{"id":"S85110872","label":"Railroad engineering","description":"Here are entered general works on railroad engineering, including surveying, construction, maintenance and repair, operation, etc. treated collectively.","source_url":"https://id.loc.gov/authorities/subjects/sh85110872","normalized_label":"railroad engineering","broader":["http://id.loc.gov/authorities/subjects/sh85137069"],"aliases":["Engineering, Railroad","Railroads--Engineering"],"source_identifier":"http://id.loc.gov/authorities/subjects/sh85110872","provider":"lcsh","revision":"0a2df08ce5e47ee2","taxonomy_revision":"f050b5d4780b1289","title":"Railroad engineering","url":"/topics/S85110872","kind":"topic-directory","aeo_cohort":"topic-directory","catalogue_revision":"f050b5d4780b1289","numeric_address":"900790570237166084","address_version":"morton4x16-v1","coordinates":[0,20,19137,24576],"answer_status":"Directory metadata; local answer requires separate source review","truth_status":"Subject descriptor, not a factual answer or a demonstrated knowledge gap","reviewed_answer":null}