Classification society DNV has granted Approval in Principle to a consortium of MSC, Zhoushan Changhong International and CIMC ORIC for a new 21,700-TEU ammonia-dual fuel ultra-large containership design, reported New York's Marine Link.

The AiP marks a milestone in zero-carbon mainline container shipping. The vessel will feature next-generation ammonia dual-fuel engines and oversized C-type ammonia tanks.

The hull incorporates a vertical bow, optimised stern and hull lines, low-resistance coatings, high-efficiency propellers and hydrodynamic features aimed at boosting fuel efficiency. Validation has been carried out through CFD simulations and model tests.

CIMC ORIC general manager Yin Xunbin said the recognition validates the consortium's commitment to future-ready vessels that reduce emissions while meeting global trade demands.

DNV experts reviewed the design against international standards covering fuel systems, propulsion, and ammonia safety. The AiP paves the way for detailed engineering studies and potential commercial construction under DNV rules.

DNV vice president Norbert Kray said ammonia-dual fuel options are advancing from concept to orders and soon deliveries. He added the approval reinforces confidence in ammonia as a viable fuel for large container ships.

The design has been optimised for high load-to-capacity ratios and efficient hold use. A twin-island deck layout and foredeck design allow additional 40-foot container bays while maintaining port compatibility. Further safety analyses and integration into the fuel system are planned as the project develops.