The best of the best and Worst of the worst

Good question. Waiting on the answer.

 

As noted, anti-aircraft armament was a key factor in USN cruisers. Most WWII cruisers had four, occasionally six or eight, AA guns on each side, with blind arcs directly forward and aft. The Cleveland, Baltimore, and Alaska classes all had eight-gun 5"/38 broadsides, with no blind spots; guns and directors could even track a target crossing the bow or stern.

The sided mounts appear to have been able to fire directly ahead or astern, maybe even a few degrees across the centerline; does anyone have data on their arcs of fire? In some aerial photos you can see five of the six 5" twin mounts, though I doubt they could all engage a target due to blast effects on the superstructure.

I would make a distinction between the two classes. The Cleveland was based on the treaty-designed Brooklyn, the same length though slightly wider, and limited in her ability to accommodate wartime additions to armament and equipment. Baltimore was a completely new design, although some characteristics were derived from earlier ships (flush deck, aircraft aft, unit machinery arrangement). AFAIK her designers were free to create the ideal 8" gun cruiser - ideal for the era before fully automatic 8" guns.

 

The Mk 37 director was the finest FDC system of the war for DP work.

I'm pretty sure the abeam mounts couldn't fire cross-deck due to superstructure or stack interference. You can see the issue in this image of the USS Cleveland:



USS Baltimore:



USS Alaska:



Even if the mounts could track across beam, firing would not be wise given blast effect. I don't know if they had physical stops to prevent such self-damage, but it would be a limit all the same. But there are obvious physical obstacles to cross-deck fire from the wing mounts.

 

The photo of Baltimore looks like a fleet review, maybe for Queen Elizabeth? Next ship back is a French La Galissioniere class cruiser, and yes I got it before I zoomed in and saw the flag Next is a Russian Sverdlov.

 

I don't know where or when it was taken, but it's pretty clear that the superstructure would limit 5" firing angles ... which was, after all, my point.

 

Actually, the Baltimore's were an improved, enlarged and modified Wichita, which was the last US cruiser built under the treaty. The Wichita was a slightly enlarged and modified Brooklyn armed with 8" guns. When the treaty expired and with war clouds gathering (Sept 1939), the US Navy lacked the time to design a cruiser from the ground up, so they took the Wichita and modified it for the new heavy cruiser class, so its design was heavily influenced by the treaty period. Most naval histories consider the Des Moines to be what a cruiser totally freed from treaty restrictions to look like.
What is interesting is that the Cleveland's were also based on the Brooklyn class, so both heavy and light cruisers had a common ancestor.

Heavy Cruiser (8" guns)
Wichita (single ship class) Laid down-28 Oct 1935-Comm.-16 Feb 1939-10,589t std (10,000 tons was the treaty limit), 608' 4" length, 61' 9" beam, 100,000 shp
Baltimore-(14 ship class+3 Oregon City-modified Baltimore's) Laid down-26 May 1941-Comm.-15 Apr 1943-13,818t std, 673' 5" length, 70' 10" beam, 120,000 shp
Des Moines-(3 ship class) Laid down-28 May 1945-Comm.-16 Nov 1948-17,532t std, 716' 6" length, 76' 6" beam, 120,000 shp

Light Cruiser (6" guns)
Brooklyn (9 ship class) Laid down-12 Mar 1935-Comm.-30 Sep 1937-9,924t std-608' 4" length, 62' beam, 100,000 shp
Cleveland (27 ship class an additional nine were converted into light carriers (Independance Class)) Laid down-1 Jul 1940-Comm.-15 Jun 1942-11,932t std-608' 4" length, 66' 4" beam, 100,000shp

There was thought about building the Cleveland's with an enlarged Brooklyn type hull, as was done with the Baltimore's, but it was decided against because it would slow production. The Baltimore's having a longer period from lapse of the treaty and before they were ordered got the enlargement. Although 20 Baltimore's had been ordered by 7 Aug 1942, and the Navy suffering heavy losses in cruisers during the Solomons campaign, when there were material shortages, construction of the Baltimore's were temporarily halted and delayed, because the Cleveland's could be built quicker, had a comparable AA suite to the Baltimore's and could be more rapidly deployed to protect the carrier groups. The Cleveland's provided stellar service in that role.


Baltimore class heavy cruiser.



Cleveland class light cruiser.

Note the similarities of their profiles. As for AA fit, they both had twelve 5"38 DP guns in six twin turrets laid out in the same manner. Similar layout for the Mk. 37 directors. Baltimore's had 48 x 40mm bofors in 12 quad mounts. The Cleveland's had 28 bofors, 4 quad mounts and six twin mounts. The Baltimore's 24 Oerlikon's, the Cleveland's 21 Oerlikon's.

 

I'm also curious about that. The British mocked up a quadruple turret for the Edinburgh class but decided to stick with triples. There's not much of a data base on quads, and a lot of what there is is negative. Twin turrets were simplest, triples were widely used, not sure why quads should be that much more complicated.

Good question about cramping. On the Clevelands, the interior diameter of the barbettes (which would be a bit narrower than the turrets) was 17' or 5' 8" per gun. On Wichita (three 8" turrets on a Brooklyn hull) the diameter was 22' 6", which suggests that a Cleveland could accommodate quad 6" (four x 5' 8" = 22' 8"). No doubt there's more to it than that.

Friedman wrote that "the General Board remained adamantly opposed to quadruple turrets" but with no further detail.

 

How many more men might it take to manhandle the more-plentiful shells between hoist and breech? Do we have that room? And the hoists ... you're getting four more shell-hoists (one per turret), which might fit, but then how much does that weigh -- along with the one extra gun?

I imagine they could make it work, with sacrifices. But I also imagine that they wanted that bad-ass AA from the 5/38s. Probably not seen as a good trade.

 

Plus, they already had a good rate of fire, very accurate fire due to the fire control system and a very effective super heavy AP shell which was about twice as effective as standard 6" naval shells.
The 6"/47 Mod16 was a very good gun, using semi-fixed ammunition it could fire 8-10+ rounds per minute (150 rpm from Brooklyn's/120 rpm from Cleveland/Fargo's) and the more effective Mk.35 130lb AP round (vs the preceding 6"/53's 105lb AP round) gave them a formidable broadside 15,600lbs and they had such rapid fire that they could range the target quickly. For comparison the Japanese Mogami's, along with the Myoko and Takao class's had ten (5 x 2) 20cm/50 (7.9") 3d Year Type guns with a rate of fire of 3-4 rounds per minute, firing the 277.4lb Type 91 AP shell or a broadside of 11,096 rounds per minute. Not too shabby (of course the 19,500lb broadside of the Brooklyn's was even more impressive).
I don't know the increase in the weight and complexity of a quad turret, which would likely slow the ROF per tube slightly, would be worth the trade off, especially since AA fit for carrier escort was the more important capability.

 

A good point, but was that a serious consideration during the design phase?

 

I do need to add his work to my library.

 

The only quad turrets i can think of were the KGV class. They were supposed to have 3 but the superturret being a quad meant too much weight too high up.

Which, to my mind, gives a logical answer to why quads were rare. With bigger guns they would just be too big and too heavy. The KGV turrets were relatively lightly armoured compared to similar RN designs, and they only used 14in guns

 

The only quad turrets i can think of were the KGV class. They were supposed to have 3 but the superturret being a quad meant too much weight too high up.

Which, to my mind, gives a logical answer to why quads were rare. With bigger guns they would just be too big and too heavy. The KGV turrets were relatively lightly armoured compared to similar RN designs, and they only used 14in guns

 

KGV had quads, and they did give lots of trouble although it appears to be mostly teething troubles rather than genuine issues with the concept.

They did plan the KGV with 3 quads, but the superturret had to be switched to a double due to weight issues. To me, that shows the problem with a quad - just too big and too heavy, particularly if well-armoured and equipped with bigger guns

 

KGV had quads, and they did give lots of trouble although it appears to be mostly teething troubles rather than genuine issues with the concept.

They did plan the KGV with 3 quads, but the superturret had to be switched to a double due to weight issues. To me, that shows the problem with a quad - just too big and too heavy, particularly if well-armoured and equipped with bigger guns

 

The French Dunkerque and Richelieu classes had quad turrets with 330mm/13" and 380mm/15" guns, two turrets both forward to concentrate the magazines and maximize protection. They estimated that the quads would be 27% lighter than eight guns in twin turrets. The guns were in two distinct pairs, divided by a bulkhead on the centerline of the turret, so each side could function independently if the other was disabled; this actually happened in Dunkerque at Mers-el-Kebir.

The planned fourth unit of the Richelieu class was going to have one turret forward and one aft.

The Dunkerques also used quad turrets for part of their 130mm/5.1" dual-purpose secondary armament. These are usually described as not very successful, with little detail.

Our North Carolina class were conceived with 14" guns in three quad turrets to comply with treaty limitations, like the original KGV design, but we had not committed to construction of ships or guns when the Japanese dropped out of the treaty system, so we were able to step up to 16".

 

Perhaps I was unclear; I was hypothesizing that if the Brooklyn class had four quadruple turrets, the Clevelands would have three and be able to accommodate the 12 5"/38s as happened historically. Twelve 6" guns in three quad turrets would be lighter than four triples, and only one turret would be superfiring; the reduction in weight and topweight would make it easier to accommodate wartime additions like 40mm guns and radars.

 

And now for something completely different...........I was looking for an illustration of the Gascogne, the planned fourth ship of the Richelieu class, and found this, one of the concepts considered for the class:




Two turrets amidships, reminiscent of some of the early turret ships of the 1800s, like the ill-fated HMS Captain.

The secondary guns appear to be the same 130mm/5.1" used in the Dunkerque class, but they were changed to triple 152mm/6" in the actual Richelieu.