▁to ▁ ▁gauge , ▁and ▁later ▁converted ▁them ▁back ▁again . ▁Also ▁in ▁the ▁ 1 9 th ▁century , ▁in ▁the ▁United ▁States , ▁some ▁broad ▁ ▁gauge ▁locomot ives ▁were ▁designed ▁for ▁easy ▁conversion ▁to ▁ ▁gauge . ▁In ▁the ▁ 2 0 th ▁century , ▁in ▁Victoria ▁station , ▁London , ▁some ▁broad ▁ ▁gauge ▁locomot ive ▁classes ▁of ▁the ▁Great ▁Western ▁Railway ▁were ▁designed ▁for ▁easy ▁conversion ▁to ▁a ▁nar ro wer ▁ ▁gauge . ▁Between ▁ 1 9 2 2 ▁and ▁ 1 9 4 9 , ▁five ▁South ▁Australian ▁Rail ways ▁T ▁class ▁narrow ▁ ▁gauge ▁locomot ives ▁were ▁converted ▁to ▁T x - class ▁broad ▁ ▁gauge , ▁and ▁later ▁back ▁again . ▁After ▁World ▁War ▁II , ▁a ▁number ▁of ▁captured ▁German ▁ 0 3 ▁class ▁Pacific s ▁locomot ives ▁were ▁reg aug ed ▁to ▁the ▁Russian ▁gauge . ▁ ▁Dies el ▁and ▁electric ▁trains ▁Most ▁dies el ▁and ▁electric ▁rolling ▁stock ▁can ▁under go ▁gauge ▁conversion ▁by ▁replacement ▁of ▁their ▁bog ies . ▁Eng ines ▁with ▁fixed ▁wheel b ases ▁are ▁more ▁difficult ▁to ▁convert . ▁In ▁Australia , ▁dies el ▁locomot ives ▁are ▁regularly ▁re - g aug ed ▁between ▁broad , ▁standard , ▁and ▁narrow ▁gau ges . ▁ ▁W ag ons ▁and ▁coach es ▁G au ge ▁conversion ▁of ▁w ag ons ▁and ▁coach es ▁involves ▁the ▁replacement ▁of ▁the ▁wheel sets ▁or ▁the ▁bog ies . ▁In ▁May ▁ 1 8 9 2 , ▁w ag ons ▁and ▁coach es