How barbettes became part of a warship's armoured structure

How integral were gun barbettes to the structure of the ships that carried them?

It varied, but barbettes were tied into the hull and often formed part of the armoured bulkheads at the ends of the citadel.

The degree of integration varied by class, but a barbette could never be wholly independent of the hull supporting it. Designers tied the cylindrical armoured structure into decks, framing, and the surrounding hull. In many ships the forward and after barbettes aligned with armoured transverse bulkheads and helped mark the ends of the protected citadel. That placement made them part of the vessel's subdivision and armour scheme as well as the support for a gun mounting. Structurally, a barbette helps transmit weight and define protection boundaries inside the ship.