Tabulating Cumulative Yardage.— The firststep in making a mass diagram is to prepare a table ofcumulative yardage, like the one shown in table 10-2.Under End Areas, you put the cross-sectional area ateach station—sometimes this is cut, sometimes fill,and sometimes (as at stations 9 + 00 and 15 + 00) partcut and part fill. Under Volumes, you put the volumesof cut or fill between stations, computed from theaverage end areas and the distance between sectionsin cubic yards. Note that, besides the sections at eachfull station, sections are taken at every plus where boththe cut and the fill are zero. Note also that cut volumesare designated as plus and fill volumes as minus.Under Algebraic Sums Volumes, Cumulative,you put the cumulative volume at each station andeach plus, computed, in each case, by determining thealgebraic sum of the volume at that station or plus andthe preceding cumulative total; for example, at station8 + 00 the cumulative total is –563. At station 9 + 00there is a volume of cut of +65 and a volume of fill of–305, making a net of –240. The cumulative total atstation 9 + 00, then, is (–563)+ (–240), or –803.Plotting Mass Diagram.— Figure 10-10showsthe values from the table of cumulative yardageplotted on a mass diagram. The vertical coordinatesare cumulative volumes, plus or minus, from a line ofzero yardage, each horizontal line representing anincrement of 200 cubic yards. The horizontalcoordinates are the stations, each vertical linerepresenting a full 100-foot station.As you can see, the mass diagram makes itpossible for you to determine by inspection theyardage of cut or fill lying between any pair ofstations. Between station 0 + 00 and station 3 + 50, forexample, there are about 800 cubic yards of cut.Between station 3 + 50 and station 7 + 00, there areabout 800 cubic yards of fill (descending curve).Between station 7 + 00 and station 10 + 50, there areabout 850 cubic yards of fill (curve still descending),and so on.Table 10-2.—Table of Cumulative Yardage10-12