The nineteenth-century Royal Navy was transformed from a fleet of sailing wooden walls into a steam powered machine. This book provides the first cultural history of technology, authority and the Royal Navy in the years of Pax Britannica. It brings to light the activities, backgrounds, concerns and skills of a group of actors who literally shaped the Royal Navy. The book demonstrates the ways in which naval architects shaped naval thinking about ship design and influenced how ships were employed in active service. The 1830 Whig government's Board of Admiralty abolished the Tory-controlled Navy Board and appointed Symonds to oversee many of its duties and made the self-fashioning of the enlightened 'sailor-designer' identity a priority. The book focuses on the implications of steam for the management of naval architecture. The shaping of the Warrior and the introduction of iron into the British warship took place against the backdrop of projecting naval power and actors building credibility for new materiel. HMS Captain fully represented Cowper Coles's ideas of what a turret ship should be, and her launch the culmination of over ten years' effort, to secure what he considered an ideal trial for demonstrating his design ideas. The Royal Sovereign was one of the Royal Navy's first warships built under the 1889 Naval Defence Act, which provided £21.5 million for ten battleships, thirty-eight cruisers and other smaller vessels. The Navy is one of the most historically significant, and yet singularly neglected, institutions in the history of technology and war.