 The secondary armament of the ships consisted of a dozen 45 @-@ caliber Canet Model 1892 6 @-@ inch ( 150 mm ) ( QF ) guns mounted in six electrically powered twin @-@ gun turrets on the upper deck . The corner turrets had an 150 ° arc of fire and the center turrets could cover 180 ° . Each six @-@ inch gun was provided with 200 rounds . Their rate of fire was 2 – 4 rounds per minute . They fired shells that weighed 91 lb ( 41 @.@ 4 kg ) with a muzzle velocity of 2 @,@ 600 ft / s ( 792 @.@ 5 m / s ) . They had a maximum range of approximately 12 @,@ 600 yards ( 11 @,@ 500 m ) . 
