I1 1942
| Name | No | Builder | Laid down | Launched | Comp | Fate |
| 伊1 <I1> (ex-第74号艦 <74-go>(No74)) | Kawasaki, Kobe | 3/1923 | 15/10/1924 | 3/1926 | sunk 29/1/1943 | |
| 伊2 <I2> (ex-第75号艦 <75-go>(No75)) | Kawasaki, Kobe | 8/1923 | 23/2/1925 | 7/1926 | sunk 7/4/1944 | |
| 伊3 <I3> (ex-第76号艦 <76-go>(No76)) | Kawasaki, Kobe | 11/1923 | 8/6/1925 | 11/1926 | sunk 9/12/1942 | |
| 伊4 <I4> | Kawasaki, Kobe | 4/1926 | 22/5/1928 | 12/1929 | sunk 25/12/1942 |
|
Displacement standard, t |
1970 |
|
Displacement normal, t |
2135 / 2791 |
|
Length, m |
94.0 pp 93.9 wl 97.5 oa |
|
Breadth, m |
9.22 |
|
Draught, m |
5.00 |
|
No of shafts |
2 |
|
Machinery |
2 MAN diesels / 2 electric motors |
|
Power, h. p. |
6000 / 2600 |
|
Max speed, kts |
18 / 8 |
|
Fuel, t |
diesel oil 175 |
| Endurance, nm | 24400(10) / 60(3) |
| Armament |
2 x 1 - 140/40 11-shiki, 2 x 1 - 7.7/87, 6 - 533 TT (4 bow, 2 stern, 20) |
|
Complement |
92 |
|
Diving depth operational, m |
80 |
Ship project history: Junsen 1 (Cruiser submarine 1) type. First submarine cruisers of IJN were built under the 1923-1928 program. According to Naval staff plans, long-distance reconnaissance far away from own bases should become a basic purpose of cruiser submarines. It has defined a huge endurance in the technical project (24000nm). Drawings of German submarine cruiser U139 are put in a project basis. As she served as a prototype for fleet submarine of Kaidai 2 type, projects of fleet and cruiser submarines have appeared are close enough under the characteristics, but thus Junsen 1 was closer to German prototype. Double-hulled. CT and free board were protected by light armour. Endurance was about 60 days.
Modernizations: 1942 - 1943, I1, 2: were converted to transports: - 1 x 1 - 140/40, torpedoes stowage was decreased, they can carry 1 14m Daihatsu-type landing craft and cargo.
Naval service: I3 was sunk 10/12/1942 in Solomons area by American MTB ÐÒ59. I4 was lost after 21/12/1942 (presumably sunk 20/12/1942 off New England by American submarine Seadragon). I1 was sunk 29/1/1943 in Solomons area by gunfire and ramming of New Zealand corvettes Kiwi and Moa. I2 was sunk 7/4/1944 E off New Hanover by American destroyer Saufley.
I1 1926
© Ivan Gogin, 2008-10