Why weaker French ironclads still mattered to a worldwide navy

Robinson counted French wooden-hulled armoured ships as ironclads when making the case for British construction. Critics argued that this overstated the threat because British iron-hulled ships were individually more powerful. A concentrated battle between the two fleets was only one possible test of that advantage. French ironclads operating separately could threaten trade or blockade ports that Britain lacked enough armoured ships to protect. An ordinary unarmoured warship confronting one of those vessels would still face a serious disadvantage. Under those conditions, superior individual British ships would not remove the risk created by insufficient numbers. Continued construction also offered a way to pay for dockyard modernisation, a financial motive proposed alongside the operational argument.