Science and Technology Daily reporter Chen Yu
"The 7,000-meter manned deep-sea submersible has been set up, we want to come and go, this chief division must be your old Xu lai!" After a series of demonstrations and studies, in 2002, the large-depth manned submersible was finally officially approved for the project, and when the chief designer was selected, everyone invariably thought of Xu Qiannan, and Academician Wu Yousheng, the former director of the 702 Institute of China Shipbuilding Industry, made an invitation call to Xu Qiannan.
Deep-sea submersibles are considered to be engines and integrated platforms for the development of deep-sea technologies, and are also an important support for deep-sea scientific research and resource development.
Before the 7,000-meter manned deep-sea submersible "Jiaolong" project was established, the maximum depth of the submersible developed in China was only 600 meters. From diving a few hundred meters to 6,000 meters, it took almost 50 years for the United States, France, Japan and Russia. The "Jiaolong" plans to use 10 years to complete the road that foreign counterparts have taken nearly 60 years to complete.
From the "Jiaolong" to the 4500-meter manned submersible "Deep Sea Warrior" and then to the 10,000-meter manned submersible, in less than 20 years, the pedigree engineering of submersibles in China has been promoted in an orderly manner, and the breakthrough of manned deep diving technology has also led to the comprehensive development of China's deep-sea science and technology field.
Inspire submersible design with film and television footage
At the end of the 20th century, with the deepening of the china Oceanic Association's investigation and research work on the international seabed, the application needs of the country for manned submersibles became more and more urgent.
"It's too late! Hurry back to the house! When he received the invitation call, Xu Qiannan had retired from the 702 Institute of China Shipbuilding Heavy Industry for 6 years, but he always had a wish in his heart, that is, to see that the large-depth manned submersible independently developed by the Chinese could travel in the deep sea.
Despite suffering from high blood pressure, heart disease, and only a sense of light in one eye, Xu Qiannan resolutely gave up the life of recuperating in the United States and returned to China with his wife.
However, at that time, xu Qiannan was facing a particularly heavy burden - domestic experience in manned submersibles at such a large depth was not experienced, and at that time, foreign countries highly blocked manned deep diving technology. Fast forward to 2005, when the project had been in place for three years, and only two members of the team had ever seen a real deep-sea submersible. This means that most people can only understand the submersible with the help of foreign popular science books and watch film and television works. For example, the picture of the submersible in "Titanic" was repeatedly studied by them and inspired the design of submersibles in China.
From 600 meters to 7000 meters, behind the numbers is a very large technical leap.
In order to coordinate the work of the 12 sub-systems of the "Jiaolong" body, Xu Qiannan made a table and worked according to the table according to the technical progress and funds of each sub-system, which greatly improved the efficiency and quality. Faced with the bottleneck of talent shortage, he paid special attention to the cultivation of young people, and also tried to invite domestic and foreign experts to give lectures to the young designer team.
In the face of this large-scale system project, hundreds of domestic scientific research institutions have gathered wisdom to solve the most cutting-edge technical problems in many fields such as pressure-resistant structure and sealing technology design, processing and forming technology of high-specific strength alloy materials, navigation performance optimization, underwater positioning, underwater communication, automatic control and so on.
The sea trial forced out the latent problems in the design
In August 2009, after technical research, design, assembly construction and pool tests, the "Jiaolong" sailed to the sea, planning to complete the 7000-meter sea test in 4 years, and verify and improve the performance indicators of the "Jiaolong" through the sea test.
Although he was more than seventy years old at the time, Xu Qiannan still insisted on getting on the ship and taking command, dragging a trolley box filled with medicines, oxygen machines, sphygmomanometers and other medical equipment, and sticking with the scientific research team.
However, Ye Cong, the current chief designer of the 10,000-meter-class manned submersible and deputy director of the 702 Institute of China Shipbuilding Heavy Industry, who is the main driver, ushered in the "first blow" in the first dive in the 50-meter sea area.
At that time, in order to test the communication ability, the staff for the first time untied the cable connecting the Jiaolong to the mother ship. Unexpectedly, the reception of communication signals is unstable, and the walkie-talkie instantly "loses its voice". In the longest time, he stayed with two colleagues in the 2.1-meter-diameter ball cabin, lost contact with the mother ship for two hours, repeated calls, and no one answered.
This is just a relatively ordinary difficulty encountered by Ye Cong and his team in several years of deep diving careers.
After 4 years of sea trials, the diving depth of the submersible has been increasing, and the problems have been continuously exposed.
In the 2012 7,000-meter sea test, in order to fully test the possible failures, the degree of disassembly and maintenance of the submersible exceeded that of any previous sea test, but the fault resolution time was greatly shortened compared with the past, and the solution ability was greatly enhanced. In several diving tests, the on-site command did not let the "Jiaolong", which is approaching 7,000 meters, rush to collide with the line, but according to the plan, one by one, verify the function, and strive to get high scores in various assessments. Repeated experimentation, through the sea test to force out possible problems, do not let it lurk, this rigorous and realistic style has also become the "soul" of the manned deep diving spirit.
"I wish Jing Haipeng, Liu Wang, Liu Yang, the three astronauts and Tiangong-1 a smooth docking!" I wish China brilliant achievements in manned spaceflight and manned deep diving! At 9:25 a.m. on June 24, 2012, through the underwater acoustic communication system, at a depth of 7,020 meters in the Mariana Trench, Ye Cong, on behalf of his fellow Yang Bo and Liu Kaizhou, clearly sent sounds from the depths of the ocean to outer space.
7062 meters, which is China's manned deep diving record, but also the world's largest diving depth record of similar submersibles, which means that China has the ability to carry manned to more than 99.8% of the world's ocean depths for operation.
2020 will create a new "China depth"
With the deepening of the understanding of the deep sea, more and more insiders have reached a consensus: there is only one "Jiaolong" to march into the deep sea, and it is necessary to fully grasp the core technology and let the pedigree submersible get support in the country in terms of technology, components, operation and maintenance.
Based on the development experience of Jiaolong and the 4500-meter manned submersible "Deep Sea Warrior", in 2016, the all-sea deep (10,000-meter class) manned submersible project was officially established. The pressure of jiaolong at 7,000 meters is 700 atmospheres, and the 10,000-meter manned submersible will increase by more than 400 atmospheres.
Ye Cong told reporters that even with the previous technical foundation, the high-pressure and low-temperature deep-sea environment has brought unprecedented challenges to ball shell welding, buoyancy material testing, lithium battery quality control, and hydraulic component adaptability.
According to the plan, in 2020, the 10,000-meter-class manned submersible will be tested and put into use, creating a new "Chinese depth" and further improving China's marine exploration capabilities and research level.
Someone always asked Ye Cong, why did he dive deeper and deeper? The answer to this question, he has repeated many times: the seabed is rich in resources, and we know more about space and the moon than the deep sea. Exploring the ocean, protecting the ocean, strategizing the ocean, and building a marine power are all closely related to deep diving, and it is necessary to draw a deep-sea "treasure map" with the help of high-tech deep diving equipment.
The pictures in this article are from the Internet