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 ships were powered by a duo of 3-cylinder triple-expansion engines that drove two screws, using steam from twenty Belleville boilers. The boilers were grouped into two funnels situated amidships. The Formidable-class ships had a peak speed of .