22 BULLETIN 463, U. S. DEPARTMENT OF AGRICULTURE. 



of the method of operation, therefore, it will be assumed that a 

 4-wheeled machine is to be used. 



To operate a grading machine successfully where the work is 

 moderately heavy requires at least six horses, while for light 

 maintenance work after the road is graded four horses usually are 

 sufficient. For satisfactory work the team must be accustomed to 

 working together and must be under complete control of the driver. 

 To break in a green team ordinarily requires two or three days of 

 relatively very light work under favorable conditions and with a 

 capable driver. Poorly trained teams and improper driving have 

 been responsible for more unsatisfactory and uneconomical grading- 

 machine work than any other one cause. 



l'-6"f- Not less than 20'-0" 



T 



CROSS SECTION SHOWING THE RESULT OF ONE TRIP WITH A GRADING MACHINE 

 The broken line shows the completed cross section 



CROSS SECTION OF A PARTIALLY COMPLETED ROAD BUILT BY MEANS OF A GRADING MACHINE 

 The broken line shows the completed cross section 



CROSS SECTION OF ROAD COMPLETED WITH A GRADING MACHINE 



"K'usually varies from 12 to 18 inches and depends on width of road and amount 

 of water to be carried. 



"H',' crown, varies from j inch to the foot for level grade, to I inch to the foot for grade 

 of 5% 



Fig. 12. 



Before any machine work is done the area to be graded should be 

 either burned or mowed over so as to remove all grass and weeds. 

 The grading then should proceed as follows : 



(1) Set a row of stakes, 100 or 200 feet apart, along the inside edge 

 of each side ditch. The purpose of these stakes is simply to aid the 

 driver in making the initial furrow of the machine conform with the 

 line of the road, and since the stakes are destroyed by the first 

 furrow they need be only sufficient to serve this temporary purpose. 

 Figure 12 shows the successive steps involved in grading up a road 

 with a grading machine after the ditch lines have been established 

 as indicated. 



(2) Set the blade of the grading machine at an angle of about 

 30 degrees with the road, so that the material loosened by the 

 cutting point of the blade will be moved in toward the center of 

 the road; also lower the cutting point and raise the heel, so that the 

 blade will plow an initial furrow about 6 inches deep and about 18 



