This chapter focuses exclusively on the implications of steam for the management of naval architecture. Steam is 'the great reformer of our century', stated an 1859 article on the Navy in Chambers. Personal and political tensions were rife, which has important implications for our understanding of the introduction of steam into the Royal Navy. The chapter examines the concerns of the actors involved in the management of naval architecture, locating the introduction of steam within a larger debate over what were the 'correct' principles of ship design. Ship designers, administrators and politicians increasingly talked about managing naval architecture in terms of 'principles' and 'systems', exploring which principles ensured conversion to steam at the least cost and waste of material and labour. The twin concerns with Symonds's record as Surveyor and the challenges of building steam warships dominated shipbuilding discussion in the second half of the 1840s.