World’s First Bidirectional Self-Unloading Ship Sets Three World Records In One Go

The world’s biggest shipbuilder, China State Shipbuilding Corp, delivered a one-of-a-kind self-discharging ship which has several records to its name.

The Wontanara is the most powerful shallow-water transhipment self-discharger by carrying capacity, is the fastest self-unloading vessel, and also the first self-discharger with bidirectional sailing capability.

Built by the Chengxi Shipyard for global mining giant Rio Tinto, it was delivered at the shipyard’s Yangzhou shipbuilding wharf.

The heavy self-discharger is 215 m long, 42 m wide, 14.5 m deep and can accommodate 29,000 m3 in its cargo holds and carry 41,800 metric tons of goods.

Powered by a full diesel-electric propulsion system, it underwent a 12-day sea trial in the East China Sea.

A self-discharger, or self-unloader vessel, can unload its cargo using its own onboard machinery, without depending on shore-based cranes, grabbers, or forklifts.

Zhang Xinlong, general manager of CSSC Chengxi Shipyard, said that Rio Tinto has placed an order for 5 such vessels and Wontanara is the first unit.

He added that construction of the Wontanara began in May 2025, and its 14-month delivery cycle has proved Chenxi shipyard’s manufacturing strength and speed.

The second ship will be delivered in October and the remaining in the next summer, per sources. The ship has AI features and automation software which enables it to operate with a small number of crew.

For instance, the steering can be handled by a single operator through control levers.

All 5 ships will sail in water off Guinea, West Africa and will work for the Simandou Iron Ore Project, carrying iron ore from shallow-water terminals to massive bulk carriers.