Control for the ships' armament relied on five main directors. Three of them were mounted on the foremast on top of each other, with the other two aft, one for the secondary guns atop the funnel in a mack-type arrangement and the other for the main battery atop a deck house. The directors for the main battery were fitted with a stereoscopic rangefinder in the foremast position and an rangefinder in the aft position, while both turrets were fitted with their own 14 m rangefinder for operations under local control. The two upper directors for the secondary battery on the foremast had 8- and rangefinders while the mack director also had a 6 m rangefinder. Each secondary turret had its own 8 m rangefinder. A pair of rangefinders for use by an admiral's flag staff were installed on sponsons in the conning tower. The directors gathered range and bearing data on targets and transmitted it to a central processing station that fed instructions to the gun crews.