Busan: South Korean shipbuilder Daewoo Shipbuilding and Marine Engineering (DSME) was pitching its 3,300 ton (surface displacement) submarine, dubbed the DSME 3000, to India for the country’s Project 75I-class (P75I) programme. South Korea’s proposal for the Indian Navy’s P-75I is based on the Republic of Korea Navy KSS III design
The DSME 3000 has a length of 83.5 meters, a beam of 9.7 meters, a draft of 14.7 meters, and a maximum submerged speed of 20 knots per hour. It is based on the Dosan Ahn Changho-class of the Republic of Korea Navy (ROKN) which is being jointly produced by DSME and Hyundai Heavy Industries (HHI) as part of the KSS III program. The class are the largest submarines ever operated by the ROKN. It is armed with six 533 millimetre torpedo tubes and six vertical launch system (VLS) cells. It also has better living quarters and amenities for seamen compared to other ROKN submarines. DSME produced the first two ships of the KSS III Batch 1 which were launched in 2018 and 2020 respectively, while construction on the third ship, by HHI, is ongoing. A total of nine vessels are planned: Three in a “Batch 2” configuration and three more in a “Batch 3”. The local content and capabilities are improved in each batch. The variant being offered to India will not have the VLS cells that are standard on the Dosan Ahn Changho-class.
“We haven’t finalized the exact design for India, but the removal of the VLS cells behind the sail of the submarine will allow for greater flexibility. We will be able to add new features to meet the Indian Navy’s needs. Moreover, there is a possibility that we will offer submarine rescue vessels alongside our subs as part of a large ‘package’ deal”. According to the representative, of the five companies shortlisted for the P75I competition, TKMS and DSME are the only contenders that have already designed and produced working fuel cell-based AIP submarines. “The Dosan Ahn Changho-class uses fuel-cell AIP technology. We believe this will give us the edge,” an official said.
Fuel-cell based AIP technology allows non-nuclear submarines to stay submerged for a significant amount of time. The system does not need a battery. As long as it receives a continuous source of fuel, such as hydrogen and oxygen which can be obtained from the ocean, it can continue to operate for an extended period of time. The representative continued, “The exact time period during which the DSME3000 can remain submerged is classified. However I can tell you that it is one of the most capable submarines in this regard.”
Another potential rubric for the P75I competition is the quality of the battery that will equip the submarine. Even if a submarine uses AIP technology, solely relying on it would be inefficient and risky. Therefore, AIP submarines still need batteries to further augment their endurance. These batteries need to be charged while the submarine surfaced or at periscope depth. Traditionally, submarines have used lead acid batteries. However, Japan (not part of the P-75I competition) became the first country to operate submarines equipped with lithium-based batteries when it commissioned the JS Oryu and JS Toryu, the last two Soryu-class submarines, in 2020 and 2021.
