Deadweight scale

The deadweight scale is a plotted or tabulated chart relating mean draft to deadweight, displacement, TPC, and freeboard, read directly to find loading at any draft. From an observed mean draft the operator enters the scale to get current displacement and deadweight, then subtracts lightship and known consumables to verify cargo on board, the basis of a draft survey. It is drawn for standard seawater density 1.025 t per cubic meter, with a density correction applied for brackish or fresh water. The scale is part of the ship’s hydrostatic documentation alongside the curves of form. It assumes upright, even-keel flotation, so trim corrections are applied separately.