HSwMS Gotland is the first of two Gotland-class submarines to receive a mid-life upgrade (MLU). The second one is HSwMS Uppland, soon to be delivered. The upgrades have entailed a new ship surveillance system, a new battle and fire control system, a diver lock and a modernised Stirling Air Independent Propulsion system (AIP), making the submarines even more silent and thereby difficult to track and destroy.
In addition, the submarines have been extended by two meters. The pressure hull has been cut off and welded back together. The new two meter-long section enables new systems for optimising energy on board. Upgrades of the two Gotland-class submarines are a big step towards the next generation of submarines in the Swedish Armed Forces, the A26.
Two new submarines are also being built and they are to be named HSwMS Blekinge and HSwMS Skåne. Since the class is given the name of the first submarine produced in the series, it will be called the Blekinge class.
Blekinge-class submarines are currently being built by Saab Kockums. Many of the systems are the same as those in the upgraded submarines, which provides advantages. One advantage is that the same systems allow the crew to work in both types of submarines, which increases operational endurance and minimises the risk of submarines lacking skilled personnel.