The 1933 Battlecruiser Study

In 1933, there was an interest around the world in the type of vessel that can be best described as a "semi-capital ship". This interest was sparked by the Germans, who designed their Deutschland Class Panzerschiff to carry the largest possible guns on a cruiser-size hull. Lacking the ability to manufacture guns over 11.1-inches, and restricted to 10,000 tons by the Treaty of Versailles, the German designers shocked the world by creating a powerful, fast, long-range design. The French answered with the much larger Dunkerque, which prompted the Italians to design several pocket battleships and battlecruisers of their own.
In addition, it seemed highly likely that the Washington Treaty's building holiday on vessels over 10,000-tons would be soon coming to an end, as the treaty expired in 1936. So these battlecruiser and semi-capital ship designs would be built in addition to, not instead of, new battleships.
In the United States, Admiral W.V. Pratt asked the Bureau of Construction and Repair for designs for a cruiser-killer type vessel. Design requirements were for a vessel of 30,000 tons standard displacement, with 33-knot speed, and carrying twelve 12-inch guns. Such a vessel could protect US lines of communication from 8-inch cruisers, raiders, pocket battleships, and even the Japanese Kongo Class battlecruisers.
Preliminary designs were ready by June of 1933.
Design A was for a slower vessel, armed with nine 14-inch guns in three turrets. It would have been capable of 31.5 knots, carried 5" DP guns in twin mounts, and offered better protection with equal firepower to the 12 x 12" requirement.

This design offered some rather unique solutions to the problem of weight conservation. The drawing above shows, in red, the position of the main side armor. Abaft the machinery spaces, the belt was an external one, and the armored deck (shaded) extended all the way to the side of the ship. Fore and aft of the machinery spaces, the belt was internal, and the armored deck only carried out as far as the torpedo defense system. The turrets were all at the main deck level, to reduce topweight and allow for more protection. Underwater protection was fairly conventional, but fore and aft of the machinery spaces the bulkheads sloped inwards at the bottom to follow the curve of the hull. A hanger in the stern was included for scout aircraft.
Specs for this design are below.

Design A

Pratt rejected this design as being too slow. A second design, meeting his original requirements for speed and 12-inch guns, was offered to the General Board in October of 1933. This vessel would have been even stranger than the first design. No sketches have survived, but the vessel mounted 4 triple turrets, with one aft and three forward. All three foreword turrets were superfiring, in a layout similar to the later Atlanta Class light cruisers. Because of the topweight, armor protection had to be reduced. The belt was only 8-inches thick, but it was still angled fore and aft of the machinery spaces, to offer more protection abreast the magazines. Power was raised to 160,000 SHP, resulting in a speed increase to 32.75 knots. My impression of the design, based on US 1930's designs for all-forward battleships and aviation cruisers, is below.



The General Board, and the Naval War Collage, evaluated these designs, comparing them to foreign battlecruisers and battleships. They found the design to be totally inadequate for facing battleships, but they felt the 14-inch gunned version would be superior to many existing battlecruisers. The battlecruiser type, however, was felt to be superfluous to the needs of the US Navy.

Admiral Pratt retired just as these designs were being prepared, and there was no further interest in the type. The C & R Design book states that these designs were "not quite carried to completion".

The requirement for a high-speed, 12-inch gunned cruiser killer would surface 5 years later, resulting in the Alaska Class.

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