Chinese state-owned carrier Zhenghe Mainline has returned to Hengli Shipbuilding for six 4,600 teu containerships in a deal worth more than RMB3bn ($443m).

The ships will be deployed on a service linking Taicang with the Baltic after delivery, giving parent Jiangsu Port Group greater control over capacity serving exporters in eastern China and adding another vessel series to a route network it is building around its own port and logistics assets. The carrier also plans to use the expanded fleet to explore additional international routes.

Zhenghe Mainline was established last year as the liner shipping arm of Jiangsu Port Group. The company draws on the group’s port and logistics network across Jiangsu province, including Taicang, Nanjing, Zhenjiang and Zhangjiagang.

Delivery dates, propulsion arrangements and other technical details for the latest series have not been disclosed.

The order adds another sizeable containership series to Hengli’s rapidly growing backlog. The revived Dalian shipyard has filled delivery positions into 2030 and is investing RMB13.5bn in further capacity as it pushes deeper into the tanker, bulker and boxship markets, underscoring how Chinese yards continue to secure repeat business from domestic owners as they expand across multiple ship types.

Zhenghe Mainline first turned to Hengli in November 2025 for three 4,900 teu ships and two 2,700 teu units, all scheduled for delivery in 2028. Including the latest six vessels, its publicly confirmed orderbook at the yard now stands at 11 ships with combined capacity of about 47,700 teu.