Capesize vessels are the largest dry bulk carriers. Too large to transit the Panama or Suez canals, they must sail around Cape Horn or the Cape of Good Hope — hence the name. They dominate iron ore trade from Brazil and Australia to China and are the most volatile BDI component. When Chinese steel mills increase iron ore imports, Capesize rates can surge dramatically.
Panamax vessels are sized to fit through the original Panama Canal locks. They carry coal, grain and fertiliser across Atlantic and Pacific routes. Panamax rates are heavily influenced by US, South American and Black Sea grain export volumes, and coal trade patterns between the Atlantic and Asia.
Supramax vessels are the workhorse of the dry bulk fleet. Their smaller size gives them access to a much wider range of ports globally, making them versatile across many commodities and routes. Many are equipped with onboard cranes, allowing them to operate in ports without loading infrastructure.
Handysize vessels are the smallest class tracked by the Baltic Exchange. Note that since March 2018, the BDI no longer includes the Handysize index in its calculation — it now consists only of Capesize (40%), Panamax (30%) and Supramax (30%). The BHSI is still published separately as a useful market indicator.
BDI Weighting — How Each Class Affects the Index
Since March 2018, the BDI is calculated using the following weighting: Capesize 40%, Panamax 30%, Supramax 30%. This means Capesize vessels have the most influence on daily BDI movements. A strong surge in Chinese iron ore imports can single-handedly drive the BDI up significantly even if Panamax and Supramax rates are flat.
What is Deadweight Tonnage (DWT)?
Deadweight tonnage measures the total weight a vessel can carry — including cargo, fuel, crew and supplies. It is the primary measure of a ship's carrying capacity and is used to classify vessel sizes in the dry bulk market.
What is a Time Charter Equivalent (TCE)?
The Time Charter Equivalent (TCE) rate is the daily earnings of a vessel after deducting voyage costs (fuel, port fees). It is the standard measure for comparing vessel profitability across different routes and is what the BDI sub-indices actually measure.