186 BULLETIN 711, V. S. DEPARTMENT OF AGRICULTURE. 



standpoint of down timber, brush, and dead snags was unusually 

 difficult. There were no heavy fills. 



GRADING THE EIGHT OF WAY. 



Fills and cuts are introduced to equalize the irregularities of the 

 soil, the process being kno^^ n as grading. 



Fills on standard gauge logging roads should be from 12 to 14 

 feet wide on top. The standard slopes for an earthwork fill are 1^ 

 horizontal to 1 vertical. When the fill is made of the material from a 

 i-ock cut, it is possible to make a stable embankment with a slope 

 ratio of 1:1. On sidehill work, where a slope of 1^ : 1 or 1 : 1 might 

 be a very long slope, it is often advisable to make a wall of rock or 

 timber tliat will have a slope ratio of f : 1 or steeper. 



In cuts the roadbed sliould be wide enough to give room for a 

 drainage ditch on either side. This will require from 2 to 3 addi- 

 tional feet on each side, and the cut should be about 16 feet at the 

 base. With cuts in the hardest rock the slopes will be J : 1, or nearly 

 perpendicular. As the soil becomes less firm the slope may be flat- 

 tened until, for a soil of firm earth or gravel, a slope of 1 : 1 may be 

 permissible, although a slope of 1^ : 1 is commonly adopted. The 

 aim is to move as little dirt as possible. 



Main-line logging roads are graded up carefully, and suitable 

 ditches are maintained. Even on level sections it is desirable to 

 elevate the track and put in ditches because of the lower cost of 

 maintenance during wet weather. On spurs a minimum of fill and 

 cutwork is done, and ditching is not resorted to unless absolutely 

 necessary. 



For the purpose of constructing a road as well as for calculating 

 the earthwork, a grade profile or profiles may be prepared. This 

 enables the engineer to fit the line to the ground in such a manner 

 as to secure the best adjustment of the alignment and grade consist- 

 ent with an economical cost of construction. It is not practical or 

 necessary, however, for a timber appraiser to secure such intensive 

 data, and his estimate of the cost of grading in a given case is not 

 more than substantially correct. The appraiser's estimate, however, 

 should be high enough to cover all cost, a liberal allowance being 

 made to cover unforeseen contingencies that may develop during con- 

 struction. Handbooks prepared for the use of civil engineers deal 

 with the methods of calculating the cubical contents of earthwork. 



The cost of the movement of earth depends to a great extent on 

 the character of the material. The following extract from " Log- 

 ging," by Bryant, shows the effect of the character of the material 

 moved on the cost of grading : 



The movement of earth and rock in the construction of cuts and fills is most 

 frequently done by contract. The unit on which payment is based is the cubic 



