82 OVERHAUL. 



is within the 500 ft. limit. Now find two points on these curves whicfe 

 are 600 ft. apart on a horizontal line, the points F and G. These mark 

 the limits of the 500-ft. haul, and the vertical distance between D and P 

 gives the quantity of earth hauled 600 ft. In the same way the quantity 

 hauled 700, 800, 900 ft, etc., can be determined, and the stations which 

 mark the limits of these different lengths of haul are found. 



Having thus disposed of that part of the cutting from Sta. 499 + 30 to 

 Sta. 504, we turn to the curve plotted backward from the grade point at 

 Sta. 498, and find that by hauling backward from 498 + 50 to 496 + 20 (the 

 center of gravity) we can make just half the fill at Sta. 496; the total 

 quantity hauled being 438 cu. yds., and the maximum distance 230 ft. 

 The balance of the cut from 498 + 50 to 499 + 30, amounting to 780 cu. 

 yds., must be wasted. 



It will be readily seen from a study of this method that an engineer 

 can tell in advance where to direct the contractors to borrow and where 

 to waste, and can determine the most advantageous method of hauling 

 out his cuts as soon as he gets his work cross-sectioned and his quanti- 

 ties calculated. 



Of course, if rock is struck in unexpected places, and the quantities 

 are thereby changed, it will be necessary to change the curves, and for 

 this reason it is better not to ink in the quantity profile until the work 

 is finished. 



I am indebted to R. P. Bruer, C.E., of the C. P. R. R., for this method 

 of calculating overhaul. T. S. RUSSELL. 



Grant, Va. 



It should be observed that earth ordinarily shrinks on being 

 packed into a fill under the blows of horses' hoofs, etc., so that 

 each 100 cu. yds. of cut make about 90 cu. yds. of fill. This 

 factor is not mentioned by Mr. Russell, but should be consid- 

 ered by the engineer, if it is desired to get a very close esti- 

 mate of overhaul. 



The next method of estimating overhaul is essentially like 

 the preceding one, although not as easily understood at first 

 reading. It appeared in Engineering News, Jan. 31, 1891, as an 

 article entitled "Estimating Overhaul in Earthwork by Means 

 of the Profile of Quantities " by S. B. Fisher, chief engineer of 

 the Minneapolis, St Paul & Sault Ste. Marie Ry. 



The article follows in full: 



No facile, practical and accurate method of calculating the 

 overhaul of earthwork is as yet in common use. The problem 

 itself, consisting of finding the relations between the centers of 

 gravity of known volumes in known positions may be, from 

 the mathematician's point of view, a comparatively simple 



