Why a Tachibana-class escort could not safely chase much more speed

How fast could a Tachibana-class destroyer go before additional hull sheathing or strengthening became necessary?

Not much beyond 29 knots; its thin wartime hull made further speed structurally unattractive.

The Tachibana subclass was rated at about 27.8 knots, and pushing it much beyond 29 knots would require hull strengthening. These ships were austere wartime escorts derived from the Matsu design rather than robust high-speed fleet destroyers. Some plating was described as roughly ten millimeters, far below the thickness associated with more substantial destroyer construction. The loss of a ship to one or two aircraft bombs illustrates how little structural margin the design offered.