Singapore has bolstered its maritime defenses with the commissioning of two new Invincible-class submarines, RSS Invincible and RSS Impeccable, part of the Republic of Singapore Navy’s (RSN) modernization in the face of evolving security challenges.
The vessels, built by Thyssenkrupp Marine Systems in Germany, are equipped with automation and air-independent propulsion that allow them to operate quietly and stay submerged longer. They also have a low-profile underwater presence and enhanced maneuverability for Singapore’s shallow, congested waters, boosting tactical flexibility and rapid threat response.
Singapore’s acquisition of the advanced naval assets underscores its determination to protect critical sea lines of communication (SLOC). In a region where major economies rely on the free passage of goods and energy supplies, Singapore’s defense strategy focuses on maintaining open and secure SLOCs, which account for much of global shipping traffic.
“The RSN’s ability to protect these channels is critical for Singapore, given its reliance on maritime trade,” Thomas Lim, a senior analyst at Singapore’s S. Rajaratnam School of International Studies, told FORUM.
The Invincible-class submarines enter service as competition in the Indo-Pacific intensifies. Naval activity has surged in the region, especially from the People’s Republic of China, which has rapidly expanded its submarine fleet as part of its military buildup. Countries such as Indonesia and Vietnam also have invested in submarines to protect their maritime interests. Singapore’s new submarines will strengthen its ability to monitor and detect threats to its SLOCs and maritime infrastructure, and to counter incursions.
“To build a strong and credible deterrent, the SAF [Singapore Armed Forces] must continue to evolve,” Singapore Prime Minister Lawrence Wong said at the commissioning ceremony in September 2024. “Because we face a world of shifting dynamics and emerging threats — both traditional and unconventional.”
The submarines are part of the SAF 2040 initiative to prepare the military for the complexities of the regional landscape, Lim said, and they underscore the city-state’s commitment to securing waters vital to its economy and security.
“Their ability to operate seamlessly with regional partners strengthens Singapore’s position as a credible partner in ensuring regional stability,” he said. Enhanced interoperability allows the RSN to participate in joint exercises and multinational initiatives, bolstering collective security across Southeast Asia.
The Invincible-class submarines are replacing Challenger-class vessels as part of the RSN’s phased upgrade. Two more of the submarines, RSS Illustrious and RSS Inimitable, are scheduled to be operational by 2028.
Given its location at the intersection of the Malacca Strait and the South China Sea, Singapore understands the strategic importance of a robust naval presence, Wong said.
“As a maritime nation, Singapore’s survival and prosperity depend on free and unimpeded movement over the seas,” he said. “Today, we have a modern and highly sophisticated naval force. The submarines are an integral part of this force.”
