SerpApi.Org
China State Shipbuilding Corporation (CSSC) delivered the first of five massive self-unloading ore carriers for Rio Tinto’s Simandou iron ore project in Guinea on July 21. Named Wontanara, the newly built vessel is expected to play a key role in moving iron ore from shallow coastal waters to large bulk carriers waiting offshore.
CSSC described the ship as the “king of self-unloading ships,” saying it sets three industry records. According to the company, the new class will be the world’s largest shallow-water transshipment self-unloaders by deadweight, the fastest specialized self-unloading vessels by discharge rate, and the first bidirectional self-unloaders in their tonnage category.
Built for shallow-water ore transport
The five ships were built specifically for Rio Tinto’s Simandou iron ore project in West Africa, which is one of the world’s largest untapped iron ore deposits. Rio Tinto is working with Chinese partners on the project, controlling two of the four mines, while a Chinese group runs the other two.
Mining operations at Simandou began in late 2025 and have continued expanding this year. The deposit has been valued at more than $24 billion.
A major challenge at the site is its shallow coastal waters, which prevent large ocean-going ore carriers from reaching the loading area. The new self-unloading ships solve that problem by transporting ore from the port to larger vessels anchored offshore.
Each vessel has a deadweight of 46,100 U.S. tons (41,800 tonnes), measures about 705 feet (215 meters) long, and can carry 1.02 million cubic feet (29,000 cubic meters) of ore. The ships operate with a draft of 47.5 feet (14.5 meters), compared with roughly 60 feet (18 meters) or more for conventional large ore carriers.
Faster unloading boosts export capacity
CSSC says each vessel can unload ore at a rate of 13,228 U.S. tons (12,000 tons) per hour, setting a new record for specialized self-unloading ships. The company says this represents a 71 percent improvement over the previous benchmark of 7,716 US tons (7,000 tonnes) per hour, which was achieved by another vessel it upgraded in 2023.
Since each ship can carry 46,100 U.S. tons (41,800 tonnes), CSSC estimates that the five ships together can fully load a 220,462 U.S. tons (200,000-ton) ocean-going bulk carrier in 24 hours.
The vessels were also designed for improved maneuverability. They can operate equally well in either direction, reducing the need for turning in confined waters. Power comes from a diesel-electric propulsion system, while onboard automation allows operations with a relatively small crew.
First vessel completed in 14 months
Construction of Wontanara began at CSSC’s Yangzhou shipyard in May 2025. The vessel was completed in just 14 months before undergoing 12 days of sea trials in late June and early July ahead of its July 21 delivery.
CSSC launched the first two ships of the class in May and June this year. The second vessel is scheduled for delivery in October, with the remaining ships expected to join the fleet before the middle of 2027.
When all five ships are in service, they will be the backbone of the offshore ore transfer system for the Simandou project. This will help move iron ore efficiently from Guinea’s shallow coast to the global shipping network.
