The Structures of English Wooden Ships: William Sutherland's Ship, circa 1710

Beginning early in the sixteenth century, English shipbuilding methods underwent a major revolution with the introduction of Mediterranean/Iberian carvel, or plank-on-frame, techniques in place of the earlier, northern European clinker or lapstrake approach. In the older method, the lower edge of each strake of the planking overlapped on the outside the upper part of the strake below, and clenches (turned over or riveted nails) were driven through this overlap. These fastenings provided much of the strength of the finished hull. The southern method, which had its roots in the late Roman era but was not fully developed until the Middle Ages, depended on a rigid framework to which planks were subsequently fastened, there being no direct fastenings between adjacent strakes. The strength and rigidity of the frame allowed larger ships to be built and, perhaps more importantly, permitted them to carry heavy guns. Some three and one-half centuries after this revolution, an even more profound change began in which wood was replaced as the primary material for ship construction by iron. The new material encouraged wholly new structural arrangements, such as watertight bulkheads and longitudinal framing, and thus led to fundamental change in every aspect of ship construction. Between these two eras of rapid technological change there was relative stability. Indeed, there is an unfortunate tendency in the current literature to suppose that this era was characterized by absolute stability of ship structures; in effect, to suppose that the structures of late Tudor ships differed only in detail from those of nineteenth or early twentieth century wooden hulls. This was not so. This misunderstanding probably has its origin in the widespread contemporary disinterest in technical matters. Artists' patrons were generally concerned with ships as finished objects and not in the means by which they were built, a bias reflected in surviving paintings and models. The shipwrights rarely felt a need to commit their knowledge to paper: many were illiterate while most who could have described their skills in writing preferred to preserve the secrets of their trade. The few senior shipwrights who did prepare technical treatises often did so in private manuscripts, and even then most confined their explanations to the geometrical methods used to lay down the lines of their creations, avoiding complex structural accounts. Historians of post-Medieval ships have understandably responded to this limited information by concerning themselves with shape, external appearance and rigging, for all of which they had useful sources, while largely leaving aside matters of hull structure and other internal detail.