| Displacement | 755t surface, 1050t submerged |
|---|---|
| Length | 70.1m oa |
| Width | 6.1m |
| Draught | 3.7m |
| Machinery | 2-shaft diesel/electric motor, 2600bhp surface, 1200shp submerged |
| Fuel | oil 75t |
| Speed | 17kt surface, 9kt submerged |
| Range | 6000nm by 10kt surface, 85nm by 4kt submerged |
| Armament | 6-45cm TT, 1-8cm/28cal AA gun |
| Complement | 45 |
| Name | Plan | Builder | Laid down | Launch | Complete | ||
|---|---|---|---|---|---|---|---|
| Ro-16 (SS-37) | FY1917 | Kure NYd | 1920.11.18 | 1921. 4.22 | 1922. 4.29 | SS2 (SS-37) | 1924.11. 1 renamed(Ro-16) 1933. 9. 1 disc |
| Ro-17 (SS-34) | FY1917 | Kure NYd | 1920. 9.24 | 1921. 2.24 | 1921.10.20 | SS2 (SS-34) | 1924.11. 1 renamed(Ro-17) 1936. 4. 1 disc |
| Ro-18 (SS-35) | FY1917 | Kure NYd | 1920.10.20 | 1921. 3.25 | 1921.12.15 | SS2 (SS-35) | 1924.11. 1 renamed(Ro-18) 1936. 4. 1 disc |
| Ro-19 (SS-36) | FY1917 | Kure NYd | 1920. 9. 9 | 1920.12.28 | 1922. 3.15 | SS2 (SS-36) | 1924.11. 1 renamed(Ro-19) 1936. 4. 1 disc |
| Ro-20 (SS-38) | FY1917 | Yokosuka NYd | 1919. 7.28 | 1920.10.26 | 1922. 2. 1 | SS2 (SS-38) | 1924.11. 1 renamed(Ro-20) 1934. 4. 1 disc |
| Ro-21 (SS-39) | FY1917 | Yokosuka NYd | 1919. 7.28 | 1920.10.26 | 1922. 2. 1 | SS2 (SS-39) | 1924.11. 1 renamed(Ro-21) 1934. 4. 1 disc |
| Ro-22 (SS-40) | FY1918 | Yokosuka NYd | 1921. 1.20 | 1921.10.15 | 1922.10.10 | SS2 (SS-40) | 1924.11. 1 renamed(Ro-22) 1934. 4. 1 disc |
| Ro-23 (SS-41) | FY1918 | Yokosuka NYd | 1921. 1.20 | 1921.10.25 | 1923. 4.28 | SS2 (SS-41) | 1924.11. 1 renamed(Ro-23) 1935. 4. 1 disc |
| Ro-24 (SS-42) | FY1918 | Sasebo NYd | 1919. 4.21 | 1919.12. 8 | 1920.11.30 | SS2 (SS-42) | 1924.11. 1 renamed(Ro-24) 1935. 4. 1 disc |
| Ro-25 (SS-43) | FY1918 | Sasebo NYd | 1920. 2.19 | 1920. 7.17 | 1921.10.25 | SS2 (SS-43) | 1924.11. 1 renamed(Ro-25) 1936. 4. 1 disc |