Using FPC to Size Truck and Loader Using FPC to Size Truck and Loader FleetsFleets

©2012 Dr. B. C. Paul©2012 Dr. B. C. Paul

Note – This presentation demonstrates fleet sizing using Caterpillar’s FPC program Note – This presentation demonstrates fleet sizing using Caterpillar’s FPC program and includes screen shots from the program. Credit is given to Caterpillar for the and includes screen shots from the program. Credit is given to Caterpillar for the

program and interfaces. Caterpillar has produced helps and directions for using the program and interfaces. Caterpillar has produced helps and directions for using the program which of course have common subject material with these slides. These program which of course have common subject material with these slides. These

slides also draw on earlier work done by the author.slides also draw on earlier work done by the author.

What Is FPC?What Is FPC?

• It is an easy to use tool for sizing truck and It is an easy to use tool for sizing truck and loader fleets for hauling ore over simple and loader fleets for hauling ore over simple and consistent haulage routesconsistent haulage routes

What Will We Do In This What Will We Do In This Demonstration?Demonstration?

• We will consider a fleet of trucks moving We will consider a fleet of trucks moving 16.5 million metric tonnes of rock every 16.5 million metric tonnes of rock every year out of a pit that is 500 meters deep.year out of a pit that is 500 meters deep.• Similar to the final pit we developed in Similar to the final pit we developed in

MineSight.MineSight.

When FPC Starts it Takes You to Its When FPC Starts it Takes You to Its First Tabbed ScreenFirst Tabbed Screen

Some Items Just InvolveLabeling Your Project

You Also Make Your Unit SelectionYou Also Make Your Unit Selection

You Need to Enter A Fuel PriceYou Need to Enter A Fuel Price

Normally the fuel is “Red Dog”Diesel.

Most Trucks run on Diesel Fuel

Most Mining Trucks do not runOn public highways. As a resultTheir diesel fuel is not subjectTo highway taxes.

To keep untaxed diesel fuel from“getting into the highway truckFleet” it is dyed red. Thus theName “Red Dog”. If a highwayTruck is cought with red fuel orRed fuel stains there will be bigTrouble.

Working Time is Also ConsideredWorking Time is Also Considered

You enter the number of hoursPer year of work

And the so called shift efficiency

Hours WorkedHours Worked

• One Begins Considering How Many Hours to One Begins Considering How Many Hours to Schedule Mining Operations and trucks.Schedule Mining Operations and trucks.• You could claim 24 hours a day and 365 days per yearYou could claim 24 hours a day and 365 days per year

• But that would imply Christmas, New Years, and other But that would imply Christmas, New Years, and other Holidays being workedHolidays being worked

• That would also imply no weather delays or scheduled That would also imply no weather delays or scheduled maintenance down-townmaintenance down-town

• It would mean no weekends offIt would mean no weekends off

• It would mean if you ever got in trouble on production there It would mean if you ever got in trouble on production there would be no place to add time for catch-upwould be no place to add time for catch-up

• Not Surprisingly – 24 hours/day 365 days per year is Not Surprisingly – 24 hours/day 365 days per year is not a usual choicenot a usual choice

Some PossibilitiesSome Possibilities

• 5 days per week5 days per week• 52 weeks per year – about 260 days/year52 weeks per year – about 260 days/year

• A month off for Miners HolidayA month off for Miners Holiday• Mines shut down and use crews for heavy maintenance Mines shut down and use crews for heavy maintenance

and prep workand prep work

• Leaves around 330 days with a few major holidaysLeaves around 330 days with a few major holidays

• 6 day work week – 52 weeks/year – about 3126 day work week – 52 weeks/year – about 312

Weather or Not You Like ItWeather or Not You Like It

• Consider how many days you may loose for Consider how many days you may loose for weather or catastrophic break-down eventsweather or catastrophic break-down events

• For my example I selected 325 days/yearFor my example I selected 325 days/year• I was going for a 7 day per week operation with I was going for a 7 day per week operation with

reasonable holiday, maintenance, and weather reasonable holiday, maintenance, and weather or break-down days.or break-down days.

• Be consistent with existing or intended Be consistent with existing or intended practice.practice.

The Shifts/Day IssueThe Shifts/Day Issue

• In theory three 8 hour shifts make 24 hours per day.In theory three 8 hour shifts make 24 hours per day.• In practice changing crews takes timeIn practice changing crews takes time• Idea behind “hot seat change outs” start the next shift before Idea behind “hot seat change outs” start the next shift before

previous endsprevious ends• Of course that will end the idea that three 8 hour shifts = 24 hoursOf course that will end the idea that three 8 hour shifts = 24 hours

• Some mines use 2 work shifts and a maintenance shiftSome mines use 2 work shifts and a maintenance shift• If they are 8 hour shifts you might get 14 or 15 hours – not 16 with If they are 8 hour shifts you might get 14 or 15 hours – not 16 with

hot seat change outshot seat change outs• Some mines use 10 hour shiftsSome mines use 10 hour shifts

• Works with 4 days on and 3 off schedules – may not be Works with 4 days on and 3 off schedules – may not be accommodating to workers with fixed weekend needs (Saturday or accommodating to workers with fixed weekend needs (Saturday or Sunday Church for example)Sunday Church for example)

• Can probably get 18 or 19 hoursCan probably get 18 or 19 hours• Often run two 10 hour work shifts with a 8 hour maintenanceOften run two 10 hour work shifts with a 8 hour maintenance

More Shift IssuesMore Shift Issues

• Day-Light hoursDay-Light hours• Lower 48 U.S. usually have around 10 or better of Lower 48 U.S. usually have around 10 or better of

some type of daylightsome type of daylight• Not an issue if you have an artificial light gridNot an issue if you have an artificial light grid

• Counting on running massive haul trucks off of “head-lights” Counting on running massive haul trucks off of “head-lights” is not likely or safeis not likely or safe

• Do you have an artificial light system?Do you have an artificial light system?• If your planning the mine is that light system in your cost If your planning the mine is that light system in your cost

projections?projections?• Many quarries lack artificial light so 10 hour days is Many quarries lack artificial light so 10 hour days is

almost forced on themalmost forced on them• If you are in the Arctic Circle you have whole months If you are in the Arctic Circle you have whole months

with no lightwith no light

My AssumptionMy Assumption

• 21 hours per day21 hours per day• It’s a three 8 hour shift schedule without hot It’s a three 8 hour shift schedule without hot

seat change outs and planned non-utilized time.seat change outs and planned non-utilized time.

• Often your days per year and hours per day Often your days per year and hours per day decisions are not independent of each otherdecisions are not independent of each other

The Shift Efficiency IssueThe Shift Efficiency Issue

• Reality is you never get 100% work time to match a Reality is you never get 100% work time to match a scheduleschedule

• First factor is “Available”First factor is “Available”• The fact that I planned on using something does not guarantee it The fact that I planned on using something does not guarantee it

will be runningwill be running• Second factor is “Utilized of Available”Second factor is “Utilized of Available”

• There are scheduling complexities – you seldom use something There are scheduling complexities – you seldom use something just because its runningjust because its running

• Third factor is “Shift Efficiency”Third factor is “Shift Efficiency”• Workers are required by law and biology to have breaks in an 8 or Workers are required by law and biology to have breaks in an 8 or

10 hour period10 hour period• Typically you get about 50 minutes out of every hour – about 83-Typically you get about 50 minutes out of every hour – about 83-

84%84%

Cat FPCCat FPC

• Cat FPC has “shift efficiency”Cat FPC has “shift efficiency”• I put in 83%I put in 83%• The program builds “shift efficiency into every shift”The program builds “shift efficiency into every shift”

• Don’t use this to cover planning related non-utilization when Don’t use this to cover planning related non-utilization when equipment is available – non-use is seldom evenly spread equipment is available – non-use is seldom evenly spread across every shiftacross every shift

• Legal and biological breaks are distributed across and shift Legal and biological breaks are distributed across and shift which is what FPC assumeswhich is what FPC assumes

• FPC will use shift efficiency to make sure your tires FPC will use shift efficiency to make sure your tires don’t overheatdon’t overheat

• If you use “shift efficiency” to cover unevenly spaced If you use “shift efficiency” to cover unevenly spaced scheduling difficulties you may blow-out tires in the field scheduling difficulties you may blow-out tires in the field when you try to implement the planwhen you try to implement the plan

More on FPCMore on FPC

• Although We Have not Seen it Yet FPC allows Although We Have not Seen it Yet FPC allows you to identify percentage availableyou to identify percentage available• Ie – allow for what % of the time the equipment is in Ie – allow for what % of the time the equipment is in

running orderrunning order

• Note FPC does not have “Utilized of Available”Note FPC does not have “Utilized of Available”• You have to build that into your working hours per year You have to build that into your working hours per year

entry (which I tried to do by scheduling 21 hours per entry (which I tried to do by scheduling 21 hours per day for three 8 hour shifts)day for three 8 hour shifts)

The Last Issues are Bunching and The Last Issues are Bunching and Operator EfficiencyOperator Efficiency

What Is Bunching?What Is Bunching?

• If you have 5 trucks and one loader in theory the If you have 5 trucks and one loader in theory the loader always has a truck available and when-ever loader always has a truck available and when-ever a truck arrives the previous truck is just pulling a truck arrives the previous truck is just pulling away.away.• But this requires perfect spacing between trucksBut this requires perfect spacing between trucks• Drivers tend to congregate, three trucks may arrive to Drivers tend to congregate, three trucks may arrive to

be loaded and have to waitbe loaded and have to wait• Then the loader has all the trucks away and nothing to load Then the loader has all the trucks away and nothing to load

intointo

• This is called BunchingThis is called Bunching• It reduces the theoretically possible productionIt reduces the theoretically possible production

FPC and BunchingFPC and Bunching

• Cat did extensive studies on production losses Cat did extensive studies on production losses from bunchingfrom bunching• It is one of the few programs to build bunching losses It is one of the few programs to build bunching losses

into predicted Production.into predicted Production.• I picked average (which means to use the Cat I picked average (which means to use the Cat

typical statistics)typical statistics)• I could pick “none” and not using bunching losses at all I could pick “none” and not using bunching losses at all

(but they will likely happen anyway)(but they will likely happen anyway)• I could pick “min”I could pick “min”• I could pick “max” – more typical of what would I could pick “max” – more typical of what would

happen if the road was congested and did not allow happen if the road was congested and did not allow passingpassing

Operator EfficiencyOperator Efficiency

• The Truck speed is limited by its own engine size The Truck speed is limited by its own engine size and drive train limitsand drive train limits

• Or by road imposed speed limitsOr by road imposed speed limits• Trucks usually don’t travel at the maximum Trucks usually don’t travel at the maximum

possible speedpossible speed• Cat has compiled statistics on the ratio and found it to Cat has compiled statistics on the ratio and found it to

be a function of distance.be a function of distance.• I picked the button to use the Cat empirical studyI picked the button to use the Cat empirical study• I could alternately choose a fixed percentage of the I could alternately choose a fixed percentage of the

ratio of my average speed to the theoretical maximum ratio of my average speed to the theoretical maximum speed.speed.

Note!Note!

• There are 4 quick to enter numbers on the There are 4 quick to enter numbers on the first panel that have huge policy and first panel that have huge policy and practice implicationspractice implications

• Fill those numbers out with a full Fill those numbers out with a full understanding of what you are planningunderstanding of what you are planning• Don’t just blow them off and expect to get good Don’t just blow them off and expect to get good

results.results.

FPC is Set Up By Moving Directly FPC is Set Up By Moving Directly Across the Tabs at the TopAcross the Tabs at the Top

Now we go to Fleet Input

You Can Try Different Fleets of You Can Try Different Fleets of TrucksTrucks

Each fleet has a name you give it – and a description you or your team use to keepStraight what you are doing.

Now Start Building Your Fleet – Now Start Building Your Fleet – Click Add HaulerClick Add Hauler

The Select Hauler Window OpensThe Select Hauler Window Opens

I wanted a Cat Standard Machine(others require user input)

I wanted a Truck(When I select this the blue listBelow opens)

And obviously for my Cat 793Fleet I wanted a Cat 793.

A Bunch of Truck Specific Default A Bunch of Truck Specific Default Data Comes UpData Comes Up

Note that this is where I get accessTo the working availability timeOf the truck unit.

Availability ConsiderationsAvailability Considerations

• Newer trucks tend to have higher availabilityNewer trucks tend to have higher availability• 90 to 95%90 to 95%• Some people “rent fleets and simply pay a cost per ton Some people “rent fleets and simply pay a cost per ton

– Cat maintains and usually guarantees around 95% – Cat maintains and usually guarantees around 95% availabilityavailability

• Old highly worn trucks tend to drop down to about Old highly worn trucks tend to drop down to about 60%60%

• 85% is usually regarded as an old middle of the 85% is usually regarded as an old middle of the road average standbyroad average standby

• In a more complex run I could change the value as In a more complex run I could change the value as my fleet aged.my fleet aged.

I’m Using an old 85% Middle of the I’m Using an old 85% Middle of the RoadRoad

I will now move onAnd select my loader.

Interesting note – I amHolding out on inputtingMy number of trucksAnd cost data till I getAn idea of how manyI need.

On the Select Loader PanelOn the Select Loader Panel

I will again pick CatStandard Machines

I’m going to try a CableShovel first

It brings up the P+H line

At this point we need aDiscussion on matchingTrucks and shovels.

The Loader and Truck Need to Be A The Loader and Truck Need to Be A MatchMatch

• The Loader Should be able to fill the truck The Loader Should be able to fill the truck in a reasonable number of passesin a reasonable number of passes

• The Loader Should be able to lift the load The Loader Should be able to lift the load up over the side of the truck and dump the up over the side of the truck and dump the material in.material in.

• At this point we better have our Cat At this point we better have our Cat Handbook handy.Handbook handy.

Need to Fill in a Reasonable Number Need to Fill in a Reasonable Number of Passesof Passes

• If you fill a truck with less than 3 passes you can’t get the If you fill a truck with less than 3 passes you can’t get the load distributed – you’ll kill the suspension system in the load distributed – you’ll kill the suspension system in the trucktruck

• If you take too many passes to fill the truck will spend a If you take too many passes to fill the truck will spend a large part of its cycle time sitting to be loaded.large part of its cycle time sitting to be loaded.

• Guidelines exist as to what tends to be workableGuidelines exist as to what tends to be workable• Cable Shovels (3 to 4 passes)Cable Shovels (3 to 4 passes)• Hydraulic Shovels (4 or 5 passes)Hydraulic Shovels (4 or 5 passes)• FEL (4 to 6 passes)FEL (4 to 6 passes)• Backhoes (often 5 to 7 passes)Backhoes (often 5 to 7 passes)

• Looks like we’ll be shooting around 3 or 4 passes.Looks like we’ll be shooting around 3 or 4 passes.

But How Much Will The Truck But How Much Will The Truck Hold?Hold?

• A Truck can be Weight or Volume LimitedA Truck can be Weight or Volume Limited• Which depends on the materialWhich depends on the material

• Our Cat 793 holds 169 cubic yards just in Our Cat 793 holds 169 cubic yards just in the bed, but 230 cubic yards if you heap it the bed, but 230 cubic yards if you heap it and it can carry 250 tons.and it can carry 250 tons.

Material Weights Tables Exist in Material Weights Tables Exist in Many HandbooksMany Handbooks

This one is from the CaterpillarPerformance Handbook

Porphyry Copper ore is Granite-Like2800 lbs/cubic yard loose4600 lbs/cubic yard bankWith a “load factor” of 0.61

A Material CautionA Material Caution

• In place rock is a solid with only internal air In place rock is a solid with only internal air spaces and poresspaces and pores

• For loading and hauling rock tends to break For loading and hauling rock tends to break into chunks that have air spaces between into chunks that have air spaces between themthem• If you’ve ever tried to put dirt back in a hole If you’ve ever tried to put dirt back in a hole

after digging it out you know what “Swell” after digging it out you know what “Swell” meansmeans

Always Distinguish Between Bank Always Distinguish Between Bank and Loose Volumeand Loose Volume

The difference between bank and loose weight is huge

Saw some students foul up homework by looking on the internetAnd grabbing a weight number with no idea what it was. ManyInternet numbers are bank weights since loose weights are oftenImportant only in mine planning.

In Our Case We Are Given the In Our Case We Are Given the Loose WeightLoose Weight

• 2800 lbs per cubic yard2800 lbs per cubic yard• 169 cubic yards * 2800 lbs/yd^3 / 2000 lbs/ton169 cubic yards * 2800 lbs/yd^3 / 2000 lbs/ton

• 237 tons237 tons• Rated weight for truck is 250Rated weight for truck is 250

• Because this truck hit the volume limit before the Because this truck hit the volume limit before the weight it is called Volume limitedweight it is called Volume limited• I bet you can guess what would happen if we were I bet you can guess what would happen if we were

weight limitedweight limited• We’ll we don’t have to – if we heap it a little we We’ll we don’t have to – if we heap it a little we

can get up to 230 cubic yards can get up to 230 cubic yards

Continuing Our CalculationContinuing Our Calculation

• 230 * 2800 / 2000 = 322 tons > 250 tons230 * 2800 / 2000 = 322 tons > 250 tons• Reality is that this truck is weight limitedReality is that this truck is weight limited

• We can slightly over or underfill a truckWe can slightly over or underfill a truck• Less than 95% of rated weight usually wasting Less than 95% of rated weight usually wasting

truck carrying capacitytruck carrying capacity• More than 105% of rated weight and you’ll tear More than 105% of rated weight and you’ll tear

up the suspensionup the suspension• Usually a good idea to aim for the middle and Usually a good idea to aim for the middle and

allow the play for iregularities in loadingallow the play for iregularities in loading

More Calculations on the SideMore Calculations on the Side

• 250 tons *2000 /2800 lbs/cubic yard250 tons *2000 /2800 lbs/cubic yard• I need about 179 cubic yards to fillI need about 179 cubic yards to fill

• Now my loader needs to do this in an Now my loader needs to do this in an integer number of passesinteger number of passes• 3.5 passes is not a real number, I can only 3.5 passes is not a real number, I can only

dump dippers of material in integer amountsdump dippers of material in integer amounts

How Much Can a Bucket or Dipper How Much Can a Bucket or Dipper Hold?Hold?

• That depends on the material its diggingThat depends on the material its digging• And on the degree of control the operator And on the degree of control the operator

has for the bucket through the dig pathhas for the bucket through the dig path• A Bucket or Dipper has a manufacture rated A Bucket or Dipper has a manufacture rated

capacity based on the volume of the Bucketcapacity based on the volume of the Bucket• But filling up all that space exactly is a trickBut filling up all that space exactly is a trick• We have “Fill Factors” that give the percentage We have “Fill Factors” that give the percentage

of the capacity that actually gets used.of the capacity that actually gets used.

By Material and Machine TypeBy Material and Machine Type

• The Hydraulic shovel can pivot its bucket in most The Hydraulic shovel can pivot its bucket in most of the ways you can pivot your hand – helps get a of the ways you can pivot your hand – helps get a good fillgood fill• It has the best fill factorsIt has the best fill factors

• Loose material out of stock-pile 100 to 110% (also written 1 to Loose material out of stock-pile 100 to 110% (also written 1 to 1.1)1.1)

• You do need an unusual material stacking angle to get over You do need an unusual material stacking angle to get over 100% (the bucket is already rated heaped)100% (the bucket is already rated heaped)

• Average well-blasted bank 0.95 to 1Average well-blasted bank 0.95 to 1• Hard digging 0.9 to .95Hard digging 0.9 to .95• Very hard digging – blocky and poorly blasted 0.85 to .9Very hard digging – blocky and poorly blasted 0.85 to .9

Moving Down the ListMoving Down the List

• Cable Shovels come in next – the dipper pushes Cable Shovels come in next – the dipper pushes through on the end of a rigid armthrough on the end of a rigid arm• But the Bucket is rated on struck capacity – not heaped.But the Bucket is rated on struck capacity – not heaped.• Loose Stockpile Like MaterialsLoose Stockpile Like Materials

• Sand and Gravel 0.95 to 1Sand and Gravel 0.95 to 1• An unconsolidated face with a few boulders 0.9 to 0.95An unconsolidated face with a few boulders 0.9 to 0.95

• Well Blasted Rock – called Hard digging for a Cable Well Blasted Rock – called Hard digging for a Cable Shovel – 0.8 to 0.9Shovel – 0.8 to 0.9

• Poor Blasted with interlocking large blocks – called Poor Blasted with interlocking large blocks – called very hard digging 0.7 to 0.8very hard digging 0.7 to 0.8

Our WorstOur Worst

• The Front End LoaderThe Front End Loader• It has little pivot and a bucket as wide as the machineIt has little pivot and a bucket as wide as the machine• It has to use its drive system to try and ram into what it digsIt has to use its drive system to try and ram into what it digs• StockpilesStockpiles

• Uniform moist or sand-like 0.95 to 1Uniform moist or sand-like 0.95 to 1• ¼ inch uniform pee gravel 0.9 to 0.95¼ inch uniform pee gravel 0.9 to 0.95• Larger sizes 0.85 to 0.9Larger sizes 0.85 to 0.9

• Well blasted face – easy to dig 0.8 to 0.95Well blasted face – easy to dig 0.8 to 0.95• Average blasted rock face – 0.75 to 0.9Average blasted rock face – 0.75 to 0.9• Poor blasting – 0.6 to 0.75Poor blasting – 0.6 to 0.75• Very hard digging - won’t go through at allVery hard digging - won’t go through at all

• Of course operator ability can play any of these numbers Of course operator ability can play any of these numbers toward the top or bottom of the rangetoward the top or bottom of the range

Consider a Cable Shovel Match for Consider a Cable Shovel Match for Our TruckOur Truck

• A 4100 has a 56 yard bucketA 4100 has a 56 yard bucket• Average blasted face about 0.85 fill (0.8 to 0.9)Average blasted face about 0.85 fill (0.8 to 0.9)• Target is 179 cubic yardsTarget is 179 cubic yards• 3 passes – 143 cubic yards3 passes – 143 cubic yards• 4 passes – 190 cubic yards4 passes – 190 cubic yards• We are betweenWe are between

• If we got 0.9 fill 3 passes would hit 151 cubic yardIf we got 0.9 fill 3 passes would hit 151 cubic yard

• It will be 4 passesIt will be 4 passes• 179 / 4 = 44.75 cubic yards179 / 4 = 44.75 cubic yards• 44.75 / 56 = 0.8 well within range for our expected digging44.75 / 56 = 0.8 well within range for our expected digging

• Note at the very end the fill factor must match a loaded Note at the very end the fill factor must match a loaded truck with an integer number of dipper passestruck with an integer number of dipper passes

Considering Other Shovel SizesConsidering Other Shovel Sizes

• I had thought about a 2800XP but I’m I had thought about a 2800XP but I’m already at 4 passes with a 56 cubic yard already at 4 passes with a 56 cubic yard bucket so a 39 yard not a good candidatebucket so a 39 yard not a good candidate

• I had also thought of the really big 5700XP I had also thought of the really big 5700XP with a 70 yard bucketwith a 70 yard bucket• 70*3*.85 = 179 cubic yards70*3*.85 = 179 cubic yards

• I can do a 4100 with 4 passesI can do a 4100 with 4 passes• Or a 5700 with 3 passesOr a 5700 with 3 passes

I Picked the Midsize 4100I Picked the Midsize 4100

If I wanted to tryMore than oneFleet I couldSelect Add NewFleet and thenPick my 793Matched to a 5700

Now I Need to Deal with Now I Need to Deal with AvailabilityAvailability

• Cable Shovels today use modular solid state Cable Shovels today use modular solid state electronicselectronics• Boards can be swapped out fast and sent for rebuildBoards can be swapped out fast and sent for rebuild

• Structural design of Cable Shovel is SimpleStructural design of Cable Shovel is Simple

• Does not have a lot of dirt sensitive highly stressed Does not have a lot of dirt sensitive highly stressed hydrualicshydrualics

• 90 to 95% availability should be fairly easy90 to 95% availability should be fairly easy

• (old units with motor generator sets more like 80 to (old units with motor generator sets more like 80 to 85%)85%)

Remaining Panel IssuesRemaining Panel Issues

Does your haulRoad allow trucksTo pass?(This is highlyRelated to yourMines trafficControl plan)

I could include support equipment for this fleet withinFPC or deal with it somewhere else – don’t miss it in your plan

I’m deliberatelyBypassing theExact numberOf trucks orLoaders andTheir cost.

Why am I bypassing?Why am I bypassing?

• FPC is designed with the intent you put the cost of FPC is designed with the intent you put the cost of your equipment in nowyour equipment in now

• It also is designed with the idea that you guess a It also is designed with the idea that you guess a number of unitsnumber of units

• Personal StylePersonal Style• I like to go quick and dirty and get routines to tell me I like to go quick and dirty and get routines to tell me

about what number of units to tryabout what number of units to try• Then I’ll make a second pass with more detailThen I’ll make a second pass with more detail• FPC will work for a first pass rough size – and that is FPC will work for a first pass rough size – and that is

what I like to do. (You may be different)what I like to do. (You may be different)

What is This Support Equipment What is This Support Equipment Issue?Issue?

• Trucks 250 ton and up are called Super TrucksTrucks 250 ton and up are called Super Trucks• They are very productive and have longer lives than an They are very productive and have longer lives than an

average truckaverage truck• They also depend on a solid haul-roadThey also depend on a solid haul-road

• That means you are doing sub-bases and almost designing the That means you are doing sub-bases and almost designing the haul roads like highwayshaul roads like highways

• Means for road work I have dozers and road Means for road work I have dozers and road graders and probably a compactorgraders and probably a compactor

• Dirt roads probably mean I have water trucks both Dirt roads probably mean I have water trucks both for environmental reasons and also to moisted for environmental reasons and also to moisted road base for maximum compactionroad base for maximum compaction

Other SupportOther Support

• Cable and Hydraulic Shovels are messy creaturesCable and Hydraulic Shovels are messy creatures• They spill part of their rockThey spill part of their rock

• Some sort of front end loader or scoop is used to collect Some sort of front end loader or scoop is used to collect spillsspills

• If the loader is large enough it loads into trucksIf the loader is large enough it loads into trucks

• If you allow rock to build up in your loading area If you allow rock to build up in your loading area it will cut your truck tiresit will cut your truck tires• There are about 40,000 + good reasons to not want that There are about 40,000 + good reasons to not want that

to happen ($$$$)to happen ($$$$)

Decisions about Support Equipment Decisions about Support Equipment in FPCin FPC

• I generally do not do my support equipment in FPCI generally do not do my support equipment in FPC• My road requirements are a function of my road length and My road requirements are a function of my road length and

how often I have to relocate roadshow often I have to relocate roads• These functions are more associated with my mine plan than the These functions are more associated with my mine plan than the

number of trucks in my fleetnumber of trucks in my fleet

• My clean-up loader is sensitive to the position of my My clean-up loader is sensitive to the position of my loading points and where else in the mine I may use them.loading points and where else in the mine I may use them.

• I keep them out of FPC because I find their specifications I keep them out of FPC because I find their specifications tend not to correlate well with exactly what I’m doing with tend not to correlate well with exactly what I’m doing with my trucks and loaders.my trucks and loaders.

When I Try to Move On I Get a When I Try to Move On I Get a Hysterical MessageHysterical Message

My loader and truckCosts are zero.

FPC really likes me toEnter now – but I’mA rough first passDesigner

I’ll tell it Ok and moveOn.

What’s Under Those SubtabsWhat’s Under Those Subtabs

It’s the rimpull andRetarder curves forThe truck.(If I did not pickCat standard I wouldGet to enter this stuffMyself)

On to the 3On to the 3rdrd Tab Tab

In this tab I will describe the road that my trucks must travel to deliver their ore or wasteLoads.

Name the Course and the Amount of Name the Course and the Amount of MaterialMaterial

I’m going to consider the routeFor ore to the mill.

I know from some things in theNext unit that I will be movingAround 9,000,000 tons of ore.

Input My InformationInput My Information

If I already know my material looseAnd bulk density I can enter itDirect. Or I can click select materialTo use Caterpillar’s built in dataBase.

On the Material WindowOn the Material Window

I select brokenGranite as mostSimilar to porphyryCopper ore.

Once I have selectedGranite Ok becomesAvailable to click.

Now I Need to Describe My Now I Need to Describe My Haulage RouteHaulage Route

I will need to identify the length of the segment, the grade resistance,A rolling resistance, a speed limit (if needed), and a description (whichComes in very handy during later review)

How do I Divide a Continuous Road How do I Divide a Continuous Road into Segment?into Segment?

• Road Segments Divide WhenRoad Segments Divide When• There is a major change in grade (slope)There is a major change in grade (slope)• There is a major change in underfoot conditionsThere is a major change in underfoot conditions• There is a major change in vehicle operating There is a major change in vehicle operating

considerationsconsiderations• StartingStarting

• StoppingStopping

• Major TurnsMajor Turns

What is Major?What is Major?

• Depends in part on what you are doingDepends in part on what you are doing• Computer Methods favor greater detailComputer Methods favor greater detail• Hand methods favor more moderationHand methods favor more moderation

• Good intuitive Check is whether sustained Good intuitive Check is whether sustained enough to change vehicle speedenough to change vehicle speed

My Haulage ProfileMy Haulage Profile

• My loading bench is level and I will go 550 My loading bench is level and I will go 550 feet to the ramp to get out of the pit.feet to the ramp to get out of the pit.

• Issue #1 – part of that distance will be in a Issue #1 – part of that distance will be in a congested loading areacongested loading area• I will probably want a speed limit on that area I will probably want a speed limit on that area

different than for the bench as a wholedifferent than for the bench as a whole

My First 150 feet in a Congested My First 150 feet in a Congested Loading AreaLoading Area

Another line appeared for more of the route. I entered 0% gradeBecause the bench itself is level.

Now I need a speed limit

Congested Area GuidelinesCongested Area Guidelines

(From Surface Mining - First Edition)

I’m going to consider my conditions average.

Enter the Data and a DescriptionEnter the Data and a Description

Now I need to deal with grade and rolling resistance

Roads Produce Forces that Influence Roads Produce Forces that Influence Vehicle MovementVehicle Movement

• Roads slope up hill and downRoads slope up hill and down• This will cause gravity to work for or against the This will cause gravity to work for or against the

forward movement of the truckforward movement of the truck• It is called grade resistanceIt is called grade resistance

• The common unit of Grade Resistance is %The common unit of Grade Resistance is %• Example – if a road goes up 1 foot for every 10 feet of Example – if a road goes up 1 foot for every 10 feet of

distance it is called 10% grade (note that 1 is 10% of distance it is called 10% grade (note that 1 is 10% of 10)10)

• Note that we are not using slope anglesNote that we are not using slope angles

Other ForcesOther Forces

• Trucks are subject to wind or air resistanceTrucks are subject to wind or air resistance• Air resistance increases dramatically with speedAir resistance increases dramatically with speed

• For a car going 70 mph wind resistance is one of the largest For a car going 70 mph wind resistance is one of the largest opposing forcesopposing forces

• Haul trucks lumber along at slow paces and wind Haul trucks lumber along at slow paces and wind resistance is usually considered 0 for an engineering resistance is usually considered 0 for an engineering approximation.approximation.

Rolling ResistanceRolling Resistance

• Tires Sink into Ground - softer ground sink Tires Sink into Ground - softer ground sink moremore

• Tires FlattenTires Flatten• Driving uphill out of a rut on a flat tire spotDriving uphill out of a rut on a flat tire spot• Need to Know Underfoot conditions and Need to Know Underfoot conditions and

Type of Tire (Radial or Bias Ply)Type of Tire (Radial or Bias Ply)

Grade Resistance in %Grade Resistance in %

• Number of feet up (or down) for every so Number of feet up (or down) for every so many feet forward (or backward).many feet forward (or backward).

• I’m on a level bench so I go up 0 feet for I’m on a level bench so I go up 0 feet for every 100 feet – thus my grade resistance is every 100 feet – thus my grade resistance is 0%0%

• Rolling Resistance will depend on the road Rolling Resistance will depend on the road and the tires.and the tires.

Hard Smooth Stabilized SurfaceHard Smooth Stabilized Surface

I like 1.7 for our established haul road withRadial tires

Enter the InformationEnter the Information

Next 400 more feet across the bench.

Enter the DataEnter the Data

Now what about the grade resistance – what is positive and what isNegative?

Sign Conventions and ResistanceSign Conventions and Resistance

• Standard ConventionStandard Convention• A positive resistance resists motionA positive resistance resists motion• A negative resistance favors motionA negative resistance favors motion

• Note that rolling resistance will always be positive Note that rolling resistance will always be positive because it always resists motion no matter what because it always resists motion no matter what the directionthe direction

• That 10% grade out of the pit is +10That 10% grade out of the pit is +10• That 5% grade down the canyon is -5That 5% grade down the canyon is -5

Now We Need to Do the Return Now We Need to Do the Return RouteRoute

I will click onThe returnRadio button

If the haul roadBack is uniqueI enter as before

If I just reverseDirections I canClick MirrorHaul Road (andIt reverses route)

The Forth Tab Lets you Match a The Forth Tab Lets you Match a Truck Fleet and Route for StudyTruck Fleet and Route for Study

Since we have only entered one of each this is not to big a choice. If you’ve entered moreThan one route or truck fleet you could have quite a few choices.

Tab 5 – Production and Costs has Tab 5 – Production and Costs has Large Number of SubtabsLarge Number of Subtabs

As before you generally work the subtabs left to right.

Oddity #1 – Double Select ButtonsOddity #1 – Double Select Buttons

The select process is really two tear. The select tab lets you create a subset of cases to workWith. Ultimately FPC can only do one case at a time – the second select picks one from theSublist we created. (Again my one truck one road combo is boring).

One of the Most Critical TabsOne of the Most Critical Tabs

The Cycle Time Tab is WhereWe Deal with Load Time,Dump Time, and any fixedDelay times on the route.

Before We Will Be Allowed to Do Anything Before We Will Be Allowed to Do Anything We Must Disclose Our Unload TimeWe Must Disclose Our Unload Time

FPC will start blocking yourOther inputs on the pageUntil you cooperate.

Typical Unloading ArrangementsTypical Unloading Arrangements

• Back the truck up – line it up with a dump point and dump Back the truck up – line it up with a dump point and dump into the pointinto the point• Such as back-up to a gyratory crusher and dump into it.Such as back-up to a gyratory crusher and dump into it.• Requires precise placementRequires precise placement• Depending on number of open gyratory dump points trucks may Depending on number of open gyratory dump points trucks may

have to wait for a previous truck to get clear.have to wait for a previous truck to get clear.

• Back up to a general point and dumpBack up to a general point and dump• Such as backing up to the edge of a leaching pile and then Such as backing up to the edge of a leaching pile and then

dumping material over the sidedumping material over the side• Requires less – line upRequires less – line up• Usually more open space and not forced to wait for a truck in front Usually more open space and not forced to wait for a truck in front

of themof them

UnloadingUnloading

• TailgateTailgate• The truck dumps pulling forward and spreading load The truck dumps pulling forward and spreading load

behind it.behind it.

• May or may not require a total stop of the truckMay or may not require a total stop of the truck

• Truck is moving forward and avoids backing manuverTruck is moving forward and avoids backing manuver

• Truck ends its unload cycle already in motionTruck ends its unload cycle already in motion

• Pull forward to dump pointPull forward to dump point• Pull over a dump point and unloadPull over a dump point and unload

• Usually done with bottom dump trucksUsually done with bottom dump trucks

Size of Truck and Difficulty of Size of Truck and Difficulty of Maneuver Control TimeManeuver Control Time

• Typical Mining Truck can dump the bed in about Typical Mining Truck can dump the bed in about 30 seconds30 seconds• Big lumbering one might be closer to 40.Big lumbering one might be closer to 40.

• A general backing maneuver takes about 30 A general backing maneuver takes about 30 secondsseconds• Make it more like 45 seconds if the dump target is Make it more like 45 seconds if the dump target is

small or the truck real bigsmall or the truck real big• Make it about 1 minute if I have to wait for another Make it about 1 minute if I have to wait for another

truck to clear out firsttruck to clear out first• If you can just pull forward and stop on a point it If you can just pull forward and stop on a point it

can probably beat 10 secondscan probably beat 10 seconds

My Case My Case

• I’ll assume I back up to one of two gyratory I’ll assume I back up to one of two gyratory crushers and dump into the crushercrushers and dump into the crusher

• I have 2 gyratories so I won’t have a wait time.I have 2 gyratories so I won’t have a wait time.• I do have a big truck backing up to a small I do have a big truck backing up to a small

specific targetspecific target• 45 seconds45 seconds

• I have a big truck bed so I’m about 40 seconds to I have a big truck bed so I’m about 40 seconds to dumpdump

• Total – about 1.5 minutesTotal – about 1.5 minutes

Input and Enter and I Get My First Input and Enter and I Get My First Truck Cycle EstimateTruck Cycle Estimate

Note that my dump strategy meansI will make a full stop at the endOf my haul and will be starting myReturn trip from a full stopPosition(This would not be true of allUnloading arangements)

Now We Reconcile Loader Passes, Now We Reconcile Loader Passes, Fill Factors and Truck VolumesFill Factors and Truck Volumes

We have discussed thePrinciples before but nowWe have to get it right.

I Remember I Needed 4 Passes at I Remember I Needed 4 Passes at 80% Fill80% Fill

Note – this is a great place toFind or commit a screw-up.

If my loader was a lousyMatch for my truck I’m goingTo get a bad number ofPasses.

The program does not checkTo see if your fill factor isRealistic for your material.You can input garbage – butGuess what you’ll get!

You must work this till you get an integer number of passes.The program will not check you.

Now I Need to Deal with My Load Now I Need to Deal with My Load TimeTime

The times that come up on the list are for smaller loaders doing single truckLoading under ideal conditions.

The Loader Cycle TimeThe Loader Cycle Time

• How Long Does it Take a Loader to take a scoop How Long Does it Take a Loader to take a scoop – turn – dump it in a truck and return to a ready – turn – dump it in a truck and return to a ready position for the next scoop.position for the next scoop.

• Hydraulic Shovels have fastest movementHydraulic Shovels have fastest movement• About 20 seconds for a little one with an easy digAbout 20 seconds for a little one with an easy dig• About 35 for a big oneAbout 35 for a big one

• Front End Loaders are worst – they have to back, Front End Loaders are worst – they have to back, maneuver and scoop.maneuver and scoop.• About 40 seconds for a small oneAbout 40 seconds for a small one• About 50 seconds for a big oneAbout 50 seconds for a big one

For A Cable ShovelFor A Cable Shovel

Graph of DipperSize and DiggingConditions forImpact on oneLoader Cycle.

But Wait – There is MoreBut Wait – There is More

• Most manufactures cheat on published dataMost manufactures cheat on published data• (This does not impact front end loaders)(This does not impact front end loaders)• They assume the angle between the digging They assume the angle between the digging

face and dump point is 90face and dump point is 90°°• For the most common configurations the angle is For the most common configurations the angle is

120° so the swing time is longer120° so the swing time is longer

• To adjust for 120° swing the published cycle needs To adjust for 120° swing the published cycle needs to be multiplied by 1.1 to 1.2to be multiplied by 1.1 to 1.2

Getting My NumberGetting My Number

• I Have a Cable Shovel with a 56 yard I Have a Cable Shovel with a 56 yard dipperdipper

• I’m assuming an average blasted face which I’m assuming an average blasted face which is “Hard Digging” for a Cable Shovelis “Hard Digging” for a Cable ShovelI’ll be about 32 seconds * 1.15

About 37 seconds

Now Lets Consider the Hauler Now Lets Consider the Hauler ExchangeExchange

This is the time it takes one truck to pull away and then another to move in andSpot and be ready to load. For larger trucks this is more like 1 minute rather than0.7

This leads to what is the First Bucket Dump?

First Bucket DumpFirst Bucket Dump

It is assumed that during the lag time when one truck is pulling out and anotherPulling in that the loader is getting a scoop of material ready. When the truck isPositioned only the short time to dump the dipper is involved.

Actual Times Depend on Field Actual Times Depend on Field Loading ConfigurationsLoading Configurations

• Depends on the type of equipment usedDepends on the type of equipment used• On the space availableOn the space available• Shovels and Hydraulic Excavators tend to Shovels and Hydraulic Excavators tend to

load in one set of waysload in one set of ways• Backhoes have some variationsBackhoes have some variations• FEL have some unique onesFEL have some unique ones

Single Truck LoadingSingle Truck Loading

Loader near the face

Truck backs up next to the loader on the drivers side(Gives the loader operator abetter view

Loader working into cut in thefaceLoader swings about 120degrees to dump

Advantages of Single Truck Advantages of Single Truck LoadingLoading

• SimpleSimple• Truck doesn’t have to back tires into the Truck doesn’t have to back tires into the

rockiest areasrockiest areas• The shovel faces armor of the tracks into The shovel faces armor of the tracks into

the dig facethe dig face• Shovel operator has optimized view of Shovel operator has optimized view of

truck bed targettruck bed target

Disadvantages of Single Truck Disadvantages of Single Truck LoadingLoading

• Backing into place can take around 1 Backing into place can take around 1 minute and may require a spotterminute and may require a spotter• Loaders expensive and idleLoaders expensive and idle

• Back time is an unproductive bottleneckBack time is an unproductive bottleneck

• Can form large ques because trucks tend to bunchCan form large ques because trucks tend to bunch

• 120 degree swing angle can be slow120 degree swing angle can be slow• Manufactures often rate on 90 degreeManufactures often rate on 90 degree

More DisadvantagesMore Disadvantages

• Limited Space Available for Oversize MaterialLimited Space Available for Oversize Material• Can set to sideCan set to side• Do a bowling ball drop into truckDo a bowling ball drop into truck

• Hydraulic shovels can set - but cable shovels drop Hydraulic shovels can set - but cable shovels drop bucket bottom openbucket bottom open

• Extension cord problems with electric Extension cord problems with electric equipmentequipment• Cord has to cut across truck pathCord has to cut across truck path• Putting on poles can cost timePutting on poles can cost time

Using Single Truck Loading in FPCUsing Single Truck Loading in FPC

• It’s easy – the screen layout assumes single It’s easy – the screen layout assumes single truck loadingtruck loading

• Do it just like we just finished doing.Do it just like we just finished doing.

Double Truck LoadingDouble Truck Loading

Same Arrangement as single truck loading onlythe trucks pull up on bothsides

Advantages of Double Truck Advantages of Double Truck LoadingLoading

• Second Loading Spot Allows a second Second Loading Spot Allows a second truck to spot during loading operationstruck to spot during loading operations• Avoids dead time on the loaderAvoids dead time on the loader• Doesn’t help the truck cycle time other than Doesn’t help the truck cycle time other than

eliminating some queingeliminating some queing

Disadvantages of Double Truck Disadvantages of Double Truck LoadingLoading

• Still have extension cord problems on Still have extension cord problems on electric unitselectric units

• Oversize boulder problem is now even Oversize boulder problem is now even more severemore severe

• Forces Loader operator to load on the blind Forces Loader operator to load on the blind side (most big loaders put the cab to one side (most big loaders put the cab to one side of equipment)side of equipment)

Doing Double Truck Loading in Doing Double Truck Loading in FPCFPC

• Loader cycle timeLoader cycle time• On one side of the truck the loader operator will On one side of the truck the loader operator will

not actually be able to see the truck bed till not actually be able to see the truck bed till he/she is on top of ithe/she is on top of it

Shovel

Cab

Truck

Note how late the operator willBe in actually seeing his dumpTarget.

You’ll need to slow the cycle downAbout 5 to 10%

Double Truck Loading in FPCDouble Truck Loading in FPC

• Hauler Exchange timeHauler Exchange time• By having a second load point the loaders wait By having a second load point the loaders wait

for another truck drops to 0for another truck drops to 0• Hauler Exchange time goes to 0Hauler Exchange time goes to 0

• Side EffectSide Effect• First Bucket Dump now takes the full cycle First Bucket Dump now takes the full cycle

time since the loader did not have a time break time since the loader did not have a time break while trucks backed in.while trucks backed in.

Another ImpactAnother Impact

• The Loader has no truck wait timeThe Loader has no truck wait time• The truck may not wait for another truck to The truck may not wait for another truck to

pull out but backing into place still puts pull out but backing into place still puts about 30 to 45 seconds onto a truck cycleabout 30 to 45 seconds onto a truck cycle• For single truck loading FPC automatically For single truck loading FPC automatically

adds the loader exchange time to both the truck adds the loader exchange time to both the truck and the loader.and the loader.

• By zeroing that time for the loader – I have lost By zeroing that time for the loader – I have lost the back time for the truckthe back time for the truck

I Need to Add This Time Back for I Need to Add This Time Back for My TruckMy Truck

I would add about 0.75 minutesInto my dump and maneuver time(even though the extraManeuver is actually at the loadPoint).

If You Get The Feeling I’m Forcing FPC to If You Get The Feeling I’m Forcing FPC to do Something it was not Designed Fordo Something it was not Designed For

• Your RightYour Right• FPC was designed assuming all trucks use FPC was designed assuming all trucks use

single truck loadingsingle truck loading• They left a loop-hole large enough to allow it to They left a loop-hole large enough to allow it to

do something else.do something else.

Drive By Truck LoadingDrive By Truck Loading

Shovel Lines up Alongthe face

Trucks pull forward andstop beside the loader

Shovel Swings 90 to 180degrees to dump

Advantages to Truck Drive-ByAdvantages to Truck Drive-By

• Greatly Reduced Spotting Time - no Greatly Reduced Spotting Time - no backing cyclebacking cycle

• Cable doesn’t cross the Trucks PathCable doesn’t cross the Trucks Path• Can Set Oversize Beside and out of the wayCan Set Oversize Beside and out of the way• Machine marches on a steady forward Machine marches on a steady forward

advanceadvance• Can do in a narrower space – your working Can do in a narrower space – your working

benches don’t have to be as wide.benches don’t have to be as wide.

Disadvantages of Drive -ByDisadvantages of Drive -By

• Often have problems with dipper swinging Often have problems with dipper swinging over the top of the drivers cabover the top of the drivers cab• Loader gets revenge for the truck running over Loader gets revenge for the truck running over

its extension cordits extension cord• If the dipper comes open your truck driver can If the dipper comes open your truck driver can

get deadget dead

• Trucks get to drive those expensive tires Trucks get to drive those expensive tires through spillsthrough spills

More DisadvantagesMore Disadvantages

• Lack of spotting makes it a one shot that Lack of spotting makes it a one shot that can lead to long swingscan lead to long swings

• Tracks are broadside to long face areaTracks are broadside to long face area

Doing Drive-By in FPCDoing Drive-By in FPC

• If the truck drivers stop well this will get a 90If the truck drivers stop well this will get a 90° ° swing – will speed up the loader cycleswing – will speed up the loader cycle• Lower your loader cycle time about 10%Lower your loader cycle time about 10%

• One truck still has to pull forward and another One truck still has to pull forward and another follow infollow in• This is about a 10 to 15 second ordeal instead of a 45 This is about a 10 to 15 second ordeal instead of a 45

second to 1 minute ordealsecond to 1 minute ordeal• Put in a smaller timePut in a smaller time• Since this affects truck and loader alike there is no need Since this affects truck and loader alike there is no need

to add extra time to the truck dump and manueverto add extra time to the truck dump and manuever

FPC and Drive-ByFPC and Drive-By

• The Truck change-out time does indeed The Truck change-out time does indeed reduce the first pass time for the loaderreduce the first pass time for the loader• First Bucket Dump = Loader Cycle – Exchange First Bucket Dump = Loader Cycle – Exchange

TimeTime

• Since Drive-By is often used in strip pits, Since Drive-By is often used in strip pits, Cat’s FPC accommodates it without really Cat’s FPC accommodates it without really forcing things.forcing things.

Modified Drive-By (Or Getting Modified Drive-By (Or Getting Fancy)Fancy)

• Shovel in Drive-By PositionShovel in Drive-By Position• Truck Drives up to Shovel as if it was a Truck Drives up to Shovel as if it was a

drive-bydrive-by• Loading drops onto a moving targetLoading drops onto a moving target

• While the Loading goes for the next bite the While the Loading goes for the next bite the truck backs into a single load like positiontruck backs into a single load like position• Shortens swing distanceShortens swing distance

AdvantagesAdvantages

• Get most of the positioning advantages of Get most of the positioning advantages of single truck load without the idle spot timesingle truck load without the idle spot time

DisadvantagesDisadvantages

• Dump onto a Moving TargetDump onto a Moving Target• With swinging over cab can be a real With swinging over cab can be a real

adventurous feeling for driveradventurous feeling for driver

• Gets the tires into some real rocky Gets the tires into some real rocky conditionsconditions

Modified Drive-By in FPCModified Drive-By in FPC

• Loader cycle time – usually no changeLoader cycle time – usually no change• Loader exchange time – drop to 0Loader exchange time – drop to 0• No need to add time to truck dump cycle – No need to add time to truck dump cycle –

he spots while the loader scoopshe spots while the loader scoops• Loader First Bucket Time IncreasesLoader First Bucket Time Increases

• The loader is trying to dump onto a moving The loader is trying to dump onto a moving trucktruck

Backhoe Loading MethodsBackhoe Loading Methods

• Backhoe works below gradeBackhoe works below grade• Can allow work to be kept off wet pit floorCan allow work to be kept off wet pit floor• can also provide multi-level loadingcan also provide multi-level loading

• Backhoes generally need good size machine Backhoes generally need good size machine relative to bucket. Doesn’t wear as well - relative to bucket. Doesn’t wear as well - generally used for special conditionsgenerally used for special conditions

Can Work Double and Single Can Work Double and Single Truck LoadsTruck Loads

Can also Load on Multiple Can also Load on Multiple LevelsLevels

Multilevel LoadingMultilevel Loading

• Double Loading configurationDouble Loading configuration• has extra room for oversize and still two truckshas extra room for oversize and still two trucks• Because truck has to come in on right level Because truck has to come in on right level

does require some additional advance data to does require some additional advance data to send truck to right spotsend truck to right spot

• Can also get 3 position loadingCan also get 3 position loading• often a bit of overkilloften a bit of overkill

FPC HandlingFPC Handling

• Like Single or Double Truck LoadingLike Single or Double Truck Loading• Remember to use loader cycle time suitable Remember to use loader cycle time suitable

for backhoefor backhoe• Since backhoe buckets tend to be small you Since backhoe buckets tend to be small you

are more likely to have 5 to 7 passes to are more likely to have 5 to 7 passes to load.load.

Front End Loader ConfigurationsFront End Loader Configurations

• FELs are less expensive than the trucks and FELs are less expensive than the trucks and are mobileare mobile

• Makes practical to consider more than one Makes practical to consider more than one loader providing loading serviceloader providing loading service

• Limited lift heights make truck match more Limited lift heights make truck match more criticalcritical

• Tires can tear up bad underfootTires can tear up bad underfoot

Single Truck LoadingSingle Truck Loading

Common Loading ArrangementsCommon Loading Arrangements

• Drive By LoadingDrive By Loading

Arrangements Putting More Than Arrangements Putting More Than One Loader at a Loading PointOne Loader at a Loading Point

How to Chain Load in FPCHow to Chain Load in FPC

• FPC assumes the number of loaders is equal to the FPC assumes the number of loaders is equal to the number of load pointsnumber of load points• If I need 5 loaders to Chain Load a TruckIf I need 5 loaders to Chain Load a Truck

• Lie – tell FPC you have a loader with a load cycle time of 0.05 Lie – tell FPC you have a loader with a load cycle time of 0.05 minutesminutes

• Tell it your loaders first bucket is also 0.05Tell it your loaders first bucket is also 0.05• (When you do enter cost tell FPC your one loader that (When you do enter cost tell FPC your one loader that

is as fast as 5 loaders also costs as much as 5 loaders)is as fast as 5 loaders also costs as much as 5 loaders)• When you count your loaders at the end of the computer run When you count your loaders at the end of the computer run

multiply the number of loaders by 5multiply the number of loaders by 5• This gets the truck loaded in the right timeThis gets the truck loaded in the right time

• The problem is if the program sends another truck to be loaded The problem is if the program sends another truck to be loaded 0.25 minutes later the loaders will not be ready to chain load 0.25 minutes later the loaders will not be ready to chain load (it takes each loader about 0.75 minutes to really scoop (it takes each loader about 0.75 minutes to really scoop material and load it).material and load it).

Building in loader lag timeBuilding in loader lag time

• Of the 0.75 minutes a real cycle takes about 0.05 Of the 0.75 minutes a real cycle takes about 0.05 is the dumpis the dump• This I did account for so I have 0.7 minutes left outThis I did account for so I have 0.7 minutes left out

• While other loaders are loading the first has time While other loaders are loading the first has time to start its cycleto start its cycle• In this example I used 5 loaders to chain loadIn this example I used 5 loaders to chain load

• There was 4*0.05 minutes while other loaders workedThere was 4*0.05 minutes while other loaders worked

• Now my unaccounted time is 0.5 minuteNow my unaccounted time is 0.5 minute

Entering the Loader Lag TimeEntering the Loader Lag Time

• Look at the Hauler exchange timeLook at the Hauler exchange time• What really happens is the truck just pulls What really happens is the truck just pulls

through the chain and is loaded on the flythrough the chain and is loaded on the fly• Thus there is no real hauler exchange timeThus there is no real hauler exchange time

• To Cope with Loader Lag TimeTo Cope with Loader Lag Time• Lie – in this case say there is a hauler spot time Lie – in this case say there is a hauler spot time

of 0.5 minutesof 0.5 minutes• This will keep FPC from sending the load point This will keep FPC from sending the load point

more trucks than it can really handle.more trucks than it can really handle.

Now We Have Problems With Truck Now We Have Problems With Truck Cycle TimeCycle Time

• The truck now has 0.5 minutes added to it’s cycle The truck now has 0.5 minutes added to it’s cycle that does not existthat does not exist• Lie – cut the dump time by 0.5 minutesLie – cut the dump time by 0.5 minutes

• Now the truck cycle time is rightNow the truck cycle time is right

• One more truck adjustmentOne more truck adjustmentThe haul end speed is about 3 to 5Mph – not 0. The same is true ofThe start speed.

Tandom LoadingTandom Loading

• This time I put two loaders on one truckThis time I put two loaders on one truck• The truck backs between two loaders that The truck backs between two loaders that

then load it from both sidesthen load it from both sides

Using Tandom Loading in FPCUsing Tandom Loading in FPC

• Tell FPC you have one loaderTell FPC you have one loader• But this loaders’ cycle time is twice as fast as a But this loaders’ cycle time is twice as fast as a

normal loadernormal loader• Its cost is also twice as much as a single loaderIts cost is also twice as much as a single loader• When you count up the number of Loaders at When you count up the number of Loaders at

the end of the run – remember to double the the end of the run – remember to double the number of loaders you buynumber of loaders you buy

• The money for this was already handled when you The money for this was already handled when you created “one” loader that cost as much to buy and created “one” loader that cost as much to buy and operate as 2operate as 2

The First Bucket Load Time The First Bucket Load Time ProblemProblem

• While the truck spotted the loaders got ready to While the truck spotted the loaders got ready to dump – thus they only need 0.05 minutes for the dump – thus they only need 0.05 minutes for the first bucket.first bucket.• The FPC problem – it allows one bucket to take only The FPC problem – it allows one bucket to take only

0.05 minute – in reality two buckets go in at the same 0.05 minute – in reality two buckets go in at the same timetime

• Solution – LieSolution – Lie• It takes about 0.7 to 1 minute to spot the truckIt takes about 0.7 to 1 minute to spot the truck• Cut the time savings from the zero time second bucket Cut the time savings from the zero time second bucket

off of the spotting time.off of the spotting time.

Staggered Tandom LoadingStaggered Tandom Loading

As the truck comes in the firstLoader hits it on the fly like itWas chain loading.

The truck then spots

During that time the two loadersWere filling their buckets andAre ready to go in dump timeOnly.

Illustrative CaseIllustrative Case

• Suppose the truck will take 4 passes to loadSuppose the truck will take 4 passes to load• It will take the truck about 1 minute to spotIt will take the truck about 1 minute to spot• During that 1 minute loader #1 has dumped the During that 1 minute loader #1 has dumped the

first bucket infirst bucket in• Loaders #1 and #2 have loaded buckets and are Loaders #1 and #2 have loaded buckets and are

ready to dump in 0.05 minutesready to dump in 0.05 minutes

• At the end of 1.05 minutes the truck has 3 At the end of 1.05 minutes the truck has 3 buckets in placebuckets in place

My Motion Timing ContinuedMy Motion Timing Continued

• Now Loaders #1 and #2 go for another Now Loaders #1 and #2 go for another bucketbucket• Loader #1 takes its bucket and positions for the Loader #1 takes its bucket and positions for the

next trucknext truck• Loader #2 dumps its bucket into the truckLoader #2 dumps its bucket into the truck• This takes 0.75 minutesThis takes 0.75 minutes

• 1.8 minutes after the truck comes in to fill – 1.8 minutes after the truck comes in to fill – it is out the door and loader fleet is ready it is out the door and loader fleet is ready for the next truckfor the next truck

Now Lets Try to Get That One into Now Lets Try to Get That One into FPCFPC

• We report the truck exchange time as 1 We report the truck exchange time as 1 minuteminute

• We now have 0.8 minutes to put in 4 We now have 0.8 minutes to put in 4 buckets of materialbuckets of material• Tell FPC the loader cycle time is 0.2 minutesTell FPC the loader cycle time is 0.2 minutes• Tell FPC the first bucket time is 0.2 minutesTell FPC the first bucket time is 0.2 minutes• Done.Done.

Front End LoadersFront End Loaders

• We are not using Front End Loaders in this We are not using Front End Loaders in this example – but front end loaders are a example – but front end loaders are a trickier match to truckstrickier match to trucks• You need to check loading heightYou need to check loading height• How high must the loader lift the material to How high must the loader lift the material to

get it over the side of the truck and then nicely get it over the side of the truck and then nicely centered in the truck bed.centered in the truck bed.

Loading HeightLoading Height

21’ 5” to get over the side of a Cat793

Check Out a 980Check Out a 980

A 980 can only get up to about 11 feet – no go on 21.

In Fact a 994 (The Big One) Cannot In Fact a 994 (The Big One) Cannot Dump Above the Edge of a 793 TruckDump Above the Edge of a 793 Truck

Be Careful of loading height limits for Front End Loaders

Commentary on LoadingCommentary on Loading

• We have spent tremendous amounts of time We have spent tremendous amounts of time analyzing miniscule details of such things analyzing miniscule details of such things as how a truck loads or dumps – Whyas how a truck loads or dumps – Why• Suppose we lower the cost per ton for loading Suppose we lower the cost per ton for loading

and hauling ore by 1and hauling ore by 1cc• 9 million tons is $90,000 – your salary for the whole 9 million tons is $90,000 – your salary for the whole

yearyear

• Little parts of a cycle done millions of time Little parts of a cycle done millions of time each year become big differenceseach year become big differences

Penny Pinching In PerspectivePenny Pinching In Perspective

• If a mine comes out non-economic the first If a mine comes out non-economic the first impulse is to begin nit-picking every dimeimpulse is to begin nit-picking every dime• The decisions that shift NPVs by hundreds of millions The decisions that shift NPVs by hundreds of millions

of dollars deal with mine size, mine method, cut-off of dollars deal with mine size, mine method, cut-off grade, and financial structuregrade, and financial structure

• If the “Air-Craft Carrier” sized decisions have been If the “Air-Craft Carrier” sized decisions have been made wrong – penny pinching will usually not save the made wrong – penny pinching will usually not save the day.day.

• Don’t rely on Penny Pinching to decide whether you Don’t rely on Penny Pinching to decide whether you get to “play the game”get to “play the game”

• Penny Pinching deals with how you play the game – Penny Pinching deals with how you play the game – after you get into the game.after you get into the game.

Understanding How Loading Relates Understanding How Loading Relates to Other Mine Plan Issuesto Other Mine Plan Issues

• Loading Configurations change the width of the space Loading Configurations change the width of the space needed for loadingneeded for loading• Drive-by is usually chosen because it works in narrower spacesDrive-by is usually chosen because it works in narrower spaces

• Your working bench width influences your working slope Your working bench width influences your working slope which greatly alters your stripping ratio – a major effect on which greatly alters your stripping ratio – a major effect on economics.economics.

• Your working bench width also controls the size of a Your working bench width also controls the size of a practical mining “push-back” in an open pit minepractical mining “push-back” in an open pit mine

• Sketch out your loading plan considering vehicle sizes – Sketch out your loading plan considering vehicle sizes – berm widths, prudent clearances and turning radiusesberm widths, prudent clearances and turning radiuses• Then pick your loading configuration.Then pick your loading configuration.

Loading Configuration and Mill Loading Configuration and Mill OperationOperation

• Some of the Loading configurations discussed can Some of the Loading configurations discussed can greatly alter the truck loading time.greatly alter the truck loading time.• For an open pit where 30 minutes is a common truck For an open pit where 30 minutes is a common truck

cycle, saving 1 minute off of loading time will probably cycle, saving 1 minute off of loading time will probably not revolutionize costnot revolutionize cost

• It can greatly alter the number of trucks that one It can greatly alter the number of trucks that one loading point can handleloading point can handle

• This in turn can change the number of loading pointsThis in turn can change the number of loading points

• Smaller numbers of loading points or loading Smaller numbers of loading points or loading points close together usually cause feed quality to points close together usually cause feed quality to the mill to swing more wildly.the mill to swing more wildly.• Mills hate unstable ore conditions and usually protest Mills hate unstable ore conditions and usually protest

by sending recoveries to – well you know where.by sending recoveries to – well you know where.

PointPoint

• Understand that just a few numbers going Understand that just a few numbers going into FPC represent major decisions in how into FPC represent major decisions in how you will run the mineyou will run the mine

• Make wise decisions about how to run the Make wise decisions about how to run the mine and then make your FPC entries mine and then make your FPC entries match those decisions.match those decisions.• Don’t just blow numbers into FPC and expect Don’t just blow numbers into FPC and expect

good results.good results.

Now I Will Close In On That Rough Now I Will Close In On That Rough Design I Talked AboutDesign I Talked About

I’ll use the Fleet SizeSub-Tab what it does isShow me what I can doWith a variable numberOf trucks and 1 loader

(Remember I wanted toAvoid committing toA number of trucks orLoaders until I had anIdea of cycle time)

Tip on a FrustrationTip on a Frustration

The default numberOf trucks FPC triesIs 1 to 4.

I wanted 1 to 10.

I typed in the 10And nothingHappened.

I had to click inAnother field to makeThe change take.

Look at ResultsLook at Results

Things I see #1 – I can reach 9 million tpy with just one loader #2 – I need 4 of 5 trucks #3 – My production per truck keeps going up fairly linearly – suggests that I am not really “over-trucking my loader”

Jump Back to My Cycle Times TabJump Back to My Cycle Times Tab

It takes about 38 minutes for a truckTo make a trip but only 3 minutesTo load

38/3 = 12.67

I would need 13 trucks to over-truckMy loader.(Over-truck means I have so manyTrucks that the loader is theProduction limit).

This is under-trucked – availability ofTrucks controls production.

What Did I Do?What Did I Do?

• I just got the program to help me ratio my trucks I just got the program to help me ratio my trucks and loaders without me doing any guessing or hand and loaders without me doing any guessing or hand calculation.calculation.

• Now I’ll go back and change # of trucks to 5.Now I’ll go back and change # of trucks to 5.

Check My Fleet ProductionCheck My Fleet Production

Yup – I need 87% of my scheduledTime to do 9,000,000 tons of oreWith 5 trucks and one cable shovel.

Issues that RemainIssues that Remain

• I need to check my Ton-Mile-Per-Hour I need to check my Ton-Mile-Per-Hour RatingsRatings• (make sure I’m not running my trucks around (make sure I’m not running my trucks around

so fast that I overheat and blow-out the tires)so fast that I overheat and blow-out the tires)

• I need to enter my cost data and see the costI need to enter my cost data and see the cost• I need to consult with my mill and ore I need to consult with my mill and ore

reserve modeling people.reserve modeling people.

Why the ConsultWhy the Consult

• I am feeding the mill from one load point onlyI am feeding the mill from one load point only• My ore reserve people can estimate the typical changes My ore reserve people can estimate the typical changes

in ore grade going to the millin ore grade going to the mill• My mill people can tell me whether this will upset my My mill people can tell me whether this will upset my

recovery rates at the mill (financially upsetting the mill recovery rates at the mill (financially upsetting the mill will cost more at most metal mines than optimizing my will cost more at most metal mines than optimizing my truck and loader fleet can save)truck and loader fleet can save)

• It is very possible we will be told that our trucks It is very possible we will be told that our trucks and loaders are too darn big for practical grade and loaders are too darn big for practical grade control at a mine this size.control at a mine this size.

Lets Put the Tire Heating Issue to Lets Put the Tire Heating Issue to RestRest

A Cat 793 needs 46/90R57 Tires

The tire is rated at 630 ton miles per hour(ie a load of 1 ton on 1 tire traveling at 1Mile per hour is 1 ton mile per hour)

(The tables are from the Cat Handbook)

Enter This Into FPCEnter This Into FPC

I am going to the fleet input tab and using the Tmph Limit field.

Now For ResultsNow For Results

Go for the Production andCost Tab and theTire Temp Subtab.

We See the Average Number of We See the Average Number of Tons Load on Each TireTons Load on Each Tire

Interesting to note that it’s the front tires that take the worst load (these tires areNot double like those in back)

We Check Tire Heating at the Technical We Check Tire Heating at the Technical Maximum Speeds for the TruckMaximum Speeds for the Truck

As we can see we are just barely over-rating on the front tires.

Then We AdjustThen We Adjust

A real operator never operates the truck and mechanical theoretical maximum andA real operator does not work an 8 hour shift with no breaks (remember the 84%Shift efficiency). Assume this allows some tire cooling and we are at 82% ofTire capacity. We won’t blow out the tires.(if the temperature is 120 or 140 for long periods of time we would have to reduceThe tire rating. If we ran a driverless truck we might also have an issue).

Time for the Cost IssueTime for the Cost Issue

• For this I will simply illustrate putting in For this I will simply illustrate putting in information for another truck. (not our 793) information for another truck. (not our 793) but it gets the point across.but it gets the point across.

Truck Production CostsTruck Production Costs

• Divided into Ownership and Operating Divided into Ownership and Operating CostsCosts

• Ownership includesOwnership includes• Annualized Investment CostsAnnualized Investment Costs• Taxes and InsuranceTaxes and Insurance• Tax advantagesTax advantages

• Operating Costs are Incurred as Vehicle Operating Costs are Incurred as Vehicle performs serviceperforms service

Operating CostsOperating Costs

• FuelFuel• TiresTires• LubricantsLubricants• RepairRepair• OperatorsOperators

Setting Costs In FPCSetting Costs In FPC

Use the HourlyCost Button

On Fleet Input Tab

Sub Menu Divides Owning and Sub Menu Divides Owning and Operating CostOperating Cost

Using Menu Requires a lot of side Using Menu Requires a lot of side calculationscalculations

Latest Editions of Cat HandbookHas removed cost estimatingSections. Have to revert toEarlier issues (which we haveOnline)

Lets Go for Fuel First

Getting Fuel Consumption RatesGetting Fuel Consumption Rates

Info from 29th Ed Cat Handbook

Our Conditions are Medium

Our truck isA 777

We getAbout17 gallons/hr

We assumed$2.0/gal.17*$2=$34/hr

Input Our Fuel CostInput Our Fuel Cost

Lets go for the LubeFilter, Oil and Grease

(Ok – you would not buy $1/gallon really)

Enter the Lube/Filter/GreaseEnter the Lube/Filter/Grease

Terex rule of thumb wasHigh and 10% of fuel

Undercarriage is a dozerOr tracked machineThing – 0 here

Repair Reserve Next

Vehicle Life Impacts Repair CostsVehicle Life Impacts Repair Costs

Cat 777 will last 40,000 to60,000 hours

Under Average ConditionsAbout 50,000

Table from Cat Handbook29th Edition (online)

Repair Reserve TablesRepair Reserve Tables

Cat 777 has a baseRepair reserve costOf $10/hour

Actual cost Varies with Life of Actual cost Varies with Life of MachineMachine

If we go forA 50,000 hourLife we willPay about1.5 times whatIs in the tableOr $15/hour

Enter Our DataEnter Our Data

Lets do TiresNext

Need to Get Tire LifeNeed to Get Tire Life

Where most tires wear outBut some cut is zone B

An average is 3,000 hours

If retread cost is about 1.5Times normal tire andLife is about 1.75

Cat Handbook does notGive a cost.

Western Mine Cost Service Has Western Mine Cost Service Has Books of CostsBooks of Costs

Including Tires in theSupply section

This resource isAvailable online forStudents or bySubscription fee forCommercial users.

Find Our 100 Ton Cat 777Find Our 100 Ton Cat 777

Lists about $8,881

A Calculation of Tire CostA Calculation of Tire Cost

• 6 tires * $8,900 each is $53,4006 tires * $8,900 each is $53,400• Because of heating considerations I’m not Because of heating considerations I’m not

retreadingretreading• $53,400 / 3,000 hours = 17.8/hour$53,400 / 3,000 hours = 17.8/hour

Adding into FPCAdding into FPC

Now Lets Go forOperator

Western Mine Cost Service Has Western Mine Cost Service Has Labor SurveysLabor Surveys

Production TruckDrivers gettingAbout $15.6

Another Source Is the US Bureau of Another Source Is the US Bureau of Labor StatisticsLabor Statistics

Note that I can pullPay and Benefit byArea and Occupation

Industries Are Listed By NAICS Industries Are Listed By NAICS Code NumbersCode Numbers

Find the Best MatchFind the Best Match

Looks like mineMachine operatorsIn quarries average$15.9 /hr

Comment on EstimatingComment on Estimating

• In addition to books, manuals and internet sourcesIn addition to books, manuals and internet sources• Remember the Buddy NetworkRemember the Buddy Network• Excerpts from Trade JournalsExcerpts from Trade Journals• Your Companies Own Historical Cost RecordsYour Companies Own Historical Cost Records• Local Union Contracts or State Wage ScalesLocal Union Contracts or State Wage Scales• Vendor QuotesVendor Quotes

Cooking Our EstimateCooking Our Estimate

• Normally there are other costsNormally there are other costs• Unemployment, workers comp, social security, Unemployment, workers comp, social security,

vacation, health etc.vacation, health etc.• You can calculate specifically or use rule of You can calculate specifically or use rule of

thumb estimatingthumb estimating• 40-60% burden40-60% burden• I’ll go at low end for quarryI’ll go at low end for quarry

• 1.4 * $15.75 = $22.051.4 * $15.75 = $22.05

Input and Switch to OwnershipInput and Switch to Ownership

Hmm – Looks likeIt costs about$70.2/hr to run.

One of My First Issues in How Long One of My First Issues in How Long it Will Lastit Will Last

Input My KnownsInput My Knowns

I already scheduled2772 hrs per yearWith 80% availabilityIn my example

I also know the truck should last about 50,000 hours

At 2,218 hours per year that about 22.5 years

Getting My Truck CostGetting My Truck Cost

Looks like I’ll beAbout $1,062,000For my Cat 777

Using WesternMine CostService

Price and TiresPrice and Tires

Most Prices are Quoted at theFactory – Your have freightAnd assembly (I added a littleExtra as you saw)

Tires are a wear item so oftenThey are deducted from the priceTo avoid double counting

Truck weighs 161,000 lbs or1,610 units of 100 lbs – use $4/100Weight rule to estimate freight about$7,000 double for assembly

The Issue of Taxes and InsuranceThe Issue of Taxes and Insurance

Rule of thumb is that Tax and InsuranceAre about 5% (2.5% each) ofAverage Annual Investment(I wish they would call it average annual value)As vehicles values go down so does tax on insurance

Average value of calculation is

(N+1)/2N * Cost where N is life

Substitute and crank

33/64*$1,600,000 = $825,000 * 0.025 = $20,625

Griping About FPCGriping About FPC

• FPC does not handle time value of moneyFPC does not handle time value of money• Taxes and Insurance are high in the early Taxes and Insurance are high in the early

years and low in the late yearsyears and low in the late years• A mathematical average does not show what A mathematical average does not show what

this can do when investors are looking for a this can do when investors are looking for a return on moneyreturn on money

The Interest ProblemThe Interest Problem

• If money is borrowed most of the interest If money is borrowed most of the interest comes earlycomes early• I’ll show a method for getting time value of I’ll show a method for getting time value of

money into it even if FPC tries to ignore it.money into it even if FPC tries to ignore it.

From Engineering Economics Get the Interest From Engineering Economics Get the Interest Rate Comparison SpreadsheetRate Comparison Spreadsheet

Standard Fixed Period Compound Interest Loan

9 Interest Rate1 Number of Compounding Periods/Year

0.09 Period interest rate (as a decimal)1 Number of Payments/Year

0.09 Payment Interest Rate (as a decimal)10 Years for Loan Payoff

1600000 Loan Amount0 Down Payment Required0 Set Up Fees0 Set Up Fees Rolled into Loan0 Points Up Front 0 Points Cost0 Points Rolled into Loan 0 Points Cost

249312.1 Initial Guess for Payment

249312.1 Payment Amount249312.8 Final Payment Amount893121.7 Interest Paid

0 Fees Paid

Put in that I borrowMoney at 9% over10 years to pay forThe Truck

The Spreadsheet Gives a Yearly The Spreadsheet Gives a Yearly History of Interest PaymentsHistory of Interest Payments

Period Debt Interest Payment Principal1 1600000 144000 249312.1 105312.12 1494688 134521.9 249312.1 114790.23 1379898 124190.8 249312.1 125121.34 1254776 112929.9 249312.1 136382.25 1118394 100655.5 249312.1 148656.66 969737.6 87276.38 249312.1 162035.77 807701.8 72693.17 249312.1 176618.98 631082.9 56797.46 249312.1 192514.69 438568.3 39471.14 249312.1 209841

10 228727.3 20585.46 249312.8 228727.311 0 0 0 012 0 0 0 0

Use Excels Copy functionAnd copy the interestColumn and paste it intoClass Assistant(Another EngineeringEconomics Spreadsheet)

Paste My Interest Cash Flow Into the Paste My Interest Cash Flow Into the Cash Flow Analyzer in Class AssistantCash Flow Analyzer in Class Assistant

Get the Total Life Cycle Cost of the Get the Total Life Cycle Cost of the InterestInterest

A typical mine looksFor 15% rate of return

The truck goes intoAlmost immediateService – time zero

Lasts for 32 years

An equivalent streamOf interest over 32Years is $79,378

Plug it Into FPCPlug it Into FPC

I could have doneThe total lifeCycle cost trick toThe InsuranceAnd Property TaxToo

At this point I know it costs me$107.85/hr to own the truck

When I Click Ok on the Subscreen I Know When I Click Ok on the Subscreen I Know Have Total Hourly Cost for My TruckHave Total Hourly Cost for My Truck

See! There it is!

This Still Needs to Be Done for My This Still Needs to Be Done for My LoaderLoader

• Much will be the same as we just did for our truckMuch will be the same as we just did for our truck• A Couple tid-bits for cable shovelsA Couple tid-bits for cable shovels

• The repair cost is a function of digging conditions and The repair cost is a function of digging conditions and tonnage movedtonnage moved

• Very Hard 5 cents/tonVery Hard 5 cents/ton• Hard 4 centsHard 4 cents• Medium 3 centsMedium 3 cents• Easy 2 centsEasy 2 cents

• Cable Shovels use about 0.6 KWH of electricity Cable Shovels use about 0.6 KWH of electricity per cubic yard of loose rock moved.per cubic yard of loose rock moved.

FPC Strengths and WeaknessesFPC Strengths and Weaknesses

• It goes into truck and loader fleets in a very It goes into truck and loader fleets in a very complete way.complete way.

• Weakness – It calculates a specific load of Weakness – It calculates a specific load of material over a specific road with a specific truck material over a specific road with a specific truck fleetfleet• May be more than one road to move the load to the May be more than one road to move the load to the

destinationdestination• FPC has no selection capacity beyond what you selectFPC has no selection capacity beyond what you select

• MineSight has a built in haulage routineMineSight has a built in haulage routine• If there is more than one route it just picks the shortestIf there is more than one route it just picks the shortest

• In practice roads may have different capacities and you In practice roads may have different capacities and you regulate traffic flow on the flyregulate traffic flow on the fly

• No standard package can optimize thisNo standard package can optimize this

FPCs Catastrophic WeaknessFPCs Catastrophic Weakness

• Probability of AvailableProbability of Available• It treats the entire truck and loader fleet as one It treats the entire truck and loader fleet as one

entity each.entity each.• Ie – if the trucks are 90% available then the entire Ie – if the trucks are 90% available then the entire

truck fleet is available 90% of the time and the truck fleet is available 90% of the time and the entire fleet is down 10% of the time.entire fleet is down 10% of the time.

• If loaders are 90% available then all loaders work If loaders are 90% available then all loaders work 90% of the time and all loaders are down 10% of the 90% of the time and all loaders are down 10% of the timetime

• Over-all production available 0.9*0.9 = 0.81Over-all production available 0.9*0.9 = 0.81• 81% of the time81% of the time

The ImpactThe Impact

• FPC is right if you have 1 truck and 1 loaderFPC is right if you have 1 truck and 1 loader• Reality of 5 trucks is thatReality of 5 trucks is that

• You can have 5 trucks runningYou can have 5 trucks running• 4 trucks running4 trucks running• 3 trucks running3 trucks running• 2 trucks running2 trucks running• 1 truck running1 truck running• The whole darn fleet downThe whole darn fleet down

• No it does not all average out – you bunching and fleet No it does not all average out – you bunching and fleet match verymatch very

• FPC under-predicts your fleet capacityFPC under-predicts your fleet capacity• (some suggested cycle times are optimistic so they get some (some suggested cycle times are optimistic so they get some

cancelation by luck – but for millions of dollars luck is rather cancelation by luck – but for millions of dollars luck is rather lame)lame)