EXCAVATING MACHINERY USED IN LAND DRAINAGE. 31 



soil. Attempts to do this have, up to this time, met with doubtful 

 success. 



COST OF OPERATION. 



Two machines of the wheel type designed to cut a ditch 4 feet deep, 



4 feet wide at the top, and 2 feet wide at the bottom, were used on 

 the excavation of some ditches in one of the Gulf States. Each 

 machine was driven by a 28-horsepower gasoline engine. The dig- 

 ging wheel was 15 feet in diameter and the 2 apron tractors each 



5 feet by 12 feet. The weight of each excavator was about 30 tons. 

 The first cost of the machine was $5,500 and freight to the point of 

 use was $338.36, making the total cost of each machine $5,838.36. 

 The soil was a hard, yellow, sandy clay overlain by a turfy muck, 

 varying in depth up to 2\ feet. The turf was easily cut, but the 

 hard clay caused excessive wearing on the bearings. A large part 

 of the work was done when water was from 2 to 3 feet deep on the 

 land. The total length of the ditches dug was 165 miles, the aver- 

 age length of ditch being 2,475 feet. The average depth of digging 

 was about 4 feet, with a 4-foot top and 2-foot bottom. The average 

 distance dug per shift of 10 hours of actual running time was 2,250 

 feet; the maximum distance dug in 10 hours was 6,600 feet. The 

 average yardages per month for the two machines were 13,245 and 

 13,180 cubic yards, respectively. The average daily outputs on the 

 basis of the actual running time were 1,000 and 1,126 cubic yards, 

 respectively. A part of the time the first machine ran a double shift, 

 which accounts for the higher monthly and less daily average. It 

 required 13 months to complete the work, the actual time of opera- 

 tion being about half this. On account of the excessive wearing on 

 the bearings, caused by the heavy sandy clay, it was necessary to 

 make frequent stops for rebuilding the machines, which operation 

 occupied an average of nearly two weeks. The total excavation was 

 317,162 cubic yards. 



The daily operating expense per 10-hour shift for each machine was 

 about as follows : 



Per day. 



One operator, at $100 per month $4. 00 



One assistant 2. 00 



50 gallons gasoline, at 16 cents 8. 00 



Repairs 6. 00 



Other charges 12. 00 



32.00 



The itemized cost for operation for the entire work was as follows : 



Labor $5, 172. 11 



Interest, discount, and exchange 202. 05 



Maintenance and repairs 2, 860. 08 



General expense 273. 10 



Management expense 1, 600. 00 



Provisions and cooking (cook's wages) ,,,.,..,,, , 2, 245. 91 



