 The fore and aft main gun turrets were given a 6 @-@ meter ( 19 ft 8 in ) rangefinder , and there was another 5 @-@ metre ( 16 ft 5 in ) unit on top of the conning tower . These would provide data for the Geisler central artillery post computer , which would then transmit commands to the gun crew . The mechanical fire @-@ control computer would have been either a Pollen Argo range clock , which had been bought in 1913 , or a domestically designed Erikson system . 
