▁preserved . ▁ ▁Description ▁ ▁Con struct ed ▁in ▁Switzerland ▁by ▁a ▁collaboration ▁between ▁Brown , ▁B over i ▁& ▁C ie ▁( B BC ), ▁who ▁provided ▁the ▁mechan ics , ▁and ▁Schweizer ische ▁Lok om ot iv - ▁und ▁Mas ch inen fab rik ▁( SL M ), ▁who ▁contributed ▁the ▁elect rics , ▁the ▁two ▁E 2 E ▁locomot ives ▁were ▁introduced ▁to ▁pull ▁goods ▁on ▁the ▁B TB . ▁ ▁They ▁were ▁equ ipped ▁with ▁two ▁ 1 9 - pole ▁electric ▁mot ors ▁of ▁ ▁which ▁power ed ▁a ▁common ▁sh aft ▁mounted ▁on ▁an ▁auxili ary ▁frame . ▁ ▁Power ▁was ▁transm itted ▁via ▁a ▁counter sh aft ▁and ▁coupling ▁ro ds ▁to ▁two ▁ax les . ▁ ▁A ▁two ▁speed ▁g ear box , ▁switch able ▁when ▁the ▁locomot ive ▁was ▁station ary , ▁was ▁fitted . ▁ ▁The ▁lower ▁speed ▁allowed ▁a ▁maximum ▁speed ▁of ▁ ▁on ▁a ▁slope ▁of ▁ 2 5 ▁ ‰ ▁drawing ▁a ▁load ▁of ▁. ▁ ▁The ▁higher ▁speed ▁was ▁designed ▁for ▁a ▁maximum ▁of ▁. ▁This ▁higher ▁speed ▁allowed ▁the ▁locomot ives ▁to ▁be ▁used ▁for ▁passenger ▁operations . ▁ ▁The ▁g ear box ▁proved ▁to ▁be ▁problem atic ▁and ▁was ▁re vised ▁by ▁S LM ▁in ▁ 1 9 0 0 . ▁Later , ▁the ▁g ear ing ▁was ▁changed ▁to ▁allow ▁for ▁a ▁higher ▁speed ▁of ▁. ▁ ▁The ▁locomot ives ▁were ▁equ ipped ▁with ▁a ▁ 1 0 0   V ▁circuit ▁for ▁light ing ,