Heavier torpedoes for the CB-class mini-submarine

How much weight would a CB-class mini-submarine gain with four 533 mm torpedoes instead of two 450 mm weapons?

At least about 6,000 pounds, and more once larger launchers, controls, and supporting systems are included.

The panel estimates at least 6,000 pounds of additional weight before fully accounting for launch, monitoring, and support systems. The proposal doubles the boat's nominal weapon count while also moving to substantially heavier torpedoes. On a very small submarine, those added systems and weights would fundamentally reshape the design rather than act as a simple armament substitution. The boat also prompts a qualified observation about Italian wartime industry: strong low-volume designs were harder to translate into mass production while the country was midway through rearmament.