OVERVIEW: The 403 Nagapasa [Imp Chang Bogo] is a diesel-electric attack submarine operated by the Indonesian Navy. Commissioned in 2021, it represents a significant upgrade to Indonesia's undersea warfare capabilities.

DETAILS: The Nagapasa class submarines are variants of the South Korean Chang Bogo class (themselves derived from the German Type 209 design). The acquisition and subsequent local construction program reflects Indonesia's strategic focus on securing its extensive archipelago and maritime borders. The design emphasizes relatively quiet operation and adaptability to the shallow waters prevalent in the region. The Chang Bogo design provided a reliable and proven platform, which was then adapted to Indonesian requirements, likely including integration of specific sensor and weapon systems tailored to the operational environment. The construction program also incorporates a degree of technology transfer, strengthening Indonesia's domestic shipbuilding industry and reducing reliance on foreign suppliers.

The primary roles of the 403 Nagapasa are anti-submarine warfare (ASW), anti-surface warfare (ASuW), intelligence gathering, surveillance, and reconnaissance (ISR). The submarine is capable of engaging both surface combatants and enemy submarines. Its diesel-electric propulsion system allows for extended submerged endurance and quiet operation during patrol missions. The deployment of such submarines bolsters Indonesia's ability to project power within its Exclusive Economic Zone (EEZ) and contributes to maritime security in the region. The platform can also be tasked with supporting special operations forces, conducting covert surveillance, and providing early warning of potential threats.

The 403 Nagapasa is equipped with a suite of advanced sensors to enhance its situational awareness and targeting capabilities. The PRS 3-15 sonar provides long-range detection and tracking of underwater contacts, while the CSU 90 hull-mounted and flank array sonars offer improved close-range detection and classification. The IPS CSU 90 integrated processing system likely fuses data from various sonar arrays for improved accuracy and reduced operator workload. The ARIES-S electronic warfare support measures (ESM) system allows for the detection and identification of radar emissions from surface vessels and aircraft, enhancing situational awareness in the electromagnetic spectrum. The Pegaso RESM is a radar electronic support measure, also allowing for detection of radar emissions. The OMS 100 / SERO 400 periscope suite provides both visual and electronic observation capabilities, with the SERO 400 likely providing enhanced low-light and thermal imaging functionality.

SPECIFICATION: Length: 55.9 m || Beam: 6.3 m || Draft: 5.5 m || Disp: 1180 t

SENSORS: PRS 3-15 || CSU 90 Hull || CSU 90 Flank || IPS CSU 90 || ARIES-S || Pegaso RESM || OMS 100 / SERO 400 Periscope Suite

ARMAMENT: 533mm TT