What barbette diameter is most plausible for the Nagato class?
Short answerThe sources conflict, but roughly 30 feet is a plausible estimate. An exact measurement is not supported.
NotesFour conflicting figures prevent an exact answer for Nagato's barbette diameter. Roughly 30 feet appears plausible against the ship's stated beam of 29.2 metres, approximately 95 feet. The cited estimates include 29 feet 2 inches and 31 feet, while contemporary American twin 14-inch turrets are offered as a comparison with barbettes around 29 feet across. An 18-foot figure is rejected because the equipment could not physically fit inside it. Different measurement points and later alterations might explain some disagreement, while the destruction of Japanese archive material complicates verification. Around 30 feet remains a provisional estimate, with an exact figure unresolved.