Half-block model

A half-block model is a carved wooden model of one side of a ship’s hull, split on the centerline, used historically to develop and record the hull form before computer fairing. The builder shaped the half hull in laminated layers (lifts), then took offsets directly off the model to lay down the lines and loft the frames full size on the mold loft floor. It captured a fair, three-dimensional shape in a way two-dimensional drawings alone could not, and surviving examples are now naval-architecture artifacts. The method was displaced by the lines plan plus mold-loft lofting, and later by numerical hull fairing.