Detailed information can be found from "Guidance/Best practices document on monitoring and
reporting of fuel consumption, CO2 emissions and other relevant parameters pursuant to Regulation 2015/757 on monitoring, reporting and verification emissions from maritime transport" and from other relevant sources; however, we would like to cover the most questioned DWT calculation.
General Cargo Ships
A ship with a multi-deck or single-deck hull designed primarily for the carriage of general cargo excluding specialized dry cargo ships livestock carrier, barge carrier, heavy load carrier, yacht carrier, nuclear fuel carrier.
General cargo carriers are a bit different when it comes to the DWT calculation definition of the regulations because they may carry various types of cargoes and some of them may have big volumes but relatively less mass. These occurrences differentiate general cargo ships from other ships' DWT calculations. Please find a quick summary for DWT calculation for both laden and ballast voyages as below:
Laden voyage:
Commission Implementing Regulation (EU) 2016/1928 defines the deadweight carried for the laden voyages of general cargo ships as follows:
DWT carried = volume displacement x water density – ship's lightweight – fuel weight
Ballast Voyages
Commission Implementing Regulation (EU) 2016/1928 defines the deadweight carried for the ballast voyages of general cargo ships as follows:
DWT is zero for ballast voyages
Sources: