Sea-Fastening of Cargos on a Platform Support Vessel Using Lashing Method

Abstract

This study examines the critical aspects of sea-fastening methodologies for securing cargo on Platform Support vessels, integrating theoretical principles, practical load plan results, and equipment certification. The methodology emphasizes a systematic approach encompassing data collection, force calculation, lashing plan design, execution, and verification, all crucial for ensuring cargo stability and vessel safety during maritime transport. The theoretical framework, rooted in Newton's laws of motion, analyzes static, dynamic (induced by vessel motions like roll, pitch, and heave), and environmental forces acting on cargo. Basic equations for inertial force, frictional force, overturning moment, and righting moment underpin the design and analysis of securing arrangements. The load plan results for twelve distinct loads reveal calculated maximum forces ranging from 10.1229 N to a critical high of 205.7179 N for specific loads (4 and 7). Correspondingly, lashing tensions were applied based on these forces, utilizing both single and dual belts at 50% (12500 N) and 75% (18750 N) of their strength, demonstrating a risk-adjusted securing strategy. The relatively consistent maximum acceleration values (around 0.10-0.11 m/s²) across loads indicate the significant influence of vessel motion on the forces experienced. The certification of a cargo lashing belt with a capacity of 2500 daN (25000 N) and the visual confirmation of such belts in practical application underscore the importance of using inspected and compliant equipment. The analysis highlights the necessity of addressing critical high-force loads with enhanced securing measures, as evidenced by dual lashings. Integrating a robust methodology, informed by theoretical calculations and validated through practical application with certified equipment, is paramount for ensuring the safe and secure cargo transportation at sea, mitigating risks to the vessel, crew, and the cargo itself. This study emphasizes the interplay between meticulous planning, accurate force assessment, and the appropriate application of securing equipment to achieve effective sea-fastening.