▁Navy ▁( 1 7 5 5 – 8 5 ) ▁By ▁or ▁soon ▁after ▁the ▁appointment ▁of ▁Baron ▁George ▁An son ▁as ▁First ▁Lord ▁of ▁the ▁Admir alty ▁in ▁ 1 7 5 1 , ▁the ▁system ▁of ▁establish ments ▁that ▁covered ▁the ▁design ▁of ▁British ▁war ships ▁was ▁abandoned , ▁and ▁with ▁the ▁appointment ▁of ▁Thomas ▁S lade ▁and ▁William ▁B ately ▁as ▁joint ▁hold ers ▁of ▁the ▁post ▁of ▁Survey or ▁of ▁the ▁Navy ▁in ▁ 1 7 5 5 , ▁new ▁principles ▁govern ed ▁the ▁composition ▁of ▁the ▁battle ▁fleet . ▁ ▁The ▁Navy ▁Board ▁stopped ▁building ▁any ▁further ▁three - de cker ▁ 8 0 - gun ▁ships . ▁Production ▁of ▁the ▁ 7 0 - gun ▁and ▁ 6 0 - gun ▁ships ▁also ▁ceased . ▁Instead , ▁new ▁ 7 4 - gun ▁and ▁ 6 4 - gun ▁ships ▁replaced ▁these ▁classes . ▁Although ▁ 5 0 - gun ▁and ▁ 4 4 - gun ▁two - deck ers ▁continued ▁to ▁be ▁built ▁for ▁cru ising ▁duties , ▁the ▁Navy ▁no ▁longer ▁considered ▁the ▁ 5 0 - gun ▁ships ▁powerful ▁enough ▁to ▁serve ▁as ▁ships ▁of ▁the ▁line . ▁Number ▁of ▁main ▁guns ▁follows ▁name ▁( see ▁rating ▁system ▁of ▁the ▁Royal ▁Navy ) ▁ ▁First ▁rate ▁of ▁ 1 0 0 ▁guns ▁( three - deck ers ) ▁ ▁Vict ory ▁class ▁( S lade ) ▁ ▁Vict ory ▁ 1 0 0 ▁( 1 7 6 5 ) ▁– ▁" gre at ▁repair