Näcken-class submarine

The Näcken-class submarines, also known as the A14 type, were built for the Swedish Navy in the late 1970s. The boats were authorised in 1972 and the programme was completed in 1981. All boats were built by Kockums in Karlskrona. The boats had a teardrop hull and diving depth was 150m. Between 1987 and 1988 the Näcken was converted to Air Independent Propulsion (AIP) using a closed cycle Stirling engine. This technology increased underwater endurance to 14 days and has been adopted in subsequent Swedish submarines.

By the early 2000s the class was decommissioned from the Swedish navy. The HMS Näcken was temporary leased to the Danish navy but was returned in 2005. As of 2011 the three submarines are laid up at the Karlskrona naval base.