Definition(s)
Lightweight Survey
A lightweight survey involves taking an audit of all items which should be added, deducted or relocated on the ship at the time of the inclining test so that the observed condition of the ship can be adjusted to the lightship condition. The mass, longitudinal, transverse and vertical location of each item should be accurately determined and recorded. Using this information, the static waterline of the ship at the time of the inclining test as determined from measuring the freeboard or verified draught marks of the ship, the ship’s hydrostatic data, and the sea water density, the lightship displacement and longitudinal centre of gravity (LCG) can be obtained. The transverse centre of gravity (TCG) may also be determined for mobile offshore drilling units (MODUs) and other ships which are asymmetrical about the centreline or whose internal arrangement or outfitting is such that an inherent list may develop from off-centre mass.
Source: IMO resolution MSC.267(85), International Code on Intact Stability, 2008 (2008 IS Code), 4 December 2008, International Maritime Organization. Regulatory Guidance
Source: IMO Resolution MSC.267(85), adoption of the International Code on Intact Stability, 2008 (2008 IS Code), 4 December 2008, International Maritime Organization. Regulatory Guidance