Draft Survey · Knowledge Note
What Is TPC in a Draft Survey?
TPC is the weight needed to change a vessel's mean draft by one centimetre. What it means, how it is derived, and where the figure is used on board.
Subject
Draft Survey
Reading draft marks, density and trim corrections, deductibles and the final cargo calculation.
Draft Survey · Explainer
Trim Correction in a Draft Survey: First, Second and the Sign Errors
Why a draft survey needs two trim corrections, how each one is calculated, and how a sign convention applied the wrong way quietly moves the cargo figure.
Draft Survey · Technical Guide
How to Perform a Draft Survey: The Full Procedure
The complete draft survey procedure, from reading the marks to the final cargo figure — with a worked example and the errors that cost the most tonnes.