Shortround6
Lieutenant General
British screw up with 5.25in gun & mount.
DP guns require a very careful balance and many navies leaned to the surface action side. The RN really leaned to surface action side with the 5.25 and the low rate of fire really hurt the AA capability of any ship that had them.
As designed the Dido's were supposed to have 5 twin 5.25 mounts and a single quad pom-pom on each side and either a quad .50 cal mg on each side or two twin .50s per side.
The 5.25 proved to have a firing rate about 2/3s what was hoped for and a single quad pom-pom per side was nowhere enough to handle large attacks (more than a few planes at once). While the 4in guns fired a smaller shell they fired about twice as fast.
One does wonder if they would have been better served by building slightly stretched Arethusa class ships and fitting the updated heavy AA of 8 four twin 4in mounts and the single quad pom-pom per side.
The 'power' of the 5.25 as an AA gun was largely an illusion. The ability to really hit a high flying airplane (or small group) from a moving ship didn't exist. Of course the ability of high flying airplanes to hit a moving ship didn't exist either. Both sides thought they could do better than they really could. Maybe, maybe, the 5.25 was better at discouraging snoopers at very long range. But at about twice the weight per twin mount/turret over the 4.5in mounts that was a high price to pay.
The US navy was pretty much a class by itself with the 5in/38. They had deliberately sacrificed long range surface fire capability for better AA (faster fire, quicker train and elevation movement). Just because you can elevate a gun to 70-80 degrees doesn't really make it an AA gun. Destroyers can't hit much of anything at 15,000-20,000 yds anyway, the hulls are moving around too much except in a dead calm. Pre radar they don't have big enough range finders to actual spot fire at those ranges and even their look outs are closer to water and moving around more (spotter in a destroyer crows nest?)
DP guns require a very careful balance and many navies leaned to the surface action side. The RN really leaned to surface action side with the 5.25 and the low rate of fire really hurt the AA capability of any ship that had them.
As designed the Dido's were supposed to have 5 twin 5.25 mounts and a single quad pom-pom on each side and either a quad .50 cal mg on each side or two twin .50s per side.
The 5.25 proved to have a firing rate about 2/3s what was hoped for and a single quad pom-pom per side was nowhere enough to handle large attacks (more than a few planes at once). While the 4in guns fired a smaller shell they fired about twice as fast.
One does wonder if they would have been better served by building slightly stretched Arethusa class ships and fitting the updated heavy AA of 8 four twin 4in mounts and the single quad pom-pom per side.
The 'power' of the 5.25 as an AA gun was largely an illusion. The ability to really hit a high flying airplane (or small group) from a moving ship didn't exist. Of course the ability of high flying airplanes to hit a moving ship didn't exist either. Both sides thought they could do better than they really could. Maybe, maybe, the 5.25 was better at discouraging snoopers at very long range. But at about twice the weight per twin mount/turret over the 4.5in mounts that was a high price to pay.
The US navy was pretty much a class by itself with the 5in/38. They had deliberately sacrificed long range surface fire capability for better AA (faster fire, quicker train and elevation movement). Just because you can elevate a gun to 70-80 degrees doesn't really make it an AA gun. Destroyers can't hit much of anything at 15,000-20,000 yds anyway, the hulls are moving around too much except in a dead calm. Pre radar they don't have big enough range finders to actual spot fire at those ranges and even their look outs are closer to water and moving around more (spotter in a destroyer crows nest?)
This is quite correct in that the 4.5in mounts fired about 50% faster than the 5.25 mounts so even the DIdo's had their full 5 mounts and they fired at 8rpm that is 80 rounds per minute. The S & C could fire at 12rpm per barrel so times eight barrels that is 96 rounds per minute. Against an 4 mount 5.25 Dido with a firing rate of 64 rounds per minute we can see the advantage the S & C had. The much lighter 4.5 mounts allowed for more ammo and the RN elected to expand the superstructure for more volume to create space for personnel for flagship duties.So you can criticise S & C as much as you want, but as AA cruisers they were considered in some quarters as the best the RN had.