"I have deep feelings for the ocean, my whole life is closely connected with the sea." This is a favorite saying of Xu Qinan, academician of the Chinese Academy of Engineering and chief designer of the "Jiaolong" submersible.
As a pioneer in China's deep-sea diving technology and a recognized leader in manned deep-sea diving, he has made outstanding contributions to the development of China's deep-sea diving technology and engineering, as well as the design, construction, and application of manned/unmanned submersibles. With a lifetime of dedication, he is scripting a new era story of "the old man and the sea."
Xu Qinan is at the equipment debugging site. Image provided by China Shipbuilding Science Research Center
Waiting a lifetime for an opportunity
"Here is the 'Jiaolong,' here is the 'Jiaolong.' We have reached the bottom at 7,020 meters!" On June 24, 2012, in the Mariana Trench in the Pacific Ocean, there was a burst of excitement in the command room of the trial ship "Xiangyanghong 09" (referred to as "Xiangjiu").
The "Jiaolong" eventually dived to a depth of 7,062 meters. This set a new record for manned deep-sea diving in China at the time, and was also the deepest dive for a manned submersible of its kind in the world at that time.
The independently developed deep-sea manned submersible that can roam the deep sea was Xu Qinan's lifelong dream. However, Xu Qinan once thought that his dream could not be realized.
China's manned deep-sea diving project was first proposed in 1992 and the project demonstration lasted for a full 10 years. Xu Qinan did not wait for the day the project was approved at his job. In 1996, at the age of 60, he retired with regret.
It wasn't until 2001 that the manned deep-sea submersible project was preliminarily approved. This news excited Xu Qinan greatly. Having personally participated in the design of almost all types of submersibles, manned/unmanned, with cables/without cables, and having served as the chief designer for four projects, Xu Qinan was eager to provide consultancy work for the construction of the 7,000-meter manned submersible project.
Almost simultaneously, Xu Qinan received a call from Wu Yousheng, the former director of the 702nd Research Institute of China Shipbuilding Industry Corporation (also known as China Shipbuilding Science Research Center) and a member of the Chinese Academy of Engineering: "Old buddy, after much consideration, we still want to invite you to lead the 7,000-meter manned submersible project as the chief designer!"
This usually calm and composed elderly man suddenly became excited: "Since 1992, I have been involved in the preparatory work for the establishment of the 7,000-meter manned submersible. I think I should be able to fulfill my wish and contribute to the country. This is the opportunity I have been waiting for all my life."
In the end, at the age of 66, Xu Qinan became the chief designer of China's first deep-sea manned submersible, the "Jiaolong."
"For the needs of the country, I will strive forward"
The development of deep-sea submersibles is a world-class technological challenge. For a long time, China has made achievements in both "going to space" and "digging into the ground," but progress in "going to the sea" has been slow.
According to the project goals, the maximum working design depth of the "Jiaolong" is 7,000 meters, covering 99.8% of the world's ocean areas. However, prior to this, the deepest working design depth of China's manned submersibles was only 600 meters.
It is important to note that with every increase of 100 meters in underwater depth, there is an increase of 10 atmospheres of pressure. The technical leap from 600 meters to 7,000 meters is incredibly challenging.
The first challenge is the complex marine environment. In the deep sea at 7,000 meters, all equipment on the manned submersible must withstand the equivalent of 70 megapascals of deep-sea pressure and resist corrosion from seawater. Additionally, the key component that houses the submersible crew—the manned sphere—must not only withstand high water pressure but also maintain a constant atmospheric pressure inside, ensuring that the crew inside the sphere feels as if they are on land. Furthermore, the life support system must maintain oxygen concentrations of 17% to 23% and carbon dioxide concentrations below 0.5% inside the sphere. In addition, there needs to be technology for communication, voice, text, and video transmission, with the submersible equipped with a comprehensive underwater communication system, underwater positioning system, and video system.
As a major scientific project, the development of the "Jiaolong" involves cutting-edge technologies from multiple fields. The chief designer's role is to coordinate these complex technologies. Xu Qinan summarized the design philosophy in 16 words: rich inheritance, key breakthroughs, integrated innovation, and overall leap.
For the "Jiaolong," Xu Qinan envisioned it as "like a whale, streamlined, needing to be stable for direct navigation, yet agile and flexible, capable of diving deep, performing tasks, coming back up, and ensuring safety..."
To achieve this goal, starting in 2002, Xu Qinan and his wife settled in the guesthouse of the 702nd Research Institute of China Shipbuilding Industry Corporation in Wuxi, where they lived for over a decade. Leading a team of more than 50 domestic units, including the China Ocean Mineral Resources Research and Development Association, the Shenyang Institute of Automation of the Chinese Academy of Sciences, and the Institute of Acoustics of the Chinese Academy of Sciences, Xu Qinan spearheaded innovation and breakthroughs, overcoming key challenges such as overall pressure resistance and seabed sitting methods, and successfully completed the design, assembly, and pool testing of the submersible.
In August 2009, the "Jiaolong" underwent its first sea trial. That year, Xu Qinan was already 73 years old.
Carrying a suitcase filled with medications, oxygen machines, blood pressure monitors, and other medical equipment, Xu Qinan boarded the trial ship "Xiangjiu" with everyone else and stood guard on the ship for over three months, just like the younger crew members. At the end of the sea trial, colleagues found Xu Qinan lying in the cabin, experiencing another bout of angina.
During his tenure as the chief designer of the "Jiaolong," even with oxygen tanks by his bedside and taking over a dozen medications daily, Xu Qinan was unwilling to leave the exhilarating field of China's manned deep-sea diving industry and continued to stay at the forefront of scientific research day after day. He said, "For the needs of the country, I will strive forward."
Subsequently, China's manned submersible underwent sea trials at increasing depths each year: 1,000 meters, 3,000 meters, 5,000 meters, and finally 7,000 meters. With each dive, the "Jiaolong" underwent corresponding technological improvements.
On June 24, 2012, the successful 7,000-meter sea trial of the "Jiaolong" took place. On that day, three divers and three astronauts from the "Tiangong-1" successfully achieved a "dialogue between sea and sky." At that moment, Xu Qinan was moved to tears.
Breaking through waves, navigating through life
With globally leading functions such as near-bottom autonomous navigation, hovering positioning, high-speed underwater communication, and more, China's "Jiaolong" sails through the deep sea, breaking through waves. However, just two days after successfully reaching the seabed, the "Jiaolong" encountered an unprecedented crisis.
On June 26th, the sea trial command decided to seize the opportunity and arranged for the "Jiaolong" to dive again to further consolidate the achievements already made. At 12:37, while already sitting at a depth of 7059 meters, the "Jiaolong" suddenly lost contact.
"Jiaolong! Jiaolong! This is Xiangjiu, where are you, what's the situation? Please respond quickly, please respond quickly..." In the acoustics control room of the mother ship, the staff anxiously called out, but received no feedback, neither in voice communication nor in text or image transmission. Even the emergency communication methods yielded no response.
The atmosphere at the scene command center was unusually tense.
Xu Qin'an's physical condition did not allow him to go to the scene, but he remained calm while overseeing the Beijing land-based support center. Xu Qin'an closely watched the large screen, closely monitoring the "Jiaolong's" trajectory. Suddenly, he noticed that although communication was interrupted, the "Jiaolong's" active track could still be traced through the ultra-short baseline. This indicated that the equipment and onboard power system of the "Jiaolong" were in normal condition.
After some thought, he told everyone, "There's no need to panic just yet. If the submersible had an accident, the ultra-short baseline wouldn't detect a signal, and it wouldn't be moving. I believe the submersible itself is fine, but the lack of contact may be due to a communication system failure." Only then did everyone breathe a sigh of relief. Just then, after a full 40 minutes of interrupted communication, the underwater acoustic communication device suddenly sounded: "Xiangjiu! Xiangjiu! This is Jiaolong! This is Jiaolong! Everything is normal..."
With his years of experience, Xu Qin'an steadied the emotions of the staff. It was only later that he learned this false alarm was caused by a mistake.
From the inception of the "Jiaolong" to the present, over the years, China has made key breakthroughs in general technologies such as underwater acoustics, propulsion systems, buoyancy materials, and underwater navigation, driving the development of the domestic deep-sea equipment industry. With each step forward in China's manned deep-sea exploration, Xu Qin'an has made significant contributions.
"After a lifetime of working with submersibles, I have always wanted the working range of Chinese submersibles to cover almost all the world's oceans, and this wish has finally come true." Xu Qin'an spent his whole life making this dream a reality.
