HULL’S MANUFACTURING COST STRUCTURE

Sa？etak This study analyses the structure of costs of several processes associated with the shipbuilding industry. The analysed productive processes are: cutting preparation procedures, steel plate cutting processes, processes of hull plates and stiffeners forming, associated transportation and assembling of plates and profiles, and finally the welding processes. The methodology allows a shipyard to identify the main costs related to the manufacturing of the hull and the aspects that should be improved for increase productivity. The methodology adopted may easily be adapted by each shipyard creating a work database in order to improve and update these formulas by adding new corrective coefficients based on the type of the built ship or construction complexity of certain ship blocks. It is analysed 2 independent case studies that took place at different Portuguese shipyards and covering different aspects of the steel hull shipbuilding processes. The first case study considers time and cost analysis of cutting preparation processes made by the design office, cutting/marking of steel plates and forming processes of stiffeners and hull plates, required for the construction of an 83m Hopper Barge, built by MPG, at LISNAVE Mitrena Shipyard, Portugal, 2010. The second case considers the time and cost analysis of stiffeners cutting, steel plates and stiffeners assembly and welding, associated with the building of several blocks of an 80m fisheries supporting vessel by JOPERINOX Shipyard at Alverca, Portugal, 2008