Quantitative assessment of material composition of end-of-life ships using onboard documentation

Ship recycling yards around the world offer a price to the ship owners for buying an obsolete vessel to demolish and recycle based on the ship's end-of-life weight. The offer price is mainly based on the type of ship and the estimated quantity of steel available. The steel weight estimation, in terms of percentage of lightweight (LDT), is carried out either on the basis of recycling yards’ experience or by an expert opinion without using any scientifically rigorous method. The accurate quantification of all the material streams of an end-of-life ship is needed for planning the ship recycling process with better resource allocation and waste management strategies, especially in light of the Hong Kong convention and the new EU regulation on ship recycling. It might also assist in better estimation of cost and income of recycling the ship. A literature survey of the subject found that a clear knowledge gap exists in this area of study, only aggregate data of materials of ships is available, no ship by ship data exist. Thus, in this paper, a methodology to quantify material streams of an individual ship using the information readily available at the end of its life is presented. The advantages of using the developed methodology are explained. Lastly, a few recommendations to improve future ship designs for safe and environmentally sound ship recycling are presented based on the knowledge gained in the methodology development process.