Shipbroker Notes: Deadweight Scale

The deadweight scale can be of great assistance in estimating the weight of cargo loaded or discharged.
For example: if
Draft before loading = 14´ 6˝
Draft after loading = 29´ 0˝
It can be seen from the scale that the deadweight has increased from 5,000 to about 15,000 tons, or 10,000 tons has been loaded.
(density of the water would have to be taken into account)
Tons Per Inch Immersion, or TPI, is the number of tons that must be loaded or discharged at that draft to alter the draft 1 inch.
Tons Per Centimeters Immersion, or TPC, is the number of tons that must be loaded or discharged at that draft to alter the draft 1 centimeters. (Centimetre to Inch TPC = 0.4 x TPI.)