Life cycle assessment in yacht industry: A case study of comparison between hand lay-up and vacuum infusion

he present study concerns the environmental impact assessment of a glass-reinforced plastic yacht built with two different technologies: hand lay-up technique and vacuum infusion. The main raw materials are: Glass Fiber, PVC for core and polyester resin. The principal difference between the two manufacturing techniques is the weight of the ship that will influence the production phase, the use phase and lastly the disposal phase. For Life Cycle Assessment for the impact assessment a commercial software has been used, GaBi software with Ecoinvent database. A specific evaluation of resistance of the ship with towing tank tests has been conducted, and an evaluation of the consumption, knowing the engine installed on board. This evaluation is possible thanks to the definition of three different profiles of usage of the yacht (low usage – 200 h/y, medium usage - 350 h/y and high usage – 500 h/y). For every profile, three different cruising conditions: navigation at maximum power (100% of the power on board), sailing cruising (85%) and lastly navigation in economic condition (65%). A curve of fuel consumption to the different percentage of power required is reported; in this way, it is possible for every navigation condition to evaluate the fuel consumption and, consequently, the environmental impact. In this paper is described that a lighter hull, with a reduction in weight of about 9% on deadweight, reduces the fuel consumption of about 656 t of diesel fuel over lifetime, with significant effect in the indicators of environmental impact in Life Cycle Assessment. Although these results may be expected, the use of Life Cycle Assessment has allowed quantifying the reduction of environmental impact in every single phase of the entire lifetime of the boats.