 The forward conning tower was the most heavily armored part of the ship . Its sides were 25 cm ( 9 @.@ 8 in ) thick and it had a roof that was 8 cm thick . The rear conning tower was significantly less well armored , with a roof that was 3 cm thick and sides that were only 14 cm ( 5 @.@ 5 in ) thick . The central citadel of the ship was protected by 16 cm ( 6 @.@ 3 in ) armor . The main battery turrets were 8 cm thick in their roofs , and had 18 cm sides . The 15 cm turret casemates were protected by 14 cm of armor . 
