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Feasibility Study Cost Estimates. ©2002 Dr. Bradley C Paul. Feasibility Study. Processes are actually worked out and planned checked for technical flaws checked for permit flaws Format Pre-feasibility may give you a lot of factored cost estimates
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Feasibility Study Cost Estimates ©2002 Dr. Bradley C Paul
Feasibility Study • Processes are actually worked out and planned • checked for technical flaws • checked for permit flaws • Format • Pre-feasibility may give you a lot of factored cost estimates • Start Shifting big ones to itemized cost estimates • Itemized estimates become more detailed
Feasibility Study Overviews • Major Cost Items are Identified • Quotes are secured on major cost items • Minor items tend to be listed with general comparison cost estimates attached. • Important error avoid - missing and double counting.
Pre-Feasibility/ Feasibility Contrast • Major Cost Items from Pre-Feasibility move either to Itemized Cost format or are expanded • Example - Our Mine Shaft could easily be a big cost • Advance rate likely to be 8 feet per day using 3 eight hour shifts in solid • Only get 2 feet day through first 200 feet of unconsolidated • Lets Detail the crew
Shafting Crew • Typical Sinking Crew would be 5 people • 4 laborers – 1 supervisor • doing rounds, support ect. (from SERPA) • wages $15.46/hr (1997 base from WMCS) • 4*24*$15.46 = $1,484/day • Time 100 days for first 200 ft • 69 days more for next 550 ft through solid rock • 169 days at $1,484/day = $250,823 • I’ll deal with supervisor later
Support People • Engineering/Technical Crew • 1 person (some would use 2) (3 for 3 shifts) SERPA • $16.15/hr 1997 cost WMCS • $388/day * 169 days = $65,504 • Mechanical Crew • 2 people (6 for 3 shifts) SERPA • $20.98/hr 1997 cost WMCS • $1007/day*169 days = $170,190
Surface Crews • Surface and Yard Workers 2 • Rate $11.89/hr • 2*$11.89*24*169 = $96,452 • Sinking Hoist Operator • $16.50/hr*24*169 = $66,924
Supervisory Crews • 1 supervisor/shift $23.94/hr • $23.94*24*169 = $97,101 • Total Labor Cost • $746,994 say $747,000 • Indexing Labor • $747,000* 17.89/16.15 = $827,500
The Burden of Burden • Workers get fringe benefits • health, vacation time etc. • government mandated programs • social security / medicare / unemployment / workers compensation • Often Expressed as a percentage of wage • Quarries around 30% • Metals commonly around 40% • Some coal may be 60% • WMCS estimates 36% for Shaft Sinking
Dropping the Burden on the Project • $827,500 * 1.36 = $1,125,000 • Explosives Cost • Rounds at 4 lbs/ton • Need to know concrete thickness • have about 15 inch thick (some squeeze for horizontal stress) • for 20 ft finished diameter - need 22.5 feet • with some over-excavation 23 feet • Rock density about 170 lb/ft^3 • 35.3 tons per foot of Advance
Having a Blast • 35.3 tons/ft * 4 lbs/ton = 141 lbs of explosive per foot of advance • 106,000 lbs @ $1.54/lb = $163,000 • At about 1 round shot/day • 110 caps/day * 169 days = 18,590 caps • @$1.81 each = $33,650 • Chord and Supplies about 50% of caps (no boosters here) • $16,824
Breaking Cost • $213,500 for explosives • Drilling Consumables at about 25% of explosives • $53,400 • Breaking Cost (less labor counted elsewhere) • $267,000 • Index to end 2002 • $267,000 * 149.7/149.1 = $268,000
Non-Labor Mucking Costs • At $2.50/ton (include disposal) • 35.3 tons/ft * $2.5 = $88.30/ft • for 750 ft $66,216 (current cost) • Concrete Cost • 23 ft outside diam - 20 ft inside • 3.75 cubic yard per foot of advance • Concrete at $80/cubic yard delivered to site • $225,000 for concrete
Other Supplies • Steel cost at about 1.5 times concrete • $337,500 • includes materials to advance utilities down shaft and put in guides for skips • Concrete and Steel • $562,500 • 10% for misc supplies • $56,250 total • Supplies Subtotal $618,750
Direct Cost of Shaft • Labor $1,125,400 + Breaking $268,000 + Mucking $66,200 + Supplies $618,750 • $2,078,350 • 10% contingency $2,286,200 • 15% contractor mark-up and mobilization • $2,629,000 • Note that we did consider some site specific problems with large amounts unconsolidated Overburden and ground stresses
Pre-Feasibility / Feasibility Contrast • At Order of Magnitude just scaled off of someone elses approximate cost • Pre-Feasibility was either a factored cost estimate or a simple itemized cost estimate (ie cost per foot of shaft) • At Feasibility stage it became a much more carefully itemized exercise • we were still flakey on cost of service lines pipes • As move to Budget Authorization likely bring in contractors to bid specifically on the job