China State Shipbuilding Corp announced on Tuesday that it has started constructing the world's largest and most capable liquefied natural gas carrier.

The State-owned conglomerate said in a statement that the first in the QC-Max class, which is yet to be named, entered the construction phase at the premises of the company's Shanghai-based subsidiary Hudong-Zhonghua Shipbuilding, marking a milestone in a historic deal between CSSC, the world's largest shipbuilder, and Middle East energy giant QatarEnergy.

In April 2024, CSSC won a contract for 18 QC-Max superheavy LNG tankers from QatarEnergy, the world's largest LNG provider. The two signed a deal for another six QC-Max ships months later.

The contracts, with a total value exceeding 56 billion yuan ($8.27 billion), represent the world's largest shipbuilding order on record.

According to CSSC, each of the carriers measures 344 meters in length, 53.6 meters in width and 12 meters in draft, with a cargo capacity of 271,000 cubic meters of LNG.

The volume of natural gas carried by a single QC-Max tanker can meet the gas consumption demand of 4.7 million households in Shanghai for one month.

Huang Huabing, deputy chief constructor of LNG carriers at the shipyard, said the QC-Max project now stands as one of the iconic landmarks in the country's path toward becoming a world-leading shipbuilding power.

Against the backdrop of a volatile geopolitical landscape and complex global economic and trade environment, the project has significantly boosted confidence among domestic and international players in the entire LNG industry, he added.

According to Huang, the QC-Max class boasts top-tier overall performance, featuring large carrying capacity, low energy consumption, low carbon emissions, eco-friendliness and high safety design.

He noted that compared with the widely used 174,000-cubic-meter vessels, the new model's carrying capacity is 57 percent more, while its energy consumption is 2 to 8 percent lower than that of rival designs from foreign shipbuilders.

Chen Jianliang, chairman of Hudong-Zhonghua Shipbuilding, noted that an LNG carrier is a giant floating cryogenic vessel designed to transport LNG at an extremely low temperature of — 163 C. It requires top-tier materials and sophisticated thermal insulation technologies, representing the highest technical prowess of the civil shipbuilding industry, he said.

According to Chen, engineers adopt stringent technical and safety standards to ensure safe ocean voyages for LNG carriers that can last for weeks.

"An LNG carrier must be built with special Invar steel because ordinary steel plates suffer immediate brittle fractures at — 163 C," Chen said. "A single carrier has more than 130 kilometers of Invar steel weld seams. The welding requires extreme precision, and not a single drop of sweat is allowed to fall on the seams, as it could cause corrosion of the Invar steel and lead to gas leakage."

Hudong-Zhonghua Shipbuilding embarked on its LNG tanker development program in 1997 and secured its first order in 2004. In 2008, China's first domestically built LNG carrier, Dapeng Sun, was completed and delivered at the Shanghai shipyard.

To date, the shipyard has built and delivered 62 LNG carriers. According to Chen, it completed construction of 13 large LNG carriers in 2025 alone and delivered 11 of them.

In January, Hudong-Zhonghua Shipbuilding signed a contract with Greek shipowner TMS Cardiff Gas for the construction of four 174,000-cubic-meter LNG carriers, with options for two additional vessels. The deal marked the first time a Greek shipowner had placed LNG carrier orders with Chinese shipyards.

Chen said that the shipyard's current order book stands at 92 LNG tankers, with deliveries scheduled through 2031, adding that Hudong-Zhonghua plans to reach an annual output of more than 20 LNG carriers by the end of the 15th Five-Year Plan (2026-30) period.

zhaolei@chinadaily.com.cn