MARTA Surveying Projects Atlanta, Georgia Client Challenge: MARTA became aware that many of the original cross-ties used to build their rail system had fallen into a state of disrepair.  Over the years they had absorbed moisture that caused many of them to rot in place.  This was recognized as an extreme safety hazard.  The problem they faced was how to replace these old cross-ties without stopping the rail service.   PRIME Solution: Prime’s surveyors performed pre and post construction as-builts of each of these lines to ensure that the rail lines, after cross-tie replacement, had not moved more than the pre-determined allowable limits.  All of the survey work was accomplished during daylight hours along active rail lines.  This required our surveyors to work within a few feet of passing trains and alongside the third or “hot” rail.  MARTA flagmen advised the survey crew when a train was approaching.  By working while the trains were in full operation, MARTA was able to prevent interruptions of service and keep their trains on schedule while completing this important task. Cross Tie Replacements - 31 Locations Prime Engineering's surveyors provided services for pre-construction and post-construction as-builts of 300 linear feet of railroad track.  Surveyed entrance and exit of 31 separate fixed track locations to compare horizontal and vertical alignment of rail line.  Survey helped determine if the work was completed within allowable tolerances.  Services also provided support for replacement of existing cross-ties with azobe wood ties at fixed track locations of MARTA line. Track Re-alignment As part of an open-ended contract, Prime Engineering's surveyors provided services for pre-construction and post-construction as-builts on 46,246 linear feet of MARTA rail line.  Surveyed MARTA North, South, East and West Lines.  Helped determine if the work was completed within allowable tolerances.  Roll over thumbnail to view picture