 The ships ' secondary battery consisted of fourteen 15 cm ( 5 @.@ 9 in ) SK L / 45 quick @-@ firing guns mounted in armored casemates along the central superstructure . Each gun was supplied with 160 rounds , and had a maximum range of 13 @,@ 500 m ( 44 @,@ 300 ft ) , though this was later extended to 16 @,@ 800 m ( 55 @,@ 100 ft ) . The guns had a sustained rate of fire of 7 rounds per minute . The shells were 45 @.@ 3 kg ( 99 @.@ 8 lb ) , and were loaded with a 13 @.@ 7 kg ( 31 @.@ 2 lb ) RPC / 12 propellant charge in a brass cartridge . The guns fired at a muzzle velocity of 835 meters per second ( 2 @,@ 740 ft / s ) . The guns were expected to fire around 1 @,@ 400 shells before they needed to be replaced . 
