In 1900, the Swedish Navy sent
Carl Richson to the United States, who was ordered to study
submarines. After his return, he was inspired by and designed , Sweden's first submarine. Over the next decade,
Hajens design was further developed to create a fleet of coastal submarines. During
World War I, Sweden primarily relied on the
Swedish Navy to enforce the nation's
neutrality. Swedish doctrine viewed submarines as a cheap method to counter enemy
capital ships, and the Navy often pushed to build more boats. Throughout the war, the
Riksdag invested in the fleet, which included expanding the number of submarines. In 1914, this included the two boats that served as the basis for the subsequent
Abborren class. Compared to their predecessors, the
Abborren class featured an additional
torpedo tube and more powerful engines and were the last costal submarines based on Richson's design. The class had a length of , a
beam of , and a
draught of . They
displaced 174 tons surfaced and 310 tons submerged, with a crew of 14. Propulsion was provided by two six-cylinder
diesel engines and two
electric motors that generated and , respectively, which drove two
propellers. Each boat could reach on the surface and submerged. Armament consisted of two torpedo tubes in the
bow, capable of carrying four torpedoes in total. Both were built at the
Karlskrona Navy Yard,
laid down in 1915, and
commissioned into the fleet in 1916. After serving throughout World War I and the interwar period, they were stricken on 18 June 1937. == Ships in class ==