▁in ▁ 1 9 5 0 , ▁were ▁reb od ied ▁by ▁H ess ▁between ▁ 1 9 6 8 ▁and ▁ 1 9 7 5 ▁and ▁fitted ▁with ▁a ▁new ▁backup ▁battery . ▁ ▁They ▁were ▁simultaneously ▁ren umber ed ▁as ▁fleet ▁nos . ▁ 1 3 1 – 1 4 8 , ▁but ▁not ▁in ▁the ▁same ▁sequence . ▁ ▁Tra iler ▁operations ▁ended ▁either ▁in ▁ 1 9 9 1 ▁or ▁in ▁March ▁ 1 9 9 2 . ▁ ▁Dis pos al ▁abroad ▁▁▁ ▁In ▁ 1 9 9 2 , ▁all ▁twelve ▁t rol ley b uses ▁of ▁the ▁ 1 9 5 7 – 5 8 ▁series ▁were ▁sold , ▁together ▁with ▁the ▁ 1 9 6 9 – 7 0 ▁tra ilers , ▁to ▁the ▁Wars aw ▁t rol ley bus ▁system ▁in ▁Poland , ▁and ▁were ▁placed ▁in ▁service . ▁ ▁That ▁system ▁was ▁never theless ▁closed ▁soon ▁afterwards , ▁in ▁ 1 9 9 5 . ▁One ▁of ▁the ▁former ▁St . ▁G allen / W ars aw ▁t rol ley b uses ▁( No . ▁ 1 2 8 ) ▁was ▁sold ▁in ▁ 2 0 0 1 ▁to ▁the ▁G d yn ia ▁t rol ley bus ▁system , ▁also ▁in ▁Poland , ▁where ▁it ▁later ▁came ▁into ▁use ▁as ▁a ▁her itage ▁vehicle , ▁ren umber ed ▁ 3 3 0 0 , ▁operating ▁service ▁occasionally . ▁By ▁ 2 0 1 2 , ▁its ▁original , ▁St . ▁G allen