| Displacement | 2184t standard, 2554t surface, 3561t submerged |
|---|---|
| Length | 103.8m pp, 106.95m wl, 109.3m oa |
| Width | 9.1m |
| Draught | 5.35m |
| Machinery | 2-shaft diesel and electoric motor, 12,400bhp surface, 2000shp submerged |
| Speed | 23.6kt surface, 8kt submerged |
| Armament | 8-53cm TT, 1-14cm/40cal gun, 2-25mm AA |
| Complement | 101 |
| Name | Plan | Builder | Laid down | Launch | Complete | ||
|---|---|---|---|---|---|---|---|
| I-16 | FY1937 | Mitsubishi, Kobe | 1937. 9.15 | 1938. 7.28 | 1940. 3.30 | SS1 | 1944. 5.19 sunk (action, off Buin) [05.10S, 158.17E] 1944. 6.25 missing 1944.10.10 disc |
| I-18 | FY1937 | Sasebo NYd | 1937. 8.25 | 1938.11.12 | 1941. 1.31 | SS1 | 1943. 2.11 sunk (action, Central Solomons) [14.15S, 161.59E] 1943. 2.11 missing 1943. 4. 1 disc |
| I-20 | FY1937 | Mitsubishi, Kobe | 1937.11.16 | 1939. 1.25 | 1940. 9.26 | SS1 | 1943. 9. 3 sunk (action, off Espiritu Santo) [13.10S, 165.28E] 1943.11.18 missing 1943.12. 1 disc |
| I-22 | FY1937 | Kawasaki, Kobe | 1937.11.25 | 1938.12.23 | 1941. 3.10 | SS1 | 1942.11.12 missing (SE of Solomons) 1942.12.15 disc |
| I-24 | FY1937 | Sasebo NYd | 1938.12. 5 | 1939.11.12 | 1941.10.31 | SS1 | 1943. 6.10 sunk (action, near Attu I.) [53.16N, 174.24E] 1943. 6.11 missing 1943. 8. 1 disc |