The engines produced a total of  which gave the ships a maximum speed of . Wivern reached a maximum speed just over  during her sea trials on 4 October 1865. The ships carried  of coal, enough to steam  at .
A total output from the engines resulted in the ships reaching a maximum speed of . Specifically, during her sea trials on October 4, 1865, Wivern attained a maximum speed exceeding . Each ship was equipped with  of coal, which allowed them to steam for at .