The shell defects extended well beyond the Royal Navy's 15-inch guns. Some 12-inch shells passed through German ships without exploding, while 13.5- and 15-inch shells could burst prematurely. Once realistic trials began, faults appeared in 13.5- and 12-inch projectiles and continued into cruiser calibres such as 9.2, 7.5, and 6 inches. That expanded the task from rearming a few battleships to checking ammunition used across capital ships, cruisers, and destroyers. It also helps explain why the historical programme took time: every new calibre tested could reveal another production problem. In the counterfactual, earlier reform changes the whole fleet's ammunition system, including ships outside the Fifth Battle Squadron.
Notable Point · 1:16:15-1:21:43
The shell crisis extended below the capital-ship guns
See why testing spread from 15-inch projectiles through 13.5-, 12-, 9.2-, 7.5-, and 6-inch ammunition instead of ending with the Queen Elizabeth class.