Development of the Brooklyn class Light Cruisers

[Tzoli]

Here I present my research and drawings of how the Brooklyn class light cruiser come to be based on Friedman's US Cruisers book.

Part 1 - The 1930 Preliminary Schemes


Scheme 1:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-1-1930-1298034072

After the 1930 First London Naval Treaty, the United States Navy was allowed to construct 7 new light and 3 new heavy cruisers out of which 2 were to be of a repeat New Orleans type and one of a new type, while the Light Cruiser were of a new development. This was due to being the USN not reached its Heavy Cruiser quota set by the previous Washington Naval Treaty.
This new cruiser development led to the 1934/37 Brookyln class Light and Wichita class Heavy Cruisers. The class's origins can be traced back to the 1929 studies drawn for the Treaty but actual development started in around mid 1930 with the first 6 proposals presented to the Admiralty in November that Year.
Among these six proposals I present here the first one, basically a modified New Orleans armed with 15x new 6" Guns in 4 turrets (3 quad, 1 triple) and the newest fire control system available. The new guns were of the quick firing 6"/47 Mark 16 in new turrets reminiscent of the 8" turrets used on the Portlands but this was later changed into the final 6" turrets used on the Brooklyns, St Louises, Clevelands and Fargos.

The Chief Constructor noted that this proposal having tremendous firepower, good speed and as well protected as any other cruiser and worthy of considerable study.

The design had the following characteristics:
Dimensions: 176,17(wl) x 179,2 (oa) x 18,8 x 6,93m
Displacement: 10.000tons (Standard)
Engines: 107.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers
Speed: 60km/h (32,5knots)
Armour: 57mm Deck, 127mm over Machinery, 102mm Over Magazines Belt
Armaments:
3x4,1x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
2x3 21" Torpedo Tubes
4x Seaplanes (Vought O3U)


Scheme 2:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-2-1930-1298325763

I present here the second one, again on a modified, slightly shorter New Orleans hull and armed with 12x new 6" Guns in 4 triple turrets.
This proposal was an answer to the quad turreted Scheme 1 which was described having too many guns and the uncertainty and impartiality of the quadruple turret. Having only twelve guns and good armour against 8" weaponry, she was thought to be a very reasonable design on 9.600tons, and indeed this design was chosen for further refinement.

The design had the following characteristics:
Dimensions: 174,04(wl) x 177,1 (oa) x 18,6m
Displacement: 9.600tons (Standard)
Engines: 107.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers
Speed: 60km/h (32,5knots)
Armour: 57mm Deck, 127mm over Machinery, 102mm Over Magazines Belt
Armaments:
4x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
2x3 21" Torpedo Tubes
4x Seaplanes (Vought O3U)


Scheme 3:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-3-1930-1299494807

I present here the third one, on a further shorter hulled New Orleans, but the same main armament as the previous proposal.
Reduction in size resulted the deletion of a pair of 5" AA guns and likely thinning the armour belt, but with the resulted smaller displacement engine power could be reduced too to 96.000shp from the previous 107.000shp.
The reduction in size was likely the cause of reducing cost and tonnage to build more ships on the allocated cruiser tonnage.

The design had the following characteristics:
Dimensions: 170,69(wl) x 173,8 (oa) x 18,25m
Displacement: 8.350tons (Standard)
Engines: 96.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers
Speed: 60km/h (32,5knots)
Armour: Unknown
Armaments:
4x3 6"/47 Mark 16 Guns
6x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
2x3 21" Torpedo Tubes
4x Seaplanes (Vought O3U)


Scheme 4:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-4-1930-1299894741

I present here the fourth one, on a further shorter hulled New Orleans, with reduced main and AA armament to save tonnage.
With the above mention reduction of armament, and smaller machinery it was possible to shove off more than 1.000tons from displacement allowing even more ships to be built on a set tonnage limit while still maintain an adequate and desirable armament.
In the meeting it was described as moderately well gunned 6inch duplicate of the existing heavy cruisers with corresponding protection and better in every aspect compared to the Omaha class except in number of guns, though broadside is superior.
It was said it is the minimal displacement on a well balanced ship could be achieved.

The design had the following characteristics:
Dimensions: 165,81(wl) x 168,85 (oa) x 17,75m
Displacement: 7.125tons (Standard)
Engines: 86.500shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers
Speed: 60km/h (32,5knots)
Armour: Unknown
Armaments:
3x3 6"/47 Mark 16 Guns
4x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
2x3 21" Torpedo Tubes
4x Seaplanes (Vought O3U)


Scheme 5:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-5-1930-1300358553

I present here the fifth one, on the smallest hull in the series.
This proposal was one of the compromise design on a minimal displacement of 6.000tons. The Compromise was either armament or armour, in this case armour was sacrificed to retain the same armament as the previous 4th proposal. There are no armour values stated but it is likely quite minimal probably on the scale of the later Atlantas.
Note about the design mentions that the armament is apparently a little too much for this hull size.

The design had the following characteristics:
Dimensions: 159,71(wl) x 162,80 (oa) x 17,1m
Displacement: 6.000tons (Standard)
Engines: 74.500shp Westinghouse Steam Turbines, 6x Babcock & Wilcox Boilers
Speed: 60km/h (32,5knots)
Armour: Unknown
Armaments:
3x3 6"/47 Mark 16 Guns
4x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
2x3 21" Torpedo Tubes
4x Seaplanes (Vought O3U)


Scheme 6:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-6-1930-1300675566

I present here the sixth and last one, on the smallest hull in the series.
This proposal was one of the compromise design on a minimal displacement of 6.000tons. The Compromise was either armament or armour, in this case armament was sacrificed to retain the same armour as the 4th proposal. There are no armour values stated but it is likely same or similar corresponding to the 4th proposal.
Note about the design mentions that while the design is quite a match to any foreign vessel of this size but it is said that these foreign vessels were due to be replaced and thus this design would be a poor match for a larger vessel.

Among the Admirals discussing these six proposals the ones favouring one or two designs as follows:
Design 1: Apparently nobody
Design 2: William Daniel Leahy (Remark: He suggested removing all Torpedo Armament, and could not guarantee the development of the quad 6" turret in time)
Design 3: Harris Laning (Remark: He favoured numbers and he liked the good armament and armour on the limited displacement)
Design 4: Montgomery Meigs Taylor (Remark: He suggested dispensing all Aircrafts because of the ships would operate close to the fleet), William Veazie Pratt (Remark: He advocated his own Flight Deck Cruiser as well as numbers)
Design 5 & 6: Montgomery Meigs Taylor (Remark: Only willing to accept these if extra protection could be attained via reducing maximum speed) Frank Hodges Clark (Remark: Agreed with Taylor and he too was dispensing with the Torpedo Armament), William Veazie Pratt (Remark: He advocated his own Flight Deck Cruiser as well as numbers)

The design had the following characteristics:
Dimensions: 159,71(wl) x 162,80 (oa) x 17,1m
Displacement: 6.000tons (Standard)
Engines: 74.500shp Westinghouse Steam Turbines, 6x Babcock & Wilcox Boilers
Speed: 60km/h (32,5knots)
Armour: Unknown
Armaments:
2x3 6"/47 Mark 16 Guns
4x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
2x3 21" Torpedo Tubes
4x Seaplanes (Vought O3U)

 

[Tzoli]

Part 2 - The 1932 Design Studies:


Scheme A:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-A-1932-1301059915

After the 1930 series of studies the Naval General Staff discussed the various proposals and included them in hypothetical war games. From these discussions the 12 gunned Scheme 2 came out as the best bargain imposed by the London Naval Treaty. While in early-mid 1931 it seemed likely that new construction can be approved for both the 1932 and 1933 Fiscal Years, the Politicans in the Congress had other plans, preferring Admiral William Veazie Pratt's Hybrid Cruiser-Carrier and in the end no new cruiser construction was approved except for two new Orleans Class Heavy Cruisers (USS Quincy and Vincennes). This allowed the further refinement of the 6inch light cruiser design, and a new set of six Schemes were presented to the General Board in 1932 March 2.

Of these new Schemes I present here the first one, Scheme A, which is modified version of the previous Scheme 2 with full enclosed twin gunhouses for the 5"/25 guns (Described being light bullet-proof gunhouses to protect the crew from strafing attacks), and some alterations to the bridge superstructures and the removal of the triple torpedo tubes. Armour would be good for a 6" cruiser though no values are provided by Friedman.

The design had the following characteristics:
Dimensions: 176,17(wl) x 179,2 (oa) x 18,8 x 6,93m
Displacement: 10.000tons (Standard)
Engines: 107.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers
Speed: 60km/h (32,5knots)
Armour: Unknown
Armaments:
4x3 6"/47 Mark 16 Guns
4x2 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O3U and Berliner-Joyce OJ)


Scheme B:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-B-1932-1302228136

I present here the second, Scheme B which is basically an alternative or companion design to Scheme A where the twin 5"/25 gunhouses got replaced by quad 1,1" Machine Guns because the designers not felt safe by the extra weight these enclosed mountings bring and also because of the original idea of mounting eight single 1,1" guns per side was not feasible due to the aircraft handling arrangement, a direct consequence of the New Orleans class heritage. Armour would be the same as Scheme A.

The design had the following characteristics:
Dimensions: 176,17(wl) x 179,2 (oa) x 18,8 x 6,93m
Displacement: 10.000tons (Standard)
Engines: 107.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers
Speed: 60km/h (32,5knots)
Armour: Unknown
Armaments:
4x3 6"/47 Mark 16 Guns
4x4 1,1"/75 Mark 1 AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O3U and Berliner-Joyce OJ)


Scheme C:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-C-1932-1302622887

I present here the third, Scheme C in which the designers reduced speed to 51km/h or 27.3knots allowing half the powerplant to propel the ship and drastically reduce the hull length to 161 meters or 530 feet. This allowed a very thick, around 216mm belt to be installed providing excellent protection for the ship itself.
The short hull meant that no 5" gun could be installed (I presume the twin gunhoused version) hence the four quad 1,1" retained from the previous variant and a single thick funnel was likely to be used instead of two small ones.
It was noted that quite an attention was invited by this design as how thick armour could be installed if slower and thus smaller hull could be accepted and as one Admiral said: "27,3knots may be looked upon as a very appreciable reduction... but the increase in protective qualities which it is thereby possible to obtain is so great as to throw the ship into an entirely new class."
So here you can see is basically a heavy light-cruiser or heavily protected light cruiser.

The design had the following characteristics:
Dimensions: 161,54(wl) x 164,6 (oa) x 17,1m
Displacement: Unknown, likley close to 10.000tons (Standard)
Engines: 53.000shp Westinghouse Steam Turbines, 4x Babcock & Wilcox Boilers, 2-shafts
Speed: 51km/h (27,3knots)
Armour: 216mm Belt to withstand 8" shells between 7-25km (8-27.000 yards)
Armaments:
4x3 6"/47 Mark 16 Guns
4x4 1,1"/75 Mark 1 AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O3U and Berliner-Joyce OJ)


Scheme D:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-D-1932-1303010582

I present here the fourth, Scheme D, first of the compromise designs featuring the full hull of Schemes A and B with the half-engine power of Scheme C and the twin 5" gun armament of Scheme A. This reduction in engine space and thus power allowed the increase of armour to 7" belt and 2,25" deck while the longer hull allowed a speed of 53km/h or 28,5knots.

The design had the following characteristics:
Dimensions: 176,17(wl) x 179,2 (oa) x 18,8 x 6,93m
Displacement: Unknown, likley close to 10.000tons (Standard)
Engines: 53.000shp Westinghouse Steam Turbines, 4x Babcock & Wilcox Boilers, 2-shafts
Speed: 53km/h (28,5knots)
Armour: 57mm Deck, 178mm belt
Armaments:
4x3 6"/47 Mark 16 Guns
4x2 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O3U and Berliner-Joyce OJ)


Scheme E:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-E-1932-1303371481

I present here the fifth, Scheme E, second of the compromise designs featuring an intermediate hull of 169 meters or 555 feet with an increased powerplant of 70.000shp to propel the ship at 54km/h or 29knots.
This longer hull still required the quad 1,1" AA Battery rather the twin 5" guns, and half an inch thicker armour belt compared to the previous design.

The design had the following characteristics:
Dimensions: 169,16(wl) x 172,2 (oa) x 18,4m
Displacement: Unknown, likley close to 10.000tons (Standard)
Engines: 70.000shp Westinghouse Steam Turbines, 6x Babcock & Wilcox Boilers 2- or 4-shafts
Speed: 54km/h (29knots)
Armour: 57mm Deck, 191mm belt
Armaments:
4x3 6"/47 Mark 16 Guns
4x4 1,1"/75 Mark 1 AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O3U and Berliner-Joyce OJ)


Scheme F:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-F-1932-1303740602

I present here the sixth and last variant the Scheme F, third of the compromise designs featuring the full hull of Schemes A and B with the intermediate powerplant of the previous scheme. It was expected that with the 70.000shp engines the maximum speed of 55km/h or 29,7knots could be achieved. This hull now allowed the reinstall the twin 5" guns and a thickness of 6,5" for the armour belt.
In a letter addressed by Captain H. S. Howard Naval Attaché in The Hague explained that speed was to be sacrificed for more armour as more and more cruisers were likely be built and it was not known that the battleship building holiday would be extended and not, and thus likely cruisers would take over the role of the battleship. This is interesting that at this time the Germans already had the Deutchland class Big Gun Cruisers, and the French were building the 2 Dunkerques suggesting the high speed fleets of the future.
The War College rejected the idea that the battleships would be abolished as they were still needed to fight heavily armoured or armed warships and it suggested retaining the high speed for future cruisers. It did not seen much point in developing specialized well armoured but slow cruisers and it preferred Scheme A from the above list as it combined high speed good firepower and armour for it's size. It also dislike the 1,1" gun as the secondary weapon of these designs as it lacked size to be equipped with time fuse and thus only a direct hit would stop an enemy aircraft approaching.
The Bureau of Aeronautics advocated aircraft facilities to be moved aft abaft of the 4th turret and to store the aircraft below deck, as the amidship position was considered the worse, taking up much space from ship equipment and AA guns, second worst place was considered forward (I presume as on some Italian cruisers).

The design had the following characteristics:
Dimensions: 176,17(wl) x 179,2 (oa) x 18,8 x 6,93m
Displacement: Unknown, likley close to 10.000tons (Standard)
Engines: 70.000shp Westinghouse Steam Turbines, 6x Babcock & Wilcox Boilers 2- or 4-shafts
Speed: 55km/h (29,7knots)
Armour: 57mm Deck, 165mm belt
Armaments:
4x3 6"/47 Mark 16 Guns
4x2 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O3U and Berliner-Joyce OJ)

 

[Tzoli]

Part 3 - The Final 1933 Preliminary Development Proposals


Scheme A:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-A-1933-1304981816

After the discussions on the 1932 series of Cruiser designs the new chief of the Preliminary Design team, Captain later Rear Admiral Alexander Hamilton Van Keuren ordered a new series of schemes to be created. Among these there were various quad and triple turreted variants were considered in a number of layouts.
I show here the first of the 1933 series of designs, Scheme A which is basically a repeat of the previous Scheme A just with modified armour scheme and superstructural elements, retaining the midship aircraft arrangements of the previous designs including the hanger and catapults but reverting to the single 5" gun layouts of the 1930 series.

The design had the following characteristics:
Dimensions: 176,17(wl) x 179,2 (oa) x 18,31 x 6,58m
Displacement: 10.000tons (Standard)
Engines: 107.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 51mm Deck, 127mm over Machinery, 83mm Over Magazines Belt
Armaments:
4x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O5U and Berliner-Joyce OJ)


Scheme B:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-B-1933-1305380530

Here I show you the second of the 1933 series of designs, Scheme B where the aircraft facilities were move aft to the stern providing more space for the AA armament as well as reducing the length of the citadel but the forecastle hull was retained. Eventually this airfract arrangement was chosen for all subsequent warship designs of the USN except for the Alaska class.
Note that while Captain Alexander Hamilton Van Keuren did not liked this layout the rest of the team preferred it.

The design had the following characteristics:
Dimensions: 176,17(wl) x 179,2 (oa) x 18,31 x 6,58m
Displacement: 10.000tons (Standard)
Engines: 107.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 51mm Deck, 127mm over Machinery, 83mm Over Magazines Belt
Armaments:
4x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O5U and Berliner-Joyce OJ)


Scheme C:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-C-1933-1305752580

On this design the stern aircraft facilities retained of the previous B design but on a new flush deck hull and the 12 6" guns were mounted in 3 quadruple turret in standard arrangement of a superfiring pair forward and one turret aft. The weight saved by using only 3 turrets were incorporated into a slightly heavier turret armour.

The design had the following characteristics:
Dimensions: 176,17(wl) x 179,2 (oa) x 18,31 x 6,58m
Displacement: 10.000tons (Standard)
Engines: 107.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 51mm Deck, 127mm over Machinery, 83mm Over Magazines Belt
Armaments:
3x4 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O5U and Berliner-Joyce OJ)


Scheme D:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-D-1933-1305752292

Here the main armament was increased to 15 barrels in five triple turrets evenly spread forward and aft while the 3rd turret was moved amidships between the aft superstructure and funnels. This variant too featured a longer but still flush decked hull though the aft part starting from the rearmost turret sloped towards the stern like on contemporary Japanese ships. Due to reduced space aft only, 3 aircrafts could be carried instead of the regular 4. Due to the longer hull a smaller engine was required to propel the ship at the desired 32,5knots speed but the longer citadel meant thinner bolt deck and belt armour.

The design had the following characteristics:
Dimensions: 186,54(wl) x 188,75 (oa) x 17,83 x 6,55m
Displacement: 10.000tons (Standard)
Engines: 91.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 43mm Deck, 108mm over Machinery, 83mm Over Magazines Belt
Armaments:
5x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
3x Seaplanes (Vought O5U and Berliner-Joyce OJ)

Scheme E:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-E-1933-1306141661

Here the main armament of 5 triple turrets was retained but the arrangement changed: all turrets moved to the ends of the citadel with 3 turret forward, all in superfiring position similar to the later Atlanta and Dido class cruisers. This design was considered comparable to the previous D variant, though it offers better ahead firing capabilities.

The design had the following characteristics:
Dimensions: 186,54(wl) x 188,75 (oa) x 17,83 x 6,55m
Displacement: 10.000tons (Standard)
Engines: 91.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 43mm Deck, 108mm over Machinery, 83mm Over Magazines Belt
Armaments:
5x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
3x Seaplanes (Vought O5U and Berliner-Joyce OJ)


Scheme F:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-F-1933-1306517306

This variant too used the long hull of the previous two designs but armament was increased to 16 barrels in 4 quadruple turrets evenly spread on the hull. This extra weight from the turrets and the fact that the designers wanted thicker belt armour negatively effected stability and thus not pursued further.

The design had the following characteristics:
Dimensions: 186,54(wl) x 188,75 (oa) x 17,83 x 6,55m
Displacement: 10.000tons (Standard)
Engines: 91.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 43mm Deck, 114mm Belt
Armaments:
4x4 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O5U and Berliner-Joyce OJ)


Scheme G:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-G-1933-1307698702

Here I show you the seventh of the 1933 series of designs, Scheme G, last of the first half of this series. This variant is a modification of the previous F design but instead of evenly spread the 4 quadruple turrets at the ship ends, this variant utilizes the layout of Design D where the 3rd turret was located between the funnels and aft superstructure. To reduce stability issues, the hull was not flush deck but rather having a forecastle deck and thus the aft turrets and aircraft handling facilities could be located lower on the hull. Though the necessity of handling the ship boats and the to clear the catapult both aft turrets were raised.

Apparently the General Board was not fully satisfied with any of these design studies and a discussion on the 23rd and 24th of March, the Preliminary Design team was asked to produce more variants, including one that was finally chosen and one that was based on Admiral Adolphus Eugene Watson's own idea for an all forward design.

The design had the following characteristics:
Dimensions: 186,54(wl) x 188,75 (oa) x 17,83 x 6,55m
Displacement: 10.000tons (Standard)
Engines: 91.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 43mm Deck, 114mm Belt
Armaments:
4x4 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O5U and Berliner-Joyce OJ)


Scheme H:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-H-1933-1308081113

Here I present the eight of the 1933 series of designs, Scheme H, the first of the second half of this series. The layout of this proposal was chosen later for further development though there still differences compared to the final version: Different superstructure elements, no 1st deck connecting the two superstructures, slightly different AA gun layout, longer hull and like Scheme F's the aft part was sloped to provide more space for the catapults and reducing blast issues on it from the aftermost turret.
It was noted at a March 30th Memorandum that Scheme H as being arranged like "Certain Japanese Ships" (Most likely the Myoko and Takao classes).

The design had the following characteristics:
Dimensions: 186,54(wl) x 188,75 (oa) x 17,83 x 6,55m
Displacement: 10.000tons (Standard)
Engines: 91.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 43mm Deck, 114mm Belt
Armaments:
5x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O5U and Berliner-Joyce OJ)


Pre-Scheme I:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-Pre-I-1933-1308445887

This proposal was Admiral Adolphus Eugene Watson's own idea, moving all 5 turrets forward of the primary superstructure, in Nelson like arrangement and alternating between main deck and superfiring turrets. His idea was that weight could be saved by moving all turrets under one armoured citadel, and controlled by the forward, primary gun director, thus eliminating the aft superstructure entirely and providing a blast free zone aft for aircraft facilities.
In my opinion this layout isn't bad, allows potential upgrades in aircraft facilities AA armament and even Helicopter space for Cold War modernizations.

The design had the following characteristics:
Dimensions: 186,54(wl) x 188,75 (oa) x 17,83 x 6,55m
Displacement: 10.000tons (Standard)
Engines: 91.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 43mm Deck, 114mm Belt
Armaments:
5x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O5U and Berliner-Joyce OJ)


Scheme I:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-I-1933-1308812194

This design is the modification of Admiral Watson's idea where only 4 turrets were located forward and one moved aft. It is not described if there would be one or two superstructures but as there is one turret moved aft it is logical that the aft superstructure and fire control statins retained.
It is noted that when this proposal was drawn up it did not looked very appealing.

The design had the following characteristics:
Dimensions: 186,54(wl) x 188,75 (oa) x 17,83 x 6,55m
Displacement: 10.000tons (Standard)
Engines: 91.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 43mm Deck, 114mm Belt
Armaments:
5x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O5U and Berliner-Joyce OJ)


Scheme J:
https://www.deviantart.com/tzoli/art/Brooklyn-Class-Preliminary-Scheme-J-J1-1933-1309203150#image-1

This proposal was basically the F design with the layout of the I (three turrets forward, Nelson arrangement and one turret aft) on a full flush deck hull.

Note that by early April the General Board definitely favoured the H variant and the Preliminary Design team was required to draw up detailed armour schemes as well as studies for mine and aircraft stowage for it. Admiral Alexander Hamilton Van Keuren did not liked this movie which in his opinion considered a reversal policy, from heavy protection and moderate gun power towards heaver gun power in expensive of the protective quality of the design.
By mid April the General Board remained opposed of the Quadruple turret (essentially killing the C,F,G,J and J1 variants), soon the slower variants too got abandoned (killing the C,D,E and F variants of the 1932 series), as they could not operate with existing cruisers and the new carriers and the more armoured ones too got discarded as firepower and speed deemed more important. This left basically the H variant to be fully developed into the new class and which was to be named from the city of Brooklyn.
This concludes the preliminary designs of the Brooklyn class Light Cruisers.

The design had the following characteristics:
Dimensions: 186,54(wl) x 188,75 (oa) x 17,83 x 6,55m
Displacement: 10.000tons (Standard)
Engines: 91.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 43mm Deck, 114mm Belt
Armaments:
4x4 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (Vought O5U and Berliner-Joyce OJ)


Scheme J1:

The J1 was a modified J version where the 2nd and 3rd turrets got changed eg the superfiring turret became the 3rd one instead of the 2nd eg a Mogami style arrangement, but funnily enough the details of the Mogami class was not yet known by the Americans.

 

[Tzoli]

Part 4 - Individual Ships
So far I've only made drawings of the changes on USS Brooklyn herself throught her carrier as well as USS St. Louis as commissioned.


USS Brooklyn - CL-40 as Commissioned in 1937
https://www.deviantart.com/tzoli/art/USS-Brooklyn-as-Looked-like-in-1937-1310354109

While the Brooklyn class light cruisers were ordered in 1929 their actual design was not finalized until mid 1933 with among the preliminary series the 1933 Scheme H was chosen for refinement. The changes compared to the H variant are as follows:
- Slightly shorter (3,64m) but wider (1m) hull which became fully flush deck with a small flare forward but without any slope aft.
- Modified Armour scheme and thickness of said armour
- 100.000shp engines
- the forward and aft superstructures were semi connected by a deck and the funnels were placed thus one deck higher then on the previous iterations
- Further refinement of the bridge superstructure and other hull elements
The above changes and some internal modifications allowed to reduce the standard displacement from 10.000tons to 9.800tons.
Initially 7 such cruisers were ordered in 1929 though actual finances separated them into a 4 and 3 ship groups, while 2 more were authorized in 1935 when necessary tonnage was freed up for further construction (19.950tons altogether)
This last two ships became the St. Lous subclass with modifications to AA armament and superstructure (especially aft) elements.
Here I show you the lead ship, USS Brooklyn CL-40 as looked like when commissioned on the 30th of September 1937 with all the usual AA armament of a pre-war design: eight single 5"/25 guns, divided between both sides, and eight 12,7mm Browning Machine Guns on the platforms of both superstructures.

The design had the following characteristics:
Dimensions: 182,9(wl) x 185,4 (oa) x 18,8 x 6,94m
Displacement: 9.800tons (Standard), 12.700tons (full load)
Engines: 100.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 51mm Deck, 127mm over Machinery, 51mm Over Magazines Belt
Armaments:
5x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (SOC-3 Seagull)


USS Brooklyn - CL-40 as Looked like in 1941-42
https://www.deviantart.com/tzoli/art/USS-Brooklyn-as-Looked-like-in-1941-42-1310728290

On these two drawings I show you how the USS Brooklyn looked like from mid-late 1941 to mid-late 1942 and from late 1942 onwards.
The first drawing shows the changes made before WW2 broke out and shortly after with expanded light AA guns in the means of 4 quadruple 1,1" and 8 single 20mm Oerlikon AA guns positioned evenly on the hull 1-1 pair of quads forward and aft and 4-4 single Oerlikons forward and aft. This necessitated the modification of various structural elements around the hull to provide space and supports for the new armaments, reduction of the ships boats as well as removal of one boat cranes, additional life rafts and unique paint scheme.
In the early part of WW2, USS Brooklyn painted in the Measure 12 (Modified) Paint Scheme which was carried by a number of ships and described by surfaces and corners of surfaces useful in estimating course angles may be broken-up by means of large splotches of paint which would be a mix of haze grey and Blue Gray or Sea Blue colours while the horizontal surfaces were painted in Deck Blue colour. There is no exact pattern for this paint scheme and each ship carried it varied in looks.
By 1942 November the ship got the standard, Measure 22 paint scheme which is quite simple: Navy Blue colour was to be applied to the hull to the height of the main deck edge at its lowest point, while Haze Gray to all remaining vertical surfaces, all masts and small gears.

The design had the following characteristics:
Dimensions: 182,9(wl) x 185,4 (oa) x 18,8 x 6,94m
Displacement: 9.800tons (Standard), 12.700tons (full load)
Engines: 100.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 51mm Deck, 127mm over Machinery, 51mm Over Magazines Belt
Armaments:
5x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
4x4 1,1"/75 Mark 1 AA Guns
8x1 20mm/70 Oerlikon Mark 2 MGs
4x Seaplanes (SOC-3 Seagull)
Sensors:
2x Mark 1 Surface Gunnery Fire Control Radars
2x Mark 4 AA Gunnery Fire Control Radars


USS Brooklyn - CL-40 as Looked like in 1943
https://www.deviantart.com/tzoli/art/USS-Brooklyn-as-Looked-like-in-1943-1311087366

On this drawing I show the look of USS Brooklyn in the mid of 1943 with extensive AA additions and full radar set including gunnery, air and Surface search. Multiple structural elements were changed to include extra close range AA armament the war necessities bought. Noticeable are the full removal of ship boats and associated cranes, in their place 3-3 single Oerlikons were added, more 20mm's were added on the stern, on the base of the forward and aft superstructures and on the nose, the bridge platform was reduced to provide clearer sky arcs for the twin Bofors there as well as for their Mark 51 directors. The searchlight platform between the funnels too got reduced to save some topweight. The Measure 22 paint scheme remained and Will do so till the end of hostilities.

The design had the following characteristics:
Dimensions: 182,9(wl) x 185,4 (oa) x 18,8 x 6,94m
Displacement: 9.800tons (Standard), 12.700tons (full load)
Engines: 100.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 51mm Deck, 127mm over Machinery, 51mm Over Magazines Belt
Armaments:
5x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
2x4,2x2 40mm/56 Bofors Mark 1 AA Guns
28x1 20mm/70 Oerlikon Mark 2 MGs
4x Seaplanes (SOC-3 Seagull)
Sensors:
2x Mark 1 Surface Gunnery Fire Control Radars
2x Mark 4 AA Gunnery Fire Control Radars
SC-1 - Air Search Radar
SG-1 - Surface Search Radar


USS Brooklyn - CL-40 as Looked like in 1945
https://www.deviantart.com/tzoli/art/USS-Brooklyn-as-Looked-like-in-1945-1311459216

Here I show you how USS Brooklyn, CL-40 looked like by the end of WW2 with it's ultimate AA suite of 4 quad and six twin 40mm Bofors guns and 12 twin 20mm Oerlikons, together with a reduced bridge structure to solve issues with top weight due to the added AA guns and crew. By this time the sensor suite, spotting aircrafts and gun directors too got modernized. The ship survived the war without any major damage, participating in the European/Mediterranean Theatre earning altogether 4 battle stars, Which were:
Naval Assault on Casablanca (Operation Torch),
The Invasion of Sicily (Operation Husky),
The Salerno Landings (Operation Avalanche), and
The Anzio-Nettuna Landings (Operation Shingle).
She also participated in the Invasion of Southern France (Operation Dragoon) and put to rest after the hostilities ended.
Eventually she was sold in 1951 to the Chilean Navy together with her sister ship USS Nashville CL-43 as O'Higgins and Capitán Prat respectively extending their service life well into the 1980's!

The design had the following characteristics:
Dimensions: 182,9(wl) x 185,4 (oa) x 18,8 x 6,94m
Displacement: 9.800tons (Standard), 12.700tons (full load)
Engines: 100.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 51mm Deck, 127mm over Machinery, 51mm Over Magazines Belt
Armaments:
5x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
4x4,6x2 40mm/56 Bofors Mark 1 AA Guns
12x2 20mm/70 Oerlikon Mark 2 MGs
4x Seaplanes (Vought OS2U Kingfisher)
Sensors:
2x Mark 13 Surface Gunnery Fire Control Radars
2x Mark 4 AA Gunnery Fire Control Radars
SK-2 - Air Search Radar
SG-1 - Surface Search Radar
SP-1 Air Search / Height Finder Radar


Chilean Cruiser O'Higgins (Previousy USS Brooklyn - CL-40) as Looked like in 1951/52
https://www.deviantart.com/tzoli/art/Chilean-Cruiser-O-Higgins-1311814037

As Looked like in 1963:

As Looked like in 1978:

These 3 drawings shows the Cruiser O'Higgins, previously USS Brooklyn as looked like in Chilean service as acquired in 1951, in the middle of her service in the early 1960's and towards the end of her service in late 1970's. When Chile received USS Brooklyn in 1951 some minor refit work was done on the cruiser compared to her end WW2 state:
-Removal of Catapults and catapult aircraft, providing space for some ship boats at the stern,
-More modern life rafts were installed on the turret sides,
-Removal of some of the twin Oerlikons
-New mark 25 Radars for the AA Gun Directors
-Some structural changes like sunscreen over the bridge and minor changes to the mast.
-Installation of various ECM sensors like the TDY-1 and communication antennas.
In this state the ship served till the early 1960's when a minor refit was done mostly on sensors:
more radio antennas were added, the more modern SPS-4 and -6 radars were also installed.
The most radical change occurred to the ship was in the 1970's when it was further modernized:
newer sensors were added, fully enclosed bridge and admirals bridge structures were erected, a spot for helicopter landing was painted and a WW2-esque camouflage paint scheme was installed in anticipation of war with Argentina during the Beagle Islands Conflict!

The design had the following characteristics:
Dimensions: 182,9(wl) x 185,4 (oa) x 18,8 x 6,94m
Displacement: 9.800tons (Standard), 12.700tons (full load)
Engines: 100.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 51mm Deck, 127mm over Machinery, 51mm Over Magazines Belt
Armaments:
5x3 6"/47 Mark 16 Guns
8x1 5"/25 Mark 11 DP-AA Guns
4x4,6x2 40mm/56 Bofors Mark 1 AA Guns
8x2 20mm/70 Oerlikon Mark 2 MGs
Sensors: (In 1951)
2x Mark 13 Surface Gunnery Fire Control Radars
2x Mark 25 AA Gunnery Fire Control Radars
SK-2 - Air Search Radar
SG-1 - Surface Search Radar
SP-1 Air Search / Height Finder Radar
TDY-1 Radar Jammer
Sensors: (In 1963)
2x Mark 13 Surface Gunnery Fire Control Radars
2x Mark 25 AA Gunnery Fire Control Radars
SPS-6A - Air Search Radar
SPS-4 - Surface Search Radar
SG-1 - Surface Search Radar
SP-1 Air Search / Height Finder Radar
Sensors: (In 1978)
2x Mark 13 Surface Gunnery Fire Control Radars
2x Mark 25 AA Gunnery Fire Control Radars
SPS-54 - Surface Search / Navigational Radar
SPS-12 - Air Search Radar
2x SPS-4 - Surface Search Radars


USS St. Louis - CL-49 as Commissioned in 1939
https://www.deviantart.com/tzoli/art/USS-St-Louis-as-Looked-like-in-1939-1313001544

Here I show you USS St. Louis CL-49 as looked like when commissioned on the 19th of May 1939 with the now becoming standard AA armament of the new USN vessels the 5"/38 Mark 12 AA guns in 4 twin turrets arranged on the corners of the superstructures.
The two St. Louis class cruisers (USS St. Louis and USS Helena) were grouped in their own Sub-class in the Brooklyn series due to their changes of secondary armament, different engine layout (Unit Machinery) as well as different superstructure, especially aft. These changes on the design was allowed by not using all the 10.000tons per hull allocated for the previous 7 ships which meant some improvement and re-design on the class could be achieved. To provide better survivability for the ships a new Unit type machinery arrangement adopted where each pair of boilers were allocated steam for it's own associated Turbine improving damage resistance primary against underwater damage though this layout meant a heavier machinery. Other noticeable change is the introduction of the better and more capable 5"/38 guns in new (unique to these two ships) twin gun turrets which while provide same number of barrels per broadside, the end on fire capability was improved and much less space was taken up by the AA guns themselves together with improved protection from elements and MG gunfire for the gun crews. To save some topweight due to the heavier AA guns, the aft superstructure was re-designed and drastically reduced in complexity and height.

The design had the following characteristics:
Dimensions: 182,9(wl) x 185,4 (oa) x 18,8 x 7,39m
Displacement: 10.560tons (Standard), 13.327tons (full load)
Engines: 100.000shp Westinghouse Steam Turbines, 8x Babcock & Wilcox Boilers 4-shafts
Speed: 60km/h (32,5knots)
Armour: 51mm Deck, 127mm over Machinery, 51mm Over Magazines Belt
Armaments:
5x3 6"/47 Mark 16 Guns
4x2 5"/38 Mark 12 DP-AA Guns
8x1 0,5"/90 M2 Browning MGs
4x Seaplanes (SOC-3 Seagull)

 

[Dilandu]

Thank you very muchfor excellent research!

 

[Dilandu]

This was due to being the USN not reached its Heavy Cruiser quota set by the previous Washington Naval Treaty.

Correction - Washington Treaty put no quota on heavy cruisers.

 

[JoeCalPo]

A fascinating evolution of designs, some rather... over-inventive. Probably my favorite cruiser series.

 

[Archibald]

Somebody has to ask THE question... will you do the ARA Belgrano ?

 

[Colonial-Marine]

Of all of the preliminary designs I'm rather fond of J1. Although one can only speculate if the quadruple 6" turret would have been as successful as the triple 6" turrets actually built for the Brooklyn, St. Louis, Cleveland, and Fargo classes.

As with the "35,000 ton" treaty battleships, I can't help but feel an extra 1,000 tons to work with would have been much appreciated. Intentionally or otherwise, some of their Japanese cruiser counterparts ended up about 1,500 tons over the limit.