Estimating Dozer Operating Costs ©2005 Dr. B. C. Paul

Application Notes Severity of Duty –Medium duty Push loading scrapers Land clearing Pushing up soils and clays (such as trapping soil) –Heavy duty Rock ripping Working on rock surfaces Dozing Rock Push loading scrapers through rock

Cost Component Fuel D11 in heavy conditions uses gallons (see Cat Handbook 35 th ed page 20-13) –Idle time –Time in reverse –Down hill all reduce fuel consumption –Our conditions probably lower end 30 gallons per hour Cost for diesel (red dog) –$1.85/gal –30gph*$1.85 = $55.5/hour

Cost Component Tires Sucker! –This is a track dozer

Undercarriage On dozers tracks and underside are so condition dependent that they need to be calculated separately Step #1 –Look up a basic cost per hour in Cat Tables 35 ed page For my D11 basic factor is $18/hour Step #2 pick adjustment factors for impact, abrasiveness, and Z

Impact Factor High corresponds to –Impenetrable surface with 6 inch or greater bumps (such as working on shot rock) Moderate corresponds to –Partially penetrable surface with 3 inch bumps Possibly trapping rocking transition Low corresponds to –Completely penetrable surface few bumps Possibly trapping top soil My Dozer is working on rock pile High –High is 0.3 (mod is 0.2 and low is 0.1) see Cat Handbook ed 35 pg

Abrasiveness Factor High –Saturated conditions with sand or sharp rock particles (like working on shot rock) Moderate –Intermittently damp with few angular rock particles (soil work might be like this) Low –Involves dry conditions with few rock particles The dampness issue causes things to stick and work into the joints of the treads Number is H=0.4, M=0.2, L=0.1 (Cat Handbook ed 35 pg 20-28) –My dozer is working on shot rock 0.4

The Z factor About 50% of Z factor is maintenance –Range about 0 for absolute top maint –0.5 for maintain if it breaks –I’ll go 0.25 for moderate About 30% of Z factor is conditions –Abrasiveness and impact with a little gut feel for how rough –I think this is rough 0.3 About 20% on operator temperament –Race track backing, tight turns, running to side angle are bad –I’ll go middle of the road 0.1 Total up for my Z factor –0.65

Step 3 in Undercarriage Cost Add up your 3 factors –Impact 0.3 –Abrasive 0.4 –Z 0.65 –Total 1.35

Step #4 for Undercarriage Cost Multiply the Basic Cost by the total of the 3 factors $18/hr * 1.35 = $24.3 Breakdown on dollars (may be important for indexing) –70% parts, 30% labor Labor was $60/shop hour –High compared to about a $25/hr wage with 60% burden –If I consider it includes my parts warehousing, secretarial and supervision its probably reasonable I better make sure I don’t count the personnel twice Parts – Steel has gone up severely –I’m going to allow about 20% here –24.3 * 0.7 = $17.01 –$17.01 *1.2 = –Add back the labor unaltered $ $7.29 $27.70/hr for Undercarriage Cost

Repair Reserve for Machine Cat Handbook ed 29 pg –D11 is $19/hour for first 10,000 hours –But D11 has 30,000 hour life under my severe duty –Multiplier for extended life is 1.3 –$24.70/hr

Lubricants Cost D11 uses about 0.25 gallons/hr –At $9.00/gallon lube $2.25/hr 13.5 lubricant changes/2000 hrs –2 labor hour per change at $60/hr –27*60/2000 = $0.81/hr 816 grease fittings/2000 hrs –About 75 cents/fitting with labor –816*.75/2000 = $0.31/hr Hourly Filter Cost $0.62/hr 53 Filters/2000 hrs –5 minutes per filter –4.42 hours/2000 hours –At $60/hr $0.13/hr Total it up $4.12/hr

Operator Cost $25/hr with 60% burden $40/hr Assuming that machine only runs when operator is not on break (no hot seat change out for 10 minute breaks)

Total Operating Cost/hr Fuel $55.50 Undercarriage $27.7/hr Repair Reserve $24.7/hr Lubricant $4.12 Wear parts $1.25 (guessed from other examples) Labor $40/hr Total $153.27/hr