Lofting

Lofting is a drafting technique to generate curved lines. It is 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 as elaborate as 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. These 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. From the early 1970s onward 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. Provided by Wikipedia