The Swedish Navy had been attempting to secure a Next Generation attack submarine since the 1980s when the Soviet Union remained the primary threat of the region - and the world for that matter. The service enacted "U-bat 2000" led by local industry player Kockums to help fulfill the requirement before the end of the millennium. However, with the fall of the Soviet Empire in 1991, the need for such an expensive attack platform waned while the service made due with its Sodermanland-class and Gotland-class diesel-electrics for the foreseeable future. However, as age has crept into these late-1980s/early-1990s designs, it has become apparent that a new submarine design is still in order and this has, in turn, spurred interest in a next gen submarine platform once again.
By March 2015, the Swedish Government committed to the venture, now recognized as "A26", and is intent on purchasing two new all-modern diesel-electric attack platforms built to the same standard by Saab Kockums AB (Saab Group). The boats will possess a displacement of 1,930 tons and have a length of 206.7 feet, a beam of 21 feet and a draught of 19.8 feet. The diesel-electric propulsion scheme will use the Stirling API system for underwater silent running and onboard stores will allow the boats to remain at sea for up to 45 days at a time before requiring resupply. The hull will be capable of depths down to 655 feet and the crew complement will number between 20 and 30 persons.
The proposed armament scheme is consistent with previous modern Swedish submarine designs, a mix of 4 x 533mm (21") torpedo tubes and 2 x 400mm (16") torpedo tubes (all bow facing). The boat will also have provision to carry naval mines as needed. There is also possible support for an 18-cell Vertical Launch System (VLS) to fire the American Tomahawk cruise missile is also planned.
The A26 will be completed with a modular design as its centerpiece, allowing a single boat framework to be customized to Swedish Navy needs while keeping operating costs minimal. Five major sections will make up the hull of the submarine to include its bow, sail and three aft sections. This allows each module to be built independently and be tested, modified, and/or replaced as needed with the new/revised section simply being reinserted into the submarines design flow. The submarine can, therefore, be customized to meet future demands as they arise and will more than likely be able to maintain a long-running career as a result.
Much thought has been placed in the submarine's acoustic signature to help the boat maintain an advantage in the undersea hunting game while long-term maintenance is to be kept at a minimum to reduce in-dock times for maintenance, repairs and general overhauls. Beyond this is attention being paid to making the A26 a long-endurance attack submarine capable of deep water ocean operation - moving the Swedish fleet away from its usual coastline duties.
Of note is that the bow of the submarine has a multi-mission porthole which can house a mini-submersible to provide an extended set of "eyes" underwater - useful when supporting rescue operations or special forces actions.
Externally, the boat exhibits a conventional submarine arrangement. The sail, of a rather unique and low-profile design, sits ahead of midships and contains the needed sensors and communications equipment as well as the dive planes. The tailplanes (including the rudder) are arranged in an "X" pattern aft and is consistent with previous Swedish Navy submarine designs. The multi-bladed propeller unit sits just outside of the tailplanes.
To date, the A26 has had something of a prolonged and somewhat troubled development history centered between logistical, industry and political meandering issues all-the-while time slips away from the existing in-service Swedish submarine fleet. The Swedish Navy is planning on having its two A26 submarines online on or around 2022 and these will most likely begin their careers operating side-by-side with the existing Gotland-class boats. The current (2017) Swedish submarine fleet numbers five boats (3 x Gotland-class and 2 x Sondermanland-class).