The Cadorna class range and displacement puzzle

The Cadorna ships retained the earlier armour, two-aircraft outfit and launcher, Parsons turbines, Yarrow boilers, 95,000 horsepower, nominal 37-knot speed, and 507-person complement. Their stated cruising range nevertheless fell to 2,930 nautical miles at 16 knots, compared with 3,800 nautical miles at 18 knots for the Giussanos. Length, beam, and draft changed very little. Published displacement figures deepen the puzzle: 5,323 tons standard and 7,113 tons at full load for the Cadorna class, against 6,570 and 6,954 tons respectively for the Giussanos. The numbers do not readily fit the visible dimensional changes, leaving either the published data or unrecorded refinements in question. Reliance on British machinery also shows that Italy's capable shipyards outpaced its domestic ability to produce high-performance propulsion metallurgy at the required scale.