 The ship was armed with a main battery of ten BL 13 @.@ 5 @-@ inch Mk V naval guns mounted in five twin gun turrets . They were arranged in two superfiring pairs , one forward and one aft ; the fifth turret was located amidships , between the funnels and the rear superstructure . Close @-@ range defence against torpedo boats was provided by a secondary armament of twelve BL 6 @-@ inch Mk VII guns . Marlborough was also fitted with a pair of QF 3 @-@ inch 20 cwt anti @-@ aircraft guns and four 47 mm ( 1 @.@ 9 in ) 3 @-@ pounder guns . As was typical for capital ships of the period , she was equipped with four 21 in ( 533 mm ) torpedo tubes submerged on the broadside . She was protected by a main armoured belt that was 12 in ( 305 mm ) thick over the ship 's vitals . Her deck was 2 @.@ 5 in ( 64 mm ) thick . The main battery turret faces were 11 in ( 279 mm ) thick , and the turrets were supported by barbettes 10 in ( 254 mm ) thick . 
 The ship was armed with a main battery of ten BL 13 @.@ 5 @-@ inch Mk V naval guns mounted in five twin gun turrets . They <a href='uninflect' title='1'><mark>were</mark></a> arranged in two superfiring pairs , one forward and one aft ; the fifth turret was located amidships , between the funnels and the rear superstructure . Close @-@ range defence against torpedo boats was provided by a secondary armament of twelve BL 6 @-@ inch Mk VII guns . Marlborough was also fitted with a pair of QF 3 @-@ inch 20 cwt anti @-@ aircraft guns and four 47 mm ( 1 @.@ 9 in ) 3 @-@ pounder guns . As was typical for capital ships of the period , she was equipped with four 21 in ( 533 mm ) torpedo tubes submerged on the broadside . She was protected by a main armoured belt <a href='null_relcl' title='2'><mark>that</mark></a>was 12 in ( 305 mm ) thick over the ship <a href='null_genetive' title='3'><mark>'s</mark></a>vitals . Her deck was 2 @.@ 5 in ( 64 mm ) thick . The main battery turret faces <a href='uninflect' title='4'><mark>were</mark></a> 11 in ( 279 mm ) thick , and the turrets <a href='uninflect' title='5'><mark>were</mark></a> supported by barbettes 10 in ( 254 mm ) thick . 
The ship was armed with a main battery of ten BL 13 @.@ 5 @-@ inch Mk V naval guns mounted in five twin gun turrets . They was arranged in two superfiring pairs , one forward and one aft ; the fifth turret was located amidships , between da funnels and tdarear superstructure . Close @-@ range defence against torpedo boats was provided by a secondary armament of twelve BL 6 @-@ inch Mk VII guns . Marlborough was also fitted wit a pair of QF 3 @-@ inch 20 cwt anti @-@ aircraft guns and 4 47 mm ( 1 @.@ 9 in ) 3 @-@ pounder guns . As was typical for capital ships of the period , she was equipped with four 21 in ( 533 mm ) torpedo tubes submerged on thdaroadside . She was protected by a main armoured belt was 12 in ( 305 mm ) thick over thedaip  vitals . Her deck was 2 @.@ 5 in ( 64 mm ) thick . The main battery turret faces was 11 in ( 279 mm ) thick , and the darets was supported by barbettes 10 in ( 254 mm ) thick .