1 9 7 3 . ▁ ▁History ▁ ▁The ▁New ▁South ▁Wales ▁Government ▁Rail ways ▁placed ▁an ▁order ▁in ▁October ▁ 1 9 6 9 ▁with ▁Walk ers ▁Limited , ▁Mary borough ▁for ▁ 2 0 ▁Bo - Bo ▁sh un ting ▁locomot ives . ▁These ▁were ▁the ▁only ▁New ▁South ▁Wales ▁locomot ives ▁to ▁be ▁built ▁in ▁Queensland . ▁ ▁D elivery ▁The ▁first ▁unit ▁was ▁delivered ▁in ▁October ▁ 1 9 7 0 . ▁When ▁the ▁whole ▁of ▁the ▁first ▁order ▁had ▁arrived , ▁all ▁steam ▁sh un ting ▁on ▁the ▁North ▁Coast ▁line ▁and ▁the ▁Sydney ▁Metropolitan ▁area , ▁as ▁well ▁as ▁at ▁G oul burn ▁had ▁been ▁replaced . ▁In ▁July ▁ 1 9 7 1 ▁a ▁further ▁ 3 0 ▁units ▁were ▁ordered . ▁The ▁last ▁of ▁these ▁arrived ▁in ▁March ▁ 1 9 7 3 ▁and ▁this ▁brought ▁to ▁an ▁end ▁all ▁remaining ▁steam ▁sh un ting ▁operations ▁in ▁New ▁South ▁Wales . ▁ ▁In ▁traffic ▁The ▁New ▁South ▁Wales ▁Government ▁Rail ways ▁purchased ▁the ▁class ▁mainly ▁for ▁sh un ting ▁and ▁their ▁prohib ition ▁from ▁main line ▁use ▁was ▁' o fficial ly ' ▁due ▁to ▁the ▁lack ▁of ▁vig il ance ▁controls . ▁However , ▁despite ▁its ▁absence , ▁the ▁class ▁was ▁still ▁seen ▁on ▁many ▁sub urban ▁trip ▁work ings ▁and ▁when ▁main line ▁operation ▁was ▁a ▁necessity , ▁there ▁seemed ▁to ▁be ▁no ▁hes itation ▁to ▁use ▁them . ▁ ▁One ▁advantage ▁a ▁dies el - h yd ra ul ic ▁locomot ive