▁on ▁the ▁Han over - B run sw ick ▁line ▁of ▁the ▁Royal ▁Han over ian ▁State ▁Rail ways . ▁By ▁ 1 8 4 7 , ▁W öh ler ▁was ▁chief ▁super int endent ▁of ▁rolling ▁stock ▁on ▁the ▁Lower ▁S iles ian - M arch er ▁railway ▁in ▁Frankfurt ▁( O der ). ▁▁ ▁The ▁rail road ▁was ▁national ised ▁by ▁the ▁Pr uss ian ▁state ▁rail ways ▁in ▁ 1 8 5 2 ▁and ▁W öh ler ' s ▁growing ▁reputation ▁led ▁to ▁his ▁appointment ▁by ▁the ▁Pr uss ian ▁Ministry ▁of ▁Com merce ▁to ▁investigate ▁the ▁causes ▁of ▁f ract ure ▁in ▁rail road ▁ax les , ▁work ▁that ▁was ▁to ▁occup y ▁W öh ler ▁over ▁the ▁next ▁two ▁dec ades . ▁The ▁recognition ▁of ▁his ▁keen ▁administration ▁and ▁technical ▁leadership ▁resulted ▁in ▁his ▁appointment ▁as ▁director ▁of ▁the ▁newly ▁formed ▁Imperial ▁Rail ways ▁in ▁Als ace - L or raine ▁in ▁ 1 8 7 4 , ▁based ▁at ▁the ▁board ' s ▁headquarters ▁in ▁Stra ß burg , ▁a ▁post ▁he ▁held ▁until ▁his ▁ret irement ▁in ▁ 1 8 8 9 . ▁ ▁F at igue ▁Studies ▁W öh ler ▁started ▁his ▁ax le ▁investig ations ▁by ▁research ▁into ▁the ▁theory ▁of ▁el astic ity ▁and ▁was ▁led , ▁in ▁ 1 8 5 5 , ▁to ▁a ▁method ▁for ▁predict ing ▁the ▁def lection ▁of ▁lattice ▁be ams ▁that ▁anticip ated ▁the ▁work ▁of ▁É mile ▁Cla pe y ron . ▁He ▁also ▁introduced