What changes if the Emerald class receives twin six-inch guns from the start?
Short answerA D-class test installation would likely precede it, potentially enabling later D-class turret upgrades as well.
NotesThe Royal Navy would need to prove the twin six-inch mounting before committing it to the Emerald class. A D-class cruiser would probably become a test ship for the installation. Successful trials could then make similar D-class upgrades plausible during the 1920s. The new turret would affect the lead class and the older ships used to mature it.