The truth about Chinese submarine technology

Western analysts say Beijing has made many advances in submarine technology, but the lack of control over the engine has left them behind.

Learn about Chinese submarine manufacturing technology

In recent years, China has invested heavily in domestic shipbuilding, especially submarine technology . Recently, Sri Lankia's prime minister said the country would allow Chinese submarines to dock their ports despite concerns from India.

From Sri Lankia, Chinese submarines can conduct reconnaissance activities throughout the Indian Ocean - an area that is considered the "backyard" of India.

Some analysts hypothesize, does Beijing create a breakthrough in submarine technology to serve its country's ambition?

Type-039 Chinese electric-diesel submarine.(Photo: Business Insider).

Beijing has adopted a strict information security policy, so the foreign military has very little detail on the quality of Chinese submarines. However, the article published in the People's Daily on April 26 provides some detailed information about the submarine technology of this country, especially the independent recirculating air engine (AIP). According to the article, the AIP engine was developed by Institute 711 based on Swedish Stirling engine.

AIP engine is researched and developed by Institute 711 for more than 10 years. The efficiency of this engine is 117% compared to Sweden's Stirling. China imported AIP engines from Sweden in the 1980s, the export version of Stirling only has a capacity of 75 kilowatt.

The 711 Institute then conducted research, improvement and production of new AIP engines with a capacity of 160 to 217 kilowatts. Meanwhile, according to Naval Technology, Yuan's latest generation of Type-041 non-nuclear submarines could be equipped with four AIP engines. Thus, the total capacity reaches from 640 to 868 kilowatt. Meanwhile, Russia's Kilo submarine is equipped with a generator of 111 kW and 2 standby generators of 76 kW.

The Chinese submarine technology evaluation, Taiwan's Want China Times newspaper, said that Chinese submarines fitted with AIP engines could create a major breakthrough. AIP engines help ships operate smoothly and longer underwater than using lithium batteries.

Still lagging

Type-039A Yuan class submarine, the type of submarine is said to be equipped with AIP engines.(Photo: Freewebs).

Commenting on the Chinese submarine fleet power, the US Navy Intelligence Office (ONI) said that by 2020, Beijing will be able to build forces from 69-78 types of submarines. In it, the core is the Yuan class non-nuclear attack submarines.

The advancement in Chinese submarine technology is undeniable, but Beijing is still poor compared to the technology of large countries. Professor Andrew Erickson, engine specialist at the US Naval War Academy, told the Diplomat that the engine is a 'bottleneck' for China's defense industry.

Beijing is almost entirely dependent on engines imported from abroad, namely Germany to equip the submarine. China is conducting research and development of AIP engines based on Swedish Stirling imported from the 1980s.

However, China has successfully produced the AIP engine and how the performance has yet to be verified.'Technology is constantly evolving, in particular, AIP engines are extremely complex technology, even if you master it,' said Professor Erickson.

Analyst Henry Holst of Johns Hopkins University, USA, is skeptical about China's ability to equip AIP engines on submarines. He told USNI News (a news sheet of the US Naval War Institute) that the world's leading submarine producers, such as Germany, France and Sweden, had to extend the hull when retrofitting AIP engines.

The compartment contains the AIP engine module of a Western submarine.(Photo: Klswatch).

For example, the export version of French submarine Agotta to Pakistan must extend the hull from 67 to 76m to equip AIP MESMA engines. Sweden's Gotland class submarine must add 8 meters to install AIP Stirling engine. Meanwhile, the length of Yuan class submarines is only 65 m, so the ability to install AIP engines is very low, Mr. Holst said.

In addition, Mr. Holst doubted the possibility that China could achieve great progress in automation that would reduce the number of devices, creating space for AIP engines without lengthening the hull.

In terms of nuclear submarine technology, Professor Erickson said, Chinese nuclear reactors are still far inferior to the West. The professor said that Beijing's reactor technology is about three decades less than the West.

Regarding marine electronics technology used on Chinese submarines, especially the hydro sound navigation system (sonar), Professor Erickson said, there is not much information available to evaluate this technology. China's naval modernization efforts do not translate into an immediate increase in strength.

'A lot of activities are going on with much effort. They have a track record, but in complex areas it takes more time for achievements to turn into a real increase in strength. They are far away in hope, they are moving forward but it is a road full of thorns , "concluded Professor Erickson.