Backhoe or LoaderMatching the machine to the applicationHitachi Construction Machinery Asia & Pacific Pte. Ltd.Naoto SannomiyaEngineer, HMAP Product Support27/04/2010

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Loader (Face Shovel)BackhoeBucket facing the bankClam & Door combination for easy dumpingFollows the traditional mining style by rope shovelsBucket facing machineBased on the general construction applicationOverview

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LoaderLoader Operation

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Face Shovel (Loader)Typical OperationBasically, the excavator is on the same surface as the hauler.

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Face Shovel (Loader)Transition from mechanical shovel (rope shovel) is smoothFloor leveling/cleaning can be carried out easilySupport machine (dozer) to clean the haul road is not neededMaterial does not stick to the bucket: better loading efficiency especially for the muddy/ sticky material.Easy to locate the seam; the seam is in front of the operatorBenefits

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Bench heightMinimum bench height25% of max cutting height3.8mMaterial does not fall into the bucket to obtain the good bucket efficiencyMaximum bench height75% of the max cutting height11.3mAnything higher might impose the risk of falling rock to damage the machineFace Shovel (Loader)

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Bucket fill factors & bench heightTop picture shows an optimum bench height for good bucket fill factor. Note that the bench height is above the cab height EX8000-6 max cutting height: 20.5m recommended bench height: 12m (58% of the max. cutting height)Face Shovel (Loader)Bottom diagram explains the effect of the bench height. Note that the material above the bucket plays an important role for improving the bucket efficiency. This material falls into the bucket

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Backhoe Backhoe Operation

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BackhoeTypical OperationExcavator should be on a bench for the optimum production.

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BackhoeApplicationSince the load point is closer to the fulcrum as compared to the loader, the bucket can be larger without losing the stability.Due to the versatile design, other non-production job such as wall cleaning is easily operatedEasy for the general construction excavator operator to operateBucket may be produced locally due to the low complexity of the construction (need to consult Hitachi for best result)Benefits

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Bench heightOptimum bench height75% of max digging depth6.4m(when the material is well blasted)Optimum digging method Digging by the arm; maximum digging force at the perpendicular angle with the boom (direct digging)Backhoe503090:maximum arm digging force

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ComparisonBackhoe vs. LoaderPros & Cons

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Comparison

BackhoeLoaderLoading Optimum cycle time is obtained if truck is positioned below the excavator undercarriageDue to the narrow bucket configuration, positioning of the bucket is easy; not much preference as for the truck size. Good machine stability at digging obtains efficient loading with less spillage.BE configuration has the equal loading capacity as the loader.Due to the ample capacity of the bucket with the bottom dump configuration, optimum loading efficiency can be obtained when the material is well blasted.

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Comparison

BackhoeLoaderDigging Due to the digging bucket position being close to the machine, the machine weight acts effectively to the digging reaction force and utilize the maximum cylinder thrust force to obtain the high penetration force. Compared to the tractor type loading equipment such as wheel loaders, the digging force is higher and the digging ability is superior.Digging position is farther as compared to the backhoe, and utilization of the machine weight as the reaction force toward the digging force is relatively inferior.

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Comparison

BackhoeLoaderMobility between benchesUsually working on the bench; mobility between benches is inferior.Since machine is at the same plane as the trucks, mobility is superior.Bench formationIn order to operate productively, bench formation is a necessity.Bench formation is not necessary since machine works at the same plane as trucks.Wall Root CuttingOptimum for the wall root cutting with the ample digging force, digging reach, and the backward digging direction.Not suitable due to the forward digging direction.

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Comparison

BackhoeLoaderWall CleaningOptimum for the wall cleaning (floating rock removal, surface preparation, root cutting).with the long reach with ample digging force.As compared to the tractor type equipment such as wheel loader, the digging force and the reach is larger. Therefore, necessity for the support equipment is less. As compared to the backhoe, the operation effectiveness is lower due to the lower digging force.

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Comparison

BackhoeLoaderOversize HandlingSince the operator can visually identify the oversized material, sorting of the material by the size is easy and less likely to load the oversize material by mistake.Not optimum to carry the material to a remote location like a wheel loader, but easy to sort the material within the working range by the size while loading the regular size material onto the truck.Wall (Bench) HeightWall (bench) height is limited by the height of the work bench and the reach.Wall height is limited by the reach, but more flexible as compared to the backhoe.Bench widthNeed the width for the working benchIf swing radius is clear, machine can work in the area.

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Comparison

BackhoeLoaderDrilling, BlastingMore flexible toward altering the drilling and blasting pattern by utilizing the high digging force for choosing more options for optimum mining systemAs compared to the backhoe, altering the drilling and blasting pattern is difficult since it may increase the stress toward the machine.

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Comparison

BackhoeLoaderTrack WearIf the operation does not require much travelling, track wear is minimal.Since the traveling surface is relatively smooth, track wear is usually small.Bucket WearDue to the higher digging force and severe working condition, bucket wear is prominent as compared to the loader. Historical data shows higher maintenance cost as compared the loader operation.Relatively moderate as compared to the backhoe.OperationRelatively easy to learnNeed longer familiarization time for effective operationMaintenance CostDue to its versatility, the stress condition could be severe to cause higher maintenance costRelatively moderate as compared to the backhoe

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Production DataProduction Data

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Production Data (EX2500 LD)

Location: IndonesiaDensity of Material: 1.74 t/m3Swell Factor: 1.3

ExcavatorModel: EX2500 LDCapacity: 14 m3TruckPayload: 91 tonneCapacity: 60.3 m3

Bucket efficiency: 65.8%Dump Time: 4 secAverage Excavator Cycle Time: 27.0 secAverage Pass for 1 truck: 6.3Average Loading Time 111.6 secAverage Exchange Time: 59.0 secTotal Truck Cycle Time: 170.6 secAverage Number of Haulage: 21.1 / hourPayload per Truck: 58.0 m3Estimated Production: 1,253LCM/hour 964 BCM/hour

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Production Data (EX2500-5 LD)

Location: IndiaDensity of Material: 1.8 t/m3Swell Factor: 1.3

ExcavatorModel: EX2500-5 LDCapacity: 15 m3TruckPayload: 95.1 tonneCapacity: 60.0 m3

Bucket efficiency: 85.0%Dump Time: 3 secAverage Excavator Cycle Time: 28.0 secAverage Pass for 1 truck: 4.2Average Loading Time 91.7 secAverage Exchange Time: 101.8 secTotal Truck Cycle Time: 193.5 secAverage Number of Haulage: 18.6 / hourPayload per Truck: 53.6 m3Estimated Production: 996.3LCM/hour 766.4 BCM/hour

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Production Data (EX2500-5 BH)

Location: IndonesiaDensity of Material: 1.8 t/m3Swell Factor: 1.3

ExcavatorModel: EX2500-5 BHCapacity: 13.8 m3TruckPayload: 91.0 tonneCapacity: 57.3 m3

Bucket efficiency: 100.0%Dump Time: 5 secAverage Excavator Cycle Time: 28.7 secAverage Pass for 1 truck: 4.0Average Loading Time 91.0 secAverage Exchange Time: 67.2 secTotal Truck Cycle Time: 158.2 secAverage Number of Haulage: 22.8 / hourPayload per Truck: 55.2 m3Estimated Production: 1256 LCM/hour 966 BCM/hour

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Production Data (EX2500-5 BH)

Location: AustraliaDensity of Material: 1.8 t/m3Swell Factor: 1.23

ExcavatorModel: EX2500-5 LDCapacity: 17 m3TruckPayload: 136.0 tonneCapacity: 78.0 m3

Bucket efficiency: 84.7%Dump Time: 4 secAverage Excavator Cycle Time: 33.6 secAverage Pass for 1 truck: 5.3Average Loading Time 150.8 secAverage Exchange Time: 48.5 secTotal Truck Cycle Time: 199.3 secAverage Number of Haulage: 18.1 / hourPayload per Truck: 75.6 m3Estimated Production: 1366 LCM/hour 1,110 BCM/hour

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