PT PAL secures contract for KSOT autonomous submarine

Indonesia's prototype KSOT submarine, seen here during its sea trials. (PT PAL)

Indonesia's PT PAL has secured a contract from the Indonesian Ministry of Defence (MoD) for an undisclosed number of Kapal Selam Otonom (KSOT) autonomous submarines, the company's CEO Kaharuddin Djenod told Janes.

Djenod disclosed the contract during a recent interview at the company's premises in Surabaya. His comments mark the first confirmation that the KSOT has moved beyond prototype and demonstration phases to evaluation procurement.

Details remain limited, but Djenod said the contracted variant will be significantly larger than the prototype demonstrated in October 2025 and will carry eight lightweight torpedoes.

Additional details about the contract and the submarine to be supplied will be revealed in October 2026 in line with events marking the 81st anniversary of the Indonesian Armed Forces, Djenod said.

Indonesia's KSOT programme was unveiled by PT PAL at Indo Defence 2022 as part of efforts to develop an indigenous underwater warfare capability.

Early concepts centred on an artificial intelligence-enabled platform designed to conduct missions including surveillance, reconnaissance, and strike, while reducing risk to personnel.

The system has since been framed as an underwater-based asymmetric warfare capability, enabling the Indonesian Navy to engage larger adversaries with a lower-cost platform capable of deploying torpedoes at stand-off distances.

A KSOT variant measuring about 15 m in length, with a displacement of roughly 37 tonnes, has been used in recent trials, including a torpedo firing carried out at Indonesian Navy facilities in Surabaya in October 2025.

That demonstration involved the launch of a lightweight torpedo from what appeared to be an externally mounted tube.

Djenod said PT PAL is also anticipating separate contracts for its domestically developed Piranha lightweight torpedo.