This chapter traces how naval architects working in distinct geographies developed a sense of profession in order to lay claim to authority over iron shipbuilding in the Royal Navy. Iron and ironclad ships had been employed in the merchant navy and in a limited way in the Royal Navy. Many of Britain's shipbuilders had a commercial stake of some kind in the reconstruction of the Royal Navy. In the early 1860s members of the Institution of Civil Engineers, specifically John Hawkshaw and George Bidder, turned their attention to the problems of designing and constructing iron steamships. In 1860, John Scott Russell and Joseph Woolley formed the Institution of Naval Architects (INA), with which they sought to patrol the boundaries of their profession and promote its authority. Russell specifically favoured those who used experiments to generate new knowledge of ship behaviour and guide their design work.