gt ▁was ▁reform ed ▁as ▁ 6 0 1 st ▁( City ▁of ▁Br istol ) ▁( M ixed ) ▁He avy ▁Anti - A ircraft ▁Regiment , ▁Royal ▁Art illery ▁(' M ixed ' ▁indicating ▁that ▁members ▁of ▁the ▁Women ' s ▁Royal ▁Army ▁Corps ▁were ▁integrated ▁into ▁the ▁unit ). ▁Now ▁equ ipped ▁with ▁H AA ▁guns ▁rather ▁than ▁S / L s ▁it ▁formed ▁part ▁of ▁Br istol - based ▁ 7 2 ▁AA ▁B de ▁( the ▁w art ime ▁ 4 6 ▁AA ▁B de ). ▁ ▁When ▁AA ▁Command ▁was ▁dis band ed ▁on ▁ 1 0 ▁March ▁ 1 9 5 5 ▁there ▁were ▁wh oles c ale ▁mer gers ▁among ▁its ▁sub ordinate ▁units : ▁ 6 0 1 ▁( City ▁of ▁Br istol ) ▁H AA ▁R gt ▁am alg am ated ▁with ▁ 3 1 2 th ▁( G lou c esters hire ) ▁and ▁ 2 6 6 th ▁( G lou c esters hire ▁Vol unte er ▁Art illery ) ▁H AA ▁R g ts ▁to ▁form ▁ 3 1 1 th ▁( City ▁of ▁Br istol ) ▁He avy ▁Anti - A ircraft ▁Regiment , ▁Royal ▁Art illery , ▁to ▁which ▁it ▁contributed ▁R ▁( City ▁of ▁Br istol ) ▁B ty . ▁ ▁On ▁ 1 ▁May ▁ 1 9 6 1 ▁there ▁was ▁a ▁further ▁re organisation : ▁part ▁of ▁the ▁regiment ▁merged ▁with ▁ 8 8 3 ▁( B rist ol ) ▁Loc ating ▁B ty ▁to