During her sea trials on 23 February 1864, Hector had a maximum speed of  and Valiant made  on 18 September 1865. The ships carried only  of coal because they were overweight, enough to steam  at full speed.
On 23 February 1864 during her sea trials, Hector attained a maximum speed of  and Valiant achieved  on 18 September 1865. Both vessels had limited coal reserves because they were overweight, enabling them to travel  at full power.