I121 1945
| Name | No | Yard No | Builder | Laid down | Launched | Comp | Fate |
| 伊21 [I21] (ex-第48号艦 [48-go]), 6.1938- 伊121 [I121] | Kawasaki, Kobe | 1/1924 | 30.3.1926 | 3.1927 | surrendered 8.1945, BU 1946 | ||
| 伊22 [I22] (ex-第49号艦 [49-go]), 6.1938- 伊122 [I122] | Kawasaki, Kobe | 10/1924 | 8.11.1926 | 10.1927 | sunk 10.6.1945 | ||
| 伊23 [I23] (ex-第50号艦 [50-go]), 6.1938- 伊123 [I123] | Kawasaki, Kobe | 10/1924 | 19.3.1927 | 4.1928 | sunk 29.8.1942 | ||
| 伊24 [I24] (ex-第60号艦 [60-go]), 6.1938- 伊124 [I124] | Kawasaki, Kobe | 10/1924 | 12.12.1927 | 12.1928 | sunk 20.1.1942 |
|
Displacement standard, t |
1142 |
|
Displacement normal, t |
1383 / 1768 |
|
Length, m |
82.0 wl 85.2 oa |
|
Breadth, m |
7.52 |
|
Draught, m |
4.42 |
|
No of shafts |
2 |
|
Machinery |
2 MAN diesels / 2 electric motors |
|
Power, h. p. |
2400 / 1100 |
|
Max speed, kts |
14.5 / 7 |
|
Fuel, t |
diesel oil 154 |
| Endurance, nm(kts) | 10500(8) / 40(4.5) |
| Armament |
1 x 1 - 140/40 11-shiki, 4 - 533 TT (bow,12), 42 mines |
|
Complement |
51 - 70 |
| Diving depth operational, m | 75 |
Project history: Kirai-Sen (Minelaying submarine) type. Unique Japanese purpose-built minelaying submarines. Drawings of the former German submarine U125 received by Japan on a reparation and commissioned by the IJN as Î1 were put in a design basis. Double-hulled, endurance was about 20 days. Submarines were built under the 1919 programme. They have appeared unsuccessful because of whimsical system of a minelaying and insufficient longitudinal stability in submerged position. Projected I25 and 26 (ex-Nos52 and 63) were cancelled in 1924.
In 1940 they were fitted with tanks for aviation petrol and then could be used for a refuelling of flying boats at a great distance from bases.
Modernizations: 1940, all: were converted to refueling of large flying boats, petrol tanks were fitted on deck.
Naval service: I121 and I122 since August, 1943 were used for training.
I124 was sunk 20.1.1942 near Darwin by US escort destroyer Edsall and Australian minesweepers Deloraine, Katoomba and Lithgow. I123 was sunk 29.8.1942 SE off Savo by US destroyer Gamble. I122 was sunk 10.6.1945 by US submarine Skate in Toyama Bay (Honshu).
I121
© Ivan Gogin, 2008-14