The historical force included HMS Nelson, HMS Renown, HMS Ark Royal, cruisers including HMS Manchester and HMS Edinburgh, the fast minelayer HMS Manxman, and numerous destroyers. Italian attacks damaged Manchester and sank HMS Fearless; Fairey Fulmars intercepted Savoia-Marchetti SM.79 torpedo bombers while CANT Z.1007 medium bombers complicated the defense. Fearless's four low-angle 4.7-inch guns left her largely dependent on quadruple machine guns against aircraft. More 4.5-inch batteries would be most useful against medium- and high-level bombers rather than guaranteeing the destruction of low-flying torpedo aircraft. That added defensive layer could let the Fulmars concentrate on the torpedo threat while ships handle the distracting higher-level attack more effectively.
Chapter · 45:32-49:35
Operation Substance tests the fleet-wide air-defense effect
Operation Substance illustrates how more high-angle guns might let Fulmars concentrate on SM.79 torpedo bombers while reducing danger to the convoy escort.