The need for an industry-recommended practice to address installation of pipeline crossings under railroads was first recognibzyed t he publication of American Petroleum Institute (API) Code 26 in 1934.
API RP 1102-1993 history
0000 API RP 1102:2007
1993API RP 1102-1993 Steel Pipelines Crossing Railroads and Highways (SIXTH EDITION)
1981API RP 1102-1981 Recommended Practice for Liquid Petroleum Pipelines Crossing Railroads and Highways (FIFTH EDITION)
1968API RP 1102-1968 RECOMMENDED PRACTICE FOR LIQUID PETROLEUM PIPELINES CROSSING RAILROADS AND HIGHWAYS (Fourth Edition)