Even after the weight savings, the design reached about 11,000 tons standard rather than the nominal treaty figure. The account distinguishes Italy's deliberate decision to exceed the limit from Japanese cruisers whose full overrun was not initially known. Zara-class turrets had 150 mm faces and 120 mm sides, while barbettes and turret trunks carried armour comparable to the hull. Protection weighed about 2,700 tons, equal to 26.5 percent of the declared displacement and roughly 23 percent of completed standard displacement. That scale put Japanese cruisers in the shade and made the proposed British Surrey design look lightly protected by comparison.
Notable Point · 4:34-5:42
Zara-class treaty breach and capital-ship armour
The completed design still exceeded its declared treaty displacement, while protection for the turrets, barbettes, and hull made the Zara class a group of mini-capital ships rather than ordinary 10,000-ton cruisers.