A majority of the labor force in shipbuilding yards comprises of structural fabricators. They rely on technical drawings to fabricate all the structures that form a part of the lightship hull. The two most important skills necessary for structural fabricators are reading of engineering drawings, and fabrication of metal jobs. After fabrication of each structure, they also install the same on the hull. Most shipyards recruit fabricators after they have completed a certified apprenticeship programmer along with a related theory course. Some shipyards segregate structural fabricators from a specialist category of ‘Structural Fitters’. The only difference in these cases is that structural fitters are specialized for installation of machined structures into the ship’s hull, which requires more advanced engineering techniques.