Tolerances: You are correct, real wooden ships could not be built exactly in accordance with the design drawings. Their hulls were complex three dimensional structures that had to be “sculpted.” During this building process, subtle variations would occur that could affect the finished vessel. This may account for differences in sailing performance of different ships supposedly built to the same design. And it may also be why historians have so much difficulty figuring out which of the several contemporary lines drawings show the “real” shape of the Schooner Yacht America. Lines recorded by the British in a dry dock are slightly different from drawings from other sources.
In his interesting book, Industrializing American Shipbuilding, historian William Thiesen explains the technical changes required by the transition from wood to iron ship building. Where wooden ships had been built on the building ways by artisans, iron, and later steel ships now required 1000’s of drawings to precisely show construction details. A rivet cannot be driven though two pieces of steel plate if the holes do not line up exactly.
This is not to encourage sloppy workmanship. Ship designs have what historians call “defining characteristics.” A knowledgable observer looking at a ship model should be able to immediately see the unique characteristics of whatever design its builder has chosen to build. Or as Bob Cleek has posted “a compelling impression of the real thing.”
Roger
