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Analyses of Diesel Use for Mine Haul and Transport OperationsEngine Control Unit modellingHaul trucks are equipped with an Engine ControlUnit (ECU) that uses an engine map to control therelationship between power, torque and enginespeed. On the Caterpillar 777F haul trucks used byFortescue, an ‘economy mode’ is available whichreduces the power of the vehicle by approximately4.5% for gears 2 and above. A reduction in powerreduces the fuel consumption of the engine, butmay also result in a reduction in productivity.The Caterpillar 777F trucks owned by Fortescuewere delivered with the economy mode availableas an option within the ECU. A technician wasable to set the ECU for economy mode usinga diagnostic computer. Other Caterpillar 777Dtrucks operating at the site, which are ownedby contractors, did not have the economy modeoption available and would require the ECU tobe re-programmed to implement the change.To help make a decision on whether to employeconomy mode on the Cat 777F fleet, Fortescuerequired an understanding of current energyPhoto courtesy of Fortescue Metals Group5use and performance, and the fuel savings andproductivity impact of a change to economy mode.Caterpillar provided Fortescue with modelsimulations for four sample haul loads. The modelcalculated the cycle time (minutes) and fuel use(litres diesel per hour) for both ‘standard’ and‘economy’ modes.The modelling showed that a 2.3% averagereduction in fuel use could be achieved across thefour sample routes, with an increase in cycle timeof 1.8%. When extrapolated across the fleet ofCat 777F trucks, the savings were estimated to be232 kL (8,955 GJ) per annum. It should be notedthat Fortescue’s operations are relatively flat andthis potential opportunity may be less applicableto deeper mining operations2.2Note: This depends on existing energy use profiles andfactors impacting on operations.

6Energy Efficiency Opportunities Case StudyKey Performance Indicators forMine Fleet ApplicationsPurpose of Key Performance Indicators(KPIs)Many industries use Key Performance Indicators(KPIs) to evaluate the performance of abusiness activity. A properly designed KPI willprovide managers with a discrete quantitativeindicator of the status of one or more importantbusiness parameters. The KPI can be assessedcontinuously or periodically, and can be trackedto monitor changes in performance over time.One indicator currently used by the miningindustry is fuel consumption expressed aslitres per bank cubic metre3 (litres/BCM). Thisindicator is easy to calculate, but does not takeinto account the differences between minesites or changes within individual mines (suchas haul routes and distances; increasing dumpheights; pit or underground depths). Given thesignificant contribution of these factors to mineefficiency, litres/BCM is potentially a very limitedperformance indicator and does not capturethe effects of other variables. It can also bemisleading to suggest that a haul fleet’s efficiencyis decreasing due to an increase in litres/BCM. Similarly, a comparison of the litres/BCMfor different mines is potentially meaninglessgiven that a mine with a lower litres/BCM valuemay actually have less efficient operations andhaulage equipment than a mine with a higherlitre/BCM value.Companies should determine the keyperformance indicators that enable an adequateanalysis and management of energy use. Inpractice this may require a set of indicatorsto be developed. To effectively track energyperformance, companies will need to developa framework that adequately considers thevariables affecting operations to provide a fair ornormalised picture of the operation’s energy useand enable potential efficiency improvements tobe identified.3A bank cubic metre (BCM) represents the contentsof a cubic metre of rock in place, before it is drilledand blasted.Downer EDI MiningDowner EDI Mining Pty Ltd (DEDIM), a divisionof the Downer Group, provides contract miningand mine services at 45 sites in Australia.In 2009–10 DEDIM employed almost 3,000people and moved over 121 million bank cubicmetres (BCM) of overburden and product onmine sites.DEDIM is a major provider of integratedcontract mining services for both open-cutand underground mining operations. Besidesoperating and managing mines, key servicesinclude exploration drilling, blasting, crushing,tyre management and rehabilitation. Coal,gold and iron ore are the main commoditiescurrently mined by DEDIM.Energy use (as reported under the EEOprogram) for which the DEDIM business unitwas deemed to have operational control inthe 2009–10 financial year was 0.27 PJ, withthe main energy sources being diesel fuel andbiodiesel B20 – a blend of 20% biodiesel and80% petroleum diesel. The majority of energyis used in mobile fleet and equipment on minesites to transport minerals and waste.DEDIM’s ApproachTo capture the effects of several variables in a singleanalysis, DEDIM developed its own energy andgreenhouse gas (GHG) performance measure – theDowner Energy and Emissions Measure (DEEM).This enables the company to measure and improveits fuel and energy efficiency. It also measuresthe reductions in GHG emissions of its miningoperations. The DEEM considers the sources anddestinations of material mined, together withthe mass and volume of material moved and thefuel used to move the material. DEDIM uses twoseparate indicators; one for haulage and anotherfor excavators and equipment.Indicator for haulage: The GJ/tonne‑km indicatorapplies to haulage-related equipment, such ashaul trucks, road trains, water trucks, scrapersand graders.

Analyses of Diesel Use for Mine Haul and Transport OperationsIndicator for excavators and equipment: TheGJ/tonne material moved indicator applies toexcavation-related equipment, such as excavators,dozers, loaders and surface miners. Ancillaryequipment, such as lighting plants, generatorsand pumps, are also considered in the non-haulindicator, as these are considered to be essentialequipment for the operation.Calculation of the DEEMThe simplified process for calculating the DEEM ispresented in Figure 3. The base data that is usedto calculate the DEEM is the total fuel consumedand the BCM moved. This is converted to thecommon measure of litres of diesel per tonnemoved (L/tonne). The L/tonne measure is thenadjusted for equipment fuel use, distance travelledand change in elevation to normalise the effect ofchanges in the material movement task, resultingin a fuel efficiency factor measured in L/tonne-kilometre. As a final step, the fuel efficiency factoris converted to units of energy (GJ) and greenhousegas emissions (tonnes CO2-e).Equivalent Flat HaulThe ‘equivalent flat haul’ (EFH) parameter wasdefined to describe the characteristics of the haulroute travelled. The EFH is a calculated parameterthat accounts for both the distance from the sourceto the destination, and the elevation change fromthe source to the destination. The EFH normalisesthe elevation change and distance travelled, whichenables a comparison of the energy consumed andtonnage moved for a mining activity.For a given material movement task, illustratedin Figure 4, the DEEM accounts for the energyrequired to move the material, the tonnage moved,and the EFH.Base DataCommon 12,000,00010,000,000Total Mine BCM0.51Total Mine Fuel 80.470.460FY 05/06FY 06/07FY 07/080.45FY 08/09FY 05/06Convert to Energy and GHGFY 06/07FY 07/080.50Non-Haul GHG t CO2-e/tonne0.400.45Haul GHG t 0.200.10FY 06/07FY 07/08FY 08/09FY 08/09Adjust for Distance0.15000FY 05/067FY 09/10Figure 3: Summary of the DEEM calculation .110000.05000FY 05/06FY 06/07FY 07/08FY 08/09YearLitres/Tonne(Excavators, dozers and ancillary)Litres/Tonne.Km(Haul Trucks, Water Trucks and Graders)

8Energy Efficiency Opportunities Case Studyrole in mine planning, design and operations,the project engineers’ involvement ensured thatthe DEEM is credible, accurate and transparent.GJ and tCO2-etonnage movedxequivalent flat haulDestinationSourceFigure 4: Illustration of Equivalent Flat HaulApplication of the DEEMThe DEEM compares and links the weekly to monthlyhaul and non-haul energy performance to on-siteoperational activities, decisions and conditions.Performance data can be analysed and comparedfor a mine site to identify trends and factors thathave either positively or negatively influencedenergy efficiency. The DEEM can reveal many factorsthat have a direct or indirect influence on energyefficiency, such as changes in equipment size, theperformance of different operators, the influence ofproduction schedules or volumes on fleet efficiency,the effect of rainfall on road conditions, and manyother factors. The DEEM’s variation can be accuratelycorrelated with and explained in terms of these andother quantifiable factors. These factors and theirinfluences are then taken into consideration in futureplanning and operational decision-making.While the DEEM is a useful energy tool forperformance tracking and reporting, it is alsomore useful for informing business improvementdecisions than a simple indicator such aslitres/BCM. DEDIM applies this approach toidentify where factors contributing to efficiencyimprovements at one mine and/or mine typemay be measured and implemented at another.Typical solutions include applying different miningmethods, mine planning and design changes,haul road changes (length, gradients, designand materials), changing equipment operatorbehaviour, mining plant selection, and fuel types.DEDIM’s Technical Services Department and itsmining project engineers developed, trialled andimplemented the DEEM to ensure its applicabilityacross all projects and sites. Given their leadingThe project engineers also have ownership ofthe DEEM, and are responsible for calculatingand reporting the monthly DEEM performanceof their respective projects. This process enablesand encourages DEDIM’s mine project managersto test and understand the energy performanceimplications of their decisions and, hence, toinclude energy-efficiency considerations in theirday-to-day decision-making.Mine comparisonsThe graphs presented in Figure 5 and Figure 6compare the annual performance, on a monthlybasis of three mines, each mining a differentcommodity. The haulage-related indicator inFigure 5 illustrates that haulage on Mine 1 is moreenergy-intensive than on Mines 2 and 3, whileFigure 6 illustrates that excavation on Mine 1is less energy-intensive than on Mines 2 and 3.Several factors can influence the energy intensitymeasured by the DEEM across different sites: Rock hardness and fragmentation. Sites with hardrock are often more energy-intensive to excavate. Density of the material being excavatedand hauled. Material moved through blasting, and workrequired by dozers and loaders to shift materialinto haul trucks. Fleet selection, including size of equipmentin use at the site, as fewer numbers of largerequipment can result in greater energyefficiency and productivity. Mine planning integrating energy efficiency,including haul slope optimisation, haul roadand dump configuration and optimisation canreduce the energy intensity. Energy-efficiency measures deployed thatinclude a cumulative suite of improvements forDEDIM, including operator training, automationof lighting plants and idle time minimisation.

Analyses of Diesel Use for Mine Haul and Transport OperationsGJ/tonne-km(haulage related indicator)0.006000.00525GJ / 0.00000Mine 1Mine 2Mine 3Figure 5: Comparison of monthly haul energy use for three sample minesGJ/tonne material moved(excavation related indicator)0.02000GJ / tonne material 02500.00000Mine 1Mine 2Mine 3Figure 6: Comparison of monthly excavation energy use for three sample minesTracking energy performance over timeThe trend presented in Figure 7 demonstratesthe link between monthly energy performanceand mining activities for an open cut coal mine.Trending of the energy indicators is more usefulthan simply trending monthly energy use. Fueluse could increase or decrease due to changesin production activity or other factors that canobscure energy-efficiency insights. The use of keyperformance indicators, such as the DEEM, canprompt managers to enquire into the observedchanges in energy efficiency over time, and deeperanalysis can reveal insights into the factors thatdrive energy efficiency on the site.There are many factors that influence energy useon a mine, and many indicators are required totrack changes in energy use. The DEEM exampleillustrates how using appropriate indicatorsthat normalise for key sources of variability canhelp to give a better indication of true energyperformance. Examination of indicators over timecan provide a useful basis for business decisionsand may help to identify opportunities to improveenergy performance.9

10Energy Efficiency Opportunities Case 00.00300.00200Non Haul GJ/tonne0.00200.00100Haul GJ/tonne.km0.00100.000000.0000Increase in digger and truckshifts to catch up on coal andO/B losses after floodsDuring power plant shut-downperiod, focussed on movingwaste over short distances tothe in-pit dumps.Low utilisation of dozer push& excavator productionFigure 7: Trend of monthly performanceIt is beneficial for mining companies to be able tocompare their performance against a consistent setof indicators. By calculating the DEEM for multiplesites, DEDIM is able to draw comparisons andinsights across different activities and operations.DEDIM has used the DEEM to set annual targetsfor reducing energy intensity, and to track projectand company performance against the target.The Commodore open-cut coal mine in SouthEast Queensland has been used as the pilot sitePhoto courtesy of Downer EDI Mining Pty Ltdfor energy-efficiency improvements at DEDIM.The energy intensity of the Commodore mine hasimproved by 18.2% over five years. DEDIM hasused the DEEM to measure an 8% reduction inenergy intensity for 2009/10, against a companywide target of 3%. With the confidence gainedfrom past performance, and a continuedimprovement program pipeline identified for2010–11, DEDIM has set an energy-intensityreduction target of a further 2%.

Analyses of Diesel Use for Mine Haul and Transport OperationsBenchmarking Truck OperationsPurpose of benchmarking, includingtheoretical benchmarkingBenchmarking provides a means to measure andidentify best-practices within a single organisation,or across multiple organisations.There are many variables that can affect haul truckenergy efficiency. Simplistic performance indicators,such as litres of diesel per tonne moved, are oftentoo blunt to provide useful insights into the factorsthat drive efficiency because they do not accountfor factors such as the distance travelled, thepayload per cycle, or other characteristics of anindividual hauling task.Calculations of theoretical energy efficiency maynot reflect the level of performance that canrealistically be achieved but can be a useful toolto track improvements in energy efficiency. Thedevelopment of relevant theoretical benchmarksprovide organisations with a practical energyefficiency measurement tool that quantifies bestpractice, and highlights areas where improvementscan be made.Best truck ratioAfter gathering real-time haul cycle data, GPS data,and mine site information, Leighton Contractorsdeveloped a series of mass and energy equationswhich were designed to compare actual truckperformance against the theoretical bestperformance. This technique essentially calculatesthe best theoretical performance a haul truck iscapable of in order to move a mass of materialfrom one location to another based on vehicle andsite characteristics. The actual performance can becompared to the theoretical energy use for a specifictruck, resulting in the ‘Best Truck Ratio’ (BTR).Actual energy useBTR ---Theoretical best truck energy useFor a defined material movement task via aspecific haul path, the BTR is the ratio of the actualenergy consumed to perform the task over thebest-practice benchmark energy consumption.11Leighton ContractorsWith operations in 19 coal, iron ore, goldand manganese mines in Australia and NewZealand, Leighton Contractors Pty Ltd is oneof Australia’s largest contract mining providers.With one of the largest mobile equipmentfleets in the country, the Leighton fleet movesin excess of 240 million cubic metres perannum. Leighton Contractors operates at bothbrown-field sites and green-field start-ups.The Leighton fleet includes over 300 large haultrucks, as well as many other types of mobileplant and equipment.For example, if a haul truck achieves a BTR of 2.0that indicates that the actual fuel consumption wastwice that of the best-practice benchmark.application of the btrThe BTR allows Leighton to compare theperformance of their operations between sites,trucks, operators, and other parameters. Morespecifically, haul trucks can be compared onevery cycle of a particular day and site. As thisis a ratio of actual performance against the bestpossible performance for a particular haul cycleit gives a much more accurate indication of theenergy efficiency of the operation than alternativeperformance indicators such as litres/tonne moved.One example is payload optimisation, presentedin Figure 8. For a fixed task of 20 million tonnesmoved, Figure 8 illustrates four payload scenariosand the corresponding BTR. The third scenario,a payload of 154.25 tonnes, is identified as theoptimal scenario with a BTR of 2.22. The other threescenarios score a higher BTR, and would resultin greater fuel use to achieve the same materialmovement outcome. For each scenario the fuelconsumption in litres is stated below the BTR, andfor the three non-optimal scenarios the values inred text indicate the additional fuel required tomove the same amount of material via the samepath at a higher BTR. In effect, setting the payloadat the optimal 154.25 tonnes per cycle would result

12Energy Efficiency Opportunities Case StudyPayloadTruck ModelResults– based on 20 million tonnes movedResults– based on 20 million tonnes movedPayload 126.21Payload 140.22Payload 154.25Payload 168.28Best Truck Ratio:

procedures influence energy use and maintenance costs. Truck velocity, especially cornering speeds, braking patterns and road surface characteristics can affect tyre wear and replacement costs. In open cut mining, many parameters can affect the efficiency of the fleet, such as: Mine plan and mine layout Speed, payload and cycle time