HMS Södermanland

History

HMS Södermanland was built by Kockums in Karlskrona as the third of four Västergötland-class submarines. She was launched in April 1988 (sources give either 12 or 21 April) and commissioned on 21 April 1989. The Västergötland-class design combined features from the Sjöormen and Näcken classes, offering greater submarine-hunting capability than previous Swedish classes.

Between 2000 and 2004, Södermanland underwent extensive modifications: the hull was extended by 12 metres from 48.5 to 60.5 metres to accommodate two Stirling air-independent propulsion (AIP) units, and the boat was adapted for international missions in hot, salty waters. The conversion was so extensive that Kockums reclassified the upgraded boats to a new Södermanland subclass (designated A17S). When her only upgraded sister, HMS Östergötland, was decommissioned in 2021, Södermanland became the sole remaining operational submarine of the subclass. In September 2022, Sweden approved SEK 470 million for further life-extension work, including battery replacement and machinery overhaul, to maintain the boat in service until 2028.

On 29 June 2026, Sweden's Defence Materiel Administration (FMV) and Poland's Armament Agency signed an intergovernmental agreement at a ceremony in Gdynia to lease HMS Södermanland to Poland from October 2026 to October 2032. The lease provides an operational submarine capability as a gap-filler following the retirement of Poland's four Kobben-class submarines between December 2017 and December 2021, which left the country with only its single Russian-built Kilo-class ORP Orzeł (commissioned 1986). On 12 October 2026, FMV and the Swedish Armed Forces signed an implementation agreement covering refurbishment, crew training, maintenance, and operational support during the lease period. Operational use in Polish service is planned to begin in 2028. Thirty Polish submariners began an 18-month training course in Karlskrona on 24 August 2026, initially covering firefighting, damage control, and language training before proceeding to instruction aboard Södermanland from October. The lease bridges the gap until Poland receives three new Saab A26 submarines under a SEK 47 billion procurement contract, with deliveries scheduled between 2031 and 2038.

Specifications

• Displacement: 1,400 tonnes surfaced; 1,500 tonnes submerged
• Length: 60.5 m (extended from 48.5 m during the 2000–2004 upgrade)
• Beam: 6.1 m
• Speed: 8 knots surfaced; 15 to 20 knots submerged (one source cites 15 knots)
• Propulsion: Diesel-electric with two Stirling AIP units burning diesel fuel with stored liquid oxygen
• Torpedo tubes: six 533 mm heavyweight; three 400 mm lightweight
• Complement: 24–28 sailors