Indonesia begins domestic construction of first French-designed Scorpene Evolved submarine.

State-owned shipbuilder PT PAL Indonesia cut the first steel for Indonesia's lead Scorpène Evolved submarine at its Surabaya shipyard on August 7, 2026, launching domestic physical construction under the Scorpène Republik Indonesia program. Executed in partnership with France's Naval Group, the milestone transitions the contract from preparation and workforce qualification to structural hull fabrication. Local fabrication aims to establish national defense-industrial autonomy across pressure hull production, equipment integration, and harbor acceptance testing within an estimated 96-month construction cycle.

The contract covers two 72-meter Scorpène Evolved conventional submarines equipped with a full lithium-ion battery energy system, an 8,000-nautical-mile operational range, and an 18-weapon maximum payload capacity across six 533 mm tubes. Lead boat delivery is scheduled for 2032 following sea trials between 2030 and 2032, while the second submarine enters production in 2027 for delivery in 2033.

Related topic: Argentina seeks a French-backed loan to acquire three Scorpène-class submarines

The Scorpène Evolved Full LiB, selected by Indonesia, is a 72-meter diesel-electric attack submarine using lithium-ion batteries to provide more than 8,000 nmi of range, 78 to 80 days of endurance, over 12 days of submerged autonomy, and speeds above 20 knots. (Picture source: Naval Group)

On August 7, 2026, Indonesia cut the first steel for its lead Scorpene Evolved submarine at PT PAL's Surabaya yard, beginning the construction of the first operational submarine to be built domestically in Indonesia. The contract with the French Naval Group covers two Scorpene Evolved Full LiB submarines, ordered in April 2024, and was brought into force on July 23, 2025, 380 days before the steel-cutting ceremony. Indonesian Navy Chief of Staff Admiral Muhammad Ali said the program had reached 20.5% overall completion and that each submarine is planned around a 96-month construction cycle. This percentage includes engineering, design readiness work, production-system establishment, infrastructure preparation, personnel training, qualification activities, and procurement performed before fabrication of the operational hull.

PT PAL had already completed a steel-cutting qualification section on December 12, 2025, after Indonesian welders and engineers trained at Naval Group's facilities in Cherbourg, giving the yard a test case for material preparation, welding, preheating, dimensional control, and inspection before identical procedures were used on the combat submarine. The second Scorpene Evolved submarine is scheduled to enter production in 2027, approximately one year behind the first, which is planned for testing and sea trials between 2030 and 2032 before delivery in 2032. Boat 2, for its part, will be tested between 2031 and 2033 and delivered in 2033. PT PAL will therefore move from qualification work into two overlapping six-year production and test cycles, with both submarines under construction simultaneously for most of the program.

The key change for Indonesia is industrial rather than ceremonial: PT PAL previously assembled KRI Alugoro, the third Nagapasa-class Type 209-derived submarine, with South Korean assistance, but the SRI program (an acronym for "Scorpene for the Republic of Indonesia") assigns the Indonesian yard responsibility for pressure hull construction, equipment installation, system integration, harbor testing, sea trials, final assembly and delivery. The Indonesian submarine is a 72-meter Scorpene Evolved Full LiB, a larger and more advanced version of the earlier conventional Scorpene configurations that established the class internationally. According to Naval Group, this configuration has a surfaced displacement of about 1,600 to 2,000 tonnes, can exceed 20 knots underwater, and is capable of diving deeper than 300 meters.

It is also designed for a crew of 31 and can remain on mission for more than 78 days within an 80-day endurance window, with over 12 days of submerged autonomy. Compared with earlier Scorpene variants, the range increases to more than 8,000 nautical miles (around 14,800 km), up from about 6,500 nautical miles (12,000 km), an improvement of over 23%. Endurance also rises from roughly 50 days to around 78 to 80 days, giving the submarine nearly an extra month of operational time at sea. The key reason for this improvement is the shift from traditional lead-acid batteries to a full lithium-ion system. This change allows the submarine to store more usable energy, recharge faster, and maintain higher performance even as battery levels drop, avoiding the sharper performance decline seen in older battery types.

This is also operationally different from fitting a MESMA air-independent propulsion (AIP), because the MESMA required an additional 8.3 m, 305-tonne hull section and generated endurance through a separate anaerobic energy-production module, whereas the Full LiB design focuses on improving battery capacity and efficiency within the existing diesel-electric framework. For Indonesia, this makes sense given its geography: an archipelago of around 17,000 islands and an exclusive economic zone of nearly 6 million km². The extended range allows a submarine to travel from Surabaya to distant operational areas and still spend more time on patrol before needing to return for resupply or maintenance. However, with only two submarines in the program, Indonesia will still not be able to maintain a constant submarine presence across all of its major maritime approaches.

The submarine’s combat load is centered on six 533 mm torpedo tubes and a total payload of up to 18 weapons, giving the Indonesian Navy a submarine able to combine heavyweight torpedoes and submarine-launched anti-ship missiles in the same loadout. The six tubes also allow several weapons to remain loaded and ready concurrently, reducing the time needed to shift from an anti-submarine engagement to an anti-surface engagement. For anti-ship warfare, the Scorpene Evolved uses the SM39 Exocet, while the wider Scorpene family is also capable of carrying heavyweight torpedoes and, when mines replace torpedoes and missiles, up to 30 naval mines. Naval Group has also noted that the Scorpene Evolved can accommodate MBDA's future SM40 submarine-launched Exocet. 

The submarine’s combat system, known as SUBTICS, acts as the central control hub, linking sonar and other sensors with target identification, tactical analysis, fire control, and weapon deployment. The Indonesian boats will also feature an upgraded sonar suite incorporating a planar array and improved signal processing, which directly improves detection range, classification confidence, and weapon tracking. In practice, the effectiveness of the 18-weapon magazine depends entirely on how the loadout is configured for each mission. A submarine carrying more anti-ship missiles will have fewer torpedoes or mines, and vice versa. Since Indonesia has not yet finalized all details of its torpedo procurement and onboard weapon mix, the 18-weapon figure should be understood as the maximum possible capacity rather than a standard operating load. 

Under the SRI program, local construction is substantial, but the industrial division of labor shows that Indonesia is not yet producing a fully indigenous submarine. PT PAL is responsible for the hull, equipment integration, testing, final assembly and handover, while France's Naval Group remains responsible for the design baseline, engineering support, transfer of industrial processes and continuous technical assistance. Naval Group initially deployed eight specialists to Indonesia and planned to increase that presence to about 50 personnel, while more than 400 Indonesian engineers are expected to receive training across welding, structural engineering, electrical integration, mechanical systems, quality assurance and submarine production methods.

The French production network also remains directly involved in several high-value areas: Cherbourg supports hull and submarine structural expertise, Lorient and Nantes-Indret contribute to propulsion and lithium-ion battery work, Ollioules supports the SUBTICS and associated combat system functions, and Angoulême-Ruelle contributes to masts, weapon-launch equipment and shaft-line systems. PT PAL will acquire the majority of general materials itself, but specialized components will continue to come from France, which means the locally built submarine will still contain imported propulsion, energy, combat system and mechanical elements. This distinction is important because final assembly in Surabaya does not by itself establish sovereign control over sustainment.

A stronger measure of Indonesian autonomy will be, for instance, whether PT PAL can later overhaul the lithium-ion battery system, repair propulsion machinery, update SUBTICS interfaces, service masts and weapon launchers, certify pressure hull repairs and conduct major modernization without requiring long-term dependence on French technicians or foreign overhaul facilities. In industrial terms, the program currently transfers the build and integration layer logically faster than the highest-value subsystem-manufacturing layer. For instance, the December 2025 qualification section provides a clearer indication of PT PAL's manufacturing readiness than the August 2026 first-steel event because pressure hull production is where submarine construction becomes unforgiving.

Indonesian personnel trained in Cherbourg for two to three months in welding, preheating and quality control, and eight Indonesian welders were specifically identified as completing Scorpene-related training before qualification work began in Surabaya. The production-readiness process also covered blasting, painting and pre-outfitting rather than only cutting steel, because each activity can affect dimensional accuracy, corrosion protection, equipment fit and later hull assembly. A qualification section allows the French shipyard to prove that the same welding parameters, heat treatment, inspection process and dimensional tolerances can be reproduced in Indonesia before those procedures are applied to an operational submarine designed to dive beyond 300 m. 

At that depth, the pressure hull is exposed to external pressure exceeding 30 bar, so even small deviations in weld geometry, material properties or section alignment can become structural problems after repeated dive cycles. The industrial challenge therefore becomes cumulative: PT PAL must reproduce the qualified process across multiple cylindrical sections, join them accurately, integrate penetrations and internal equipment, maintain shaft alignment, complete electrical and piping runs, and then demonstrate hull integrity during harbor tests and sea trials. Harbor Acceptance Tests and Sea Acceptance Trials are planned in Surabaya, meaning PT PAL is expected to retain responsibility through the validation phase rather than handing the boats to France for final acceptance.

Successful pressure testing, section joining, deep-diving trials and systems acceptance will therefore be more meaningful indicators of domestic competence than the simple fact that first steel was cut in Indonesia. The schedule also illustrates the industrial cost of entering submarine construction from a limited domestic base. Indonesia ordered the boats in April 2024, but the contract became effective only on July 23, 2025, a delay of roughly 15 months before the formal production program could proceed. Qualification-section fabrication followed five months later, in December 2025, and first steel for the operational hull came eight months after that, in August 2026. The second submarine is scheduled to begin in 2027, creating a one-year stagger that should allow PT PAL to reuse trained teams and production stations as Boat 1 moves from early fabrication into later assembly stages.

Testing and sea trials are then planned for 2030-2032 for the first submarine and 2031-2033 for the second, giving PT PAL a long overlap in which both hulls are simultaneously consuming engineering, integration and test resources. From April 2024 to first delivery in 2032, the acquisition-to-delivery cycle is about eight years; from first steel in August 2026 to delivery, about six years remain. The 20.5% program completion figure announced at first steel therefore reflects front-loaded non-hull work and cannot be interpreted as physical completion of one-fifth of the submarine. PT PAL's facilities can reportedly accommodate simultaneous construction or MRO of as many as four Scorpenes, so there is nominal physical capacity for potential follow-on hulls.

The central constraint is whether Indonesia orders them in time to keep welders, inspectors, production engineers and suppliers continuously employed, because a gap of several years after Boat 2 would logically force the country to rebuild qualifications and experience that the SRI program is spending years and substantial capital to establish. India and Brazil provide the most relevant comparisons because both used Scorpene procurement to build domestic submarine production capacity, but each did so with more hulls than Indonesia has currently ordered. India ordered six Scorpenes in 2005 for roughly $3 billion, and assigned their production to Mazagon Dock in Mumbai.

INS Kalvari began construction in 2009, was launched in 2015, and entered service on December 14, 2017, while the sixth submarine, INS Vagsheer, entered service on January 15, 2025. India's six-boat series therefore kept Scorpene new-build activity active for roughly 16 years from the start of lead-hull construction to commissioning of the final boat, giving the workforce multiple opportunities to repeat the same production stages and transfer experience from one hull to the next. Brazil, for its part, ordered four enlarged Scorpenes and combined the submarine program with technology transfer, major infrastructure investment and French assistance for its nuclear-submarine effort. The Riachuelo entered service in September 2022, Humaitá in January 2024 and Tonelero in November 2025, while Almirante Karam was launched in November 2025.

Indonesia's current production run of two hulls is therefore only 33% of India's original six-boat series and 50% of Brazil's four-boat conventional program. The industrial implication is straightforward: Indonesia must recover the cost of training, tooling, certification, supplier development and infrastructure over only two submarines unless additional orders follow, which makes the sustainability of the Surabaya line more dependent on political decisions after the initial contract than either the Indian or Brazilian cases. Within ASEAN, the SRI program gives Indonesia a different type of submarine capability from Malaysia, even though both navies operate the Scorpene family. Malaysia's KD Tunku Abdul Rahman and KD Tun Abdul Razak entered service in 2009 and were constructed abroad, while Indonesia is building the newer Full LiB configuration domestically in Surabaya.

Admiral Muhammad Ali said Indonesia was the first ASEAN state to build a submarine locally from the beginning of production, which distinguishes the country from other regional programs, in which submarines were purchased complete or assembled with a narrower domestic role. PT PAL has therefore placed the project within Phase II of Indonesia's National Submarine Technology Mastery Program, with longer-term ambitions to design, build and potentially export an indigenous submarine between 2042 and 2050, while major overhaul autonomy is targeted earlier. The immediate operational impact will, for now, remain limited by force size: two Scorpene Evolved submarines cannot logically cover Indonesia's nearly 6 million km² EEZ continuously because one boat may be on patrol while the other is undergoing training, corrective maintenance, scheduled upkeep or deeper overhaul.

A two-boat class also creates a readiness problem during major maintenance, when availability can temporarily fall to one boat or zero if schedules overlap. Industrially, the program is expected to support about 2,250 jobs across construction, support and long-term maintenance, but no third SRI submarine is included in the current contract. PT PAL President Director Kaharuddin Djenod has also linked domestic submarine construction to growing power competition in ASEAN, arguing that national industrial capability increases Indonesia's strategic leverage in the region.

The decisive fact will therefore be what happens before Boat 2 leaves the main construction phase. If Indonesia orders additional Scorpenes early enough to keep the Surabaya line active, PT PAL can convert a two-hull technology-transfer effort into a recurring production system with retained welders, engineers, suppliers and test personnel. If the program stops at two boats, Indonesia will still gain MRO and integration capability, but the most specialized new-build skills will face a workload gap before the country reaches its stated 2042-2050 indigenous submarine objective.

Written by Jérôme Brahy

Jérôme Brahy is a defense analyst and documentalist at Army Recognition. He specializes in naval modernization, aviation, drones, armored vehicles, and artillery, with a focus on strategic developments in the United States, China, Ukraine, Russia, Türkiye, and Belgium. His analyses go beyond the facts, providing context, identifying key actors, and explaining why defense news matters on a global scale.

Explore More Defense News

• Land Defense News
• Naval Defense News
• Defense Aerospace News