Uncertainty in lightship data

摘要

Lightship is used as the basis for stability assessment and loading capacity so that, by addition of the deadweight, the live load of the ship, is estimated. The lightship weight and horizontal coordinates of the centre of gravity are determined from a deadweight audit, the vertical coordinate of the centre of gravity results from inclining experiments.2018 and 2019 have seen a lot of travelling for the naval architects of Tymor Marine Ltd in carrying out deadweight audits and inclining experiments. Taking the 'lessons learned' from each of a series of trips onboard vessels, Tymor did a review of the inclining experiment that led both to a paper presented to the Society of Allied Weight Engineers this year, where the deficiencies in the traditional inclining experiment and possible solutions are discussed, and developments in the company's MOSIS system. The deficiencies that we feel exist in the traditional approach to ship stability include many aspects that are not discussed further here but a major shortfall is the failure to prescribe calculation of measurement uncertainty, an aspect which could be easily remedied.