How treaty limits contributed to destroyer turbine wear

Why not fit destroyers with more robust turbines so sustained high speed would not wear them out?

More robust machinery added weight, and treaty-limited destroyers lacked margin; the problem eased when later ships were no longer designed so tightly to treaty displacement.

Designers could not simply add heavier, more durable turbines without risking an overweight machinery plant and an overstrained hull. The worst problem appears in ships tightly constrained by treaty displacement, including the Tribals. Sustained high-speed service also wore the class hard, and every Tribal suffered some degree of what the discussion calls turbinitis after being overworked. Once treaty limits ceased to govern new construction, designers gained more machinery and structural margin and the problem became less defining. Design displacement and wartime operating tempo mattered alongside turbine technology.