I121 1945
| Name | No | Builder | Laid down | Launched | Comp | Fate |
| 伊21 <I21> (ex-第48号艦 <48-go> (No48)), 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> (No49)), 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> (No50)), 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>(No60)), 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 |
Ship 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 are put in a project basis. Double-hulled, endurance was about 20 days. Submarines were built under the 1919 program. 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 American escort destroyer Edsall and Australian minesweepers Deloraine, Katoomba and Lithgow. I123 was sunk 29/8/1942 SE off Savo by American destroyer Gamble. I122 was sunk 10/6/1945 by American submarine Skate in Toyama Bay (Honshu).
I121
© Ivan Gogin, 2008-10