CONCRETE LINING FOE IRRIGATION CANALS. 73 
All concrete was mixed by hand and transported in wheelbarrows. 
The work was performed with gangs of about 30 men, paid for a 
9-hour day, as follows : 
Wages of labor lining canal of Tucson Farms Co. 
1 foreman r . . $4. 00 
Mixing boss and 2 plasterers 2. 50 
2 water boys 1. 00 
25 men 2. 00 
The gang was used in the following manner: Eight men on mixing 
board, 2 tampers, 2 men pulling plates and spreaders, 2 men setting 
forms and putting in expansion joints, 2 men laying steel reinforce- 
ment, 14 men transporting and depositing materials and concrete, 
finishing, screening sand, etc. The forms were usually all moved at 
one time and the whole force engaged on that work. 
It required this gang 21 days to place lining in 3,000 feet of canal 
in dry excavation having a bottom width of 3 feet. The cost to the 
contractor was distributed as follows : 
Contractor's cost of lining canal of Tucson Farms Co. 
Labor, including the building of forms $1, 297. 83 
1,712 sacks of cement, at $0.81 each 1, 386. 72 
232 cubic yards of rock, at $1.75 per cubic yard 406. 00 
232 cubic yards of sand, at $0.75 per cubic yard 174. 00 
Lumber in 15 sections of 12-foot forms, 3,900 feet b. m., at $30 per M 117. 00 
Lumber for expansion joints, 750 feet b. m., at $30 per M 22. 50 
Lumber for spreaders, runways, etc., 750 feet b. m., at $30 per M 22. 50 
Water purchased from the city of Tucson, 21 days at $2 42. 00 
Hauling steel reinforcement 10. 00 
Depreciation of plant, breakage of tools, etc 20. 00 
Office expenses and expenses of contractor and superintendent, amounting 
to about $2 per day for this gang, 21 days 42. 00 
Total 3, 540. 55 
Computations made on the above basis for 298.9 cubic yards, the 
cost was $11,845 per cubic yard. However, there were in addition 
the following costs to the Tucson Farms Co. : 
Additional cost of lining canal of Tucson Farms Co. 
9,300 pounds of steel, at $0.04 $372. 00 
One coat of cement wash, 34,500 square feet, at $0.0025 86. 25 
Engineering, about 5 per cent ' 195. 00 
Total 653. 50 
On this basis the actual cost of the completed lining was SI 4. 03 per 
cubic yard. 
