China has been suffering poor technologies for submarines for a long period, especially for its nuclear submarines, which feature big noise. But in recent years, China has made great progress in development of conventional submarines, and developed AIP technology.
Pakistani official announced several days ago that Pakistan is to buy eight conventional submarines from China, which are considered to be representing the latest technologies owned by Chinese Navy. Such Chinese conventional submarines are much quieter than Chinese nuclear submarines, but are nuclear deterrents.
The type of Chinese submarine to be exported to Pakistan is the so-called Yuan-class submarine, i.e. Type 039A Submarine, which is estimated to be able to submerge for weeks to avoid detection of the enemy.
Four of the submarines will be built in China, and the other four will be built in Pakistan, and related technologies will also be transferred to Pakistan. It is analyzed that with the advanced submarines from China, Pakistan will get a new kind of powerful weapon superior to India.
Experts think after selling submarines to Pakistan, China might deploy nuclear submarines and conventional submarines in Indian Ocean, and maintain and upgrade them here. Indian Ocean is deemed as a lifeline for Chinese economy.
Chinese military media unveiled today that Chinese scientists have taken the lead in developing two kinds of materials, one can help Chinese submarines to avoid track of underwater sonar system, the one is just like “invisible cloak” in “Harry Potter”, which will enable submarines to “vanish completely”.
The first kind of material can change sound waves of submarines, such as pulse released by antisubmarine ships; therefore, the sonar operators would judge the submarine as a whale, a group of fishes, or even a friendly submarine.
Chinese researchers unveiled that such material for Chinese submarines is a kind of photonic crystal, which has been developed to control, guide and change sound waves in air, liquid or solid.
Physical features of photonic crystal could be fixed and thus enemies might find its acoustic law. But Chinese scientists solved that problem; their photonic crystal can have various sound features, just like a sound “chameleon”.
The other kind of material is like invisible cloak, which is still a prototype for submarine. The coating can currently make an object with the size of a smart phone undiscoverable via sonar, even when it releases low frequency sound waves.
Prof. Wu from Xi’an Jiaotong University, the leader of the team said, “At present, no submarine can avoid low frequency track, but our research will change the hide and seek game under the sea.” “Chinese military hope their submarine cannot be seen, instead of being masked.”
Besides, according to National Interest, Type 039A and 636 Kilo-class submarines are so quiet that they are hard to detect in South China Sea. American report from Land said Chinese submarines are becoming quieter and are equipped with more advanced weapons, with greatly improved capabilities of discovering and attacking surface ships.
The report also said Chinese submarines are able to launch long-range supersonic anti-ship cruise missiles like YJ-18, which can be fatal for US naval vessels.
Aviation Week and Space Technology reported that Yalong Bay at the southernmost end of Hainan Island might be the largest submarine base in the world. The Chinese submarine base in Yalong Bay is deep in the mountains, and even U.S. satellites or P-8A anti-submarine aircraft cannot shoot a photo of it.
The website thinks Chinese submarine owns potential strategic impact, especially when Chinese Navy takes offshore actions with SSBNs (Nuclear Ballistic-missile Submarine).
The latest report indicates that UK is to export LR-7 deep submergence rescue vehicle, which will be very useful in possible accidents of Chinese nuclear submarines and conventional submarines, but this action has irritated U.S., according to Chinese media.