 A revised design was approved on 28 February 1938 and the first ship was to be laid down on 15 July , but even this design was incomplete and would be revised later . Trials with similarly shaped motor launches suggested that the hull 's propulsive efficiency would be 1 knot ( 1 @.@ 9 km / h ; 1 @.@ 2 mph ) less than planned , and this was accepted in the November 1938 revision as a maximum speed of 27 @.@ 5 knots ( 50 @.@ 9 km / h ; 31 @.@ 6 mph ) . However , a new propeller design proved to be more efficient and was predicted to increase speed to 28 knots ( 52 km / h ; 32 mph ) . Another change was the <unk> of the centerline rudder when tests showed that the two wing rudders would not be able to counteract its effects if it jammed . The weight toward the stern of the boat was calculated to be too great , producing a substantial stern @-@ down trim . To remedy this , the two 100 mm turrets mounted on the quarterdeck were deleted and the height of the armor belt abreast the rear turret was lowered , but this decision was reversed and they were restored by a decision of the State Defense Committee on 14 January 1941 . This forced a revision of the aircraft arrangements as the aircraft catapult had to be removed from the centerline of the quarterdeck ; two <unk> were added to the sides of the quarterdeck instead . 
