Sweden manages an long-ranging coastline bordering the Gulf of Bothnia and the Baltic Sea to the East with access to the English Channel (and then the Atlantic Ocean) in the West. As such, it behooves the Scandinavian power to keep an all-modern navy service and, among the inventory of warship available are five diesel-electric submarines belonging to two distinct classes, the Gotland-class and the older Sodermanland-class. Three boats currently make up the Gotland-class, launched in the mid-1990s, and two make up the Sodermanland-class, appearing at the end of the 1980s.
The Gotland-class is led by HSwMS Gotland (Gtd). Built by Kockums AB shipyard of Malmo, Sweden, she saw her keel laid down on October 10th, 1992. The boat was launched on February 2nd, 1995 and she was formally commissioned for service in the Swedish Navy during April of 1996. She remains in active service as of this writing (December 2017) and fights under the motto of "Gothus sum, Cave Cornua" meaning "I am a Gothlander, Watch out for the horns". She homeports out of Karlskrona, Sweden.
As built, the boat displaces 1,380 tons surfaced and 1,600 tons when submerged. Dimensions include an overall length of 198.1 feet with a beam measuring 20.3 feet and a draught of 18.3 feet. Propulsion is by way of 2 x German-originated MTU diesel engines outputting 1,300 horsepower with 2 x Stirling AIP engines of 101 horsepower each and 1 x Electric motor of 1,800 horsepower. The diesels are used for surface-running while the electric motor is used in submerged travel. The boat can make headway at 11 knots surfaced and 20 knots submerged and range out over fourteen days with its crew of twenty-two. The hull has been tested to depths of 500 feet.
Aboard is a standard Swedish armament fit of 4 x 533mm (21") torpedo tubes with 2 x 400mm (16") torpedo tubes. Twelve reloads are carried in 533mm caliber and six in 400mm caliber. The boat can also serve as a mine dispersing platform and carry up to 48 naval mines externally.
As an all-modern design, the Gotland features a blunt bow section with flat top hull. The sail is of a slim, low profile and is seated slightly ahead of midships. The dive planes are affixed to the forward section of the sail. The tail planes and rudder control are arranged in an "X" pattern as opposed to cruciform.
HSwMS Gotland is joined in service by two sister ships of same design, HSwMS Uppland (Upd) and HSwMS Halland (Hnd). All are in active service as of December 2017 and all are assigned to the 1st Submarine Flotilla of the Swedish Navy.
In service, HSwMS is prized for her silent operation, agility and capability in intelligence-gathering as well as Anti-Submarine/Anti-Ship and mine warfare. Her value is such that she was used in war games with the United States to test out the services effectiveness against modern diesel-electric-powered types - to which Gotland managed to succeed against the American carrier group centered around the USS Ronald Reagan. In another earlier exercise against American forces, the boat "sunk" USS Houston, a highly-touted Los Angeles-class submarine.
The Gotland-class is set to be succeeded by the in-development, next-generation A26-class to come online in, or around, 2022. In the meantime, the class is scheduled to be modernized from 2017 to 2019 (by Saab Kockums) to keep them viable for the near future - particularly as Russian submarine activity increases in the Baltic Sea. The class will also be fielded side-by-side with the new A26-class at least for a time.