Delivery Timeline for Thailand’s S26T Submarine
Progress Update from CSSC
The China State Shipbuilding Corporation (CSSC) has affirmed that the delivery of the Royal Thai Navy’s (RTN) S26T diesel-electric submarine is on schedule, with an expected completion date within three years. This confirmation comes during the Defense & Security 2025 exhibition in Bangkok, where a CSSC representative provided insights into the current status of the project on November 10.
Engine Selection Finalized
After extensive delays primarily attributed to the selection of an appropriate engine, the S26T program is reportedly gaining momentum. The CSSC representative noted that the RTN has fully endorsed the new engine, which is being integrated into the submarine as part of the updated agreement. The marine propulsion system has shifted from the originally planned German MTU 396 engine to China’s CHD620 diesel engine, following export restrictions imposed by Germany.
Future Orders Under Discussion
Discussions regarding the potential procurement of additional S26T submarines have taken place between CSSC and the RTN; however, a decision on further acquisitions is anticipated only after the novel vessel’s operational performance is assessed. The CSSC official indicated that the RTN prefers to evaluate the effectiveness of the initial unit before committing to any further orders.
Revised Contractual Agreement
In September 2025, the RTN and China Shipbuilding & Offshore International Co Ltd (CSOC), a subsidiary of CSSC, amended their original contract to stipulate the delivery timeline of approximately 40 months. This updated framework reinforces the shift in engine technology and reflects both parties’ commitment to advancing the capabilities of Thailand’s naval fleet.
Conclusion
The S26T program exemplifies Thailand’s strategic intent to modernize its naval assets amidst regional security dynamics. The successful delivery of the S26T submarine, along with the associated technological upgrades, not only underscores the evolving defense collaboration between Thailand and China but also positions the RTN to enhance its operational readiness in the maritime domain.
