Construction of two container ships with the carrying capacity of 22,000 TEUs, which would make them the largest container vessels in the world, began on Thursday, the paper.cn reported.

The two are among nine 22,000 TEU vessels deal signed by French container shipping operator CMA CGM and China State Shipbuilding Corporation (CSSC) in September last year.

Built by Shanghai-based Jiangnan Shipyard and Hudong-Zhonghua Shipbuilding, the two container vessels measure 400 meters in length, 61.3 meters in breadth and 33.5 meters in depth. The deadweight of the box ship is 220,000 DWT, which can contain 1,000,000,000 iPhoneX (with standard packing box). Moreover, it can still hold 2,200 4-foot refrigerated containers, accounting 20 percent of the whole TEU.

Besides, they are also the world's first giant container ships propelling with engines burning liquefied natural gas, a technology breakthrough for environmental protection. They have distinctive advantages compared to the current ships using heavy fuel oil: Up to 25 percent less CO2, 99 percent less sulphur emissions, 99 percent less fine particles and 85 percent nitrogen oxides emissions.

The two vessels are expected to be delivered in 2019.