GUN NOTES
This is something I've been thinking about for some time, some common sense ideas on weapons and layouts. I'm posting it on several boards for feedback:
I'm thinking there's three usual situations that occur with weapon design:
1) Technologically feasible and practical
2) Technologically feasible but not practical
3) Technologically unfeasible (at least at this time)
So these are my thoughts...
DECK MOUNTS & HOISTS
Without a hoist ROF will be impacted, but smaller weapons can't usually justify a hoist. Guns up to 4.33-inch (110mm) can easily get around not having a hoist, although DP and AA weapons needing a high ROF should have them. Guns in the 4.5-inch (115mm) to 5.12-inch (130mm) range can get by without hoists, but ROF will be compromised. A 5.3-inch gun (135mm) should have a hoist and anything larger in my mind must have one although shells up to 6-inches (152mm) can be hand-loaded.
Historically the biggest deck mounts were 10-inch (254mm) guns on some UK export cruisers to Japan and a 9.2-inch (230mm) gun on the 1892 RN BB Victorious. I have no problem with an 11-inch or even 12-inch deck gun but they must have a hoist and these are probably technologically feasible but not very practical; having a low ROF, slow to train and requiring a large crew with minimal cover.
TWIN AND TRIPLE MOUNTS
Historically nothing larger than 6-inch (152mm) guns have been in twin mounts. Trying to do a twin 6.5-inch (165mm), 7.5-inch (190mm) or 8-inch (203mm) falls under technologically feasible but not practical in my mind. And any twin mount must have a hoist.
The only triple mount I can think of were the triple 4-inch mounts on BC's Renown and Repulse plus the Light BC's Courageous and Glorious. They were, according to Anthony Preston, "clumsy and required a very large crew." I'm sure loading the middle gun was difficult at best. I would require these to be mount and hoist, and wouldn't allow anything bigger than a 5-inch (127mm) or 5.12-inch (130mm) triple mount, anything bigger should be experimental and almost certainly a failure.
CASEMATES
Historically the largest casemate guns were 8-inch (203mm) on the Russian Andrey Prevanssany-class Intermediate Dreadnoughts and 8.27-inch (210mm) on the German AC's Scharnhorst and Gneisneau. These were wet. I would have no problem with a 9-inch (228mm), 9.06-inch (230mm) or 10-inch (254mm) gun in a casemate but would not allow more than 4 per beam and these must be mounted low. If just two per beam then they can be mounted high but will take up a lot of space forcing smaller weapons to be low and wet. Anything larger (like an Italian PDN with eight 12-inch guns [2 twin turrets and 4 casemates]) should end up an interesting but failed experiment.
All casemates were historically single. Twin 5.91 (150mm) casemates were proposed for CV Graf Zeppelin which, in my mind, would have proved abject failures. Any twin casemate mount over 4-inch (102mm) or 4.13-inch (105mm) should prove technologically unfeasible and even the smaller ones should prove impractical.
TURRETS
These aren't a problem, although quads should prove problematical in the early years. Anything larger (5 or more barrels) should prove very troublesome and probably not practical (by the time the technology works the battleship will be obsolete).
These are just my thoughts, any feedback is appreciated.