Sea Pole-class bathyscaphe
The Sea Pole class bathyscaphe is a class of bathyscaphe of the People's Republic of China. They are capable of diving up to 7,000 meters, covering 99.8% of the oceanic floor of the world. Two units of this class are planned, with derivatives to follow and are used by both the civilian and military establishments in China.
Design
Sea Pole class bathyscaphe is designed by the of China Shipbuilding Industry Corporation. The general designer is Mr. Xu Huangnan, a professor of of Shanghai Jiao Tong University, who also designed many other Chinese submersibles and unmanned underwater vehicles. The first deputy general designer is Mr. Cui Weicheng, and the deputy general designer was Mr. Zhu Weiqing, all of the three are academicians of the Chinese Academy of Sciences. There are two mechanical arms with associated tools that enable the bathyscaphe to perform a various tasks at its maximum operational depth, and this pair of mechanical arms with 7 degrees of freedom are mounted on the right and left sides of the vehicle, which is powered by 110 kWh silver oxide – zinc batteries.The Sea Pole bathyscaphe is equipped with various communication systems, but the data transfer rate remains a bottleneck, with the transmission rate only being 80 kbit/s, compared to 100 Mbit/s in the usual internet transmissions. As a result, the transmission of an ordinary color image from the bathyscaphe to the mothership takes approximately half a minute.
The pressure hull is built of titanium alloy, and the manufacturing method for the pressure hull involves producing two hemispherical parts by tungsten inert gas welding six-side plates to a top plate, followed by heat treatments and polishing by machining; the two halves are then TIG welded together to form a complete sphere. The plate thickness is 76 – 78 mm, with deviations of ±4 mm in the completed radius, and sphericity is 0.4% or less. Pressure testing of the pressure hull was performed in Russia, and included a one-hour test at a water pressure equivalent to 7,700 meters, or a 10% greater depth than the vessel's, 7,000 m maximum operational depth, a continuous hour-long test at water pressure equivalent to 7,000 m, and a test simulating 0 to 7,000 m ascent/descent of the submersible, which was repeated six times. There were no problems reported in any of these tests, and the pressure hull passed with flying colors.
All viewports of Sea Pole class bathyscaphe have a circular truncated cone shape. There is a large viewport with diameter of 20 cm mounted in the bow, and this central view port is the same type of that of Russian Mir class bathyscaphe. The two additional smaller side viewports of 12 cm diameter are mounted on portside and starboard side, closer to the front than other bathyscaphes. The advantage of this arrangement is that it enables navigation while both the pilot and the scientists simultaneously
observe an objective in front of the vehicle. However, the side views have limited field of vision. There are two onboard life supporting system based on that of Shenzhou 6 spacecraft, and additionally, there are two onboard oxygen generating systems independent of life supporting system for additional safety. The pressure hull is built of titanium.
Sea Pole class bathyscaphe has a teardrop shape tapering toward the stern and four tail fins which form an X shape. The main thruster system is based on the same design principle as that of the Russian Mir class bathyscaphe. Four main thrusters inclined in a narrowing shape are mounted in the spaces between the four fins. One horizontal thruster is mounted on the top of the bow, and thrusters for vertical / horizontal turning and auxiliary propulsion are provided on the two sides of the hull. Parallel movement in the horizontal direction is achieved by using a combination of the horizontal thruster on the bow and the right and left stern thrusters, while vertical movement uses a combination of the bow side thrusters and the top and bottom stern thrusters.
Sea Pole 1
Sea Pole 1 or Sea Pole #1, was the first Sea Pole class bathyscaphe. Due to the high standard of design requirement, the Chinese industrial capability was not adequate enough to meet the requirements, and as a result, the titanium pressure hull was built in Russia, the mechanical arms were built in the US, and the buoyancy system was built in the UK. Sea Pole 1 begun its sea trials in October 2008, and reportedly entered service in 2009. Trials were mostly conducted with a mother ship named, a modified research ship. Although Sea Pole class bathyscaphe was designed to carry an operator and two scientists, Chinese authorities have announced that in the near future, Sea Pole 1 will carry three operators and no scientists for test and evaluation purposes. The unit price of Sea Pole 1 is around 180 million ¥, or roughly 25 million US dollars.Sea Pole 2
Sea Pole 2 or Sea Pole #2, was the second Sea Pole class bathyscaphe, and possibly the last unit of this class. Unconfirmed Chinese reports have suggested that previous deals China signed with foreign contractors for Sea Pole 1 included technological transfer, and Sea Pole 2 would utilize more domestically produced components once Chinese manufacturers mastered the technologies transferred, but such claims have yet to be confirmed by independent or official sources. One of the most important upgrade of Sea Pole 2 is to increase its communication capability by boosting the data transmission rate via fiber optics. Based on the experience of sea trials of Sea Pole 1, it was recommended that a class of dedicated mother ships be built, with the first one being Great Ocean II.Specifications
The specification for Sea Pole 2 bathyscaphe is not yet publicized, but it is reportedly differs from that of Sea Pole 1 slightly. The specification of Sea Pole 1 is listed here.- Length: 8.2 meters
- Width: 3 meters
- Height: 3.4 meters
- Inner diameter of the pressure hull: 2.1 meters
- Mass: 24 tons in air
- Payload: 220 kg
- Maximum speed: 2.5 kt
- Cruise speed: 1 kt
- Worst weather condition for deployment: Sea state 4
- Crew: 3
- Endurance: 12 hr
- Maximum operating depth: 7,000 meters
- Never to exceed depth: 7,100 meters
- Crash depth: 7,700 meter
- Life support: 3 x 12 hr