| Displacement | 1635t standard, 1800t surface, 2300t submerged |
|---|---|
| Length | 94.0m pp, 98.9m wl, 101.0m oa |
| Width | 7.9m |
| Draught | 4.90m |
| Machinery | 2-shaft diesel/electric motor, 6800bhp surface, 1800shp submerged |
| Speed | 20kt surface, 8kt submerged |
| Armament | 8-53cm TT, 1-12cm/45cal gun |
| Complement | 79 |
| Name | Plan | Builder | Laid down | Launch | Complete | ||
|---|---|---|---|---|---|---|---|
| I-56 (I-156) | FY1923 | Kure NYd | 1926.11. 3 | 1928. 3.23 | 1929. 3.31 | SS1 | 1942. 5.20 renamed (I-156) 1945.11.30 disc 1946. 4. 1 scuttled |
| I-57 (I-157) | FY1923 | Kure NYd | 1927. 7. 8 | 1928.10. 1 | 1929.12.24 | SS1 | 1942. 5.20 renamed (I-157) 1945.11.30 disc 1946. 4. 1 scuttled |
| I-59 (I-159) | FY1923 | Yokosuka NYd | 1927. 3.25 | 1929. 3.25 | 1930. 3.31 | SS1 | 1942. 5.20 renamed (I-159) 1945.11.30 disc 1946. 4. 1 scuttled |
| I-60 | FY1923 | Sasebo NYd | 1927.10.10 | 1929. 4.24 | 1929.12.20 | SS1 | 1942. 1.17 sunk (action, Sunda Strait) [06S, 105E] 1942. 3.15 disc |
| I-63 | FY1923 | Sasebo NYd | 1926. 8.12 | 1927. 9.28 | 1928.12.20 | SS1 | 1939. 2. 2 lost (collision with I-60, Bungo Strait) 1940. 6. 1 disc |