Shipbucket

Smurf said: there was even a proposal to arm Hawkins class with six twin 5.25".

Though the proposal was not proceeded with, here is my take on what that might have looked like.




Armament:
12 x 5.25" (6x2)
8 x 40mm STAAG (4x2)
20 x 2pd (5x4)





Armament:
12 x 5.25" (6x2)
20 x 2pd (5x4)
16 x 20mm (4x2 8x1)


Twin 4" as per BCRenowns comments later in the thread on page 1.



Armament:
18 x 4" (9x2)
20 x 2pd (5x4)
18 x 20mm (4x2 10x1)


Twin 4.5" in place of the 4".





Last 5.25" drawings with midships mountings.

Looks good.
I could buy that as a plausible fit, especially late war when the STAAG became available.
Needs some 20mm though, I'd expect several singles and powered twins to be added 1942-44.
You probably want a Type 273 surface search radar too, and perhaps 283 or 284 on the main director for the 5.25in.

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As Hood says, looks good, BUT
This proposal was 1938, and was then a serious one, so this is a "neverwere".
The 5.25in were ordered. But no chance of STAAG, which was a post-war gun, by which time the Hawkins machinery would be worn out.
The quad 2pdr are more the mark. Also a quad 2pdr weighed about 8.6 tons, (or 10 with remote power control later in the war). A STAAG was about 17 tons.
If I were you I would drop X turret to the forecastle level of Y turret, or even put it down on the quarterdeck with Z. Loss of direct aft low angle fire is no great deal. There is a general tendency on sites like this to think that you can replace gun A by Gun B if the weights roughly match, but stability depends on turning moment. Reconstructions are dodgy. It always surprises me how soon the point is reached at which adding A can only be done if other weights are removed, particularly if A is a radar aerial at the top of a mast. The problem is that a ship to be reconstructed was not designed in the first place with a great reserve of stability, so that you are restricted in what you can change (or especially, add) by the initial design. A ship which is 'too stable' recovers undesirably slowly from a roll. It may well be that a 10,000ton ship designed in 1938 could easily carry much more weaponry than a reconstructed Hawkins. Much can be done at the initial design stage with hull form and armour distribution. Not generally easy at reconstruction, unless that is very extensive eg Renown. London was a failure, not getting the (presumably lighter) new machinery intended.
The Hawkins AA was very much an emergency measure to use available time-expired hulls.
Consider the forecastle guns. The revised main armament doesn't leave a lot spare for light AA. A STAAG weighs as much as an Effingham central pivot 6in.
Original A,B 7.5in central pivot, each weighing 46 tons total 92
Effingham ABC 6in central pivot PXII* each weighing 16tons total 48
Hawkins AA ABC (or ABQ if you will) 5.25in twin each weighing 84 tons total 252tons

Before reconstruction, aft, Effingham carried one 7.5 raised above forecastle deck level and two widely separated at quarterdeck level. Total weight 138 tons, with 92 tons of it at quarterdeck level. There were also two wing 7.5in at forecastle deck level.
Your reconstruction has the same 252 tons aft as forward, with altogether two turrets a deck higher than forecastle, and one a deck higher still. Total 504tons. I think somehow you ave to lower some of this armament, bearing in mind that with quarterdeck mountings you will probably have to use the MkI short trunk type fitted on KGV, though they did weigh only 77.5tons each, total 465tons
Remember only half the Didos had Q turret before the bridge.
Effingham lost two after boilers (not much effect on top weight) but the single funnel helped as did lowering the spotting top.

I must admit smurf, when you mentioned the 5.25in Effingham I did wonder how they were going to fit six mounts.
I wondered about perhaps 2 on the quarterdeck, A and B and two admidships on each beam. Four quad pom-poms would seem the ideal AA fit a probably a couple of quad MGs.

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Although it looks good, Nigel, you must consider the weights involved, apart from the the issues mentioned by smurf.
The first thing to consider is the fact that a twin 5.25" twin mounting Mk.II (like on the Dido's) weighed about 84 tons, while the single 7.5" gun of the Hawkins was only 46 tons, that is about half. I don't believe that the Hawkins good be fitted with 6 twin mountings (even though space wise, they might be fitted). Your best bet would be 5 or even 4 twin mountings and four (maybe only two) quad Pom-Poms.

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yeah, I think the weight of the new guns should be equal to what was originally there, unless more is removed at the same time (armour, equipment, magazine weight)
while checking that, you also have to keep in mind that the center of gravity of the ship needs to stay the same to avoid stability problems. when you start with an existing (and thus proven stable) ship, guessing the center of gravity of the equipment you remove and placing the new equipment so that the center of gravity remains the same is the easiest method of making sure it works.

btw, seeing that this is an AA cruiser, it would make sense to me to NOT have the guns superfiring in at least some of the mountings. in addition, I think I miss some additional HA directors or at the very least some additional directors for the large number of new guns.

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Ok all your comments are valid ones and I will put together a Mk-2 version and post it later.

Drop STAAG - replace with single and twin 20mm.
Add designated RADAR systems
Lower C and X 5.25" turrets to lower level. (topweight issues)
Lower masts and Bridge (if possible) to lower topweight.

At present I have a main cruiser director for controlled surface shooting and 3 HACS for AA fire. Do I need more than that?
I have one tachymetric director per quad pom-pom - total 5. (do not increase number of pom-pom units)

Anything else?


Does this need to go into Never-Never Land as per Smurfs comment?

You can put as many 5.25" Mk.I turrets and HACS on Hawkins as you like and you will still not achieve a decent AA cruiser that's worth 9,500 tons. The truth is, the Mk.Is were designed to defend against straight-flying, high-evel bombers approaching on a predictabe course and height. The 5.25s were very much useless against faster and more maneuverable aerial attackers. In fact the whole of the 16 Dido and Bellona class cruisers only shot down 15 enemy aircraft during the war. Meanwhile, the converted AA cruiser HMS Carlisle, re-armed with 4x2 - 4-inch AA guns, accounted for 11 enemy aircraft.

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Keep well and keep drawing,

Monty

Howdy BCRenown,
I quite agree. But try and get the Admiralty to agree to a Heavy Cruiser armed with 4"? Pack your woollies, you would be serving in Greenland for a suggestion like that!

Here is my take 2 on the design with the suggested modifications.

I wonder If its tight for weight could you could bulge it (and accept the speed lost) ?

How fast does a AA ship need to be if it is escorting battleships/convoys that are mostly 24 or less Kn (apart from the CVs, KVGs and ones R&R) ?