This design was a US development of the "River" class frigate, 100 of which were to built for the Royal Navy. The design was simplified and made utilitarian for the purposes of mass productio by US shipyards - it took only 4 moths to lay down, launch and complete some of these vessels, and they featured welding from end-to-end, effectively being one big lump of metal :-)
One thing that remained British in the design was the use of recprocating machinery, not normally found in US designs. Only 21 were completed and supplied however, as compensations to the loss of Destroyer-Escorts to the USN, and these vessels seem far better and more useful than the DE's, and the RN crews were already familiar with the design.
They were well and uniformly armed with three single 3" AA, two RDF tower controlled twin Bofors, and six single 20mm AA guns. A hedgehog and four DC mortars were carried.
USN SA AW and SL SW RDF was carried.
Caicos was later converted to a fighter direction ship, carrying GW.277 RDF and served off the east coast detecting V.1 bombs before it was too late, and vectoring in RAF fighters.