EXCAVATING MACHINERY USED IN LAND DRAINAGE. 23 
COST OF OPERATION. 
A drag-line excavator of the rotary type, having a 2-yard scraper 
bucket and a 60-foot boom, was used in the construction of some 
drainage ditches in southern Texas. It was built mostly of wood and 
moved on rollers. Power was derived from an 80-horsepower internal- 
combustion engine, burning oil. The cost of the excavator, ready to 
operate, was $12,000. It was operated about 10 months in two daily 
shifts of 10 hours each, a shift consisting of 10 men. The actual 
working time was not recorded. The ditch ranged from 4 to 22 feet 
in bottom width, from 3 to 12 feet in depth, and had 1 to 1 side 
slopes. The soil varied from a stiff, heavy clay to a fine sand. The 
excavation amounted to 230,000 cubic yards; the cost was as follows: 
Operating expenses $22, 313. 36 
Miscellaneous expenses 374. 70 
Interest and depreciation 4, 100. 00 
Cost per cubic yard, $0.1164. 26 ' m ° 6 
On another drainage project in southern Texas, a 2-yard rotary 
excavator was used. The machine was of steel throughout, had a 
60-foot boom, and was mounted on caterpillar traction. The crew 
consisted of a foreman, operator, engineman, oiler, and two laborers. 
The machine was operated by a 110-horsepower internal-combustion 
engine, with oil as fuel. The total cost of the machine was about 
$17,500. The cost of erection was $509. During the four months of 
operation two 10-hour shifts were run. The ditches ranged from 4 to 
22 feet in bottom width and from 3 to 12 feet in depth, with 1 to 1 
side slopes and 8-foot berms. The material excavated was a stiff, 
heavy clay. The excavation amounted to 91,400 cubic yards; the 
cost was as follows: 
Operating expenses $8, 873. 82 
Miscellaneous. 371. 00 
Interest and depreciation 2, 391. 00 
Cost per cubic yard, $0.1273. U ' 635 ' 82 
In the same general locality as the last example a l§-yard rotary 
drag-line excavator, operated by a 50-horsepower internal-combustion 
engine and mounted on caterpillar traction, was used in the con- 
struction of some ditches in soil ranging from stiff, heavy clay to fine 
sand. The ditches were of the same dimensions as in the foregoing 
example. The machine was rebuilt from an old dipper dredge at a 
cost of about $1,200. It was operated in two daily shifts of 10 hours 
each. The crew for each shift consisted of from 5 to 6 men. During 
the five months of operation the machine moved 59,014 cubic yards 
at an expense, exclusive of interest and depreciation, of $8,921, or 
$0.1512 per cubic yard. 
