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Youdian Type 911-II

The Youdian-class ARC ["Post and Telecommunications One"] is a twin-stack, cable-laying repair ship. The first two ships, one of which was civilian, were built at Shanghai Shipyard Zhonghua (Chung-hui). From 1979 to 1981 , Zhonghua Shipyard successively built 6 cable-laying ships of the same type for the Navy , and engaged in laying, salvaging and repairing submarine cables between islands in the Chinese Sea. This type of ship won the 1978 National Science and Technology Conference Award. [Western sources report two additional vessels were built at Shanghai Shipyard Dongfanghong (Tung-fang-hung)]. The naval version had, in addition to four 14.5mm guns, a movable overhead crane mounted on the fantail. All four ships had a prominent bow that supported a cable-laying sheave. While the civilian vessel was probably engaged in laying commercial phone cable, the naval units may be involved in expanding secure communications between various naval installations. Prior to the construction of the Youdian class, the Chinese Navy had only one cable-laying vessel, the Wulai-class ARC. This ship was constructed at Guangzhou Shipyard Donglong in the late 1960s.

The outer profile of the "Youdian No. 1" cable-laying ship is special, with a V-shaped cross section. In this way, it is conducive to maintaining good stability and can improve the propulsion efficiency. The part above the waterline of its bow floats outwards, so that splashing and breaking waves on the bow deck can be reduced, and the deck area can also be enlarged. In order to lay and repair the cables, the bow of the cable-laying ship is built very high, with fairlead pulleys installed on it. The stern of the rope-laying vessel adopts a square tail to increase the area of ??the stern deck and facilitate the rope-laying operation. In 1972, after the normalization of diplomatic relations between China and Japan, in order to strengthen the communication between China and Japan, the two governments agreed to jointly build a submarine cable with sufficient circuit capacity between China and Japan. In May 1973, China and Japan formally signed the "Agreement on the Construction of China-Japan Submarine Cables" in Beijing. The Sino-Japanese Submarine Cable runs from Nanhui County, Shanghai, China to Reihoku Town, Kumamoto County, Japan, with a total length of 872 kilometers and 480 telephone lines. According to the agreement, both parties need to complete their respective submarine cable laying projects.

To ensure the smooth completion of this project, the cable-laying vessel is indispensable. But at that time, most of the navys existing cable-laying ships were modified from other ships. They were not only small in tonnage but also relatively backward in equipment, and could not afford this task at all. Therefore, the construction of a new type of cabling vessel is imminent.

In the early 1970s, only a few countries in the world could build this new type of cable-laying ship, and China was still in a blank stage. Build it yourself, it takes time to develop. According to the agreement signed between China and Japan, time is obviously too late. For this reason, relevant departments began to plan to import cable-laying ships from abroad and conducted business negotiations with foreign representatives.

Among Chinese representatives participating in the negotiations was a staff officer of a certain naval communications office named Zeng Daren. Since joining the army in 1951, he has carried out more than 30 technological innovations in the field of submarine cables, and has been awarded many meritorious services. During the talks to purchase foreign cable-laying ships, the foreign representatives always put forward various harsh conditions, either asking for excessive prices or putting forward some conditions that infringe on China's sovereignty, and even laughed. "Engineers who only have bricks and tiles want to build the cable boat, simply ridiculous."

After the meeting, Zeng Daren said: "I don't believe in relying on our own strength to get the cable-laying ship we need, and I have to let the foreign capitalists dominate." Therefore, after studying and analyzing the favorable conditions and unfavorable factors, he wrote a letter to the party organization, proposing that China should develop a cable-laying ship. Zeng Daren's suggestion was quickly supported by superiors. The task of research and design of the cable-laying vessel was commissioned in June 1974 to the third design and research office of 708 Institute.

As a domestic leader in the field of shipbuilding and ocean engineering, the 708 Institute had researched, developed, and designed more than 1,200 models of products, creating many firsts in China's shipbuilding industry. After receiving the design task, the institute immediately deployed design experts to form a project team to concentrate on designing a new type of cabling vessel. However, from the very beginning of the project, problems followed one after another.

For offshore operations, stability is the most critical. The cable-laying ship not only needs to install a lot of mechanical equipment required for cable-laying on the deck, but also the load changes between full load and empty load during the operation. These problems will affect the stability of the ship. Therefore, how to make the cable-laying vessel always maintain stability during operation has become a difficult problem for designers.

According to researcher Wang Xinming who participated in the design at that time, in view of the characteristics of the stability change of the rope-laying ship, the designers designed a deep oil water tank and 10 ballast water tanks for the ship, and a total of 250 tons of ballast water was loaded to adjust the ships center of gravity and trim to ensure good stability and proper swing cycle.

Submarine cable is a very expensive communication equipment. At that time, based on its price, its length was equivalent to the value of silver dollars arranged together. Once an accident occurs, the loss is huge, so there is no room for error. This requires designers to fully consider the stability and maneuverability of the ship during the design process, so as to ensure that the cable-laying vessel can accurately lay the cable according to its scheduled route. For this reason, the designers set up the bow lateral propulsion device and automatic steering systems on the ship, and the course can be corrected in time through the remote control of the bridge to ensure the accuracy of cable laying and minimize costs. At the same time, the lateral propulsion device can also make the ship like a compass, with the cable as the center, and the hull can rotate 360 ??degrees to meet the requirements of the rope fishing operation.

After the stability of the cable-laying vessel, the length of cable loading is determined. According to requirements, the ship uses a smaller tonnage, a shallower draft and a larger cable load. The point to be clear is to try to get the maximum working capacity with the smallest displacement. In this regard, researcher Xu Shouqin, who is in charge of the overall design, installed the cable cabin at the widest amidships of the ship in accordance with the principles of focusing on the key points, distinguishing the priorities, comprehensive considerations, reasonable arrangements, and taking into account the beautiful appearance. And it is conducive to the cable reel.

According to reports, most of the shape of the cable-laying ship has a guide rail bow like a bull nose. Such a peculiar design is for the ship to get the cable under severe shaking. It can not only ensure that the cable will not be stuck, but also will not slip off. The stern, as an important operating area of ??the cable-laying vessel, cannot be ignored in design. The design of the guide rail stern like a snail tail can ensure that the ship can smoothly retract the fairlead and cable embedding devices in wind and waves. This is the first attempt in cable-laying ships at home and abroad. Through the joint efforts of all the designers, the mooring vessel has realized the automatic control of many operations such as stern mooring, bow mooring, and lateral propulsion, which has been praised by Chinese and foreign experts.

The matching of cable-laying vessels is another big problem. The key equipment involved on the ship is still in the initial development stage in China, and China had not even touched some equipment. In order to provide advanced technology and equipment to the "Post and Telecommunications One", many unknown "heroes" paid hard work for it.

The cable routing machine is the most important core equipment on the cable routing ship. It has many functions and uses. It is an indispensable equipment for laying submarine cables, especially for salvaging and repairing submarine cables. It requires strong technical support. In order to develop the cable laying machine as soon as possible, a development team composed of navy, shipyard, technicians, and workers was quickly established. However, the work of developing the cabling machine encountered difficulties from the very beginning.

The Post and Telecommunications One cable-laying ship is equipped with a crawler-type cable-laying machine. It uses a hydraulic motor to drive two chain belts on the top and bottom of the cable-laying machine synchronously through a reduction gear to clamp the cable. It can be used to lay the cable with a diameter of 27-100 mm. Cables of various specifications are sent to the seabed along a chute arranged in the stern of the ship.

The bow of the "Youdian No. 1" cable-laying ship is equipped with a drum-type cable-laying machine. It has a large drum whose diameter is equivalent to that of the bow pulley, so it is also called a drum-type cable-laying machine. When the submarine cable fails, drop the cable anchor from the bow pulley, grab the faulty cable, and then pull the submarine cable onto the ship by the drum-type cable laying machine. In order to avoid the cable being broken when the cable is fishing, a special control system is also installed on the drum cable laying machine.

The buried plow is also a main cable-laying equipment on the cable-laying ship. It is a symmetrical multi-blade plough with a certain angle, used for trenching in shallow seas. It can be towed on the bottom of the sea, plowing trenches with a depth of 0.7 to 1 meters for burying cables. A fairlead cage is also used with the buried plough to avoid entanglement of the signal cable and the cable steel cable.

The cable-laying vessel is also equipped with cable-drawing machines, electric pulleys, towing winches, slide pulleys, buoys, cable-grabbing anchors and various measuring instruments, all of which are indispensable equipment for the cable-laying vessel to carry out the cabling operations.

On the one hand, at the time when the fallacy of "not producing for the wrong route" prevailed, it was quite difficult to carry out the work. Zeng Daren pointed to the 10,000-ton oil tanker in the port and said to the workers: "The oil underground in Daqing is produced by Daqing workers with the blue sky above their heads and their feet on the wasteland. They rely on a red heart and two hands. Shipbuilders dont build warships. Rising like a tide? If we dont build a cable-laying ship, can the "Long Lord" pull the cable to the island? Foreigners bully us like that, and we must give the Chinese people a breath!" The enthusiasm of the workers rose suddenly. Without a workshop, they set up a shed on the dock; without tools, all units put together all the tools they could find; without equipment, they refit themselves; without materials, they went to various places for help.

On the other hand, the lack of relevant professional technology brought great obstacles to the development work. However, under the leadership of Zeng Daren, the research team worked diligently. After more than a year of hard work and conducted hundreds of experiments, it finally developed Chinas first machine with automatic speed measurement, force measurement, distance measurement and ship tracking. Crawler-type cabling machine and supporting cabling equipment. Subsequently, Wuzhou Machinery Plant took 3 months to successfully manufacture. The equipment uses all domestic original components, filling a gap in the mechanization of China's submarine cable engineering operations.

Although challenge of the cabling machine was solved, the program then encountered problems in the development of the lateral propulsion device. The helical gear, one of the main components of the lateral propulsion device, is difficult to process in the factory. The designers and technicians have visited dozens of units in Shanghai, and finally found an alternative product. The twin propellers used in this type of cable-laying ship have been continuously improved by 704 scientific and technical personnel and have been trial-produced for 2000 hours successively, which proves good performance. However, due to the high processing requirements, many factories were unwilling to produce it. At that time, the Suzhou Marine Machinery Factory, which had only a few hundred people, took the initiative to ask after hearing the news, and immediately organized a large number of cadres and employees throughout the factory to implement a general mobilization of the whole factory with the assistance of technical personnel, and finally succeeded in trial production.

At this point, the "Post and Telecommunications One" has finally overcome all difficulties with the joint efforts of scientific research, production, and use departments.

In the summer of 1976, Chinas first self-designed and built cable-laying vessel "Youdian No. 1" was delivered. The ship has a total length of 71.55 meters, a molded width of 10.5 meters, a molded depth of 5.2 meters, a draft of 3.6 meters, a full load displacement of 1,327 tons, a speed of 14 knots, and a total power of 1,641 kilowatts (2200 horsepower).

On the first day of laying the submarine cable, the "Post and Telecommunications One" attracted much attention. She faced the sunrise, braved the wind and waves, and started the Sino-Japanese submarine cable laying work-10 meters, 20 meters, 30 meters... the ship was sailing at low speeds, The cable routing machine sent the black cable meter by meter into the seabed, extending into the depths of the sea like a dragon entering the sea. The construction site was extremely spectacular. Messages of normal operation of various remote control equipment and instruments are continuously transmitted from the cab, and the cabling operation is proceeding smoothly. After 16 hours of hard work, the laying project undertaken by our side won the first battle.

On October 25, 1976, on the occasion of the 4th anniversary of the normalization of diplomatic relations between China and Japan, China and Japan held the opening ceremony of the China-Japan submarine cable in Beijing and Tokyo respectively. The "Post and Telecommunications No. 1" cable-laying vessel was proved to have excellent performance and advanced technology, and in many respects it has caught up with or exceeded the international advanced level. Her birth not only contributed to the laying of submarine cables between China and Japan, but also provided modern tools for China's development of communications and coastal defense.

From 1975 to 1983, China successively built six cable-laying ships of this type, all of which were handed over to the navy for cable laying, salvage and repair work between islands on the sea. At the National Science and Technology Conference in 1978, "YouTian No. 1" was awarded the highest honor of the conference as the first ship of this type.

However, the record of "Post and Telecommunications One" is much more than that. She successively carried out nearly 10,000 kilometers of submarine cable laying tasks from Liaoning in the north, Guangdong in the south, Anhui in the west, and Japan in the east. In the early 1990s, the "Post and Telecommunications One" assumed another important mission, participating in the construction of China's first international submarine optical cable. This optical cable runs from Shanghai Nanhui to Miyazaki, Kyushu, Japan. The total distance is 1252 kilometers. The total communication capacity of the system reaches 7560 communication circuits, which is equivalent to more than 15 times that of the Sino-Japanese submarine coaxial cable built in 1976. This increased China's international communication capacity more than 80%.

With the rapid development of the submarine cable business, "Post One" also participated in major projects such as global optical cables, Asia-Europe optical cables, Sino-US optical cables, Trans-East Asia Optical Cable 1, Asia Pacific 2, and C2C submarine optical cable networks, as well as domestic submarine cable systems, such as Yantai-Dalian, Beihai-Lingao and other year-round maintenance services.

On December 18, 2003, the first submarine cable-laying vessel "Youdian No. 1" in the history of China's communications was honorably retired, marking a successful end to her 33-year service voyage. " Post and Telecommunications One " honorable discharge and handed over the East China Sea Branch of the State Oceanic Administration, after carrying out technological transformation renamed the China Marine Surveillance 53 , started rights patrol mission, took part in laying buoys and marine environmental monitoring work (relevant reports show at least 1999 Nian One of Posts and Telecommunications has changed its name to Marine surveillance 53 , taking into account the time of the completion of submarine cables and submarine systems company Fuhai No. cabling ship in 2000 Nian 11 completed in May, I think of Posts One Before decommissioning , it was actually handed over to the Bureau of Oceans in 1999 and had the name of Marine Supervisor 53 ). Restored repairs were carried out in 2012, and the current name is China Coast Guard 2153.

There are also two other units [East cable 868, East cable 882] that may be of a slightly modified Type 911-IB design, though this designation may apply to the somewhat smaller Youzhong Class.

In the face of such a meritorious ship, it is a little regrettable that since the 1980s, China had never built a cable-laying ship except for the small 50-ton submarine cable repair ship. According to reports from the user department, the current submarine cable vessels in China can no longer meet the needs of submarine optical cable construction and maintenance. According to the development trend of the modern submarine cable industry and cable-laying ship types, China should intervene in the development and construction of medium and large modern cable-laying ships as soon as possible.

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Page last modified: 01-08-2021 14:08:51 ZULU