Like the O and Ps, they were armed with what weapons were available: 4.7-inch (119 mm) guns on single mountings that allowed only 40° elevation, which do not compare favourably on paper with many contemporaries.

[1] This facilitated the change in watchkeepers in inclement weather; the main deck of a destroyer would often be entirely awash in heavy seas, and catwalks were not fitted to connect fore and aft until the V class ordered in 1941.

In surviving ships, the single 20 mm Oerlikon guns in the bridge wings were later replaced by hydraulically operated Mark V twin mountings.

The centimetric wavelength Type 272 set was added on a platform between the torpedo tubes in Rotherham, Racehorse, Rapid, Raider and Roebuck, or at the foremast truck in other ships.

Racehorse, Raider, Rapid, Redoubt and Relentless had Huff-Duff (High-frequency Direction-finder) added on a lattice mainmast.