Massive vessels, the biggest in world, will be able to carry 23,000 containers

China is building the world's largest container ships, each of which will be able to carry more than 23,000 standard containers, which together can hold, for example, more than 1 billion units of the Apple iPhone X.

The construction of the first two megaships started in late July. They're being built by Jiangnan Shipyard Group and Hudong-Zhonghua Shipbuilding Group, both of Shanghai, according to China State Shipbuilding Corp, a State-owned giant that owns the two companies.

The ships are expected to be delivered to the customer, CMA CGM, a French container transportation and shipping company, in 2020.

The Marine Design and Research Institute of China, a CSSC research arm that designed the ships, said they will be the latest and biggest in its Heracles class－named after the hero of Greek mythology.

Each of the vessels will be 400 meters long and 61.3 m wide, and will be capable of moving 220,000 metric tons of cargo.

They will be propelled by liquefied natural gas, making these the first large container ships to be driven by the eco-friendly fuel, as opposed to diesel, the traditional propellant for large vessels, the institute said. Polluting emissions will be exponentially reduced, it added.

CSSC beat five world-class competitors－including Japan's Imabari Shipbuilding Co and South Korea's Daewoo Shipbuilding and Marine Engineering Co and Hyundai Heavy Industries－before signing a contract for nine 23,000 container-capable vessels with the French carrier.

Yu Lai, chief designer of the new ships at the Shanghai institute, said on Thursday that the design and construction of the gigantic vessels makes China a leader in the field of container shipping.

"In the past, we followed others; now we are running ahead of them," he said. "Compared with its predecessors, this new class of container ship is larger, has a high level of automation and features better safety and environmental performance. Its construction requires state-of-the-art manufacturing techniques."

Yu said the ships will require only about 30 crew members to operate. The maximum design speed will be 22 knots, or about 41 kilometers per hour.

Currently, the largest container ships are the six vessels built by South Korea's Samsung Heavy Industries for the Hong Kong-based container shipping and logistics service company Orient Overseas Container Line. They can hold 21,413 containers.

The second-largest is the COSCO Shipping Universe, which was designed and built by China State Shipbuilding Corp and which can hold 21,237 containers.