Estimating Dozer Operating Costs2005 Dr. B. C. Paul

Application NotesSeverity of DutyMedium dutyPush loading scrapersLand clearingPushing up soils and clays (such as trapping soil)Heavy dutyRock rippingWorking on rock surfacesDozing RockPush loading scrapers through rock

Cost Component FuelD11 in heavy conditions uses 30-37 gallons (see Cat Handbook 35th ed page 20-13)Idle timeTime in reverseDown hill all reduce fuel consumptionOur conditions probably lower end 30 gallons per hourCost for diesel (red dog)$1.85/gal30gph*$1.85 = $55.5/hour

Cost Component TiresSucker!This is a track dozer

UndercarriageOn dozers tracks and underside are so condition dependent that they need to be calculated separatelyStep #1Look up a basic cost per hour in Cat Tables35 ed page 20-28For my D11 basic factor is $18/hourStep #2 pick adjustment factors for impact, abrasiveness, and Z

Impact FactorHigh corresponds toImpenetrable surface with 6 inch or greater bumps (such as working on shot rock)Moderate corresponds toPartially penetrable surface with 3 inch bumpsPossibly trapping rocking transitionLow corresponds toCompletely penetrable surface few bumpsPossibly trapping top soilMy Dozer is working on rock pile HighHigh is 0.3 (mod is 0.2 and low is 0.1) see Cat Handbook ed 35 pg. 20-28

Abrasiveness FactorHighSaturated conditions with sand or sharp rock particles (like working on shot rock)ModerateIntermittently damp with few angular rock particles (soil work might be like this)LowInvolves dry conditions with few rock particlesThe dampness issue causes things to stick and work into the joints of the treadsNumber 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 factorAbout 50% of Z factor is maintenanceRange about 0 for absolute top maint0.5 for maintain if it breaksIll go 0.25 for moderateAbout 30% of Z factor is conditionsAbrasiveness and impact with a little gut feel for how roughI think this is rough 0.3About 20% on operator temperamentRace track backing, tight turns, running to side angle are badIll go middle of the road 0.1Total up for my Z factor0.65

Step 3 in Undercarriage CostAdd up your 3 factorsImpact 0.3Abrasive 0.4Z 0.65Total 1.35

Step #4 for Undercarriage CostMultiply the Basic Cost by the total of the 3 factors$18/hr * 1.35 = $24.3Breakdown on dollars (may be important for indexing)70% parts, 30% laborLabor was $60/shop hourHigh compared to about a $25/hr wage with 60% burdenIf I consider it includes my parts warehousing, secretarial and supervision its probably reasonableI better make sure I dont count the personnel twiceParts Steel has gone up severelyIm going to allow about 20% here24.3 * 0.7 = $17.01$17.01 *1.2 = 20.41Add back the labor unaltered $20.41+ $7.29 $27.70/hr for Undercarriage Cost

Repair Reserve for MachineCat Handbook ed 29 pg. 21-36D11 is $19/hour for first 10,000 hoursBut D11 has 30,000 hour life under my severe dutyMultiplier for extended life is 1.3$24.70/hr

Lubricants CostD11 uses about 0.25 gallons/hrAt $9.00/gallon lube $2.25/hr13.5 lubricant changes/2000 hrs2 labor hour per change at $60/hr27*60/2000 = $0.81/hr816 grease fittings/2000 hrsAbout 75 cents/fitting with labor816*.75/2000 = $0.31/hrHourly Filter Cost $0.62/hr53 Filters/2000 hrs5 minutes per filter4.42 hours/2000 hoursAt $60/hr $0.13/hrTotal it up $4.12/hr

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

Total Operating Cost/hrFuel $55.50Undercarriage $27.7/hrRepair Reserve $24.7/hrLubricant $4.12Wear parts $1.25 (guessed from other examples)Labor $40/hrTotal $153.27/hr