| Displacement | 291t surface, 326t submerged |
|---|---|
| Length | 40.1m pp, 43.3m oa |
| Width | 4.1m |
| Draught | 3.4m |
| Machinery | 1-shaft diesel/electric motor, 600bhp surface, 300shp submerged |
| Fuel | oil 15.5t |
| Speed | 12kt surface, 8.5kt submerged |
| Range | 660nm by 12kt surface, 60nm by 4kt submerged |
| Armament | 2-45cm TT, 1 MG |
| Complement | 25 |
| Name | Plan | Builder | Laid down | Launch | Complete | ||
|---|---|---|---|---|---|---|---|
| Ha-3 (SS-10) | FY1904 | UK Vickers | 1910. 8. 1 | 1911. 3. 4 | 1911. 8.12 | SB(SS-10) | 1916. 8. 4 SB2 1919. 4. 1 SS3 1923. 6.15 renamed(Ha-3) 1929.12. 1 disc |
| Ha-4 (SS-11) | FY1904 | UK Vickers | 1910. 8. 1 | 1911. 3.13 | 1911. 8.26 | SB(SS-11) | 1916. 8. 4 SB2 1919. 4. 1 SS3 1923. 6.15 renamed(Ha-4) 1929.12. 1 disc |
| Ha-5 (SS-12) | FY1904 | UK Vickers | 1910. 8. 1 | 1911. 3.27 | 1911. 8. 3 | SB(SS-12) | 1916. 8. 4 SB2 1919. 4. 1 SS3 1923. 6.15 renamed(Ha-5) 1929.12. 1 disc |