The principal motivation driving the Admiralty was the French policy, already well advanced, of dispatching their own small ironclads to these same distant stations.

The Admiralty, however, decided that as there had been built a long succession of successful broadside ironclads, and no turret-armed ships had been produced other than some coastal defence ships of low displacement and limited range, it would be better to await the assessment of Monarch and Captain before departing from the broadside principle.

As the ships were intended for service in waters far distant from Britain, and given the limited efficiency of the steam engines of the period, it was necessary to equip them with a full sailing rig.

Reed found that, on the dimensions of the older ship, the armament, armour and machinery would all be insufficient for the stated requirements, and asked for an increase in tonnage, which was reluctantly granted by the Board.

All were determined to be in some way inadequate, and ultimately the third and fourth ships were built, with some delay, to the Admiralty design.