After building 6 Brooklyn-class cruisers, the US came to the point where they reached the ceiling in terms of light cruisers’ displacement regulated by the Washington Naval Treaty. They had only 17,600 of 143,500 tons left, but they needed 20,000 more for two additional Brooklyn cruisers. This whole situation was the reason for designing this project.
They had to design the project for the new cruisers and by the end of 1934, 6 variants of ship designs with displacements of 5 thousand to 10 thousand tons were presented. All variants were lighter and smaller versions of Brooklyn. To reduce displacement, the following solutions were proposed: placing the main turrets in the quadruple turrets (this is not where they decided to reduce weight, they had 16 main guns within the same dimensions), twin turrets, reducing the number of triple turrets, reducing the armor thickness, and, accordingly, reducing the propulsion output. However, they managed to count in the tonnage of the amortized Omaha-class cruisers, destroyers, and Brooklyn cruisers that were already constructed and able to match the tonnage restrictions. As a result, all cruisers that actually were constructed were slightly modified and upgraded versions of Brooklyn.
Our project differs from the draft design №389 4C scheme by the new compact high-pressure tanks that were actually mounted on a couple of St. Louis and Helena cruisers. This made it possible to use the echelon scheme of the main propulsion with additional compartments for power and damage control central and turret magazines of dual-purpose artillery and AA artillery. The changes outside can be seen in the presence of two small smoke stacks instead of a single large and wide one. Also, the lighter main propulsion allowed for installing two triple turrets of the main turret instead of twin-turrets. 5”/38 Dual-purpose artillery in two twin-turrets and two single-turrets were used (instead of six single turrets, and there was no space left on the sides for twin-barreled guns because of aircraft catapults).
The guns were similar to those used on St. Louis and Helena, as well as Wichita that were built at approximately the same time as the ships of our project. The beam-length ratio in the draft design №389 4C scheme wasn’t credible: more than 11:1, while it doesn’t exceed 10:1 for real ships (including swift and low destroyers). And even with that, the ships had problems with stability, which had to be solved by installing sinking ballast, which, in its turn, imposed certain limitations on future upgrades. That’s why we increased the hull beam by almost 2 meters, this caused the water resistance to increase, which was compensated by the increased propulsion output.
Hull, hull lines, and design
Currently, we have two variants of the hull: hull А (year 1940, before the Second World War) and hull В (year 1942, after the war had started).
The hull was designed from scratch based on the theoretical blueprint of cruiser Cleveland (direct evolution of the Brooklyn class). The hull and superstructure design are typical of the US shipbuilding of that time — it’s mixed: riveted for the most part, while the end sections and some of the superstructure elements are welded.
- The shafts, propellers, rolling keels, and rudder are taken from Cleveland-class cruisers.
- The main armor belt is external, fitted on plating and bolted from the inside. The armor belt was 1.5 inches thinner compared to Brooklyn (to match the displacement limit). At the height of 1.97 m it was 89 mm thick and 45 mm on the lower edges. The full armor belt height is 2.88 m. The armor belt length is 46.32 m from the forward bulkhead of the boiler room to the after bulkhead of the engine room. There are fairings on the fore and aft of the armor belt. The magazine and steering gear armor are made in the form of internal armored boxes that are 37/51 mm and 25 mm thick respectively, and aren’t visible from the outside.
- Masts, equipment, piping, and small details are borrowed from cruisers St. Louis and Helena, as well as Atlanta and Cleveland-class cruisers.
- Two turret mounts with two and three 152 mm guns. Barrel length is 47 calibers. The armament is taken from Brooklyn/Cleveland and their characteristics are identical.
- The twin turret was designed from scratch based on the triple turret of the Brooklyn cruiser by demounting the intermediate gun and reducing the size, as a consequence. The armor is thinner than that of Brooklyn/Cleveland, the turrets are lighter, guidance systems are less powerful. The turret characteristics (traverse speed, elevations speed, loading time, etc.) are identical to those of the turrets of Brooklyn/Cleveland.
- The triple turret is taken from Brooklyn/Cleveland, but its armor is lighter (which can’t be seen, it only influences the parameters and weight, and weight is everything to us).
- The main battery guidance system is similar to those of Brooklyn/Cleveland, there are only 7.35 m rangefinders in turrets №2 and №3.
- Four battle lanterns with 0.9 m mirrors are installed on the sides of the smoke stacks.
Dual-purpose and antiaircraft artillery
- Two turret mounts of 2×127/38 dual-purpose battery (from St. Louis and Helena).
- Two open mounts of 127/38 dual-purpose battery.
- For hull А and В, the composition and placement of the dual-purpose battery is identical.
- Small antiaircraft artillery on hull А: 6 Chicago 4×28 Pianos and 14 12.7 mm machine guns.
- Small antiaircraft artillery on hull В: quadruple “pianos” are replaced with twin 40 mm and 20 mm Oerlikon automatic AA mounts installed instead of machine guns.
- Six Oerlikon automatic AA mounts or an additional pair of 40 mm Bofors automatic AA mounts can be installed on hull B in place of the floating crafts that were removed in accordance with the trends of that time. But we didn’t implement that in the game.
- The directors of the dual-purpose Mk33 type artillery of St. Louis and Helena.
- AA guns were controlled by the AA directors placed next to the mounts, machine guns and Oerlikons only have local control (i.e. by feel).
- There’s a catapult for the monoplane in the central part between the smoke stacks. The catapult is mounted on the stand in the centerline plane: aircraft can be launched on either side. The stand is also a ventilation shaft for the forward engine room.
- The aircraft are lifted from the water with the help of a crane borrowed from cruiser Indianapolis. This crane is also used for floating crafts.
Radio and radar equipment
- There are three radio compartments: forward radio compartment on the forecastle deck, upper radio compartment on the first tier of the superstructure, the after radio compartment on the forecastle deck.
- The direction finder is installed on the foremast.
- The radar equipment was designed to be installed only on hull B: SA-1 type radar on the foremast and the SG type radar on the aftermast. However, currently there are radars on both hulls in the game. The only difference of hull B is the main battery directors with radar guidance.
- There is a motorboat and a longboat on a skid on the main deck, a boat crane, and two whale boats on davits; the floating crafts themselves are similar to Brooklyn/Cleveland.
- Initially we planned to remove the longboat and motorboat on hull B, leave only the whaleboats, and “scatter” floats across the ships, but in the end all floating crafts were added for both hulls.
Armor and torpedo protection
- Armored deck above the citadel and magazines — 32 mm.
- The magazines of the main and dual-purpose battery are protected by 37 mm armored “boxes”, cross beam — 51 mm.
- Steering gears armor box — 25 mm.
- Armored tower with a wall thickness up to 64 mm and a 37 mm roof, the armor of the director pipes is 37 mm.
- Barbettes are protected by 51 mm armor.
- The turrets’ armor is 75 mm in the front, 51 mm in the walls and 37 mm in the roof.
- The torpedo protection system has a double bottom and double sides (within the citadel). The thickness is the same as Brooklyn’s — 6.5 mm (i.e. it’s almost non-existent).
- Main battery ammunition is placed in the gun bays protected by the armored boxes. The ammunition is transported directly to the turrets and loaded through the deck hatches next to the turrets.
- The magazines for the dual-purpose artillery turrets are placed to the right of the main battery №2 magazine and slightly ahead of the main battery №3 magazine in the same armor boxes. The ammunition is transported and loaded with the help of elevators through the handling rooms under the turrets.
- The magazines for the open mounts of the dual-purpose artillery and a part of the small-caliber AA guns are placed around the citadel between the boiler compartments, the ammunition is transported to the deck with the help of elevators.
- We placed the ammunition boxes next to each open dual-purpose artillery and small-caliber AA gun mounts.