 During the Russian war of 1788 – 1790 , Sweden built three hemmemas of a new design . They were considerably larger , 44 @.@ 5 by 11 m ( 146 by 36 ft ) , and the number of oars were increased to 20 pairs . They also had some of the heaviest broadsides , even when compared with the much larger frigates of the high seas navy . The artillery officer Carl Fredrik <unk> had cooperated with Chapman to increase the main armament to twenty @-@ two 36 @-@ pounders and two 12 @-@ pounders , which increased the draft by about 30 cm ( 1 ft ) . The addition of diagonal <unk> to reinforce the hull allowed the later hemmemas to carry guns more powerful even than those on the largest sailing frigates of the high seas navy . Due to their considerable firepower and relative size , naval historian Jan <unk> has described the hemmemas as " super archipelago frigates " . 
