Tool for life cycle assessment of ship material and structures at the concept level stage using the industrial work breakdown structure

Abstract

The International Maritime Organisation (IMO) and EU have taken wider steps towards decarbonisation of maritime industry with new set targets, introducing tariffs and penalties to motivate the maritime sector. Therefore, Life Cycle Assessment (LCA) is important part of the early design stage of ship design to evaluate the carbon emission impact of the design, which supports the investors, and designers to take decisions at the early stage of ship design. This thesis develops a tool for LCA of ship materials and structures at the concept level stage using the Industrial Work Breakdown Structure. The tool is developed based on the spreadsheet database with four main worksheets: SWBS, LCAI reference, LCA calculation, and result sheet. The tool follows cradle to grave LCA process including four stages: building, operation, maintenance, and scrapping. The tool presents the results as total global warming potential as carbon dioxide equivalent. The LCAI reference data base follows the EN 15804 module to store environmental impact data of the material. The tool applied to a case study Ro-Pax vessel and validated against four published reference vessels. The tool verified through compliance check, formula verification test, consistency check following the ISO 14040/14044 standards. A sensitivity analysis was carried out for the case study Ro-Pax vessel for seven categories. The case study result shows the major contributor for GWP factor is the operational stage (96.5%) for conventional fuelled vessel, and GWP intensity factor lies within the reference vessels. The tool produced maximum gap is 3.1% for four validation case studies. The sensitivity analysis of the main case study vessel shows that operational stage assumptions are dominating and highly sensitive. The tool is complying to the ISO 14040/14044 standards following the formula verification test and consistency check confirming correctness and uniformity. This study presents a generic LCA calculation tool to evaluate LCA at concept level stage for all commercial vessels. The tool is based on spreadsheet database, and it is incorporated with industrial work breakdown structure to organise material at concept level ship design. The tool has been verified and validated with independently published LCA studies. The Future work could focus on populating the LCAI reference database enabling automated import of material records to LCAI Reference database, program to direct import data from bill of materials.