Lofting

Lofting is a drafting technique (sometimes using mathematical tables) whereby curved lines are generated, to be used in plans for streamlined objects such as aircraft and boats. The lines may be drawn on wood and the wood then cut for advanced woodworking. The technique can be as simple as bending a flexible object, such as a long strip of thin wood or thin plastic, so that it passes over three non-linear points and scribing the resultant curved line, or plotting the line using computers or mathematical tables.

Lofting is particularly useful in boat building, when it is used to draw and cut pieces for hulls and keels, which are usually curved, often in three dimensions. Loftsmen at the mould lofts of shipyards were responsible for taking the dimensions, and details from drawings and plans and translating this information into templates, battens, ordinates, cutting sketches, profiles, margins and other data.Since the early 1970s computer-aided design (CAD) became normal for the shipbuilding design and lofting process.

Lofting was also commonly used in aircraft design before the widespread adoption of computer-generated shaping programs.

As ship design evolved from craft to science, designers learned various ways to produce long curves on a flat surface. Generating and drawing such curves became a part of ship lofting; "lofting" means drawing full-sized patterns, so called because it was often done in large, lightly constructed mezzanines or lofts above the factory floor. When aircraft design progressed beyond the stick-and-fabric boxes of its first decade of existence, the practice of lofting moved naturally into the aeronautical realm. As the storm clouds of World War II gathered in Europe, a US aircraft company, North American Aviation, took the practice into the purely mathematical realm. One of that war's outstanding warplanes, the North American P-51 Mustang, was designed using mathematical charts and tables rather than lofting tables.

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