HSwMS ''Sjöbjörnen'' (Sbj), Sw. meaning ''sea bear'', was the third ship of the Swedish submarine class ''Sjöormen'', project name A11.

Development

The planning of the class included a number of different AIP solutions including

nuclear propulsion Nuclear propulsion includes a wide variety of propulsion methods that use some form of nuclear reaction as their primary power source. Many aircraft carriers and submarines currently use uranium fueled nuclear reactors that can provide propulsio ...

. However, the ships where finally completed with for the time extremely large batteries. The ship was a single-hulled submarine, with the hull shape influenced by the American experimental submarine . The hull was covered with rubber tiles to reduce the acoustic signature (

anechoic tile __NOTOC__ Anechoic tiles are rubber or synthetic polymer tiles containing thousands of tiny voids, applied to the outer hulls of military ships and submarines, as well as anechoic chambers. Their function is twofold: *To absorb the sound waves ...

s), at this time a pioneering technology. The also pioneered the use of an x-shaped (as opposed to cross-shaped) rudder as a standard (as opposed to experimental) feature.

Service in Sweden

The submarine served in the

Swedish Navy The Swedish Navy () is the maritime service branch of the Swedish Armed Forces. It is composed of surface and submarine naval units – the Fleet (), formally sometimes referred to as the Royal Navy () – as well as marine units, the Amph ...

for almost 30 years and was then sold to

Singapore Singapore, officially the Republic of Singapore, is an island country and city-state in Southeast Asia. The country's territory comprises one main island, 63 satellite islands and islets, and one outlying islet. It is about one degree ...

in 1997 together with its four sister ships.

Service in Singapore

HSwMS ''Sjöbjörnen'' was renamed RSS ''Challenger'' after Singapore acquired the boat on 28 May 1999. She was commissioned on 26 June 2004 after a major refit. After 11 years in the

Republic of Singapore Navy The Republic of Singapore Navy (RSN) is the Naval warfare, maritime Military branch, service branch of the Singapore Armed Forces (SAF) responsible for defending the country against any seaborne threats and as a guarantor of its sea lines of ...

, she was decommissioned on 11 March 2015 and scrapped.

Gallery

File:HMS Sjöbjörnen (Sbj) Fo36571.jpg, HSwMS ''Sjöbjörnen'' being launched on 9 January 1968. File:HMS Sjöbjörnen (Sbj) Fo36575.jpg, HSwMS ''Sjöbjörnen'' surfacing in 1968. File:RSS Challenger.jpg, RSS ''Challenger'' undergoing session trials on 23 March 2010.

References

Sjöormen-class submarines Ships built in Malmö 1968 ships Challenger-class submarines Republic of Singapore Navy {{Sweden-stub