World War I modifications gave the Indomito class mine-laying rails and changed its gun armament. Fuel capacity increased from 100 to 128 tons, which was expected to improve the ships' usefulness. Added weight and the placement of the extra fuel slowed them and reduced efficiency. The resulting endurance penalty meant that carrying more fuel did not allow them to travel farther. The suggestion that Cattolica probably advised against these changes remains speculation.
Notable Point · 30:26-31:20
Why more fuel reduced Indomito's endurance
Extra fuel capacity brought a weight and stowage penalty that reduced speed, efficiency, and range.