Bookings for capesize vessels to deliver cargoes to China fell 31 percent last month, according to figures from a unit of the world’s biggest shipbroker. Raw-materials producers and traders hired 53 such vessels to make shipments to China, compared with 77 in November,

data from Clarkson Research Services Ltd. showed. Capesizes typically haul coal and iron ore to make steel. China is the world’s biggest steel producer.

The data provide a snapshot of single-voyage, or spot, charters. They exclude long-term freight contracts that commodity producers and steel mills may have in place, and may be incomplete because brokers and traders are free to leave shipping deals unreported.

Lease rates for capesizes dropped 27 percent in December to $20,009 a day, according to the Baltic Exchange in London. The vessels are too big to fit through the Panama Canal’s locks and must instead sail around South America’s Cape Horn or South Africa’s Cape of Good Hope.

Capesizes, the largest vessels tracked by the Baltic Dry Index of commodity-shipping costs, have a carrying capacity of at least 100,000 deadweight tons, according to Clarkson Research Services, a unit of London-based Clarkson Plc.