China's large engineering ship technology towards a high level of self-reliance

Skywhale is a large cutter suction dredger designed by Tan Jiahua. Its success indicates that the design, construction and use technology of China's large cutter suction dredger at sea have reached the international advanced level. Shanghai Jiao Tong University

With the continuous expansion of human ability to rationally utilize Marine resources, the development of Marine science and technology has become one of the major strategies for maritime countries to improve their comprehensive national strength. The particularity of the Marine environment determines that all Marine activities, such as exploring and understanding the ocean, developing and utilizing Marine resources, protecting the Marine environment, and maintaining national Marine security, must rely on corresponding Marine equipment and technology. It can be said that whoever has advanced equipment and technology will have an advantage in future Marine development. Large offshore engineering ship is a special ship with high investment and high technology that can complete various construction tasks above and below water. It is a major core equipment to achieve the strategic goal of national maritime power, and its design and manufacturing technology is the core key technology of the country.

Due to the numerous fields involved in the research and development of China's large offshore engineering ships, they have been developed independently for a long time, with dispersed forces and low information and equipment sharing rate. As a long-term research and designer of large offshore engineering ships, the author deeply feels that the research, development and use of China's large offshore engineering ships are in a historical turning point and rapid development period, so we must take a high level and high quality development path, improve the original innovation ability, concentrate on overcoming the "bottleneck" problem, and carry out the "land-sea overall planning" of large offshore engineering ships. To realize the joint development of large-scale offshore projects and upstream and downstream industries, and make greater contributions to the construction of a maritime power.

Struggle to catch up

Some technologies have reached the international leading level

Due to the complete industrial system of European countries and the strong research and development capabilities of large offshore engineering ships, many new types of large offshore engineering ships were first developed in Europe. Large European shipbuilding groups have strong design, construction and supporting strength, flexible and diversified management methods, and the relevant construction market is still dominated by European shipyards. China started late in the field of large offshore engineering ships, and still lags behind developed countries in Europe and the United States in terms of equipment core technology, but since the reform and opening up, especially in the past 20 years, China's industrial system has gradually improved, the shipbuilding industry has developed rapidly, and great progress has been made in the field of large offshore dredgers, large cranes and wind power installation ships, and some technologies have reached the international leading level.

In terms of large offshore dredgers, China has realized domestic design and manufacturing in the field of main types of cutter suction dredgers and rake suction dredgers, and has got rid of the dependence on foreign countries. Especially since the beginning of the 21st century, due to the strategic needs of coastal port and waterway dredging, offshore major infrastructure and industrial base construction, and far sea islands and reefs construction, a large number of high-tech and high value-added dredgers with independent intellectual property rights have been launched. In particular, the development of large cutter suction dredgers at sea has broken through core technologies such as offshore positioning, rock excavation, long-distance transportation and complex system integration, and has designed and built a number of large cutter suction dredgers at sea. The working sea area extends from coastal and offshore to far sea, and the digging soil has expanded from silt and hard sand to hard rocks. The operation capacity of a single ship has been increased from 2,500 cubic meters per hour to 6,500 cubic meters, forming a series of products, and driving the rapid development of equipment technology and industry in the dredging industry. In the past 20 years, China's annual dredging capacity has increased from 300 million cubic meters to 1.7 billion cubic meters, accounting for about 40 percent of the world dredging market. China's large dredgers have realized the leapfrog development from being blocked to export control, not only meeting domestic demand, but also playing an important role in the construction of ports and waterways in the "Belt and Road".

In terms of large cranes, according to different operational needs, foreign countries have developed a variety of large offshore cranes such as single-hull, multi-hull and semi-submersible vessels, which are used for the installation and removal of jacket platforms, the lifting installation of Bridges and tunnels, the laying of submarine pipelines, maritime salvage and rescue. At present, the world's largest lifting capacity of semi-submersible crane capacity of 20,000 tons. Compared with foreign countries, the domestic large crane market is in a stage of rapid development. With the implementation of the national energy strategy, the exploration and exploitation of deep-sea oil and gas fields have entered the concrete implementation stage, and the demand for large crane ships is quite large. Domestic research institutions, design units, and ship manufacturing enterprises have made breakthroughs in some key technologies such as improving the ship's ability to withstand wind and waves, ship positioning and shifting technology, the impact of ship motion on crane design, and crane control and operation technology through the combination of independent research and development and introduction, digestion and absorption in the past 20 years. Gradually formed a number of products with independent intellectual property rights, so that the lifting capacity of China's large offshore crane ships from hundreds of tons to 10,000 tons. China has independently designed and manufactured the world's largest single-hull crane, with a lifting capacity of 12,000 tons. At present, the overall situation is that the number of large cranes in China is large, the variety is single, and the lifting capacity is still small.