SURVEYING FOR HIGHWAY ALIGNMENT AND GRADE WITH GYROSCOPIC EQUIPMENT

THE AUXILLIARY EQUIPMENT NECESSARY TO RUN TWO GYROSCOPES INCLUDES A 750-WATT GENERATOR, CONVERTOR, VOLTAGE REGULATOR, AND INCLINOMETER TUBES. ONE OF THE GYROS IS HORIZONTALLY MOUNTED AND GIVES READINGS OF AZIMUTH AND IS CONTINUALLY CONTROLLED BY OR ORIENTED TO THE EARTH'S MAGNETIC FIELD FOR A REFERENCE BASE. THE OTHER GYRO IS VERTICALLY MOUNTED WHICH GIVES READINGS OF GRADE AND OF SUPERELEVATION. NOTES ARE TAKEN WHICH ARE SUBSEQUENTLY REDUCED OR CALCULATED BY IBM MACHINE METHODS. TABULATIONS ARE FURNISHED WHICH GIVE INFORMATION IN COORDINATES THAT ENABLE THE DRAFTSMAN TO READILY PLOT THE ALIGNMENT FEATURES OF THE ROAD. GRADES ARE CALCULATED AND THE ELEVATIONS OF RECORDED POINTS ARE LISTED IN FEET OR IN ANY OTHER UNIT DESIRED. IN ADDITION TO THE COORDINATE POINTS FOR ALIGNMENT PLOTS AND THE GRADE ELEVATIONS, THE IBM PHASE INCLUDE THE DETERMINATION OF OTHER DETAIL SUCH AS RADII OF CURVES, CENTRAL ANGLE OF CURVES AND SAFE DRIVING SPEEDS. ACCURACIES WITHIN 1 PERCENT CAN BE GENERALLY ACHIEVED IN THE MATTER OF CLOSURES OF TRAVERSES CALCULATED BY THIS METHOD AND ERRORS IN GRADE DETERMINATION CAN BE KEPT BELOW 1/2 PERCENT OF GRADE. THE METHOD MAKES A PROVISION FOR CORRECTING GRADE AND ALIGNMENT CLOSURES BY USING A CORRECTION FACTOR APPLIED TO THE LEGS OF THE TRAVERSES RUN. /AUTHOR/

  • Supplemental Notes:
    • Vol 32, pp 437-451, 8 FIG, 2 TAB
  • Authors:
    • Mcwilliam, J T
  • Publication Date: 1953

Media Info

  • Monograph Title: Proceedings of the Thirty-Second Annual Meeting of the Highway Research Board, Washington, D.C., January 13-16, 1953
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00202930
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Aug 23 1971 12:00AM