AHC/WK: Dedicated AA capital ships?

[jsb]

Germans armed a group of ships as AA batteries, although the engines were useless on some and removed (and not replaced) http://german-navy.de/kriegsmarine/ships/aabattery/index.html

always thought they could have used those or similarly equipped ships as AA escorts not for capital ships but for their S-boats and Torpedo Boats on minelaying missions as neither had radar or (effective) AA defense.

But what happens if they bump into the bigger RN ?

The S-boats and Torpedo Boats are hard targets and can run, but the 1900 (or earlier) ships get to stand a fight RN CLs

 

[thaddeus]

Germans armed a group of ships as AA batteries, although the engines were useless on some and removed (and not replaced) http://german-navy.de/kriegsmarine/ships/aabattery/index.html

always thought they could have used those or similarly equipped ships as AA escorts not for capital ships but for their S-boats and Torpedo Boats on minelaying missions as neither had radar or (effective) AA defense.

But what happens if they bump into the bigger RN ?

The S-boats and Torpedo Boats are hard targets and can run, but the 1900 (or earlier) ships get to stand a fight RN CLs

they upgraded the engines on the WWI-era ships even when used for target ships and/or they built a class of 5,000t fleet tenders for S-boats, so they could outpace the British corvettes and converted ships, requiring a destroyer or destroyer escort size ship.

the diversion of DD and larger ships to chase WWI-era ship and handful of S-boats could be considered effective strategy in and of itself?

(and might lead to S-boat being able to torpedo DDs as they were able to do early in the war?)

of course the main focus would be to shield (somewhat) the fast attack boats from air attack, the primary threat to them and one for which AA boats would be well equipped to fight.

 

[Cryhavoc101]

Considering how carriers proved to be the key to allied victory in the Pacific during WWII, would it be feasible to use a heavy cruiser-sized or larger hull design and just mount as much AA guns on the ship as possible, dedicated to carrier protection? Like say a Baltimore class hull that trades the main batteries for additional 5-inch/38 guns and more 40mm Bofors guns. Or even the hated Alaska-class being used as just AAA platforms?

Would it be a waste of resources, or would it be a useful vessel that serves as a path towards an analog of OTL's Aegis equipped warships?

The only way I see this working is using an older hull such as the USS Wyoming or HMS Iron Duke - removing their main guns and spamming them with AAA and automatic weapons - which is pretty much what happened to them anyway - IIRC both were used as gunnery training ships.

 

[Gunner's_Quadrant]

The USN did just that!

I do not think 6in or 8in AAA guns are the most viable. Better to use the 5inch, but maybe increase the barrel length for extra velocity and range. Getting higher caliber guns in possibly the same mounts as existing 5/38s could be a start.

The USN developed the 5"/54 caliber dual purpose mount for installation on the Montana class battleships and Midway class aircraft carriers. They were eventually installed on the Midway class. However, they weren't very popular with the gun crews. They fired a heavier and longer round than the 5"/38 which caused gun crews to tire faster. The 5"/38 ended up being just about the perfect combination of weight and performance.

A Columbia class light cruiser with the 6" mounts replaced with twin 5"/38's would have been an excellent concept as a dedicated AAA ship.

 

[Delta Force]

The real issue isn't rate of fire, it is train rate and ammo capacity.

The USN worked wonders with the 6"/47DP mount on the Worcester class getting a 25 degree/sec rate, but the 8"/55 HF mount was 60% heavier and had a more reasonable train rate of 5 degree/sec (if they had gotten the same success on the gun feed system the weapon would have been spectacular, unfortunately, that was not to be).

The 8" shell itself is also substantially larger than either the 6" or 5" (50% longer then the 5", 30% than the 6", more than 5x the weight of the 5" AAC & 2.5x the 6" HC). Ships commonly carried 450-500 5" round per gun, the 6"/47 had 405 rounds per gun, but the Des Moines class only managed 150 RPG for the 8"/55 (which weighed only 3,000 pound less than the 405 6" rounds). Even if you could get the train rate needed you would be forced to put 8" guns on an Iowa size hull to provide enough stowage. That may be the definition of diminishing returns.

The Atlanta class only had enough 5" shells for 20 minutes of sustained fire (450 rounds at 22 rounds per minute). Since the Des Moines fired more slowly, shouldn't it have been good with 240 shells or so? Also, an 8" shell could have a 51 pound bursting charge, which is much larger than the 8.4 pound charge of the 5" and gives a kill radius 1.84 times as large. The shells even had around the same muzzle velocity.

The big issue is that the train rate for the autoloading 8" was on par with the battleship caliber guns. Of course, the 8" could shoot much more rapidly than a battleship caliber gun.

 

[Simon Darkshade]

There were some design studies on a modified Illinois or Kentucky that featured additional 5" guns and improved sky arcs. The details are in Friedman and there might be some Springstyles of it around the place; the best information and pictures went down with Warships Projects.

 

[bsmart]

The big advantage the Battleships had over the Atlanta/Oakland ships was the 2 extra Fire control directors the BBs had. The Atlantas only had 2 fire control systems for the 5" guns the BBs had 4. I think an Atlanta with two aditional FC systems (possibly replacing the wing turrets to handle the weight) would make them pretty much optimal AA ships for the period.

Another problem with having an AA Capital ship is numbers. Having all that firepower concentrated in one ship means that you have to make sure you have it in the optimal location to defend against an air strike. Having two or three smaller ships allow you to protect more quadrants from attack and provide a more consistent shield. It also allows you to detach a single ship for resupply without denuding the task force of coverage.