Mance: Quarry Industry of Southern Indiana 187 



The cost of drilling a Sf-incli hole ^ath a well drill varies from 20 cents 

 to 50 cents per foot, the general average being somewhere around 30 cents. 

 A good operator and helper in ordinary limestone can make from 15 to 40 

 feet per day of 10 hours. 



A 25-foot headway is a very good average. Room for comparison — 180 

 feet of drilling Tvdth each type of drill. Relative cost 15 cents per foot for 

 steam drilling, and 30 cents per foot for well drilling. Steam drill drilling 

 180 feet at 15 cents is $27. At a 7x7 spacing nine 2G-foot holes will break 

 about 325 cubic j^ards. About 140 pounds of 40 per cent dynamite would 

 be required, which would amount to $17.50. This plus the cost of drilling 

 makes $44.50. Breakage of 325 cubic yards would mean a cost of about 

 13.6 cents. Working this by well drill system, take three 60-foot holes, 

 drilling 180 feet at 30 cents equals $54. At 20x20 spacing thirty 60-foot 

 holes will break approximately 2,600 cubic yards. About 1,300 pounds of 

 40 per cent explosive would be needed, which would cost $168.75, making 

 total of $222.75 to get out 2,600 cubic yards or about .085 cents per cubic 

 yard. 



We trust that this information will be of some interest and benefit to 

 you, and that we have not delayed so long that you cannot use it in your 

 paper, which we understand you are preparing for report of the State Geologist. 



Yours very truly, 



Manager Technical Division. 



Practically all the data furnished by other companies, altho 

 not given in detail, agreed with the above figures as to cost when 

 the conditions under which the blasting was done were the same. 



Much work has been done by the United States Bureau of 

 Mines on the production of explosives especially fitted to different 

 grades of work, and as a result much information is at hand as to 

 the explosives best fitted to the work in hand and the uses to 

 which it can be put. These bulletins are for free distribution by 

 the Director of the Bureau of Mines, Washington, D.C., and can 

 be had by asking for them. 



It will be seen that the approximate cost of blasting out ma- 

 terial in large amounts in localities such as this district would 

 approximate 8 cents per cubic yard. The cost of transporting this 

 material to the crushers in a form in which they can use it (that 

 is, including the cost of extra blasting and sledging where neces- 

 sary) would be about the same, while labor and capital charges 

 on the machinery would be about 26 cents per cubic yard, giving 

 a total of about 44 cents per cubic yard for the limestone, which 

 is about 19 cents per ton. Calculating along the same lines, 

 the cost of shale winning is about 11 cents per ton under favorable 

 conditions. This makes the raw material cost on an average 

 173^ cents per ton or about b\ cents per barrel of output. These 

 figures are made on the basis of four parts of limestone to one 



