1:600 Skate modified for escort work, with 4 single Oerlikons, a 12 pound AA gun and extra depth charges aft © Andrew Arthur

The Skate was the only survivor from the 39 standard units of the old "R" class - WWI emergency destroyers.
They appeared to be repeats of the previous "M" class, but had twin geared screws as opposed to triple direct-drive screws like their predeccesors. "Y" gun was also raised onto a bandstand to help when rough seas swept across the deck.
A single 2 pound AA gun was mounted amidships for local and AA defence, with twin 21" tubes fore and aft of it.
Early in WWII she was modified as an escort, where all but "A" 4" gun was removed, along with the pom-pom and tubes, the funnels cut down in height and extra depth charges were added aft. A 12 pounder AA gun was added amidships and 4 single 20mm Oerlikons were added fore and aft on raised platforms. Air warning, type 291, radar was added at the head of the mast.
They were the last triple funnelled destroyers ( "three pipers" ) ordered and built for the Royal Navy if one does not count the curious 1970's Bristol's split after funnel.
Anecdotally, Radiant, supplied to Siam in 1920 as Phra Ruang, was not scrapped until late in 1957 - a 40 year old lady then.

Pictures of old "R" class destroyers

Skate ( F46 was her old sytem pennant, H39 came later ) in 1919. Note the tubes and raised "Y" gun.