24 BULLETIN" 300, TJ. S. DEPARTMENT OF AGRICULTURE. 



A rotary drag-line excavator with a 2|-yard bucket and 65-foot 

 boom, mounted on skids and rollers, was used in the excavation of 

 222,500 cubic yards in South Dakota. The power was obtained from 

 a 50-horsepower internal-combustion engine, using gasoline. The 

 cost of the machine, complete, was $10,500. The total time of con- 

 struction was 148 working days, or approximately 6 months, of which 

 23 days were occupied in making repairs. Two shifts of 1 1 hours each 

 were run. The soil was a loam underlain by clay. The crew and 

 rates per month were as follows: One superintendent, $125; 2 crane- 

 men, at $100; 4 trackmen, at $50; 1 teamster, $45; 1 cook, $40. 

 The operating expenses were as follows : 



Gasoline, 15,444 gallons, at $0.124 $1, 915. 05 



Labor 3, 060. 00 



Subsistence 561. 81 



Cables 978. 87 



Repairs and renewals 845. 93 



Miscellaneous 2, 078. 72 



Interest and depreciation 2, 152. 50 



11, 592. 88 

 Cost per cubic yard, $0.0521. 



The following costs were secured on the operation of a rotary drag- 

 line excavator with an 85-foot boom, 2-yard bucket, and a 50-horse- 

 power engine. The work was done on the New York State Barge 

 Canal. The machine weighed 147 tons and cost $10,000. It exca- 

 vated earth 90 feet from center on one side and deposited it 100 feet 

 from center on the other. It dug a channel 25 feet deep and deposited 

 the material on waste bank 15 to 25 feet high. The material was a 

 stiff clay, with few stumps or bowlders. The following is a condensed 

 cost record for 5 months' work: 



Month. 



Total ex- 

 pense for 

 month. 



Yards ex- 

 cavated 

 during 

 month. 



Average 



cost per 



yard. 



April . . . 



May 



June 



July 



August. 



$1,088.21 

 1,041.53 

 1,152.04 

 1,317.61 

 1,535.36 



5,205 

 18,365 

 25,333 

 33,055 

 47,363 



SO. 209 

 .0568 

 .0455 

 .0399 

 .0324 



Average cost per yard for 5 months, including all charges, 



In May, items of cost were as follows: 



Engineer, at $90 per month 



Engineer, at $95 per month 



Fireman, pumpmen, watchmen, etc., at $1.75 per day 



Coal, at $3 per ton 



Repairs, including labor and material 



Interest and depreciation 



).0474. 



$90.00 

 84.04 



363. 00 



147. 00 

 15.82 



341. 67 



Total 1, 041. 53 



