The 24,000 TEU Megamax class, once regarded as the "ceiling" for container ship size, may soon be surpassed.

In its latest weekly report, consultancy Alphaliner has revived the concept of a new "Gigamax" ship type, arguing that thanks to advances in ship design, rising fuel costs and carbon pricing mechanisms, a vessel of about 27,500 TEU could become commercially viable in the 2030s.

According to Alphaliner's concept, the Gigamax-25 would be about 414 meters long and 63.3 meters wide, an increase over the current largest Megamax-24 (about 400 meters long and 61 meters wide). It could carry 25 rows of containers and add one extra slot at the forecastle, pushing capacity beyond 27,000 TEU. The ship would have a design speed of no more than 18 knots and use LNG dual-fuel propulsion. After a high degree of optimization, its fuel consumption would rise only slightly compared with older 20,500 TEU-class ships, while carrying about 7,000 TEU more.

As for port infrastructure, Alphaliner believes that the additional 14 meters in length and 2.5 meters in beam could be absorbed by the existing quay cranes, berths, turning basins and navigational channels at most terminals already serving 24,000 TEU ships, possibly without the need for large-scale modifications.

As for potential first users, Alphaliner considers Maersk the most likely to move first. As the only member among the world's top eight liner companies that has never ordered 24,000 TEU-class ships, its largest 31 vessels have an average capacity of about 19,600 TEU. Introducing the Gigamax would increase its flagship capacity by about 40%; at the same time, the "Gemini" hub network it operates with Hapag-Lloyd has fewer mainline port calls, making it suitable for larger ships. In addition, MSC and COSCO Shipping are seen as other obvious potential candidates.

Global container ship orderbooks currently stand at a record 14.7 million TEU, involving 1,795 ships, of which vessels of more than 10,000 TEU account for 68% of total ordered capacity.