TRANSPORTATION ON LAND BY VEH1CLES:-THE ROADS 



47 



The first column gives the percentage and the second the grade in degrees of the natural slope. 

 The subsequent ten columns give the cross sections in square yards for cuts or fills from five feet to 

 fifty feet deep, the depth being measured at the center of the road. 



(c) The volumes of cuts and fills. The actual amount of dirt to be moved between two stations 

 is ascertained as distance between stations times arithmetical mean of sectional areas of stations. 



If it is found that the total volume of fills exceeds the total volume of cuts, two remedies are possible :- 



1. Lowering the road line parallel to itself; 



2. Shifting the road line into the slope of the hill. 



If one of two consecutive road points is to be cut while the other requires filling, then an auxiliary 

 point (grade point) must be established and its distance from the end points of the section ascertained with 

 the help of the mapped length profile. The 

 dirt volumes to be moved have a wedge shape 

 and their volume equals sectional area by '/■_' 

 of length of subsection. 



Stoetzer recommends to allow for the 

 "spreading" of the dirt, in equalizing the vol- 

 umes of cut and fill. Sand volumes increase 

 by 3°o, loam by 6Vu, clay by 15%, rock 

 by 20 7o. 



On the Pacific Coast, with wet soil, shift- 

 ing sand, and difficult grading, some firms 

 prefer to build the entire railroad on piles. It 

 is claimed that the only disadvantage of this 

 method is the increased danger from fire. Six 

 men construct 100 feet of pile road per day, 

 including clearing of right of way. (See Tim- 

 berman. Logging Congress 1910, page 18.) 



At Coos Bay, Oregon, the piledriver crew 

 constructs, under normal conditions, 10 com- 

 plete "bents" per day. The cost per mile (not counting the value of 300,000 feet of stumpage used) is 

 given as x 5,500. 



IV. Instruments and implements for grading. 



(a) Instruments. 



Shovels: -Short handled, round pointed billies at a'10 per dozen are preferred; 



Mattocks, #6 per dozen; 



Picks, #4'50 per dozen; 



Crowbars, 5 feet long, 12 to 20 pounds in weight, price 40 to 60 cents each; 



Drilling or striking sledges, 6 to 10 pounds in weight, price 32 to 53 cents each. 



A portable blacksmithing outfit is required to relay with steel all mattocks, picks, and driving 

 steel when worn. 



(b) Implements. 



1. Black blasting powder comes in kegs of 6'/4, 12'/,,, and 25 pounds each; it costs 20 to 25 cents 

 per pound. It is used notably in soft rock. It is composed of 75 per cent saltpetre, 12 per 

 cent sulphur, and 13 per cent carbon. Per cubic yard of rock to be removed, between Vi ^nd 

 '/o pound of powder is required. One quart of powder forms when exploding 880 quarts of 



gas. The charge of powder for a given blast should be pounds, wherein L represents, in 



feet, the line of least resistance, and wherein V varies, according to hardness of rock, between 

 25 and 32. The line of least resistance should not exceed one half of the depth of the hole. 



Piledriver of Smith-Powers Logging Co. at work on Coos Bay, Oregon. 



