Table 2 

 OPERATING COSTS 



Norton Sound 



Sheltered Coast 



Number of Operating days 

 Annual Yardage 

 Direct Costs: 



Supervision 6 @ $20,000 



Labor 31 @ $50/dav 



Supplies @ 100 per cent labor 



Power @ 2 cents/yd 



Indirect costs: 



Support vessel $300/day 

 Shore station $100/day 

 Depreciation on dredge (20 yrs) 

 Depreciation on vessel (10 yrs) 

 Ins. & Taxes, Equipment 6.5 per cent 



Total Operating Cost 

 Operating costs/yd^ 

 Direct costs/yds^ 



185 

 8,100,000 



120,000 

 308,000 

 308,000 

 162,000 



898,000 



59,700 

 19,900 



640,000 

 25,000 



210,000 



954,600 



1,852,600 

 22.9 cents 

 11.1 cents 



362 

 15,675,000 



120,000 

 566,000 

 566,000 

 314,000 



1 ,566,000 



108,500 

 36,200 



640,000 

 25,000 



210,000 



1,019,700 



2,585,700 

 16.5 cents 

 10.0 cents 



expected. On this basis, reserves will equal 30 million tons and extend over an area of nearly 1,100 

 square miles. 



The seafloor in the deposit area is assumed to be flat and of sufficient strength to support a properly 

 designed mining vehicle. 



AU of the foregoing assumptions on the deposit characteristics have a bearing on the choice of the 

 mining system. Other significant factors are: 



-Rate of production. The production rate stipulated is 5,000 tons per day. The following rates are used 

 for all computations: 



208 tons/hour 

 5 ,000 tons/day (24 hours) 

 150,000 tons/month (30 days) 

 1,500,000 tons/year (300 days) 



The figure for working days is low to allow for regular maintenance and severe storm conditions. 



-Mining method. The total area required to be covered each day is 5 million square feet or nearly 1 15 

 acres. A miner having a pick-up width of 30 feet would be required to traverse 31.5 miles per day at a 

 speed of 1.3 miles per hour or 1 15 ft per minute. It is assumed for the purpose of this study that there 

 will be available a scraper type vehicle which would be remotely controlled by an operator in a 

 submerged central control habitat to which the mining vehicle is linked by a short power hne. The 

 mining pattern would be rectangular, the scraper vehicle traversing back and forth in a direction normal 

 to the direction of movement of the control habitat. On each return traverse, the scraper would dump its 

 load into a hopper in the habitat structure, from where it would be pumped to the surface. 



VIM 81 



