I1 1942
| Name | No | Yard No | Builder | Laid down | Launched | Comp | Fate |
| 伊1 [I1] (ex-第74号艦 [74-go]) | Kawasaki, Kobe | 3/1923 | 15.10.1924 | 3.1926 | sunk 29.1.1943 | ||
| 伊2 [I2] (ex-第75号艦 [75-go]) | Kawasaki, Kobe | 8/1923 | 23.2.1925 | 7.1926 | sunk 7.4.1944 | ||
| 伊3 [I3] (ex-第76号艦 [76-go]) | 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 |
Project history: Junsen 1 (Cruiser submarine 1) type. First submarine cruisers of IJN were built under the 1923-1928 programme. 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 became a design basis. As she served as a prototype for fleet submarine of Kaidai 2 type, designs 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 US MTB ÐÒ59. I4 was lost after 21.12.1942 (presumably sunk 20.12.1942 off New England by US 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 US destroyer Saufley.
I1 1926
© Ivan Gogin, 2008-14