Italy designed its cruisers for Mediterranean speed and firepower yet still failed to keep them within the nominal 10,000-ton limit. Trento carried real belt armor, while members of the Zara class differed from one another by hundreds of tons and Bolzano combined high power with a declared performance that did not fit the visible hull. British knowledge came through observations of heavily laden ships in ports such as Gibraltar and through industrial connections. Yarrow and Thornycroft boilers, Parsons turbines, spare parts, and Royal Navy-supervised repairs exposed machinery weights and performance that made false declarations difficult to sustain.
Chapter · 1:46:18-1:59:29
Italian heavy cruisers exceeded the limit in plain sight
Trento-, Zara-, and Bolzano-class performance exposed tonnage claims that British dockyards and suppliers could independently test.