Background

Each welding operation (and heating in general) in metal structures causes deformation (shrinkage) of the structural elements involved. This means that if for example, plate parts are described to their nominal sizes they will in the fabrication and assembly process become too small to fit. Thus when fabricating the parts they should already have been compensated for the shrinkage so that the nominal dimensions are reached when the assembly process is completed.

Hull has a facility for shrinkage compensation that allows a user to describe his model to nominal dimensions but to extract parts which are expanded for the shrinkage. The purpose of this chapter is to describe this facility, including how a yard's experience may be loaded into a shrinkage compensation object for automatic or semi-automatic shrinkage compensation.