Written by / Huang Yuxi (Management Cadre College, Ministry of Agriculture and Rural Affairs) Long Denggao (Tsinghua University)
Whether it is the world's longest cross-sea bridge - Hong Kong-Zhuhai-Macao Bridge, the world's largest estuary improvement project - Yangtze River estuary deep-water channel improvement project, or the world's widest submarine immersed tunnel - deep-middle passage island tunnel project, they are inseparable from the figure of the "steel giant ship" dredger. So, what is a dredger? What are its magical powers?
A boat that can "eat" sand
As a major country, dredgers play an important role in waterway dredging and cargo trade, urban infrastructure construction, energy development and utilization, coastal protection, tourism development, farmland water conservancy and disaster prevention, and national defense construction. It also has a function of reclaiming the sea to create islands, so it is called "the editor of the earth's surface".
Dredgers serve the water transport infrastructure industry and act as excavators in land infrastructure. Especially in China, where the water system is developed and the sea area is vast, dredgers have played a role in a series of super projects, such as: the world's highest level artificial deep-water port - Tianjin Port, the world's largest automated terminal - Shanghai Yangshan Port Phase IV, etc.
There are many types of dredgers, and the most widely used are rake suction dredgers and suction dredgers.
Among them, the working principle of the rake suction dredger is similar to that of a household vacuum cleaner, and the sediment on the seabed is continuously sucked up through a centrifugal pump. The "New Sea Tiger" ship, completed in June 2007, belongs to the rake suction dredger, which is the first time that China has realized the design and construction of a large rake suction dredger.
Another type of suction dredger works by twisting the sediment on the bottom of the sea through a winch knife, "loosening the soil" and then "eating" the sediment into the "belly" - the mud tank. The Tiankun dredger, which was successfully launched in November 2017, is a suction dredger. It was the world's largest dredger with the largest installed capacity, the strongest dredging capacity and the world's first long-range conveying capacity in China at that time.
"The run of the country, since the beginning of dredging", dredgers can always be associated with people's lives. In March 2021, the heavy cargo ship Changci ran aground in a new channel of Egypt's Suez Canal, causing a blockage in the channel and severely affecting global trade. Later, the Suez Canal Authority brought in the strongest foreign aid, dredgers, to help widen the channel of the Suez Canal.
National wheel and national manufacturing
The design and construction of Chinese dredgers is more than 100 years later than that of European and American countries, starting from imitation in the 60s of the 20th century, independent development in the 70~80s, rapid development in the 90s, and independent innovation in the 21st century; From relying on the import of the whole ship from the Netherlands, Japan, Germany and other countries, to the digestion and absorption of technology, the introduction of ship design and key equipment for domestic construction, and then to the self-design and construction of modern dredgers, it has completed leapfrog development and made major breakthroughs in ship type, dredging technology, power configuration, dredging control and other aspects. In 2019, "independent research and development and industrialization of offshore large-scale suction and dredging equipment" won the special prize of the National Science and Technology Progress Award, proving that China's dredger technology has been at the international leading level.
Sea "Hercules" - "Throughway" ship
The "Tongtu" ship completed in 2011 was the largest and deepest self-propelled rake suction dredger in Asia at that time, marking that China initially had the ability to independently design and build a super-large modern rake suction dredger. This maritime "Herlys", which once helped the construction of Tianjin Port, has a total length of more than 160 meters, a width of 30 meters, a depth of 15 meters, and a mud tank capacity of 20,000 cubic meters, equivalent to the volume of dirt of three standard football fields 1 meter deep.
Sand blowing and reclamation - the Sky Whale dredger
In 2010, China's self-developed Tianwhale dredger was the largest self-propelled suction equipment in Asia at that time, marking that China's suction dredger technology entered the world's advanced ranking. The seafloor mixture dug by the Sky Whale dredger every hour can fill a pit the size of a standard football field and a depth of half a meter, which is no overstatement to describe it as "cutting rock like mud". It has experienced three years and seven months to successfully complete the task of building port and waterway infrastructure in countries along the "Belt and Road".
Today, China has become a big country in the design and construction of dredgers, with the world's largest dredger fleet, stepping into the world's advanced ranks of dredger design and construction, and truly realizing the dream of "national ship and national construction"!
This article is comprehensively compiled from "Knowledge is Power" magazine, the original title is "The Editor of the Earth's Surface - Dredger", the author Huang Yuxi, Long Denggao, there are deletions and modifications, and the original works are reprinted please indicate the source.