ros ive ▁attack ▁on ▁the ▁joint ▁and ▁sudden ▁failure ▁is ▁possible . ▁The ▁maintenance ▁costs ▁of ▁such ▁systems ▁are ▁greater ▁and ▁less ▁predict able . ▁A ▁trial ▁of ▁approximately ▁ 3 0 0 0 ▁solid - co pper ▁h anger ▁bars , ▁found ▁over ▁time ▁a ▁lower ▁current ▁efficiency ▁in ▁the ▁solid - co pper ▁h anger ▁bars ▁of ▁about ▁ 2 . 4 %. ▁ ▁The ▁M IM ▁development ▁team ▁looked ▁for ▁other ▁ways ▁to ▁reduce ▁the ▁resistance ▁of ▁the ▁c ath ode ▁pl ates ▁and ▁developed ▁a ▁new ▁low - res istance ▁c ath ode , ▁which ▁it ▁called ▁I SA ▁C ath ode ▁BR . ▁This ▁new ▁design ▁extended ▁the ▁co pper ▁pl ating ▁from ▁ 1 5 – 1 7   mm ▁down ▁the ▁bla de ▁to ▁approximately ▁ 5 5   mm , ▁and ▁it ▁increased ▁the ▁thick ness ▁of ▁the ▁co pper ▁to ▁ 3 . 0   mm ▁from ▁the ▁ 2 . 5   mm ▁used ▁on ▁the ▁standard ▁c ath ode . ▁▁ ▁The ▁new ▁c ath ode ▁plate ▁design ▁was ▁tested ▁in ▁the ▁C RL ▁ref in ery ▁in ▁Town sv ille ▁and ▁at ▁Comp ania ▁Min era ▁Z ald iv ar ▁in ▁Chile . ▁The ▁Chile an ▁results ▁indicated ▁the ▁new ▁c ath ode ▁design ▁had ▁the ▁potential ▁to ▁reduce ▁power ▁costs ▁by ▁approximately ▁US $ 1 0 0 , 0 0 0 ▁in ▁ 2 0 0 3 ▁for ▁the ▁plant , ▁compared ▁to ▁using ▁conventional ▁Isa ▁Process ▁c ath ode