I must confess that I had trouble fitting the machinery into the available space

It turns out that I needed to increase the depth and width of the machinery spaces to reduce the length of the boiler rooms and engine rooms. I might well still have to increase the power output of the plant to decrease the size further. The ship is overweight, still, from what I really wanted and the powerplant is busting out at the seems. The only thing left to do is to increase the power output above 66 SHP/ton of machinery.

OK, so I have been experimenting with a small CL

I have opted for a small CL rather than a large DL type. I have removed the torpedo tubes and added a small amount of side and deck armor. I have been struggling with the correct dimensions, as I would have liked a lower displacement. The dimensions that I have settled on for now are 439ft x 44ft x 13.8ft. The coefficients are the same: Cp=0.66 and Cm=0.82. The power is 72,000 SHP. That is good for 34 knots at the normal displacement of 4,116 tons. The speed at deep load is 31.2 knots. The range at 15 knots at normal load is 4308nm and the range at 15 knots and a deep load displacement of 5,261 tons. The deep draft is 17.3ft. The metacentric height at normal displacement is 2.76ft and at deep load is 4.57ft.

A larger DL or small CL

I want to design a large DL or small CL to act as a leader for my 2400 ton destroyers. I have been toying with a design that has 10-5.1in/50 guns in five twin turrets (three forward, two aft). I started with dimensions of 405ft x 41ft x 13ft, but all that will carry, reasonably, is 8-5.1in/50 guns. I could probably make it 9-5.1in/50 guns, but I suspect that triple turrets would be problematic for DP guns on a small vessel. My current thinking is something like 439ft x 43ft x 13.5ft.

I highly recommend 1/600 scale for doing ship drawing

I drew my last destroyer drawing at 1/600 scale (50ft/in) and I remembered why I like the scale. That is large enough that drawing accuracy is greatly improved. 1/12oo scale is too small. Small errors have a large effect on the drawing. I have done 770ft battlecruisers at 1/600 scale and it really helps for that size as well. The only problem with it is that scans must be pieced together graphically, and there are always small alignment errors.

I ran my big US destroyer design

I entered the initial values into a spec for my 2400 ton destroyer. I ran the program, and then drew a drawing. I tweaked the values based on my drawing and then reran the program. The normal range is 5110 nm at 15 knots and the maximum range is 10586nm, also at 15 knots. The metacentric height is very acceptable. At normal load, it is 3.3ft and and deep load is 5ft. The normal fuel load is 420 tons with an additional 450 tons at deep load. My design is flush decked with two funnels. There are two twin 5.1in/50 turrets forward and one twin turret aft. There are two quintuple torpedo tube mountings astern, but on top of the superstructure. My stability figures really do not account for those weights, but the stability situation is good enough that it should not be a problem.

Destroyers for War in the Pacific

If a 2100 ton destroyer is good for Pacific War fighting, why not a 2200 ton destroyer? The Gearing class dimensions also seem to be pretty reasonable. I would have thought that I would at least go with a 390ft ship. I would probably use coefficients of Cp=0.66 and Cm=0.82. For my liking, I am seeing 390ft as too long for a ship whose NORMAL displacement is 2200 tons. The draft is too shallow to be reasonable. The problem is that a Standard Displacement is quite different from a normal displacement. The normal displacement needs to be at least 2400 tons. Given that, then the dimensions would be 370ft x 38ft x 11ft. The guns would still be 6-5.1in/50 with 10-21in TT. The speed need only be 34 knots.

Super-Destroyers

Frank Fox told me that he had designed an American-style large destroyer for the WWII period. I have an interest in such a thing, myself. I have thought that a 5.1in gun (13cm) would be the thing to use. The gun is considerably more potent than a 5in/38 or a British 4.7in gun. The 5.1in shell is about the upper limit of what is easily manhandled. The British almost adopted such a gun in the 1930's, and then decided that the shell was too heavy. They stayed with the 4.7in gun until they finally adopted a more modern 4.5in DP gun during WWII. I would want a ship about 2750 tons with 6-5.1in/50 guns, and a torpedo armament of 10-21in TT. We all would wish for a 24in torpedo with capabilities equal to the Long Lance, but no one but the Japanese had done the work required to develop such a weapon. That gave the Japanese destroyers and cruisers a great advantage into 1943, until American night tactics and radar fire control finally gave them an edge.

Cruiser design patterns

I think that high-freeboard, flush-decked cruisers are a good design pattern. I have typically included at least a small transom stern, as well. The bow should have some flare and should be 5-10 ft above the amidships freeboard. The stern should be at least 2-3 ft above the amidships freeboard. I would only follow that pattern for larger cruisers. For smaller cruisers, I would either have a raised forecastle or at least a low stern and a fairly high, flared bow, even if the ship were flush-decked. An example would be the Atlanta class ships. For the larger ships, I would use triple turrets, usually 9 guns in three turrets. For ships with guns smaller than 8in, I would have at least 12, if not 15 guns in triple turrets, similar to the Brooklyn class and the original Mogami class design.

President Roosevelt was interested in having a ship like the French super-destroyers

In 1940, President Roosevelt expressed an interest in having a super-destroyer like those used by the French (such as the Fantasque or Volta). Given how the American designers gold-plated everything, the design turned out over4,000 tons, at which point all interest died. American design standards were quite different from those of the French, and there were some things you just couldn't due (regrettably). President Roosevelt had influence. The only reason that the Iowa class ships were built was due to his interest. The navy establishment had no interest. They wanted to build worse ships. They had no interest in a really fast battleship, despite the fact that they turned out to be the best American battleships ever built.

The 12-7.5in gun cruiser design works

I just did a preliminary run of my program with the design that I proposed. The dimensions are 665ft x 66ft x 23ft with a normal displacement of 13,620 tons. The coefficients are Cp=0.56 and Cm=0.84. The power plant is 90,000 SHP for a speed of 32 knots at normal load. I was able to have a 4in belt, barbettes and turrets, with 3in + 2in decks. The metacentric height at normal load is 3.86 ft. The range at a normal load, with 1,000 tons of fuel is 4,709 nm at 15 knots. The range with 2,700 tons of fuel, at 15 knots, is 12,715 nm. The full load displacement is 15,976 tons. The speed at full load displacement is 30.8 knots. The armament is 12-7.5in/50 and 8-4.7in/50 guns. The 4.7in/50 guns are DP. The design includes a catapult and hanger.

A cruiser with 12-7.5in/50 guns would make sense

The 7.5in/50 gun still has merit for a 1921 ship. The gun needs to be mounted in a turret. I would prefer a triple turret, rather than twin. The 7.5in/50 Mk.III weighed 15 tons 9 cwt and 3 qrs. The AP shot was 200 lbs. The rate of fire was 5 rounds per minute. I would put the gun on a 13,500 ton ship with a speed of 32 knots. The primary role would be commerce protection, although I could see a role in fleet actions, or at least in detached task forces (as they came to be known in WW II). I would retain a secondary armament of 8-4.7in/50 guns. I would have a 4in belt. If I didn't say, the ship would be built for the British navy.

Calculating the rudder post position

I have a factor that I use to determine the postion of the rudder post. I take the waterline length and divide by 1.045. That seems to give a good rudder post position. I have been using this for the last 3-1/2 years. Not actually having built and run a ship, it is somewhat hard to know if this is a reasonable thing, but it is based on some example ships that were sufficiently maneuverable.

I just ran my program for my 9.2in/50 gunned cruiser

It is a little problemmatic to try and build a spec for a ship without a drawing, but I did it anyway. The Washington Naval Treaty Standard displacement was 16,036 tons. I was able to give the ship 9-9.2in/50 and 8-4.7in/50 guns, a 6in belt, a 3in deck, and 32 knots of speed. The normal displacement ended up as 17,861 tons. The dimensions are 670ft x 75ft x 23.6ft. The coefficients are Cp=0.585 and Cm=0.9. The ship is flush-decked with a 120,000 SHP machinery plant.

I still believe that there is room for a 9.2in gun ship for the 1921 building program

The British 9.2in/50 gun was a pretty effective gun, with a good range and rate of fire (4 rounds per minute). The AP shot weight was 380 lbs. The piece weighed 28 tons. My preference would be for a 17,000 ton ship with 9-9.2in/50 guns and a 4.7in/50 secondary armament. I would like to see a 6in belt and a 3in deck on such a ship, and a maximum speed, at normal displacement, of 32 knots.

In the early 1900's William Hovgaard suggested that the best battleship would be large and fast, with good armor and guns

William Hovgaard's crystal ball was pretty accurate. About 30 0r 35 years early, he predicted the fast battleship (or at least recommended it as the best bargain). Don't build battlecruisers, but build "battleship-cruisers", which would be fast, have the biggest guns and the heaviest armor. New developments and larger ships would make the older ships less capable, and they would then be used as ordinary battleships. Why build inferior ships when time would produce them, anyway.

Battleships and Battlecruisers

In effect, the fast battleships built in the 1930's and 1940's were battlecruisers with a new name. The North Carolina class ships definitely sacrificed protection to achieve speed and a heavy armament. They also sacrificed structural strength and ridigidy in the process. Except for their armament layout, the 1921 British battlecruisers (the G3 design) were better than most of the ships built as fast battleships. They sacrificed gunpower to achieve speed and protection. While the corresponding battleships would have carried 9-18in guns, the G3's had 9-16in guns. Due to the frenzy to achieve the most on a given displacement that was rampant in Britain in 1921, the armament layout was strange. They would have not given up that much by having a more conventional layout (two turrets forward, one aft), and they would have been superior ships.

SpringSharp

A business associate pointed out a website and warship general design program: SpringSharp.com. They started with the SpringStyle code and greatly improved the program (according to all accounts). The new program is a .NET Windows program. By all indications, this will be interesting to try. I can understand that they are keeping the source code to themselves, as there always might be a commercial value to this sort of work. I will evaluate the program to see if I might learn anything I could use.

WWII-era cruisers were largely "belted cruisers"

From the 1920's on, most cruisers had such a narrow swatch of armor that they had become "belted cruisers", along the lines of the Orlando class ships. The belt was covered by a deck, and the belt was almost submerged, being essentially one deck high. The British cruisers tended to have more coverage, in that they had armor that rose above the machinery spaces on the side, for a shorter distance than was covered at the waterline. As ships were increasingly overweight, much as in the 1880's, the belt was almost totally submerged. In the British case, the only part that had much above-water coverage was that above the machinery spaces. You can see it on the Edinburgh, Southampton, and Dido class ships, as well as others.

An amusing exercise: "modernizing ironclads"

I have been looking through my journal for 1999, which contains many ship drawings. One feature of early 1999 were my drawings of "modernized ironclads". "Modernized" almost doesn't do justice to what I did. For example, there is a ship with a tower foremast, a single funnel, flush deck, anti-aircraft guns, and a modern-looking flush decked hull. The bow is flared, and there are two stockless anchors. There is a ship labeled: "Inflexible", as if this were a ship with 4-16in guns (now BL, not MLR), 6-secondary guns, and 40mm and 20mm AA guns. On an earlier page are shps named "Shannon" (like the original belted cruiser) and "Narcissus", another cruiser. Then, there is a ship that looks rather WWII-like, but labelled "Southampton", and obviously a light cruiser built to something like the dimensions of the British pre-WWI light cruiser. The armament is 9-6in/50 guns, with two triple turrets forward and one aft.

I am pushing the upper limits on ship size

When I just tried to see what the top end for the very large battleship with 21in guns was, I ended up with a Reynolds number above 5.99x10^9! I need to add some more data for Schoenherr frictional resistance coefficients. I tried increasing the power to 350,000 SHP. To actually do that requires 6 shafts, as there is the approximate limit of 70,000 SHP per shaft. Above that loading, the shaft will fail. So to increase power to 350,000 SHP requires 6 shafts with 58,333-1/3 SHP per shaft.

The very large battleship design

I found out that the very large battleship, at higher speeds had a Reynolds number on the order of 5.6x10^9. My Schoenherr table, before this morning, only had values up to 4.999x10^9. I extended the table, and that solved the problem I was seeing last night. I had to turn on some printing so that I could see what was happening and what I needed to do to fix the problem. For Reynolds numbers above 5.0x10^9, the frictional resistance ended up as zero.

I can see now how I can improve the modeling of superstructure, so that I can get better stability calculation results. I also need to account for the heavy rangefinder and main battery fire control director mounted very high on a tower mast.

The optimal super-large battleship

I spent much of 1999 drawing very large battleships and battlecruisers. I just opened a record book to a page that has a large battleship drawing with some specifications. The ship carries 9-21in/45, 12-6in/50, 8-4inAA, and 44-40mm AA guns. The displacement is given as 115,000 tons. The speed given is 31 knots. The armor mentioned was 17in belt and 7in + 4in decks. I did a few calculations with the BigGun program and designed the 21in/45 gun. The muzzle velocity is 2,575 ft/sec, and the AP shot is 5,000 lbs. The piece weighs 311 tons. That is using my design coefficients, and may be heavier than someone else's design. The question is: how well does this design stand up with the preliminary design program? I had some sort of problem on my first run, but one goodie is that the triple 21in gun barbette is 45 ft in diameter. I suspect that some table lookup in the power calculations was out of range for a ship of this size! If I give a power of 190,000 SHP, the expected speed is 29.6 knots. The normal displacement is 108,008 tons. I should probably be able to tell what the issue is, with a little debugging, sometime tomorrow.

Cruisers and torpedoes

As long ago as the Spanish American War, naval officers realized that carrying torpedo tubes above water on cruisers was extremely hazardous. The conventional response was to carry below-water torpedo tubes on the larger cruisers. The smaller scouts carried torpedo tubes almost like they were destroyers. The modern light cruisers, such as the Arethusa, carried substantial above-water torpedo armaments during World War One. They were frequently used in action, with some success. By the 1930's, the US Navy had removed torpedo tubes from their cruisers. The only exceptions were the Omaha's and the Atlanta class. The British never removed their torpedo tubes, while the Japanese carried highly effective and sophisticated torpedo armaments on their cruisers, especially the heavy cruisers. They proved their effectiveness at Savo Island and other battles. The Allies, especially the Americans, were shocked by the range and effectiveness of the Japanese 24in Long Lance torpedoes. At one point, the Americans actually were considering remounting torpedoes on 6in and 8in cruisers. It only happened post war, however, and only as ASW weapons.

Is there any benefit to speed in large ships?

Admiral Fisher would say, "Speed is armor". Without thinking about it, the natural reaction would be to say that the more speed the better. John Paul Jones didn't say "Give me a slow ship for I intend to go in harm's way". The lessons of World War II in the Pacific showed that there was still a need for ships that could make 34 to 35 knots. The requirement was caused by the need for escorts to "run" with the fast carriers. The Japanese had retained the requirement for 35 knots through the 1920's and 1930's. Their first examples were the 5,500 ton light cruisers. All of the 8in gun cruisers also aspired to 35 knots, although as the ships became heavier, they lost the ability to make that sort of speed. The United States had made a conscious decision in the 1920's to abandon high speed, after heading that direction in the 1916 to 1921 time frame. The only ships from that period to complete were the Omaha class light cruisers and the Lexington and Saratoga. They ultimately were not as fast as originally planned. They originally were all 35 knot ships. The change in direction was because of the idea that aviation obviated the need for fast ships. If anything, in the modern era, the situation has gotten even "worse" in the sense that the new ships we building and planning are slow by early 20th Century standards.

More about the light cruiser design

One merit of the light cruiser design I just described is that it has substantial freeboard. The bow has a substantial rake with the bow suitably flared. A more balanced design might scale the speed back to 35 knots and add a fourth twin turret. I actually happen to prefer triple turrets, although from a purely gunnery perspective, four twin turrets is preferable. With the barrels in separate sleeves, you can alternatively fire four gun salvos. This can produce much smaller spread at long range than triple turrets, especially of the guns are in a single sleeve.

My second Italian-looking light cruiser

I had glanced at the drawing, last night, and though that this design must be like the Muzio Attendolo, or Raimondo di Monteccucoli, but I was wrong. The dimensions are: 575ft x 52ft x 17.4ft (designed). The normal designed displacement was intended to be 6,000 tons with a 7,500 ton full load displacement. The armament surprised me, as it was only 6-6in/50 guns. There are some small patches of 1in armor, with a 1/2in deck. There was room to give the design more power, so I did. The original intent was to make 37 knots. The only thing was, is that it takes more like 104,000 SHP to reach that, rather than the original 67,400 SHP.

I can report my light cruiser could reach 39 knots

I just did a quick data entry job and ran my program for my fast light cruiser (5,000 tons). The displacement was a good estimate. At 5,093 tons the ship could reach 39 knots. The deep load speed is 36 knots. The actual Washington Naval treaty Standard Displacement was 4,452 tons. The deep load displacement was 6,680 tons. The normal range was 3,351 nm. The maximum cruising range at 15 knots was 10,054 nm. The max fuel capacity was 1,200 tons. The normal fuel load was just 400 tons.

My attempt at a Bartolomeo Colleoni-style light cruiser

My attempt at an Italian-style light cruiser caught my eye, tonight. I am guessing that my design dates from about 1973. The standard displacement was to be 5,000 tons with a 6,500 ton full load displacement. The dimensions were 555ft x 50ft x 16.3ft, with a 30ft hull depth. The coefficients were Cp=0.56 and Cm=0.90. The hull structure is rather light, the factor being 2.85 x 10^-3. That produced a hull weight of 2,370 tons. The power was 90,000 SHP normal and 108,000 SHP on overload. The machinery weight was 1,800 tons. That means that the overload SHP was 60 SHP/ton of machinery. The armament was 8-6in/50 and 4-4in/50 QF. There was only 55 tons of protection, so that ship was essentially unarmored. The design speed was 42 knots. I suspect that the actual speed would be much less than that.

My friend's GB/DL/1905 design

My friend Cliff conceived of a family of destroyer-type ships that would fill the role of both light cruisers and destroyers. The 1905 DL type was 1,200 tons with a speed of 35 knots. The armament was strange, in that the guns he specified were 4-88mm/50 QF. He also specified 2-21in torpedo tubes, although I don't believe that anyone had a 21in torpedo in service at that date. The coefficients were Cp=0.56 and Cm=0.85. The dimensions were 326ft x 30ft x 9ft. The design incorporated superfiring guns, fore and aft. There were three funnels, with two low and the first funnel raised. There was the usual raised forecastle. When I try to run my program, I am having a problem with the design being overweight. I will need to look at what could be done to solve the problem.

Narrower beam producing a better ship seems counterintuitive to me

When I narrow the beam for the Ger/BB/1907 down to 90ft, I seem to produce a better ship. The speed is somewhat higher and the metacentric height is reasonable: 3.27ft at normal load and 4.68ft at deep load. The displacement comes down to 24,948 tons for the normal displacement. The design goal was 25,000 tons, so this works very nicely. The thing is, why shouldn't a 105ft beam work? Isn't more, better, even for beam?

The problem seems to be "excessive beam"

I experimented with a 95ft beam for the Ger/BB/1907 design, and the metacentric height dropped to something closer to an acceptable number. That tells me that the problem is related to a beam being greater than needed, given the other design parameters.

My Ger/BB/1907 design

I'm experimenting with my Ger/BB/1907 design. The basic concept was a 25,000 ton ship with 8-12in/50 guns and 12-4in QF. The lower belt was 13in as was the turret face thickness. The barbettes were 10in. The decks are 3in + 1in. The designed speed was 24 knots. The dimensions were: 620ft x 105ft x 26ft, with coefficients of Cp=0.56 and Cm=0.95. The main problem I am seeing is a metacentric height that is too high. The ship would be excessively stiff, which I would think would mean that it would have a tendency to roll. The speed isn't a problem. Because of the combination of length and displacement, 46,591 SHP is sufficient to reach 24 knots. What seems to have been my originally designed power, 54,000 SHP, would actually give a speed of 25 knots. I can't tell if the stability issue is a "bug" in the specification or the actual design.

There is not as much weight information for WWI destroyers as I would like to see

The definitive book on British Destroyers (March) is sorely lacking in the sort of data that we need to be able to design WWI-era destroyers. That is not to say that there is none, for there is a bit. There is just not the breadth of data that would need to design a range of destroyers (large and small, from 1905 to 1921). D. K. Brown generally doesn't have that sort of data, either. He is more concerned with what I would call "structures".

An 870 ton 1905 destroyer

My German 1905 destroyer (admittedly, a "super ship") was 870 tons designed displacement. I seem not to be able to make that work with my program. The "Standard Displacement" is 865 tons, but the "normal displacement" is 1,103 tons. The machinery produces 27,000 SHP and a speed of 32 knots at the normal displacement. The dimensions are 270ft x 28ft x 10.46ft, with coefficients of Cp=0.66 and Cm=0.74. The armament is 2-4in/50 QF and 2-18in TT (actually 17.7in). All 18in torpedoes of this era were actually 45cm in diameter, even the British "18in".

Nathan Okun on the Bismarck, compared to contemporaries

Nathan Okun is the foremost expert on armor and penetration of our time. He has an instructive article about the Bismarck's protection system compared to contemporary ships. By the time he wrote this article, the wreck of the Bismarch had been found and explored.

D. K. Brown's book A Century of Naval Construction

The book is dated, but has a good deal of information about what happened with British warship design and shipbuilding from 1919 to 1945 (he covers the earlier periods as well). D. K. Brown writes that Stanley Goodall was the greatest naval architect of all time. He certainly was a giant in his field. His first ship design was for the Arethusa class light cruisers of 1912. They set the pattern for modern cruiser design. He had his hand in submarines, destroyers, and aircraft carriers, as well. His best ships were never built: the 1921 battlecruisers cancelled because of the Washington Naval Treaty.

You couldn't build a balanced cruiser within the 10,000 ton limit

Norman Friedman's reflection of considered opinion up until WWII was that you couldn't really build an 8-in gun cruiser that would be a balanced design within a standard displacement of 10,000 tons. The Japanese approach was to try to build 10,000 ton ships but do whatever was needed to build a successful ship. That mean that their ships exceeded 10,000 tons by a good amount. That was true for the Italians, as well. I have written previously about the Trento and Trieste. The Americans, who wanted the treaty regime to "work" tried hard to stay within the 10,000 ton limit. The result was that they produced ships that were seriously compromised. Some of their best ships were "taken apart" at Savo Island. Those were ships that they sorely needed, as well, such as the Astoria, Quincy, and Vincennes. Of the 18 pre-war heavy cruisers, they lost the Chicago, Houston, Northampton, Indianapolis, Astoria, Quincy, and Vincennes. The Indianapolis had almost survived the war, before being torpedoed.

The North Carolina Class Battleships

I was amazed at how Garzke and Dulin blow off any criticism of the North Carolina and Washington. Norman Friedman makes clear how close they came to failing. My estimate as to the cause of the disease was the extreme measures taken to keep the design within the 35,000 tons standard displacement. They failed, but in doing so, they severely compromised the design. The worst feature was the severe longitudinal vibration. That problem was "bandaided" by trying various combinations of propellors, which partially helped. Almost as bad was the lack of hull strength. The symptoms showed up when the North Carolina was torpedoed, and flooding was much more extensive than should have been for a new ship. Another example was the collapse of the Washington's bow after a collision with the Indiana. A battleship should have been able to shrug off such a collision, but that was not the case with the Washington. The ships were also too wet, as the hull depth had been drastically reduced as another weight-saving measure. There is a picture showing whitewater breaking over the bow, almost continuously, and a huge wake, while escorting a carrier in wartime. The basic concept for the class was sound. They just had a poor implementation.

The Japanese heavy cruiser Takao

Janusz Skulski's book about the Takao gives some of the coefficients and other numbers, which I found very instructive. Left to my own devices, I have typically thought that cruisers would have a prismatic coefficient (Cp) less than 0.6 and the midship coefficient around 0.9. I seem to be pretty much wrong, at least for fast cruisers. The coefficients for the Takao were Cp=0.627, Cm=0.822, waterplane coefficient=0.721, B/H=2.776. The weight basis for machinery seems to have been 51.42 SHP/ton of machinery.

American triple turrets with guns all in the same sleave

I consider that the American practice of having triple turrets with three guns in the same sleeve was a bad practice. The opposite extreme was the British triple 4in gun mounts on the Renown and Repulse, as originally built, which added unneeded complexity for rapid fire guns. The American triple 14in gun turrets on battleships were the first appearance of three guns in a single sleeve, as far as I can tell. I suppose that it was an attempt to simplify the design. Apparently, saving weight was also a factor. The real reason that the single sleeve happened is that the Americans lacked experience with long range firing with triple turrets. To get smaller spreads, individual sleeves were critical. There needed to be a way to make small corrections in elevation for individual guns. Apparently, the American system didn't allow for this feature. If the guns got out of alignment from firing, there was no way to realign them. The same bad practice was continued for the "Treaty Cruisers", apparently up through the New Orleans class.

DL-1 Norfolk: another Atlanta class variant

The DL-1 Norfolk was based on the Atlanta class light cruiser hull. The post-war goofiness had set in by the time she was designed. She was armed with only 8-3in/70 rapid fire guns and 4-twin 20mm AA mounts. She also had 8-ASW torpedoes in single mounts and 4 of the "Weapon Alpha" devices. He speed was 33 knots, showing how the navy had backed off from higher speeds after the end of the war. Since 1949, armaments and speeds have decreased. Much of the weight and volume now goes to electronics. The navy decided that the Norfolk type was too little capability for the cost: a self-inflicted wound, typical of the Cold War era.

The fast AA cruiser devolved to the Mitscher class DL design

When the fast anti-aircraft cruiser armed with twin 5in/54 guns seemed to grow too large, the navy ended up building a very large destroyer in place of that design. The ships were originally classified as destroyers (DD), but ended up as destroyer leaders (DL). These were the Mitscher class ships. They had several of the twin 5in/54 gun mounts. They had a very similar look, as they had the twin cruiser funnels, similar to the Atlanta class ships.

US Navy thinking about speed in cruisers

Before 1921, the US Navy still believed in fast cruisers. In the 1920's, that thinking changed. The idea was that aviation made speed in cruisers irrelevant. Given that, 32 knots was more than adequate. What they didn't realize was the impact that aircraft carriers would have on tactics. By 1944-1945, American thinking had changed. Now, they wanted 35 knot cruisers, if they could get them, to run with the aircraft carriers. There was a replacement for the Atlanta class cruisers that would have been armed with with twin 5in/54 guns in power mounts. The Atlanta class turned out to be too slow, although they had a good anti-aircraft armament. The idea was to build a faster ship that would still be a good anti-aircraft platform. Again, this was needed for the fast carrier task forces. A good source on the subject is Norman Friedman's book U. S. Cruisers.