The Mago class was still under construction when a further twelve units were ordered but these would be armed with the Coventry works 5.5" gun originally designed for the Greek light cruisers that became the Chester class. The new class would replace the mixed armament of 6" and 4" of the Mago, with a uniform armament of six 5.5". The torpedo armament went from 18" to 21". A 3" AA gun was added in 1917. So why switch from the 6" to the 5.5"? Size of shell and rate of fire. Both relate to crew fatigue. The bigger the shell being handled the shorter time it takes the gun crew to become fatigued. This means that the rate of fire will slow considerably. If the gun is rated at eight rounds a minute in exceptional conditions, in actual battle conditions, this figure could easily halve. The 6"/100lb shell fatigued its gun crew much quicker than the 5.5"/84lb shell. Both weapons fired about the same distance.
The last of the class joined the fleet in November 1917. Only one of the class was lost during WW1 when it was torpedoes by a U-boat in 1917, on convoy duty, off the Irish coast. The Caporeal was on its delivery voyage from Greenland to Scapa Flow, to join the fleet, and it was felt that lack of training led to the ships loss. The crew not knowing all of the emergency procedures to take after a torpedo hit. The ship might have been saved by a more experienced crew.
The Shapash class had the previous Mago type to follow when these ships started being converted to AA cruisers from 1936 onwards. Replace the 5.5" with 5" DP guns on a one for one basis, and replace the original bridge superstructures with new ones as per the Mago. Add a few more modern AA weapons and 'hey presto' more shadows for the Melqart class CVE's and the older CVL's.
