The forward conning tower was protected with heavy armor: the sides were thick and the roof was 170 mm thick. The rear conning tower was less well armored; its sides were only 170 mm thick and the roof was covered with of armor plate. The main battery gun turrets were also heavily armored: the turret sides were 350 mm thick and the roofs were 200 mm thick. The 15 cm guns had 170 mm thick armor plating on the casemates; the guns themselves had 80 mm thick shields to protect their crews from shell splinters.