The Republic of Singapore Navy (RSN) has decommissioned its final two Challenger-class submarines, RSS Conqueror and RSS Chieftain, at RSS Singapura – Changi Naval Base.

Singapore's Chief of Navy Sean Wat officiated the ceremony, marking the transition of duties from the Challenger-class submarines to the new Invincible-class submarines.

In September, Singaporean Prime Minister Lawrence Wong and senior defence officials commissioned the first two Invincible-class submarines, RSS Invincible and RSS Impeccable.

Challenger-class submarines, formerly the Royal Swedish Navy’s Sjoormen-class, joined the RSN in the 1990s.  

The then-deputy prime minister and minister for defence Dr Tony Tan Keng Yam commissioned RSS Conqueror and RSS Chieftain on 22 July 2000 and 24 August 2002, respectively.  

Launched in May 1999 at the Kockums shipyard in Karlskrona, Sweden, RSS Conqueror was the first of the four RSN submarines to arrive in Singapore. 

Before its return in 2000, it underwent refurbishment and tropicalisation in Sweden, followed by sea trials in Singapore to verify its systems' performance in local conditions. 

The last of the four ex-Sjoormen class submarines, RSS Chieftain, was launched on 22 May 2001. 

The Challenger-class submarines, along with RSN’s pioneer submariners trained in Sweden, contributed to developing a submarine operating capability.  

Over the years, these submarines protected Singapore’s maritime interests and territorial integrity through operations and participated in bilateral and multilateral exercises. 

Fleet commander RADM Kwon Hon Chung said: “RSS Conqueror and RSS Chieftain’s achievements are a testament to the unwavering resolve and courage of the RSN’s pioneer submariners, who laid strong foundations for the growth of 7th Flotilla and the RSN into a world-class submarine operating force.  

“It was on board these submarines where we dived into the underwater domain some 29 years ago and overcame numerous challenges with the invaluable assistance from the Royal Swedish Navy.”

During the ceremony, Wat also launched the new submarine training school (STS), named after the RSS Challenger.

The facility marks a milestone in RSN’s local submarine training history and leverages technological advancements to enhance training realism, effectiveness, and efficiency.

The STS features simulators for individual and team training, incorporating realistic scenarios in a safe environment.