Represent free haul and overhaul from grade points along the mass haul line.
Grade Point Method: The arrows indicate free haul distance, The number (1) indicates grade points. Freehaul volume is indicated in green (and by the grid between the green areas and the balance line) and overhaul volume is indicated in red.
From grade point s, a segment the length of the free haul distance, which is parallel to the balance line , is dropped so that the ends of the segment just touch the mass haul line . The area enclosed within the segment and the mass haul line represents the free haul volume. Further, perpendicular lines from the ends of the segment are dropped so that they touch the balance line. The areas enclosed within these lines, the balance line, and the mass haul line represent the overhaul volume.