Thailand Shelves Attack Submarine Purchase Plans

Thailand’s defense minister Sutin Klungsang has announced Thailand’s suspension of its purchase of a Chinese-built S26T diesel-electric attack submarine, with the government accepting the Royal Thai Navy’s proposal to instead procure a frigate from China with the funding allocated for the submarine.

On Monday, Sutin said that he was ready to explain the reasoning for the change of plans to the House Military Affairs Committee, explaining that strategic cooperation and trade ties between China and Thailand were factors contributing to the decision to alter the plans rather than canceling the deal. He defended the 1 billion baht increase in costs caused by the change, saying that the 17 billion baht cost (USD466.27 million) to procure the frigate was the “best way out”.

During his Friday announcement that the submarine procurement was being suspended, Sutin insisted that the project had not been scrapped, saying during a visit to the Royal Thai Navy’s headquarters that it would resume “when the country is ready”.

The Thai submarine program has stalled due to Germany refusing to export the MTU 396 engine intended to power the submarine, with Berlin citing compliance with an European Union embargo on arms exports to China that has been in place since the 1989 Tiananmen Square massacre. 

While the previous Royal Thai Navy chief Admiral Choeingchai Chomchoengpaet approved a plan to use the Chinese-made CHD620 engine as an alternative to the MTU engine after receiving additional performance guarantees from China last month, the new Thai government did not accept the proposal to proceed with the CHD620. Instead, it requested the Navy propose alternatives to procuring the submarine. The Navy proposed purchasing either a frigate or an offshore patrol vessel as alternatives to the submarine, with the government selecting the frigate.

The S26T Program

The Royal Thai Navy announced its intent to procure three attack submarines in 2015, selecting a modified export variant of China’s Yuan-class attack submarines. The 2,550 ton, 77.7 meters long S26T design features a Stirling-type air-independent propulsion system in addition to the MTU 396 diesel engine, providing at-sea endurance of up to 65 days with mixed use of the conventional diesel-electric and AIP systems.

A government-to-government contract worth USD 390 million for the first submarine was signed in May 2017, with steel on the submarine cut on 4 September 2018. The submarine was supposed to have been completed last month, but its completion date has slipped to April 2024, with builders China Shipbuilding and Offshore International Company blaming the delay on the impact of COVID-19.

The navy’s requests since 2020 for funding of the remaining two submarines have not been approved to date, with lawmakers questioning the program’s necessity as the Thai economy recovers from the effects of the COVID-19 pandemic.

A different export variant of the Yuan-class is being built for the Pakistan Navy as the Hangor class of submarines.