[Video/ntfabu.com]

CMHI-16302, the world's most advanced sub-submersible platform with heavy lift cranes, set sail from Nantong, East China's Jiangsu province, on Feb 20.

The vessel, measuring 137.75 meters long and 81 meters wide and extending 96.3 meters above water, was tugged out of the Yangtze River and started its journey in the early morning on Feb 21.

"It was the most challenging tugging task ever carried out on the river," said Sun Xinyu, deputy director of the Nantong administration of maritime safety.

"A 399-meter-long, 101-meter-wide ship formation carried out the tugging work. Nantong authorities worked with their counterparts in Changshu and Taicang to ensure that everything progressed smoothly," Sun added.

The platform was independently designed and built by the Haimen-based China Merchants Heavy Industry (Jiangsu) Co and received more than 2 billion yuan ($309 million) in investment.

The platform is equipped with six 3,800-kW propellers and two 2,200-ton heavy lift cranes and is capable of producing oil and gas, as well as stripping down, assembling, and tugging offshore drilling platforms.

It is capable of operating under harsh conditions and offers a safe and comfortable living and working space for 750 people.

Over the past few years, Nantong has seen a significant expansion of its maritime engineering equipment and shipbuilding industries, which account for 25 percent and 10 percent of their respective industries in China.