World's largest pile-driving vessel delivered

NANJING — China's new self-developed pile-driving vessel, the largest of its kind in the world, has been delivered to a company in Jiangsu province. The delivery marks a milestone in the country's marine engineering equipment manufacturing industry.

The record-breaking vessel, named Erhang Changqing, features the world's highest derrick at the stern, with the largest piling capacity and strongest resistance to wind and waves, investor Second Harbor Engineering Co, a subsidiary of China Communications Construction Co, told Xinhua on Monday.

The vessel, built by Shanghai Zhenhua Heavy Industries Co, measures 130.5 meters in length, 40.8 meters in width and 8.4 meters in depth. It is equipped with a 150-meter-high derrick, capable of handling massive pile foundations weighing up to 700 metric tons with a diameter of 7 meters.

The former record holder, Yihang Jinzhuang, also built by Zhenhua, was delivered to CCCC First Harbor Engineering Co in 2022 with a slightly shorter derrick, 142 meters.

China leads the world in the production of large offshore wind turbines, which have become essential for foundation and turbine installations.

In the construction of large bridges and offshore wind farms, multiple steel pipes must be driven into the seabed to form a pile foundation, a task performed by pile-driving vessels.

A pile-driving vessel consists of three main components — the hull, the derrick and the oil cylinder. The hull serves as the platform, the derrick provides support and the cylinder acts as the vessel's "heart" to power the moves of the pile frame.

A technological breakthrough made by the CCCC Second Harbor Engineering Co is the critical component of an oil cylinder. The one on the new vessel is fully self-developed and weighs 385 tons, with a nearly 2-meter diameter and a world record-breaking length of 28 meters.

Equal to the height of a 10-story building, the oil cylinder is the heaviest and tallest in the world.

Historically, the manufacturing of large oil cylinders in China has faced challenges, as components such as sealing rings, bearing lubrication pads and corrosion-resistant materials are mainly imported with complicated procurement and high costs, said Yang Xiuli, deputy chief engineer of the CCCC Second Harbor Engineering Co.

In collaboration with six leading related domestic enterprises and four universities, including the prestigious Tsinghua University and Tongji University, "we have successively developed domestic sealing rings, bearing lubrication pads and corrosion-resistant materials, achieving the goal of localizing super-large and superlong oil cylinders," Yang said.

In addition, the vessel's advanced position system ensures incredible precision, placing piles within just a few centimeters of their designated location on the seabed.

The Erhang Changqing is designed to be more environmentally friendly and intelligent than traditional piling vessels.

It uses supercapacitors and energy storage batteries to smooth power fluctuations in the grid, paired with a high-efficiency permanent magnet motor for hoisting, resulting in lower fuel consumption and significantly reduced carbon emissions.

Before piling operations, the computer automatically calculates the positioning precision of the piles, while during the piling operation, it conducts real-time safety monitoring, automatically detects operational processes and generates construction reports, Yang said.

XINHUA