The South China Sea, surrounded by the Chinese mainland, Chinese Taiwan island, Philippines archipelago and the Indo-China Peninsula, is also known as Nan Zhongguo Hai (Chinese pinyin) due to its location to the south of the Chinese mainland. It is China's biggest, deepest and purest sea with an area of 3.56 million square kilometres, equivalent to three times the combined area of the Bohai Sea, the Yellow Sea and the East China Sea. It is the world's third largest marginal sea, right next to the Coral Sea in the South Pacific and the Arabian Sea in the Indian Ocean.
About 2.1 million square kilometres within the nine-dash line are under China's jurisdiction, with an average water depth of 1,212 metres and a maximum depth of 5,567 metres. The South China Sea contains four islands, namely the Dongsha, Xisha, Zhongsha and Nansha Islands, which are scattered across the vast, endless deep blue sea. If you look down from the sky, you will find these islands laid out like sleeping lotuses in full bloom one after another, or like strings of dazzling pearls...
This sea was chosen as the location of China's first deep- sea manned submersible sea trial. In early August 2009, the test mothership Xiangyanghong 09 sailed from the Yangtze River and entered the East China Sea, bearing its crew of test members and the elaborately built Hexie. It made a stop at Luhuashan Anchorage to avoid Typhoon Morakot. Meanwhile, various preparations were underway, including the publication and implementation of the sea trial files, institutional organization building, machine and equipment inspection, as well as operating procedure and emergency relief and rescue drills practiced by the team members. After braving the wind and waves for the entire journey, the mothership arrived at a certain spot in the South China Sea, somewhere to the south of Sanya City.
According to the scheduled plan, the sea trial would be carried out in stages from the shallow areas to the deep areas. The sea trial of the manned submersible was divided into four stages in terms of depth, namely depths of 1,000 metres, 3,000 metres, 5,000 metres and 7,000 metres. The first stage was further divided into three substages, consisting of 50 metres, 300 metres and 1,000 metres. Each stage had an elaborate test plan. At the end of each test stage, expert review meetings will be organized to evaluate the test results, which will assist the leading group in making collective decisions regarding the next stage of the mission.
After thorough analysis and research, they classified the trial area of the South China Sea into Al, A2, B1 B2 and other marine areas. The 50-metre sea trial was located in the A1 area, which came to be regarded as the cradle of China's manned submersible project and where a glorious new chapter in modern technological history would unravel.
15th August was a special day. It was on 15th August 1945 that Japan announced its surrender. The command headquarters decided to launch the first test at a spot 25 miles south of the anchorage at Sanya on this date, which was to be the first dive of the sea trial. The day was laden with meaning.
The target of this test was to review the compatibility and coordination between the launch and recovery systems of both submersible and mothership, to improve operating procedures, to launch the submersible from the deck into the water and back again and to accumulate operational experience. Furthermore, the test aimed to debug the underwater communication apparatus and positioning sonar; conduct a functional review of all of the submersible's sub-systems and equipment when floating on the sea's surface; provide the oceanauts with some initial practice in operating the submersible at sea; enhance the coordination and support capabilities of different departments and positions; revise and improve operating procedures with practice; enhance the leadership capabilities of command headquarters, etc.
Just as the sun started to peek over the horizon, the rear deck of Xiang 9 was already bustling with people. Personnel from the surface support system, frogmen responsible for connecting and disconnecting cables, along with other sea trial support members, were carrying out the duties inherent in their roles and were performing their daily drills in an organized way. Two young men entered into the cabin one after another at 8:30 am. They were oceanaut Tang Jialing and technician Zhang Dongsheng from the Institute of Acoustics.
Cui Weicheng, the first Vice Chief Engineer of the manned submersible and Deputy Director of the 702 Institute, climbed down the ladder and entered the cabin straight after them. He was also a member of the command headquarters and was in charge of the submersible body. He made a statement at the outset of the research and construction stage: "As designers, we must have the confidence to dive first. Chief Engineer Xu is elderly. I must shoulder this responsibility!" Therefore, he was quite sure of himself and had no nerves whatsoever. That morning, Fu Jinling, the doctor on the ship tested his blood pressure as usual, and it was 80/120. Very normal!
Tang Jialing efficiently checked all of the equipment at 8:55 am and reported headquarters that everything had gone well. At the order of "LAUNCH", the machines roared to life, the railcar moved backward, the A-frame went forward and the hoist cable was lowered to connect to the submersible. After the submersible had been hoisted, it was connected with the auxiliary cables while the A-frame went backward. However, once the A-frame was in position and the submersible had been lifted from the ship, the secondary hook failed to disconnect after several attempts. Yu Jianxun was a big man from the 701 Institute, and it was he who was responsible for the A-frame. He sweated, making his pale face look even greyer.
Back in the submersible cabin, the three pilots were left hanging in mid-air, confused as to why the submersible had not yet dived. Two of them in particular kept looking at each other. Director Cui was the composed one. He calmed them down by saying, "Don't worry about it, guys. There is nothing you can do about it. Let's leave the issue to our comrades outside and take care of our own business." Little Tang and Little Zhang were relieved and started to discuss submersible operating procedures. The command headquarters gave instructions to recover the submersible for now. The A-frame put them on the railcar and returned them to the deck. Technicians did a quick inspection and found that the main cable had not been in the right position during the hoist. Only one of the two secondary hooks was connected. The other one had failed to disconnect because the force being exerted upon it was too powerful.
After the troubleshooting, the submersible was hoisted again and launched smoothly into the water. The pilots started to carry out surface inspections. Zhang Dongsheng initiated the debugging of the acoustic system, but failed to communicate with the surface. The Very High Frequency (VHF) that was supposed to be capable of bridging the radio communication between the mothership and the submersible was too noisy to be heard. The pilot, Tang, and the acoustic technician, Zhang, were running around like headless chickens and couldn't figure out any solutions. This issue was reported to a research fellow, Zhu Min, who was responsible for the acoustics. He was also in a panic, but failed to solve the problem. The radio signal even ended up going off completely.
According to sea trial standards, if there is no communication between the surface and the submersible, then the submersible is not allowed to dive. Chief Commander Liu Feng had to give the order to once again call the submersible back. It was not a good start, having debugging problems two launches in a row. However, it led to further examination of the communication and integration of the organization and command systems, enhanced coordination between different positions, guaranteed the safety of the first sea trial and explored the characteristics and regularities of sea trial implementation, all of which could be considered as achievements.
The headquarters conducted an in-depth analysis that night, and concluded that the major issue that needed to be urgently resolved was communications failure. If it was not sorted out, the sea trial would not go ahead. An underwater submersible with no communications is like a blind man riding a horse near the edge of a cliff in the middle of the night. The danger is indescribable. All of the team members looking after acoustics on the submersible were under extreme pressure, in particular Zhu Min, a research fellow from the CAS Institute of Acoustics. He was a student of Professor Zhu Weiqing, the Chief Designer of the communications system of 7,000-metre manned submersible. Zhu Min was also a Deputy Chief Engineer at the head of a team of young 30-somethings, including Zhang Dongsheng, Yang Bo, Xu Lijun and Liu Yeyao, on behalf of Professor Zhu, and were fully responsible for underwater communications debugging.
Of course, they were not alone. The "Old Boss", Professor Zhu Weiqing, had also originally been on the ship. However, he did not attend the sea trial due to poor health. Instead, he stayed at the Sanya base to provide remote support. Besides, they had the support of the CAS Institute of Acoustics, which could be contacted via a hotline at any time. The Chief Engineer of the submersible body, Xu Qinan, also joined them to tackle the problem. Li Yubo, a chief mate on the Xiang 9, who used to be a radio engineer, offered to help. After carrying out overnight troubleshooting and urgent repair, they finally solved the problem.
The Xiangyanghong 09 mothership set sail for the 50-metre depth contour of the A1 marine area on 17th August, from which the Hexie would take its first 50-metre dive. When the lights of Sanya City were still twinkling across the sea like the eyes of playful children, and the sun was just beginning to shed its early morning light on the sea, the rear deck of the Xiang 9, where the submersible was located, was already bustling with activity. In order to maintain and inspect some of the equipment and to adjust the weight of the ballast block, certain light shells and buoyancy blocks needed to be removed.
Early in the morning, Zhang Guibao, Gu Qiuliang, Zhang Jianping and other personnel from the 702 Institute put on anti- slip shoes and safety helmets and gathered around the submersible. Under the ship's sidelights, they started to perform the delicate and meticulous operation after stepping onto the shaky scaffold and climbing on top of the submersible, which was still covered in morning dew. It did not take them very long to remove the light shells and install the iron ballast in preparation for the dive. Smiles of joy and relief lit their faces as they wiped away their sweat and looked at the sun rising in the east.
The test kicked off as the Hexie was smoothly launched into the water. Its main task was to adjust balance of the submersible. However, an accident occurred when the frogmen untied the bridle towing and towline after a positive surface inspection and order to "DIVE" was given by Chief Commander Liu Feng. The submersible was supposed to gradually dive in freefall as the ballast tank filled with water after the initiation of the injection system. However, it seemed that the submersible was very reluctant to leave behind the engineers with whom it had grown up. It kept floating on the water's surface and refused to dive!
The command headquarters was at a loss, not knowing what had happened. Liu Feng held a telephone in his hand and kept saying, "Hexie! Hexie! Check the water tank!"
"The tank is normal. It's full of water."
"Use its propeller."
"OK." The pilot was operating the dive equipment as he responded. But this did not work either. The submersible seemed to be teasing the team by staying afloat on the water. Good grief! Was the submersible going to turn out to be a landlubber who did not dare to dive?
The Chief Engineer Xu Qinan was standing on the rear deck and had been watching what was happening the whole time. Deep down, he understood what the problem was. He murmured to himself: "Too conservative, too conservative..." As it turned out, the Hexie had controlled the ballast weight and load jettison so as to be able to dive and surface without a power supply. Considering that this was the first sea trial, the principles were "safety first" and "the ability to dive down and come back", in order to ensure the safety of the submersible and its pilots. As a result, they were too conservative in their calculations of the weight of the iron ballast, and thus underestimated the weight. Even though the tank was filled with water, the submersible was still too light to sink into the sea water. The dive failed.
It was with a heavy heart that Xu Qinan said at the summary meeting: "It is humiliating to have made such a stupid mistake."
"Director Xu, you are being too harsh on yourself. The fact that you and Mrs Fang have accompanied us for this sea trial at such an old age is already impressive!" The provisional Secretary of the Party Committee, Liu Xincheng, consoled him.
Chief Commander Liu Feng added, "Yes, Director Xu, the point of experiment is to make progress by learning lessons from our experiences. Next time, we will do it right!"
When the State Oceanic Administration announced the sea trial mission in 2009, the Chief Engineer of the 7,000-metre manned submersible, Xu Qinan, was already 74 years old, while his wife Fang Zhifen was 68. They were not supposed to participate in the sea trial. However, Xu Qinan insisted on being on board, so that he could be there in person to see his years of dedication become reality. He said: "If I cannot attend the sea trial as the Chief Engineer, then for me, the mission will be incomplete. It will not be a success either!"
"It would be great to have you on site. But your body..."
"I am fine. On the other hand, I may not be well if you don't let me go and keep me in suspense. Haha!"
So, the leading group made an exception for them, making this couple the oldest team members in this sea trial. As a result, lots of medicine and oxygen bags were brought on board for them. They attended study seminars, discussed technical details, participated in escape drills and wore life jackets alongside the young personnel. Fang Zhifen overcame her seasickness and discomfort to take care of Director Xu as the ship lay at anchor to avoid Typhoon Morakot. Meanwhile, she continued to write test logs and manage files. She often wrote to the Sea Trial Express to keep the team members motivated.
Moreover, there were three other elderly scientists over the age of 60 in the sea trial team. They were 68-year-old Xu Guangqing, 62-year-old Zhang Guibao and 61-year-old Hua Yiyi from the 702 Institute. Like the Xu couple, they had set themselves high goals and spent years working hard on the design and construction of China's manned submersible. They offered to attend the sea trial and give the young people a lift, despite their old age and weak bodies. They were extremely self-disciplined and prepared for the operations seriously, winning the respect of everyone on board.
The command headquarters and the Provisional CPC Committee responsible for the sea trial paid special attention to these elderly scientists. Their presence on the front line at such an advanced age not only showed their strong dedication to their careers, but also demonstrated the importance of having experienced and knowledgeable personnel on board for the sea trial. It was arranged that doctors would be present on the ship to take care of their health, while servants and a catering team were there to attend to their life needs. Party Secretary Liu Xincheng, Chief Commander Liu Feng, leader of the technological consultation team Professor Yu, the Captain, the political commissar, many others would visit them frequently and ask for their opinions when they had the time, which ensured that these scientists were enjoying their work and life.
This atmosphere of hope and belief enabled the sea trial team to constantly make progress.
No pain, no gain. The team led by Xu Qinan learned from this lesson and increased the proposed weight to 140 kg overnight. Improvements were also made to the underwater acoustic communications system. The command headquarters decided to strike while the iron was hot and dive into the sea once again.
The next day was 18th August. The weather was fine and sunny with a southeast wind of force three-four, wave heights ranging between 0.6 and 1.4 metres, a current velocity of 0.7 knots and a temperature of 29.1 degrees Celsius. The sea trial team continued their 50-metre manned dive in the A 1 area. The Chief Pilot was one of the engineers in charge of the submersible body, Ye Cong, while the port pilot was Tang Jialing and the starboard pilot was Professor Yu Hang. He was a famous marine scientist and served as the leader of the expert technical team. He did not have to dive in person, but he took the lead in this dive as he had already had various overseas experiences diving in submersibles. In particular, his strong passion for our country's submersible development motivated him to set a good example through his own actions by volunteering without hesitation, something which greatly encouraged and motivated the young oceanauts.
"Ready all!" The order given by Chief Commander Liu marked the beginning of the eighth dive, the aim of which was focused on adjusting the balance of the submersible.
Preparation began at 10:35 am and the pilots entered the cabin at 10:48 am. This was followed by the submersible launch and water injection. After 10 minutes of water injection, Ye Cong operated the propeller to descend the submersible, which stopped at a depth of 28.5 metres to conduct various adjustment tests. Profess Yu and Tang Jialing assisted in performing five sonar tests, including an obstacle avoidance sonar and a bathymetric side-scan sonar. The working conditions were good. Hexie continued its dive to reach 38 metres, and then took a short pause before resurfacing. It conducted the load jettison test 10 metres before reaching the surface and then immediately returned to the surface. When its red backbone emerged from the blue water, the crowd aboard the Xiang 9 all burst into cheers.
However, a 38 metre dive was far from the designated target of 7,000 metres. On the other hand, it was the first step in the sea trial team's joint efforts to explore the depths of the ocean, and the first step in China's manned submersible project.
A journey of 1,000 miles begins with a single step. This 38 metre dive was a tiny one compared with the huge 100-metre and 1,000-metre diving successes that were to follow. However, its meaning was significant. It showcased the fact that our self-designed submersible with integrated innovation could dive and surface safely!
(selected from Jiaolong's Sea Explorations by Xu Chen, published by China Intercontinental Press in 2019)
