| Displacement | 13,750t normal, 15,400t full load |
|---|---|
| Length | 134.1m wl, 137.1m oa |
| Width | 23.0m (Ikoma 22.8m) |
| Draught | 8.0m |
| Machinery | 2-shaft VTE recipro, 20 boilers, 20,500ihp |
| Fuel | coal 2000t (Ikoma oil 160t, coal 1911t) |
| Speed | 20.5kt |
| Armour | belt 100-180mm, barbette 180mm, turret 180mm, CT 200mm, deck 75mm |
| Armament | 4-30.5cm/45cal (2x2), 12-15.2cm/45cal gun, 12-12cm/40cal gun, 4-8cm/40cal gun, 3-45cm TT (below WL) |
| Complement | 879 |
| Name | Plan | Builder | Laid down | Launch | Complete | ||
|---|---|---|---|---|---|---|---|
| Tsukuba | FY1904 | Kure NYd | 1905. 1.14 | 1905.12.26 | 1907. 1.14 | C1 | 1912. 8.28 BC 1917. 1.14 Lost (explosion, Yokosuka) 1917. 9. 1 disc 1918 BU |
| Ikoma | FY1904 | Kure NYd | 1905. 3.15 | 1906. 4. 9 | 1908. 3.24 | C1 | 1912. 8.28 BC 1923. 9.20 disc 1924 BU |