Editing Q and R-class destroyer (section)

==Design==
The Q and R class were repeats of the preceding {{sclass2|O and P|destroyer|4}}, but reverted to the larger [[J-, K- and N-class destroyer|J-, K- and N-class]] hull to allow for the inevitable growth in topweight. As they had fewer main guns than the J, K and Ns, some magazine space was replaced by fuel bunkers,<ref name="lenton"/> allowing some {{convert|4675|nmi|km}} to be made at {{convert|20|kn|km/h}}, rather than the {{convert|3700|nmi|km|abbr=on}} of their predecessors. Like the O and Ps, they were armed with what weapons were available: {{convert|4.7|in|mm|adj=on|0}} guns on single mountings that allowed only 40° elevation, which do not compare favourably on paper with many contemporaries. These ships used the [[Fuze Keeping Clock]] HA Fire Control Computer.<ref>Destroyer Weapons of WW2, Hodges/Friedman, {{ISBN|0-85177-137-8}}</ref>

In the Q class, 'Y' gun could be removed, allowing additional depth charges and projectors, or [[minesweeper|minesweeps]], to be carried.

The R class were repeats of the Qs, except that the officers' accommodation was moved from its traditional location right aft to the more accessible location amidships.<ref name="lenton"/> 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 [[U and V-class destroyer|V class]] ordered in 1941.

In surviving ships, the single 20&nbsp;mm Oerlikon guns in the bridge wings were later replaced by hydraulically operated Mark V twin mountings. ''Rotherham'', ''Raider'' and ''Rocket'' later had the Oerlikons and searchlight amidships replaced by four single [[Bofors 40 mm Automatic Gun L/60|QF 40 mm Bofors]]. The searchlight was later reinstated at the cost of depth charge stowage. ''Raider'' only had an additional pair of twin Mark V Oerlikon mounts added on the after shelter deck. Radar Type 290 was replaced by Type 291, and later by Type 293 in some ships. 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.