 The armor of the main gun turrets and their supporting tubes was 250 millimetres thick with roofs 63 millimetres ( 2 @.@ 5 in ) thick . Below the upper armour deck the armour of the support tubes decreased to 100 millimetres ( 3 @.@ 9 in ) . The turrets of the secondary armament had 150 @-@ millimetre ( 5 @.@ 9 in ) sides with 30 millimetres ( 1 @.@ 2 in ) roofs . The sides of the conning tower were 254 millimetres ( 10 @.@ 0 in ) thick and it had a 63 @-@ millimetre roof . It had a communications tube that extended down to the upper armoured deck that was protected by 100 @-@ millimetre armour . The funnel uptakes were protected by 19 millimetres ( 0 @.@ 7 in ) of armour for the height of one deck above the upper armoured deck . 
