A loose alternate history fleshed out via a combination of writing and experimenting with SpringSharp. In this AU, the U.S. Navy is more aggressive in its adoption of new technologies and benefits from a less parsimonious Congress, although it operates under the same fundamentals for construction time and number of ships budgeted.
Subchasers
During both World War I and World War II, the U.S. Navy fielded large numbers of small warships designed as anti-submarine escorts.
Destroyer Escorts
Treaty Sloops
The provisions of the London Naval Treaty allowed for an unlimited tonnage of warships between 600 and 2000 tons as long as they had no guns exceeding 6", a maximum of four gun mounts above 3", no torpedo armament, and a top speed not exceeding 20 knots.
Superior Class Sloop
As a non-signatory nation in this timeline, the U.S. Navy has even less than its historically minimal interest in this type of minor warship. However, the high cost of its preferred fleet destroyers does lead to a design being selected in the early 1930s and two being authorized as a proof-of-concept auxiliary which can be easily mass produced. No need for production sloops ever arises, but the Coast Guard adapts the design to produce its long-serving Treasury-class high endurance cutters.
The Superior design emphasizes endurance and seaworthiness with a high freeboard, raised forecastle, and a relatively generous beam. In order to avoid competing with fleet destroyers for geared turbines, they utilize turbo-electric propulsion with two turbines and two generators. For the same reason, they are fitted with "leftover" 5"⁄51 and 3"⁄50 guns rather than 5"⁄38. Their most notable feature is the inclusion of a single Curtiss SOC scout floatplane on an amidships catapult.
The Superiors are built with a main armament of four 5"⁄51 guns in single mounts fore and aft, a secondary armament of four 3"⁄50 anti-aircraft guns on single pedestal mounts amidships, and a tertiary armament of eight M2 .50-caliber machine guns in four twin mounts. They also have two depth charge racks and one Y-gun depth charge projector.
(The Superior class sloop is a loose counterpart to the Erie class patrol gunboat, but it is primarily inspired by the French Bougainville class colonial aviso. The Erie's use of precious geared turbines and a unique new 6"47 Mark 17 gun were both highly nonsensical decisions by Adm. Pratt, so those very specically don't happen.)
Destroyer-Escorts
During World War II, the need for extremely numerous convoy escorts and anti-submarine