According to related news, the Royal Thai Navy plans to file an application in 2020 to increase the number of submarines purchased from 3 to 5 to increase the Royal Thai Navy’s underwater combat capabilities.
The Royal Thai Navy has already purchased three S26T AIP submarines from China. These two submarines will probably still be S26 AIP submarines. This is another big order for China’s domestic submarines following the Pakistani Navy’s eight AIP submarines.
In the new century, in order to strengthen the underwater combat capabilities, the Royal Thai Navy decided to form a submarine force. After comparison, the Royal Thai Navy chose the Chinese S26T AIP submarine, becoming the second ASEAN country equipped with AIP submarines after Singapore.
In May 2017, China and Thailand signed a formal agreement. The first S26T submarine was started construction in September 2018. It is planned to be delivered to the Royal Thai Navy in 2023. In 2019, the Royal Thai Navy ordered the second S26T AIP submarine. And a third S26T AIP submarine is expected to be ordered after 2020. These three submarines will be delivered by 2028, forming a full combat capability in 2030.
According to overseas data, the S26T submarine has a reduced size of China Navy’s Type 039A AIP submarine, with mainly size and displacement reduced. However, its performance has not been reduced.
Type S26T submarine uses the Stirling engine of Type 039A AIP submarine. Its underwater endurance is close to 800 nautical miles, or it can continue to be active underwater for 20 days. This indicator has a qualitative leap over traditional conventional submarines. The S26T submarine is equipped with a bow array, a side array and a towed line sonar, with omnidirectional detection and alert capabilities. It mainly includes six 533 mm torpedo launch tubes for boats, which can launch torpedoes, anti-ship missiles and anti-submarine missiles. The boat can carry up to 18 types of torpedoes and missile weapons or 30 types of mines. Previously, the Royal Thai Navy revealed that relevant Chinese authorities have approved the export of a variety of new weapons as complements to S26T submarines, such as new anti-submarine / anti-ship torpedoes using fiber optic guidance, with a three-speed system, better detection performance, stronger attack capabilities, and can fight against modern quiet submarines. The new CM-708UNB submarine-launched anti-ship missile has a maximum range of 280 kilometers. It can not only hit surface targets, but also attack targets on shore. It is a type of economically applicable Tomahawk cruise missile.
Furthermore, the performance of the S26T AIP submarine is significantly better than its main potential combat target Kilo class submarine. The biggest disadvantage of the Kilo-class submarine compared with the S26T is that it does not have an AIP system, so its underwater activity capability is greatly limited, and it needs to float and charge frequently. In wartime, the S26T can be set under water for a long time, and when the Kilo level floats and charges, it launches an attack.
In addition, the Kilo class only has a comprehensive bow array, no side array and tow line array. It can only target within a certain range of the bow, and during its cruise, it has to change directions a lot to determine if there is any enemy submarines, while the S26T AIP submarine has omnidirectional detection and alert capabilities, and can even rely on the AIP system for a long time to reach around the Kilo-class submarine base, and deploy towed line sonars for detection and monitoring.
The only disadvantage of the S26T AIP submarine for Thailand is its small number – only 3 of them, but Vietnam has 6 Kilo-class submarines.
In this case, the Royal Thai Navy decided to increase number of the submarines to five, further consolidating and expanding its own advantages. Although the Royal Thai Navy has not said clearly whether to purchase additional S26T submarines, according to military analyst Xiao Feizhu, from the perspective of training and logistical support, the continued purchase of S26T AIP submarines obviously means the best cost-effective ratio.