-23)
Completed	12 November 1951(1951-11-12)
Technical
Line length	198.7 km (123.5 mi)
Number of tracks	1
Character	Rural
Track gauge	1,067 mm(3 ft 6 in)
Minimum radius	200 m (660 ft)
Electrification	1,500 V DC overhead catenary (Tadotsu - Kotohira)
Operating speed	120 km/h (75 mph)
Route map Dosan Line

Dosan line train pulling intoZentsūji Station,2021

Dosan Line(Thổ tán tuyến,Dosan-sen)is a railway line inShikoku,Japan, operated by theShikoku Railway Company(JR Shikoku). It connectsTadotsu StationinTadotsu,Kagawa,andKubokawa StationinShimanto,Kōchi.The line links the city ofKōchiwith northern Shikoku and the island ofHonshūvia theSeto-Ōhashi Line.The first section of the line between Tadotsu andKotohiraopened in 1889, Kochi was connected to the northern section of the line in 1935, and the western extension of the line was completed in 1951. The name of the line comes from "Tosa"(ThổTá)and "Sanuki"(TánKỳ),the oldprovincialnames of present-dayKōchi PrefectureandKagawa Prefecture,respectively.

History

The first section opened, between Tadotsu and Kotohira, was constructed by the Sanuki Railway Co. in 1889. The company was nationalised in 1906.

The Kotohira - Awa Ikeda section was opened in 1914 and connected to the Tokushima line.

The Susaki - Kochi - Kusaka section opened in 1924, and was extended north in sections 1925-35, where it connected to the northern section at Minawa, the line from Awa Ikeda having been extended there in 1931.

The Susaki - Tosakume section opened 1939, with extensions to Kageno opening 1947 and to Kubakawa in 1951.

CTC signalling was commissioned between Tadotsu - Kochi in 1967, and the 4,180m Oboke tunnel and associated realignment opened the following year.

The 2,583m Osugi tunnel and associated realignment opened in 1973. CTC signalling was extended to Kubokawa in 1986, and the Tadotsu - Kotohira section was electrified the following year prior to the privatization of JNR. However, the maximum speed of electric trains in this section is limited to 85 km/h due to the overhead catenary being a direct-line suspension system (similar to trams) as a result of a lack of funds during construction at the end of the JNR era. On the other hand, the diesel-powered limited expressJR Shikoku 2000 seriesis able to run at 120 km/h, while regular diesel trains can run at 95 km/h. As such, the diesel trains operating in this section is able to run faster than electric trains. To reduce the burden on the overhead catenary, electric trains operate with only one raised pantograph in addition to the speed limit. The overhead catenary of platform 1 at Kotohira Station is the only section along the entire line to have a Simple Catenary System typically used on electrified JR lines.

After the privatization of JNR, there was a plan to electrify the Dosan Line to Awa-Ikeda along with theYosan Line,but the former did not come to fruition. The reasoning being the low return on investments due to the sharp decline in traffic south of Kotohira, and the many narrow tunnels making the installation of overhead wires difficult. As such, it was decided that a more rational plan was to introduce new high-speed diesel trains for limited express operations as opposed to electrification. In a 2006 submission to the subcommittees of the Ministry of Land, Infrastructure, Transport and Tourism, JR Shikoku cited the electrification of the Kotohira - Kochi section as one of the desired long-term investments.

Freight trains ceased operating between Tadotsu - Kochi in 2005.

Former connecting lines

• Kotohira station - The Kotohira Express Railway Co. operated a 16 km line to Sakaide on theYosan Line1930-44, with the line formally closing in 1954.
• Tadotsu station - The Kotohira Sangu Railway Co. operated a 27 km line to Sakaide 1922/28 - 1963, with a 7 km branch to Kotohira operated 1923-63.

Services

RapidSunport7000 series EMU

Nanpū(Nam phong)limited express trains make 14 round-trips per day betweenOkayamaandKōchi,Nakamura,orSukumo.Shimanto(しまんと)limited expresses make five round trips per day betweenTakamatsuand Kōchi, Nakamura, or Sukumo. TheSunport(サンポート)rapid service trains linkKotohiraand Takamatsu once an hour.

The line is generally divided into three parts for local services atAwa-Ikedaand Kōchi. For the segment betweenTadotsuand Kotohira, there are through services to/from Okayama and Takamatsu. TheTosa Kuroshio RailwayGomen-Nahari Linehas through service to/from Kōchi.

Stations

• Local trains generally stop at all stations, but sometimes skip stations marked "▽".
• Sunport(Takamatsu - Tadotsu - Kotohira) rapid trains stop at all stations on the Dosan Line.
• See the articles on theNanpūandShimantolimited express services for details of station stops.
• Trains are able to pass each other at stations marked "◇" and "◆" (switchback); trains cannot pass at stations marked "｜".

Station No.	Station name	Japanese	Distance (km)		Transfers		Location
			Between stations	Total
Through service to/from theYosan Lineand theSeto-Ōhashi Line
D12	Tadotsu	Đa độ tân	-	0.0	Yosan Line(Y12) (some trains through toUtazu)	◇	Tadotsu,Nakatado District	Kagawa
D13	Konzōji	Kim tàng tự	3.7	3.7		◇	Zentsūji
D14	Zentsūji	Thiện thông tự	2.3	6.0		◇
D15	Kotohira	Cầm bình	5.3	11.3	Kotoden Kotohira Line(Kotoden-Kotohira) Electrified section ends at this station	◇	Kotohira,Nakatado District
D16	Shioiri	Diêm nhập	6.4	17.7		◇	Mannō,Nakatado District
D17	Kurokawa	Hắc xuyên	3.9	21.6		｜
D18	Sanuki-Saida	Tán kỳ tài điền	2.3	23.9		◇	Mitoyo
D19	Tsubojiri▽	Bình khào	8.2	32.1		◆	Miyoshi	Tokushima
D20	Hashikura	Trứ tàng	3.3	35.4		◇
D21	Tsukuda	Điền	3.4	38.8	Tokushima Line(B24)	◇
D22	Awa-Ikeda	A ba trì điền	5.1	43.9	Tokushima Line (B25)	◇
D23	Minawa	Tam 縄	3.9	47.8		◇
D24	Iyaguchi	Tổ cốc khẩu	4.5	52.3		｜
D25	Awa-Kawaguchi	A ba xuyên khẩu	2.8	55.1		◇
D26	Koboke	Tiểu bộ nguy	4.7	59.8		◇
D27	Ōboke	Đại bộ nguy	5.7	65.5		◇
D28	Tosa-Iwahara	Thổ tá nham nguyên	7.2	72.7		◇	Ōtoyo,Nagaoka District	Kōchi
D29	Toyonaga	Phong vĩnh	4.0	76.7		◇
D30	Ōtaguchi	Đại điền khẩu	3.7	80.4		◇
D31	Tosa-Ananai	Thổ tá huyệt nội	2.8	83.2		｜
D32	Ōsugi	Đại sam	4.0	87.2		◇
D33	Tosa-Kitagawa	Thổ tá bắc xuyên	6.1	93.3		◇
D34	Kakumodani	Giác mậu cốc	2.2	95.5		｜
D35	Shigetō	Phồn đằng	2.1	97.6		◇	Kami
D36	Shingai▽	Tân cải	6.3	103.9		◆
D37	Tosa-Yamada	Thổ tá sơn điền	7.4	111.3		◇
D38	Yamada-Nishimachi▽	Sơn điền tây đinh	0.8	112.1		｜
D39	Tosa-Nagaoka▽	Thổ tá trường cương	2.0	114.1		｜	Nankoku
D40	Gomen	Hậu miễn	2.1	116.2	Tosa Kuroshio Railway Gomen-Nahari Line(some trains through toKōchi;GN40)	◇
D41	Tosa-Ōtsu	Thổ tá đại tân	3.2	119.4		◇	Kōchi
D42	Nunoshida▽	Bố sư điền	2.0	121.4		｜
D43	Tosa-Ikku	Thổ tá nhất cung	1.3	122.7		◇
D44	Azōno▽	Kế dã	1.8	124.5		◇
D45 K00	Kōchi	Cao tri	2.1	126.6	Tosaden Sanbashi Line(Kōchi-Ekimae)	◇
K01	Iriake	Nhập minh	1.3	127.9		｜
K02	Engyōjiguchi	Viên hành tự khẩu	0.8	128.7		｜
K03	Asahi	Húc	1.5	130.2	Tosaden Ino Line(Asahi-Ekimae-Dōri)	◇
K04	Kōchi-Shōgyō-Mae	Cao tri thương nghiệp tiền	1.1	131.3	Tosaden Ino Line (Kagamigawabashi)	｜
K05	Asakura	Triều thương	1.4	132.7	Tosaden Ino Line (Asakura-Ekimae)	◇
K06	Edagawa	Chi xuyên	3.5	136.2	Tosaden Ino Line (Edagawa)	｜	Ino,Agawa District
K07	Ino	Y dã	1.8	138.0	Tosaden Ino Line (Ino-Ekimae)	◇
K08	Hakawa	Ba xuyên	1.5	139.5		｜
K08-1	Omura-Jinja-Mae	Tiểu thôn thần xã tiền	2.1	141.6		｜	Hidaka,Takaoka District
K09	Kusaka	Nhật hạ	2.1	143.7		◇
K10	Okabana	Cương hoa	2.0	145.7		｜
K11	Tosa-Kamo	Thổ tá gia mậu	2.9	148.6		◇	Sakawa,Takaoka District
K12	Nishi-Sakawa	Tây tá xuyên	3.8	152.4		◇
K13	Sakawa	Tá xuyên	1.8	154.2		◇
K14	Erinono	Khâm dã 々	1.8	156.0		｜
K15	Togano	Đấu hạ dã	2.0	158.0		◇
K16	Asō	Ngô tang	5.4	163.4		◇	Susaki
K17	Ōnogō	Đa ノ hương	2.7	166.1		◇
K18	Ōma	Đại gian	0.9	167.0		｜
K19	Susaki	Tu kỳ	1.7	168.7		◇
K20	Tosa-Shinjō	Thổ tá tân trang	1.9	170.6		｜
K21	Awa	An hòa	3.0	173.6		｜
K22	Tosa-Kure	Thổ tá cửu lễ	6.1	179.7		◇	Nakatosa,Takaoka District
K23	Kageno	Ảnh dã	10.7	190.4		◇	Shimanto,Takaoka District
K24	Rokutanji	Lục phản địa	1.8	192.2		｜
K25	Niida	Nhân tỉnh điền	2.0	194.2		｜
K26	Kubokawa	Oa xuyên	4.5	198.7	Tosa Kuroshio Railway Nakamura Line(TK26) (all JR ShikokuYodo Linetrains run through to Kubokawa)	◇

See also

• List of railway lines in Japan

References

This article incorporates material from the corresponding article in the Japanese Wikipedia

External links

• JR Shikoku official website(in Japanese)