Why is the bulged Nagato 24 seconds?

The original cutoff point for 26/24 seconds was 740 feet, changed in 1991 to 720 feet, which sped up both the Nagato and North Carolina at the same time.  [Hullbusters August and October 1991]. Deal for Nagato exception to 6 units was made in 1992 when the membership voted to specify the bylaws were supposed to override the shiplist ( stuff was really inconsistent back then, if I recall right the shiplist already had it listed at 6 units ).  Hullbusters December 1992.