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Kaichū type submarine

{{Short description|Class of WW2-era Japanese submarines}}

{{Infobox ship begin}}

{{Infobox ship class overview

|Name=Kaichū type submarines

|Builders=*Kure Naval Arsenal

|Operators=20px Imperial Japanese Navy

|Class before=

|Class after=

|Subclasses=*Kaichū I (Ro-11 class)

  • Kaichū II (Ro-13 class)
  • Kaichū III (Ro-16 class)
  • Kaichū IV (Ro-26 class)
  • Toku-Chū/Kaichū V (Ro-29 class)
  • Kaichū VI (Ro-33 class)
  • Sen-Chū/Kaichū VII (Ro-35 class)

|Cost=

|Built range=1917-1944

|In service range=

|In commission range=1919-1945

|Total ships building=

|Total ships planned=

|Total ships completed=

|Total ships cancelled=

|Total ships active=

|Total ships laid up=

|Total ships lost=

|Total ships retired=

|Total ships preserved=

}}

The {{nihongo|Kaichū type submarine|海中型潜水艦|Kaichū-gata sensuikan}} submarines were double-hulled medium-sized submarines of the Imperial Japanese Navy during World War II. The name was derived from the {{nihongo|Kaigun-shiki Chū-gata Sensuikan|海軍式中型潜水艦|Navy Medium Type submarine}}.

Several variants existed. From 1934 to 1944, the K6 type (Ro-33 Class) and the K7 type (Senchū, Ro-35 Class) were built. They were equipped with a 8 cm/40 3rd Year Type naval gun L/40 gun and four 53 cm torpedo tubes for ten type 95 Long Lance torpedoes.

Most of these submarines were destroyed in combat, suffering from Allied anti-submarine warfare measures, and only {{ship|Japanese submarine|Ro-50||2}} survived the war.

Class variants

The Kaichū type submarines were divided into seven classes:

  • {{nihongo|Kaichū I|海中1型（呂一一型）|Kaichū-ichi-gata, Ro-11-class}}
  • {{nihongo|Kaichū II|海中2型（呂一三型）|Kaichū-ni-gata, Ro-13-class}}
  • {{nihongo|Kaichū III|海中3型（呂一六型）|Kaichū-san-gata, Ro-16-class}}
  • {{nihongo|Kaichū IV|海中4型（呂二六型）|Kaichū-yon-gata, Ro-26-class}}
  • {{nihongo|Toku-Chū/Kaichū V|特中型/海中5型（呂二九型）|Toku-Chū-gata/Kaichū-go-gata, Ro-29-class}}
  • {{nihongo|Kaichū VI|海中6型（呂三三型）|Kaichū-roku-gata, Ro-33-class}}
  • {{nihongo|Sen-Chū/Kaichū VII|潜中型/海中7型（呂三五型）|Sen-Chū-gata/Kaichū-nana-gata, Ro-35-class}}

=''Kaichū I (Ro-11 class)''=

Image:Japanese submarine Ro-11 1919.jpg

Project number S7. In 1910s, the Imperial Japanese Navy (IJN) bought a license of Schneider-Laubeuf design submarine. The IJN used the design as model and built the S Type (Schneider Type) submarine, the {{ship|Japanese submarine|Ha-9||2}} and {{ship|Japanese submarine|Ha-10||2}}. The Kaichū I is the submarine which jumboized the S Type submarines.

  • Boats in class

class="wikitable"

! width="10%" | Boat

! width="13%" | Builder

! width="6%" | Laid down

! width="6%" | Launched

! width="6%" | Completed

! width="15%" | Fate

Submarine No. 19
{{ship|Japanese submarine|Ro-11		2}}{{nihongo|呂号第11潜水艦|Ro-Gō Dai-11 Sensuikan}}. The same shall apply hereinafter.

| Kure Naval Arsenal

| 25-04-1917

| 25-10-1917

| 31-07-1919 as Submarine No. 19

| Renamed Ro-11 01-11-1924. Decommissioned 01-04-1932.

Submarine No. 20
{{ship|Japanese submarine|Ro-12		2}}

| Kure Naval Arsenal

| 25-04-1917

| 01-12-1917

| 18-09-1919 as Submarine No. 20

| Renamed Ro-12 01-11-1924. Decommissioned 01-04-1932.

=''Kaichū II (Ro-13 class)''=

Image:Japanese submarine Ro-15.jpg

Project number S18. The Kaichū II had an increased range compared with the Kaichū I, and the turning torpedo tubes were removed.

  • Boats in class

class="wikitable"

! width="8%" | Boat

! width="13%" | Builder

! width="6%" | Laid down

! width="6%" | Launched

! width="6%" | Completed

! width="15%" | Fate

Submarine No. 23
{{ship|Japanese submarine|Ro-13		2}}

| Kure Naval Arsenal

| 14-09-1918

| 26-08-1919

| 30-09-1920 as Submarine No. 23

| Renamed Ro-13 01-11-1924. Decommissioned 01-04-1932.

Submarine No. 22
{{ship|Japanese submarine|Ro-14		2}}

| Kure Naval Arsenal

| 14-09-1918

| 31-03-1919

| 17-02-1921 as Submarine No. 22

| Renamed Ro-14 01-11-1924. Decommissioned 01-09-1933.

Submarine No. 24
{{ship|Japanese submarine|Ro-15		2}}

| Kure Naval Arsenal

| 12-06-1920

| 14-10-1920

| 30-06-1921 as Submarine No. 24

| Renamed Ro-15 01-11-1924. Decommissioned 01-09-1933.

=''Kaichū III (Ro-16 class)''=

Image:Japanese submarine Ro-16 in the 1920s.jpg

Project number S18. Their project number was the same as in the Kaichū II type submarine, however their performance was improved.

  • Boats in class

class="wikitable"

! width="8%" | Boat

! width="13%" | Builder

! width="6%" | Laid down

! width="6%" | Launched

! width="6%" | Completed

! width="15%" | Fate

Submarine No. 37
{{ship|Japanese submarine|Ro-16		2}}

| Kure Naval Arsenal

| 18-11-1920

| 22-04-1921

| 29-04-1922 as Submarine No. 37

| Renamed Ro-16 01-11-1924. Decommissioned 01-09-1933.

Submarine No. 34
{{ship|Japanese submarine|Ro-17		2}}

| Kure Naval Arsenal

| 24-09-1920

| 24-02-1921

| 20-10-1921 as Submarine No. 34

| Renamed Ro-17 01-11-1924. Decommissioned 01-04-1936.

Submarine No. 35
{{ship|Japanese submarine|Ro-18		2}}

| Kure Naval Arsenal

| 20-10-1920

| 25-03-1921

| 15-12-1921 as Submarine No. 35

| Renamed Ro-18 01-11-1924. Decommissioned 01-04-1936.

Submarine No. 36
{{ship|Japanese submarine|Ro-19		2}}

| Kure Naval Arsenal

| 09-09-1920

| 28-12-1920

| 15-03-1922 as Submarine No. 36

| Renamed Ro-19 01-11-1924. Decommissioned 01-04-1936.

Submarine No. 38
{{ship|Japanese submarine|Ro-20		2}}

| Yokosuka Naval Arsenal

| 28-07-1919

| 26-10-1920

| 01-02-1922 as Submarine No. 38

| Renamed Ro-20 01-11-1924. Decommissioned 01-04-1934.

Submarine No. 39
{{ship|Japanese submarine|Ro-21		2}}

| Yokosuka Naval Arsenal

| 28-07-1919

| 26-10-1920

| 01-02-1922 as Submarine No. 39

| Renamed Ro-21 01-11-1924. Decommissioned 01-04-1934.

Submarine No. 40
{{ship|Japanese submarine|Ro-22		2}}

| Yokosuka Naval Arsenal

| 22-01-1921

| 15-10-1921

| 10-10-1922 as Submarine No. 40

| Renamed Ro-22 01-11-1924. Decommissioned 01-04-1934.

Submarine No. 41
{{ship|Japanese submarine|Ro-23		2}}

| Yokosuka Naval Arsenal

| 22-01-1921

| 15-10-1921

| 28-04-1923 as Submarine No. 41

| Renamed Ro-23 01-11-1924. Decommissioned 01-04-1935.

Submarine No. 42
{{ship|Japanese submarine|Ro-24		2}}

| Sasebo Naval Arsenal

| 21-04-1919

| 08-12-1919

| 30-11-1920 as Submarine No. 42

| Renamed Ro-24 01-11-1924. Decommissioned 01-04-1935.

Submarine No. 43
{{ship|Japanese submarine|Ro-25		2}}

| Sasebo Naval Arsenal

| 19-02-1920

| 17-07-1920

| 25-10-1921 as Submarine No. 43

| Renamed Ro-25 01-11-1924. Decommissioned 01-04-1936.

=''Kaichū IV (Ro-26 class)''=

Image:Japanese submarine Ro-26 in 1923.jpg

Project number S18A. Improved model from the Kaichū III type.

  • Boats in class

class="wikitable"

! width="8%" | Boat

! width="13%" | Builder

! width="6%" | Laid down

! width="6%" | Launched

! width="6%" | Completed

! width="15%" | Fate

Submarine No. 45
{{ship|Japanese submarine|Ro-26		2}}

| Sasebo Naval Arsenal

| 10-03-1921

| 18-10-1921

| 25-01-1923 as Submarine No. 45

| Renamed Ro-26 01-11-1924. Decommissioned 01-04-1940. Scrapped 1948. Her anchor is displaying at Yokosuka Naval Base.

Submarine No. 58
{{ship|Japanese submarine|Ro-27		2}}

| Yokosuka Naval Arsenal

| 16-07-1921

| 22-07-1922

| 31-07-1924 as Submarine No. 58

| Renamed Ro-27 01-11-1924. Decommissioned 01-04-1936. Scrapped 1948.

Submarine No. 62
{{ship|Japanese submarine|Ro-28		2}}

| Sasebo Naval Arsenal

| 10-11-1921

| 13-04-1922

| 30-11-1923 as Submarine No. 62

| Renamed Ro-28 01-11-1924. Decommissioned 01-04-1940. Scrapped 1948.

=''Kaichū V (Toku-Chū, Ro-29 class)''=

Image:Japanese submarine Ro-31 in 1935.jpg

Project number S18B. They were built for the commerce raiding role. The IJN official designation of these boats was {{nihongo|Special Purpose-Medium Type submarine|特中型潜水艦|Toku-Chū-gata sensuikan}}.

  • Boats in class

class="wikitable"

! width="8%" | Boat

! width="13%" | Builder

! width="6%" | Laid down

! width="6%" | Launched

! width="6%" | Completed

! width="15%" | Fate

Submarine No. 68
{{ship|Japanese submarine|Ro-29		2}}

| Kawasaki-Kōbe Shipyard

| 02-06-1921

| 05-12-1922

| 15-09-1923 as Submarine No. 68

| Renamed Ro-29 01-11-1924. Decommissioned 01-04-1936.

Submarine No. 69
{{ship|Japanese submarine|Ro-30		2}}

| Kawasaki-Kōbe Shipyard

| 27-06-1921

| 18-01-1923

| 29-04-1924 as Submarine No. 69

| Renamed Ro-30 01-11-1924. Decommissioned 01-04-1942. Scrapped 1945.

Submarine No. 70

| Kawasaki-Kōbe Shipyard

| 25-09-1921

| 15-02-1923 as Submarine No. 70

|

| Lost in an accident off Awaji Island 21-08-1923. Salvaged and scrapped October 1923. Her materials were used for Ro-31.

{{ship|Japanese submarine|Ro-312}}

| Kawasaki-Kōbe Shipyard

| 20-12-1924

| 25-09-1926

| 10-05-1927

| Decommissioned 25-05-1945. Scuttled off Sasebo 05-04-1946.

Submarine No. 71
{{ship|Japanese submarine|Ro-32		2}}

| Kawasaki-Kōbe Shipyard

| 24-10-1921

| 19-03-1923

| 21-05-1924 as Submarine No. 71

| Renamed Ro-32 01-11-1924. Decommissioned 01-04-1942. Scrapped 1945.

=''Kaichū VI (Ro-33 class)''=

Image:Japanese submarine Ro-33 in 1939.jpg

Project number S30. They were planned as a prototype for a mass production submarines in the wartime under the Maru 1 Programme.

  • Boats in class

class="wikitable"

! width="3%" | Boat

! width="11%" | Builder

! width="5%" | Laid down

! width="5%" | Launched

! width="5%" | Completed

! width="15%" | Results

! width="15%" | Fate

{{ship|Japanese submarine|Ro-332}}

| Kure Naval Arsenal

| 08-08-1933

| 10-10-1934

| 07-10-1935

| Sank Australian merchant ship {{ship|MV|Mamutu

6}} 07-08-1942

| Sunk by {{ship|HMAS|Arunta|I30|6}} and RAF patrol aircraft off Port Moresby 29-08-1942.

{{ship|Japanese submarine|Ro-342}}

| Mitsubishi-Kōbe Shipyard

| 25-04-1934

| 12-12-1935

| 31-05-1937

|

| Sunk by {{ship|USS|O'Bannon|DD-450|6}} and {{ship|USS|Strong|DD-467|6}} near Russell Islands 06-04-1943.

=''Kaichū VII (Sen-Chū, Ro-35 class)''=

Image:Japanese submarine RO-50 in 1944.jpg

Project number S44. The final design in the Kaichū series. They were equipped with a Freon air-conditioner, because the IJN took into consideration that they were to be active on the equator area too. The official IJN designation of these boats was {{nihongo|Medium Type submarine|中型潜水艦|Chū-gata sensuikan}}, also called for short, {{nihongo|Medium Type|中型|Chū-gata}} or {{nihongo|Submarine-Medium Type|潜中型|Sen-Chū-gata}}.

The IJN planned to build these boats under the following Naval Armaments Supplement Programmes:

However some of the boats were cancelled and their naval budgets, materials and staffs were transferred to the I-201 class submarines.

  • Boats in class

class="wikitable"

! width="5%" | Boat No.

! width="4%" | Boat

! width="10%" | Builder

! width="5%" | Laid down

! width="5%" | Launched

! width="5%" | Completed

! width="15%" | Results

! width="25%" | Fate

201

| {{ship|Japanese submarine|Ro-35

2}}

| Mitsubishi-Kōbe Shipyard

| 09-10-1941

| 09-06-1942

| 25-03-1943

|

| Sunk by {{ship|USS|Patterson|DD-392|6}} near of Espiritu Santo 25-08-1943.

202

| {{ship|Japanese submarine|Ro-36

2}}

| Mitsubishi-Kōbe Shipyard

| 07-03-1942

| 14-10-1942

| 27-05-1943

|

| Sunk by {{ship|USS|Melvin|DD-680|6}} north of Saipan 13-06-1944.

203

| {{ship|Japanese submarine|Ro-37

2}}

| Sasebo Naval Arsenal

| 09-10-1941

| 30-06-1942

| 30-06-1943

| Damaged {{ship|USS|Cache|AO-67|6}} 22-01-1944

| Sunk by {{ship|USS|Buchanan|DD-484|6}} near of Santa Cruz Islands {{coord|11|47|S|164|17|E

} 22-01-1944.

|-

| 204

| {{ship|Japanese submarine|Ro-38||2}}

| Mitsubishi-Kōbe Shipyard

| 20-06-1942

| 24-12-1942

| 24-07-1943

|

| Disappeared after 19-11-1943.

|-

| 205

| {{ship|Japanese submarine|Ro-39||2}}

| Mitsubishi-Kōbe Shipyard

| 08-08-1942

| 06-03-1943

| 12-09-1943

|

| Sunk by {{ship|USS|Charrette|DD-581|6}} and {{ship|USS|Fair|DE-35|6}} east of Wotje Atoll {{coord|06|48|N|168|08|E|}} 03-02-1944.

|-

| 206

| {{ship|Japanese submarine|Ro-40||2}}

| Mitsubishi-Kōbe Shipyard

| 08-08-1942

| 06-03-1943

| 28-09-1943

|

| Sunk by {{ship|USS|Phelps|DD-360|6}} north of Marshall Islands {{coord|09|50|N|166|35|E|}} 16-02-1944.

|-

| 207

| {{ship|Japanese submarine|Ro-41||2}}

| Mitsubishi-Kōbe Shipyard

| 06-10-1942

| 05-05-1943

| 26-11-1943

| Sank {{ship|USS|Shelton|DE-407|6}} 03-10-1944

| Sunk by {{ship|USS|Haggard|DD-555|6}} south of Okinawa {{coord|22|57|N|132|19|E|}} 23-03-1945.

|-

| 208

| {{ship|Japanese submarine|Ro-42||2}}

| Sasebo Naval Arsenal

| 27-04-1942

| 25-10-1942

| 31-08-1943

|

| Sunk by {{ship|USS|Bangust|DE-739|6}} northeast of Marshall Islands {{coord|10|05|N|168|22|E|}} 10-06-1945.

|-

| 209

| {{ship|Japanese submarine|Ro-43||2}}

| Mitsubishi-Kōbe Shipyard

| 06-10-1942

| 05-06-1943

| 16-12-1943

| Damaged {{ship|USS|Renshaw|DD-499|6}} 21-02-1945

| Sunk by aircraft from {{ship|USS|Anzio|CVE-57|6}} off Iwo Jima {{coord|25|07|N|140|19|E|}} 27-02-1945.

|-

| 385

| {{ship|Japanese submarine|Ro-44||2}}

| Mitsui-Tamano Shipyard

| 14-02-1942

| 11-11-1942

| 13-09-1943

|

| Sunk by {{ship|USS|Burden R. Hastings|DE-19|6}} near of Enewetak {{coord|11|13|N|164|15|E|}} 16-06-1944.

|-

| 386

| {{ship|Japanese submarine|Ro-45||2}}

| Mitsubishi-Kōbe Shipyard

| 20-10-1942

| 21-07-1943

| 11-01-1944

|

| Sunk by {{ship|USS|Macdonough|DD-351|6}}, {{ship|USS|Stephen Potter|DD-538|6}} and aircraft from {{ship|USS|Monterey|CVL-26|6}} south of Truk {{coord|06|13|N|151|19|E|}} 01-05-1944.

|-

| 387

| {{ship|Japanese submarine|Ro-46||2}}

| Mitsui-Tamano Shipyard

| 13-06-1942

| 23-04-1943

| 19-02-1944

| Damaged {{ship|USS|Cavalier|APA-37|6}} 29-01-1945

| Sunk by aircraft from {{ship|USS|Tulagi|CVE-72|6}} near of Oki Daitō {{coord|24|15|N|131|16|E|}} 29-04-1945.

|-

| 388

| {{ship|Japanese submarine|Ro-47||2}}

| Mitsubishi-Kōbe Shipyard

| 28-12-1942

| 20-08-1943

| 31-01-1944

|

| Sunk by {{ship|USS|McCoy Reynolds|DE-440|6}} northeast of Palau {{coord|09|19|N|136|44|E|}} 26-09-1944.

|-

| 389

| {{ship|Japanese submarine|Ro-48||2}}

| Mitsubishi-Kōbe Shipyard

| 17-03-1943

| 15-10-1943

| 31-03-1944

|

| (1) Sunk by {{ship|USS|William C. Miller|DE-259|6}} northwest of Saipan 14-07-1944.
(2) Sunk by {{ship|USS|Wyman|DE-38|6}} northwest of Saipan 18-07-1944.

|-

| 390

| {{ship|Japanese submarine|Ro-49||2}}

| Mitsui-Tamano Shipyard

| 16-11-1942

| 03-08-1943

| 19-05-1944

|

| Sunk by {{ship|USS|Hudson|DD-475|6}}.

|-

| 391

| {{ship|Japanese submarine|Ro-50||2}}

| Mitsui-Tamano Shipyard

| 18-02-1943

| 27-11-1943

| 31-07-1944

| Sank USS LST-577 11-02-1945

| Decommissioned 30-11-1945. Sunk as target off Gotō Islands 01-04-1946.

|-

| 392 - 395

|

|

|

|

|

|

| Cancelled in 1943.

|-

| 396

| {{ship|Japanese submarine|Ro-55|1944|2}}

| Mitsui-Tamano Shipyard

| 05-08-1943

| 23-04-1944

| 30-09-1944

|

| Sunk by {{ship|USS|Thomason|DE-203|6}} west of Luzon {{coord|15|27|N|119|25|E|}} 07-02-1945.

|-

| 640 - 644

|

|

|

|

|

|

| Cancelled in 1943.

|-

| 645

| {{ship|Japanese submarine|Ro-56|1944|2}}
(ex-Ro-75)

| Mitsui-Tamano Shipyard

| 02-12-1943 as Ro-75

| 05-07-1944

| 15-11-1944

|

| Sunk by {{ship|USS|Mertz|DD-691|6}} and {{ship|USS|Monssen|DD-798|6}} near of Oki Daitō {{coord|26|09|N|130|21|E|}} 09-04-1945.

|-

| 646 - 654

|

|

|

|

|

|

| Cancelled in 1943.

|-

| 5181 - 5223

|

|

|

|

|

|

| Cancelled in 1943.

|-

|}

Characteristics

class="wikitable" width="90%"

| width="15%" colspan="2"| Type

| width="16%" | Kaichū I (Ro-11)

| width="16%" | Kaichū II (Ro-13)

| width="16%" | Kaichū III (Ro-16)

| width="16%" | Kaichū IV (Ro-26)

rowspan="2"|Displacement

| Surfaced

| {{convert|720|LT|t|0}}

| {{convert|740|LT|t|0}}

| {{convert|740|LT|t|0}}

| {{convert|750|LT|t|0}}

Submerged

| {{convert|1000|LT|t|0}}

| {{convert|1003.1|LT|t|0}}

| {{convert|997|LT|t|0}}

| {{convert|1080|LT|t|0}}

colspan="2"| Length (overall)

| {{convert|69.19|m|ftin|abbr=on}}

| {{convert|70.10|m|ftin|abbr=on}}

| {{convert|70.10|m|ftin|abbr=on}}

| {{convert|74.22|m|ftin|abbr=on}}

colspan="2"| Beam

| {{convert|6.35|m|ftin|abbr=on}}

| {{convert|6.10|m|ftin|abbr=on}}

| {{convert|6.12|m|ftin|abbr=on}}

| {{convert|6.12|m|ftin|abbr=on}}

colspan="2"| Draft

| {{convert|3.43|m|ftin|abbr=on}}

| {{convert|3.68|m|ftin|abbr=on}}

| {{convert|3.70|m|ftin|abbr=on}}

| {{convert|3.73|m|ftin|abbr=on}}

colspan="2"| Power plant and shaft

| 2 × Sulzer Mk.2 diesels
2 shafts

| 2 × Sulzer Mk.2 diesels
2 shafts

| 2 × Sulzer Mk.2 diesels
2 shafts

| 2 × Sulzer Mk.2 diesels
2 shafts

rowspan="2"|Power

| Surfaced

| 2,900 bhp

| 2,900 bhp

| 2,900 bhp

| 2,900 bhp

Submerged

| 1,200 shp

| 1,200 shp

| 1,200 shp

| 1,200 shp

rowspan="2"|Speed

| Surfaced

| {{convert|18.2|kn|km/h|lk=in}}

| {{convert|16.5|kn|km/h|lk=in}}

| {{convert|16.5|kn|km/h|lk=in}}

| {{convert|16.0|kn|km/h|lk=in}}

Submerged

| {{convert|9.1|kn|km/h|lk=in}}

| {{convert|8.5|kn|km/h|lk=in}}

| {{convert|8.5|kn|km/h|lk=in}}

| {{convert|8.5|kn|km/h|lk=in}}

rowspan="2"|Range

| Surfaced

| {{convert|4000|nmi|km|abbr=on|lk=in}} at {{convert|10|kn|km/h}}

| {{convert|6000|nmi|km|abbr=on|lk=in}} at {{convert|10|kn|km/h}}

| {{convert|6000|nmi|km|abbr=on|lk=in}} at {{convert|10|kn|km/h}}

| {{convert|6000|nmi|km|abbr=on|lk=in}} at {{convert|10|kn|km/h}}

Submerged

| {{convert|85|nmi|km|abbr=on|lk=in}} at {{convert|4|kn|km/h}}

| {{convert|85|nmi|km|abbr=on|lk=in}} at {{convert|4|kn|km/h}}

| {{convert|85|nmi|km|abbr=on|lk=in}} at {{convert|4|kn|km/h}}

| {{convert|85|nmi|km|abbr=on|lk=in}} at {{convert|4|kn|km/h}}

colspan="2"| Test depth

| {{convert|30|m|ft|abbr=on}}

| {{convert|30|m|ft|abbr=on}}

| {{convert|45.7|m|ft|abbr=on}}

| {{convert|45.7|m|ft|abbr=on}}

colspan="2"| Fuel

| 58.4 tons

| 75 tons

| 75 tons

| 75 tons

colspan="2"| Complement

| 43

| 43

| 46

| 46

colspan="2"| Armament (initial)

| • 6 × {{convert|450|mm|in|0|abbr=on}} TTs
(4 × front, 2 × turret)
• 10 × Type 44 torpedoes
• 1 × 8_cm/40_3rd_Year_Type_naval_gun#Variants L/23.5 5th Year Type AA gun

| • 6 × {{convert|450|mm|in|0|abbr=on}} TTs
(4 × front, 2 × upper deck)
• 10 × Type 44 torpedoes
• 1 × {{convert|76.2|mm|in|abbr=on}} L/23.5 5th Year Type AA gun

| • 6 × {{convert|450|mm|in|0|abbr=on}} TTs
(4 × front, 2 × upper deck)
• 10 × Type 44 torpedoes
• 1 × {{convert|76.2|mm|in|abbr=on}} L/23.5 5th Year Type AA gun

| • 4 × {{convert|533|mm|in|0|abbr=on}} TTs
(4 × front)
• 8 × 6th Year Type torpedoes
• 1 × {{convert|76.2|mm|in|abbr=on}} L/23.5 5th Year Type AA gun

class="wikitable" width="74%"

| width="15%" colspan="2"| Type

| width="16%" | Kaichū V (Ro-29)

| width="16%" | Kaichū VI (Ro-33)

| width="16%" | Kaichū VII (Ro-35)

rowspan="2"|Displacement

| Surfaced

| {{convert|852|LT|t|0}}

| {{convert|700|LT|t|0}}

| {{convert|960|LT|t|0}}

Submerged

| {{convert|1030|LT|t|0}}

| {{convert|1200|LT|t|0}}

| {{convert|1447|LT|t|0}}

colspan="2"| Length (overall)

| {{convert|74.22|m|ftin|abbr=on}}

| {{convert|73.00|m|ftin|abbr=on}}

| {{convert|80.50|m|ftin|abbr=on}}

colspan="2"| Beam

| {{convert|6.12|m|ftin|abbr=on}}

| {{convert|6.70|m|ftin|abbr=on}}

| {{convert|7.05|m|ftin|abbr=on}}

colspan="2"| Draft

| {{convert|3.73|m|ftin|abbr=on}}

| {{convert|3.25|m|ftin|abbr=on}}

| {{convert|4.07|m|ftin|abbr=on}}

colspan="2"| Power plant and shaft

| 2 × Sulzer Mk.1 diesels
2 shafts

| 2 × Kampon Mk.21 Model 8 diesels
2 shafts

| 2 × Kampon Mk.22 Model 10 diesels
2 shafts

rowspan="2"|Power

| Surfaced

| 1,200 bhp

| 3,000 bhp

| 4,200 bhp

Submerged

| 1,200 shp

| 1,200 shp

| 1,200 shp

rowspan="2"|Speed

| Surfaced

| {{convert|13.0|kn|km/h|lk=in}}

| {{convert|19.0|kn|km/h|lk=in}}

| {{convert|19.8|kn|km/h|lk=in}}

Submerged

| {{convert|8.5|kn|km/h|lk=in}}

| {{convert|8.2|kn|km/h|lk=in}}

| {{convert|8.0|kn|km/h|lk=in}}

rowspan="2"|Range

| Surfaced

| {{convert|6000|nmi|km|abbr=on|lk=in}} at {{convert|10|kn|km/h}}

| {{convert|8000|nmi|km|abbr=on|lk=in}} at {{convert|12|kn|km/h}}

| {{convert|5000|nmi|km|abbr=on|lk=in}} at {{convert|16|kn|km/h}}

Submerged

| {{convert|85|nmi|km|abbr=on|lk=in}} at {{convert|4|kn|km/h}}

| {{convert|90|nmi|km|abbr=on|lk=in}} at {{convert|3.5|kn|km/h}}

| {{convert|45|nmi|km|abbr=on|lk=in}} at {{convert|5|kn|km/h}}

colspan="2"| Test depth

| {{convert|45.7|m|ft|abbr=on}}

| {{convert|75|m|ft|abbr=on}}

| {{convert|80|m|ft|abbr=on}}

colspan="2"| Fuel

| 143 tons

| 109 tons

| 218 tons

colspan="2"| Complement

| 44

| 61

| 61

colspan="2"| Armament (initial)

| • 4 × {{convert|533|mm|in|0|abbr=on}} TTs
(4 × front)
• 8 × 6th Year Type torpedoes
• 1 × Type 3 120 mm 45 caliber naval gun L/45 11th Year Type Naval gun
• 1 × 6.5 mm machine gun

| • 4 × {{convert|533|mm|in|0|abbr=on}} TTs
(4 × front)
• 8 × Type 89 torpedoes
• 1 × 8 cm/40 3rd Year Type naval gun L/40 11th Year Type AA gun
• 1 × Hotchkiss M1929 machine gun AA gun

| • 4 × {{convert|533|mm|in|0|abbr=on}} TTs
(4 × front)
• 10 × Type 95 torpedoes
• 1 × {{convert|76.2|mm|in|abbr=on}} L/40 11th Year Type AA gun
• 2 × Type 96 25mm AA guns

Bibliography

  • {{cite web |url=http://rekigun.net/ |title=Rekishi Gunzō}}, History of Pacific War Vol.17 I-Gō Submarines, Gakken (Japan), January 1998, {{ISBN|4-05-601767-0}}
  • Rekishi Gunzō, History of Pacific War Extra, "Perfect guide, The submarines of the Imperial Japanese Forces", Gakken (Japan), March 2005, {{ISBN|4-05-603890-2}}
  • The Maru Special, Japanese Naval Vessels No.43 Japanese Submarines III, Ushio Shobō (Japan), September 1980, Book code 68343-44
  • The Maru Special, Japanese Naval Vessels No.132 Japanese Submarines I "Revised edition", Ushio Shobō (Japan), February 1988, Book code 68344-36
  • The Maru Special, Japanese Naval Vessels No.133 Japanese Submarines II "Revised edition", Ushio Shobō (Japan), March 1988, Book code 68344-37
  • The Maru Special, Japanese Naval Vessels No.135 Japanese Submarines IV, Ushio Shobō (Japan), May 1988, Book code 68344-39

References

{{Reflist}}

{{Kaichū type submarine}}

{{WWI Japanese ships}}

{{WWII Japanese ships}}

{{DEFAULTSORT:Kaichu}}

Category:Submarine classes

Category:Submarines of the Imperial Japanese Navy