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

Challenger class Between 1995 and 1997, the RSN bought four Sjoormen-class submarines from the Swedes, refurbished them and renamed them the Challenger class.

The Republic of Singapore Navy (RSN) has retired its last two Challenger-class submarines, making way for the new Invincible-class submarines. RSS Conqueror and RSS Chieftain were decommissioned ...

The history of Singapore’s submarine program dates back to the mid-1990s, when the RSN bought four Sjoormen-class submarines from Sweden, which it refurbished and renamed the Challenger class.

1995: RSN begins submarine development by acquiring a refurbished Sjoormen-class submarine built in the 1960s from the Swedish Navy. It acquires another three in 1997.

Sweden’s Sjöormen-class Submarines Proved Cost-Effective – During the Cold War, Sweden maintained a policy of neutrality that included developing the means to ensure its independence and ...

An Ohio-class submarine was used Thursday night as part of large scale retaliatory strikes against sites in Yemen on Thursday.

Sweden’s Sjöormen-class Submarines Proved Cost-Effective – During the Cold War, Sweden maintained a policy of neutrality that included developing the means to ensure its independence and ...

The development of two other Invincible-class submarines, Illustrious and Inimitable, is "progressing well" in Germany, and are expected to return to Singapore by 2028, said MINDEF.