The Formidable-class ships were powered by a pair of 3-cylinder triple-expansion engines that drove two screws, with steam provided by twenty Belleville boilers. The boilers were trunked into two funnels located amidships. The Formidable-class ships had a top speed of  from .
The Formidable-class vessels utilized a pair of 3-cylinder triple-expansion engines to drive their two screws, with steam sourced by twenty Belleville boilers. These boilers were concentrated in two funnels located centrally on the ship. The Formidable-class ships could reach a maximum speed of .