726 ECONOMICAL ASPECTS 



cubic yards of concrete. The detailed cost of excavation and con- 

 crete for the intake was as follows : 



Excavation: Per Cubic Yard. 



Lumber $0.974 



Explosives . 065 



Miscellaneous supplies . 123 



Transportation . 071 



Liability insurance . 049 



Removing debris . 235 



Total $1.517 



Concrete: 



Labor $3.902 



Cement 1 .982 



Lumber 0.794 



Freight: 0.042 



Transportation . 203 



Liability insurance . 136 



Erection of plant 0.400 



Crusher 1 .280 



Miscellaneous supplies . 205 



Removing debris . 086 



Total : $9.030 



Tunnel. The tunnel is 6666 feet long, and has a net area of 

 151 square feet inside the concrete lining. About 75 per cent of 

 the tunnel was driven by the top-heading method and for the 

 remainder the lower heading or stopping method, which proved 

 to be much cheaper. The total excavations amounted to 56,000 

 cubic yards. 



The unit cost of excavating 39,831 yards of this tunnel was as 

 follows: 



Per Cubic Yard. 



Labor $3.833 



Explosives . 604 



Lubricants 0.019 



Piping . 026 



Drill repairs . 172 



Miscellaneous supplies . 237 



Freight 0.087 



Transportation . 247 



Liability insurance . 181 



Miscellaneous charges . 066 



Depreciation on equipment . 150 



Power... 0.306 



Total. . . $5.928 



