Mance: Quarry Industry of Southern Indiana 



109 



POWER AND OPERATING COSTS 



Fixed charges- 

 Interest at 5 per cent 



Depreciation at 8 per cent 



Taxes and insurance, 2 per cent 



$3,205.00 

 5,128.00 

 1,282.00 



Total 



$9,615.00 



Operating cost — 



Coal, 5,000 tons at $1.55 per ton 



Labor 



Repairs 



Oil, waste, etc 



$7,750.00 

 3,640.00 

 1,100.00 

 1,350.00 



Total 



$13,840.00 



Tota.l power cost 



$23,455.00 



Figuring on a 75 per cent load 10 hours per day for 300 days in 

 the year, the cost of power per horse-power per hour would be 

 about 1 cent, and if the run were but 200 days per year with the 

 smaller operating cost of a shorter run it would make the cost 

 about 1.3 cents per horse-power per hour, since the fixed charges 

 would remain the same. 



With steam turbines and mechanical draft, and with coal and 

 ash handling machinery, the total investment would be about 

 $63,500, but the total cost of power would be cut to about $21 

 per horse-power per year, or, if figured on the same basis as above, 

 the cost would be about .93 cents for the longer run and about 

 1.3 cents for the short year. 



It is of interest to compare the approximate figures on the 

 cost of power with a producer-gas plant with the above figures 

 for a steam plant. With the grade of bituminous coal available 

 in the stone belt the cost would be approximately as follows : 



Investment cost — 



Bituminous gas producers, figured at $23 per 



horse-power $23 , 000 . 00 



Two 500 horse-power gas engines 38 , 000 . 00 



Accessories, including draft equipment at $9 per 



horse -power 9,000.00 



Two 400-kilowatt generators 10,000.00 



Exciters for the same 800 . 00 



Switchboard equipment and wiring 3 , 300 . 00 



Foundations 3,000.00 



Incidentals 5,000.00 



Total 



$92,100.00 



