Sverige - class coastal defence ship The Sverige class coastal defence ships were the largest ships to serve in the Swedish Navy until that point . Their design was completely new and was influenced by the ships of the time . Their armament consisted of four 28 . 3 cm Bofors guns in two turrets and eight 15 . 2 cm guns in one double and six single turrets . During the Second World War they were the backbone of the Swedish Navy . All three ships looked similar until reconstruction . Gustav V had funnels trunked into one and the upper works modified heavily . Sverige had the fore funnel trunked back away from the superstructure which was modified , and kept the second funnel , making the ships very different in appearance between the main turrets . Specification as built . " Gustav - V " also har her forward superfiring 2x152mm tower removed , and replaced with a platform for gyro stabilized AA - artillery ( 4 x 40mm bofors ) while " Sverige " and " Drottning Victoria " had their midship single 1x152mm towers removed and replaced with gyro stabilized AA - plattforms ( Bofors 40mm double mountings ) Ships . Three of these ships were built : A fourth ship was considered but not built due to economic difficulties The ships were modernised in the 1930s with oil - fired boilers replacing the old coal - fired boilers , removal of underwater torpedo equipment , new anti - aircraft guns and fire control equipment " Sverige - class " , tactical doctrine and effectiveness . The Sverige - class ships differed in several ways from the classical coastal defence ship ; at first by heavier armament as well as better speed and armor , but still small enough to operate and hide in the archipelagos and shallow waters . But the main difference was to be noted in their tactical doctrine and operations . Unlike other coastal defence ships the " Sverige - class " formed the core of a traditional open sea battle group ( Kustflottan ) , operating with cruisers , destroyers , torpedo boats and air reconnaissance like traditional battleship tactics of the time . This “ mini - battle group ” had no intention to challenge the superpowers in blue sea battles but to operate as defensive shield to aggression challenging Swedish interests and territory . Based on the doctrine that you need a battle group , to challenge a battle groups this force intended to form a problematic obstacle in the confined and shallow Baltic and Kattegat theatre where traditional large warships would be limited to very predictable moving patterns exposing them to submarines , fast torpedo crafts and minefields . It has been suggested that the Sverige class ships were one reason why Germany did not invade Sweden during World War II . This speculation appeared in Warship Magazine 1992 Edition , in the article ' The Sverige Class Coastal Defence Ships , by Daniel G Harris . ' This could partly said to be confirmed in the post war publication of German tactical orders , and when tactical scenarios regarding attacking Sweden was published . The problems of maintaining an army in Sweden without sea superiority was underlined and lack of available suitable units to face the Swedish navy was pointed out ( “ Stations for battle ” , Insulander / Olsson , 2001 ) Summarizing the question of effectiveness for the “ Sverige - class ” it likely that despite a good armament they would have been too small , too cramped , too slow and without enough range to perform against any traditional battlecruiser or battleship in blue water scenario . However , if used rightly in their home waters and in a defensive situation they would probably have presented a major challenge for any aggressor .