SHOVEL TRUCK HAULAGE

MATERIAL HANDLING 2011

CHAPTER 1

INTRODUCTION

1.1 PROBLEM DEFINITION

SHOVEL TRUCK HAULAGE

Tarkwa Rocky Gold Mining Company is proposing to develop a new open pit mine. Overburden will initially be removed by scraper and is therefore not the subject of this problem. The remaining oxidised ore must be drilled, blasted and transported to a crusher dump point, where it will be dumped for a front-end-loader to rehandle into the crusher. The anticipated haul profile for the first five years is given in Table 1. Speed limit is 44 kmph.

Table 1 Haul Profile from Mining Face to Crusher

Haul Segment Length (ft) Rolling Grade (%) Remarks Resistance (%)1 400 (122m) 3 0 Pit Bottom2 1700 (518.2m) 2 83 800 (243.8m) 4 34 2800 (853.4m) 2.5 85 900 (274.3m) 3 86 1600 (487.7m) 3.5 -27 300 (91m) 4 0 Crusher Approach 8500 (2610.4m)

The ore material is quite hard and fragments badly upon blasting and therefore management has recommended the use of diesel powered hydraulic front shovels for the excavation. However, the best shovel (model) is to be investigated and selected. Since Tarkwa Rocky Gold Mine has got a long-standing relationship with Caterpillar, it intends to consider only Caterpillar shovels. They are considering two models of hydraulic shovels. Table 2 presents some details on the shovels and their specifications.

Table 2 Shovel Data Model 5110 5130Bucket Capacity 7.8 m3 9.5m3

Operating Weight 120000kg (264500lbs) 179000kg (390000 lbs.)Flywheel Kilowatt 447kw (600hp) 563kw (755hp)Availability 0.91 0.92Economic Life (hr) 25000 40000Cycle Time (min) 0.43 0.46

1MINI PROJECT GROUP 12


The loose density of blasted ore = 2.2t/m3 (141.63 lb/ft3)Material swell = 20%Size range = Run-of-mineClimate = TropicalAltitude = 200m (656ft)Quantity of material to be hauled per year = 12000000 tonnes

The company is considering a selection of two types of rear dump trucks manufactured by Euclid: EUR50C (50 ton capacity), EUR100C (100 ton capacity)

Table 3 presents data on each of these trucks.

Table 3 Data on Trucks

Truck Type EUR100C EUR50CManoeuvre and Dump time (min) 1.2 1.0Spot time (min) 0.55 0.45Availability 0.87 0.87Economic life (hr) 30000 30000

1. Determine the shovel model (size) and truck model (size) and the corresponding shovel and truck fleets that will be required to meet production target, taking into consideration both technical and economic factors.

Make assumptions where necessary, justify your assumptions. Make use of the Terex Vehicle performance and retarder charts and speed factors.

2. Present your results in the form of a report Each member of a group should actively participate in the work. This will be ascertained

during an oral defense at the end of the semester. Make use of all recommended textbooks and class notes. Consult lecturer for clarification

when necessary.

1.2 OBJECTIVES OF PROJECTTo determine the shovel model (size) and the truck model (size) and the corresponding shovel and truck fleets that will be required to meet production target, taking into consideration both technical and economic factors.

1.3 SCOPE OF WORKThis project work is limited to the process involved in the selection of Model Trucks and caterpillar Shovels for the most economic and optimum production of Gold at Rocky Gold Mining Company, Tarkwa.



CHAPTER TWO

COMPARING ECONOMIC LIFE OF EACH SHOVELWITH THE ANTICIPATED HOURS OF THE MINE.

Anticipated years of operation = 5 years

Number of days of working = 304 days

(Taking into consideration 52 Sundays of not working plus 10days considered as holidays by management)٭

Number of effective hours of working per day = 21 hours (One hour delays for each of the 3 shifts)

Quantity of material to be hauled per year = 12000000 tonnes

Quantity of material to be hauled per day = 12000000

304 = 39473.68 tonnes / day

Quantity of material to be hauled per hour =39473.68

21 = 1879.70 t/hr

Number of hours the shovel would be put to work in a day = 20 hrs ٭

Number of hours the shovel would be put to work in a year = 20× 300 = 6000 hrs

Number of hours the shovel would be put to work in five years = 6000× 5 = 30000 hrs

From our result above, it is clearly seen that it is not advisable to go in for the shovel model 5110 unless two of them is to be purchased since it has a lesser economic life hours (25000 hrs) than -anticipated.

However, this may not warrant rejection since it may make it up for the other factors of much importance.

Please note: all remarks with symbol ٭ are assumptions.



2.1 Considering Truck Model EUR 100C

Travel Time

Truck gradeability when loaded:

Gradeability = GrossVehicle Weight (GVW )

Horse Power( Hp)

= 3489001050

= 332.29 1bs/hp

This lies between 300 – 380 1bs/hp

2.2 Travel Time

Table 2.1 Travel Time When Loaded

Haul Seg. Length in (ft). RR (%) GR (%) TR (%) Max Vel.(Km/hr)

SF Mean Vel. (Km/hr)

Time (sec)

1234567

400 (122m)1700 (518.2m)800 (243.8m)2800 (853.4m)900 (274.3m)1600 (487.7m)300 (91m)

3242.533.54

08388-20

3107

10.5111.54

43152113125634

0.431.001.001.001.000.890.44

18.49 (5.14m/s)15.00 (4.17m/s)21.00 (5.83m/s)13.00 (3.61m/s)12.00 (3.33m/s)44.00 (12.22m/s)14.96 (4.16m/s)

23.74124.2741.82236.4082.3739.9121.88

Total Time = 570.39

Please Note: Mean Vel. Value for Haul Seg. 6 is originally, 49.84 km/hr (13.844m/s) but has been cut down to the speed limit 44km/hr as required.

5 6

4 7

3

1 2



Some interpolations that were made:

Haul Seg.6 = 2000−15011600−1501 = 0.91−0.88

x−0.88

x=0.89

Hence, the S.F for haul seg. 6 is 0.89.

Haul Seg.7 = 400−201300−201 = 0.48−0.39

x−0.39

x=0.44

Hence, the S.F for haul seg. 7 is 0.44.

Truck gradeability when empty:

Gradeability = Net VehicleWeight (NVW )

Horse Power (Hp)

= 1489001050 = 141.81 lb/hp

This lies under 300 lb/hp

Table 2.2 Travel Time When Empty

Haul Seg. Length (ft) RR (%) GR (%) TR (%) Max Vel. SF Mean Vel. (Km/hr)

Time (sec)

7654321

300 (91m)1600 (487.7m)900 (274.3m)2800 (853.4m)800 (243.8m)1700 (518.2m)400 (122m)

4.03.53.02.54.02.03.0

0.0 2.0-8.0-8.0-3.0-8.0 0.0

4.0 5.5-5.0-5.5 1.0-6.0 3.0

55.055.059.059.055.059.055.0

0.441.000.810.960.800.910.70

24.20 (6.72m/s)44.00 (12.22m/s)44.00 (12.22m/s)44.00 (12.22m/s)44.00 (12.22m/s)44.00 (12.22m/s)38.50 (10.69m/s)

13.5439.9122.4569.8419.9542.4111.41

Total Time = 219.51


MATERIAL HANDLING 2011Total Time Travelled = 570.39 + 219.51

= 789.9 seconds

= 13.17 minutes

2.3 Cycle Time with Shovel Model 5110

Cycle time = Spot & Load Time + Travel Time + Turn & Dump Time

For The Spot & Load Time

Pay Load of Truck (100c) = 100 ton

= 200000 lbs

Tonnage per pass = dipper volume x loose density x fill factor (Assumed to be 0.9)

= 7.8m3 x 2.2t/m3 x 0.9

= 15.44t

= 34029.76 lbsNB 1tonne=2204Ibs

Number of passes, Pt =payload

tonnage / pass=¿ 200000lbs

34029.76lbs

= 5.88 ≈ 6 passes

Actual payload of Truck = Number of passes x tonnage/pass

= 6 x 15.44t

= 92.64t

Spot time = 0.55 min > shovel cycle time = 0.43 min

Spot and load time = NptIC + tS –tlC

= (6x 0.43) + 0.55 – 0.43

= 2.70 minutes

Manoeuvre and Dump time = 1.2min

Truck Cycle Time = Spot & load time + total truck travel time + manoeuver and dump time

= 2.7 + 13.17 + 1.2

= 17.07 minutes6MINI PROJECT GROUP 12


Production per one Truck in Hour

=60 x Actual load (t ) x Productivity factor

CycleTime (min)

Actual Load = Number of passes x tonnage per pass

= 6 x 15.44 = 92.64t

Production = 60 x 92.64 x 0.85 ٭

17.07

= 276.78 t/hr

.is assumed value for productivity factor ٭0.85

Number of Operating Trucks = Required Production/h rProductionof Truck /hr

= 1879.70tonnes /hr276.78tonnes /hr

= 6.79

Truck fleet = Number of operating trucks

Availability

= 6.790.87

= 7.80 ≈ 8 trucks

Number of Shovel required, NL

= Required tonnage /hr x Spot∧load time

Truck actual load x60 x prouctivity factor

= 1879.70 x2.7

92.64 x60 x 0.85

= 1.07

Availability of shovel = 0.91

Number of shovels = 1.070.91


MATERIAL HANDLING 2011 = 1.1 ≈ 1 shovel

CheckMaximum number of trucks to match shovel

=truck Cycle timeSpot∧load time

= 17.07 minutes

2.70 minutes = 6.32

= 6.32 x 1.07

= 6.76 ≈ 7 trucks

2.4 Cycle Time With Shovel Model 5130 Cycle Time = Spot and Load Time + Travel Time + Turn and Dump Time

For The Spot and Load TimeSpot time = 0.55min > Shovel Cycle Time = 0.46min Spot & Load Time = Nptlc + ts – tlc

Tonnage per pass = dipper volume x loose density x ( Assumed ) fill factor = 9.5m3 x 2.2t/m3 x 0.9 = 18.81t = 41457.24lbs

NB 1tonne : 2204IbsPayload of Truck = 100 tons

= 200,000 lbs

Number of Passes = 100 tons

18.81tons

= 5.3 ≈ 5 passes

Actual Payload of truck = 5 x 18.81 = 94.05 t

Spot & Load Time = (5 x 0.46) + 0.55 – 0.46

= 2.39 minutes

Manoeuvre and Dump Time = 1.2 min

Truck Cycle Time = 2.39 + 13.17 + 1.2


MATERIAL HANDLING 2011 = 16.76 minutes

Production per One Truck in an Hour

= 60. x Actual load (t ) x Productivity factor

CycleTime (min)

= 60 x 94.05 x0.85

16.76

= 286.19 t/hr

Number of operating trucks = Required Production/hrProductionof Truck /hr

= 1879.70tonnes /hr286.19tonnes /hr

= 6.57

Truck Fleet = Number of operating trucks

Availability

= 6.570.87

= 7.55 ≈ 8 Trucks

Number of Shovels, NL

= Required tonnage

hrx Spot∧Load Time

Truck actual load x60 x Productivity factor

= 1879.70 x2.39

94.05 x60 x0.85

= 0.94



= 1.02 = 1 shovel


MATERIAL HANDLING 2011CheckMaximum number of trucks to match shovel

= Truck cycle time

Spot∧Load Time = 17.022.7 = 6.3

= 6.30 x 0.94 = 5.93 trucks

= 6 trucks

CHAPTER THREE10MINI PROJECT GROUP 12


3.1 Considering Truck Model EUR 50C

Gradeability of truck when loaded

Gradeability = GrossVehicleWeight (GVW )

Horse Power( Hp)

= 177075

608

= 291.24 lbs/hp

This falls below 300 lbs/hp

3.2 Travel Time

Table 3.1 Travel Time When Loaded

Haul Seg. Length (ft) RR (%) GR (%) TR (%) Max Vel. SF Mean Vel. (km/hr)

Time (sec)

1234567

400 (122m)1700 (518.2m)800 (243.8m)2800 (853.4m)900 (274.3m)1600 (487.7m)300 (91m)

3.02.04.02.53.03.54.0

0.0 8.0 3.0 8.0 8.0-2.0 0

3.010.07.010.511.01.54.0

55.0015.5022.0015.0015.0055.0037.00

0.511.001.001.001.000.910.70

28.05 (7.79m/s)15.00 (4.17 m/s)22.00 (6.11 m/s)15.00 (4.17 m/s)15.00 (4.17 m/s)44.00 (12.22 m/s)25.90 (7.19 m/s)

15.66124.2739.90204.6565.7839.9112.66

Total Time = 502.83

Please Note; The original Mean Vel. for haul seg. 6 is 50.05km/hr (13.90m/s) but has been cut to 44km/hr which is the speed limit required.

Some interpolations that were made:

Haul seg. 6 = 2000−15011600−1501 = 0.93−0.90

x−0.90

x=0.91

Travel Time When Empty

Gradeability of truck when empty:



Gradeability = Net VehicleWeight (NVW )

Horse Power (Hp)

= 77075lbs

608 hp

= 126.77 lbs/hp

This also falls below 300 lbs/hp

Table 3.2 Travel Time When Empty

Haul Seg. Length (ft) RR (%) GR (%) TR (%) Max Vel. SF Mean Vel.(km/hr)

Time (sec)

7654321

300 (91m)1600 (487.7m)900 (274.3m)2800 (853.4m)800 (243.8m)1700 (518.2m)400 (122m)

4.03.53.02.54.02.03.0

0.0 2.0-8.0-8.0-3.0-8.0 0.0

4.0 5.5-5.0-5.5 1.0-6.0 3.0

54.0054.0058.0058.0054.0058.0054.00

0.451.000.810.960.800.910.70

24.3 (6.75 m/s)44.00 (12.22 m/s)44.00 (12.22 m/s)44.00 (12.22 m/s)43.20 (12.00 m/s)44.00 (12.22 m/s)37.80 (10.50 m/s)

13.4839.9122.4569.8320.3242.4111.62

Total Time = 220.02

Please Note; The original Mean Vel. of haul segments; 6, 5, 4 and 2 are 54.0km/hr (15.00m/s), 46 .98km/hr (13.05m/s), 55.68km/hr (15.47m/s) and 52.78km/hr (14.66m/s) respectively but have been reduced to 44km/hr which is the speed limit.

Some of the interpolations made:

S.F of haul seg 7 = 400−201300−201 =0.51−0.40

x−0.40

x=0.45

Total Travel Time = 502.83 + 220.02

= 722.85 seconds

= 12.04 minutes



MATERIAL HANDLING 2011Cycle Time = Spot & Load Time + Travel Time + Turn & dump Time

For The Spot and Load time Payload of Truck (50c) = 50 ton

= 100,000 lbs

Tonnage per pass = dipper volume x loose density x (Assumed) fill factor = 7.8m3 x 2.2t/m3 x 0.9 = 15.44 t = 34029.76 lbs

Number of Pass, Pt = payload

tonnage / pass=¿

100,000lbs34029.76lbs

= 2.94

= 3 passes

Actual Payload of Truck = 3 x 15.44 t = 46.32 t

Spot Time = 0.45 min > shovel cycle Time = 0.43 min

Spot and Load Time = Nptlc + ts - tlc

= (3x0.43) + 0.45 – 0.43 = 1.31 min

Manoeuvre and Dump Time = 1.0 minutes

Truck Cycle Time = 1.31 + 12.04 + 1.0 = 14.35 minutes

Production Per One Truck in an Hour

= 60 x Actual load (t ) x Productivity factor

CycleTime (min)

= 60 x 46.32 x0.85 ٭

14.35 = 164.62 t/hr

is the assumed productivity factor٭0.85

Number of Operating Trucks = required Production/hrProductionof Truck /hr



= 1879.70t /hr164.62t /hr

= 11.41


Availability

= 11.410.87

= 13.11 ≈ 13 trucks

Number of shovels required, NL= Required tonnage

hrx spot∧load time


= 1879.70 x1.31

46.32 x60 x0.85 =1.04



= 1.14 ≈ 1 shovel


= Truck cycle timeSpot∧load time

= 14.351.31

= 10.95 = 10.95 x 1.04

= 11.39 trucks ≈ 11trucks


Cycle Time = Spot and load Time + Travel Time + Turn and Dump Time



The Spot and Load Time Spot Time = 0.45mins ˂Shovel Cycle Time = 0.46 min.

Spot and Load Time = Nptlc

Payload of Truck (50 c) = 50 ton = 100,000 lbs

Tonnage per pass = dipper volume x loose density x (Assumed) fill factor = 9.5m3 x 2.2t/m3 x 0.9 = 18.81 t = 41457.24 lbs

Number of Passes Pt = 100,000 lbs

41457.24 lbs

= 2.41 ≈ 2 passes

Actual Payload of Truck = 2 x 18.81 t = 37.62 t

Spot and Load Time = 2 × 0.46 = 0.92 minutes

Manoeuvre and Dump Time = 1.0 mins

Truck Cycle Time = 0.92 + 12.04 + 1.0 = 13.96 minutes

Production Per one Truck in an Hour

= 60 x Sctual Load (t ) x Productivity factor

CycleTime (mins)

= 60 x 37.62 x 0.85

13.96 = 137.44 t/hr

Number of Operating Trucks = Required Production/hrProductionof Truck /hr



= 1879.70t /hr137.44 t /hr

= 13.68


Availability

= 13.680.87

= 15.72 ≈ 16 trucks

Number of Shovel required, NL

= Required tonnage /hr x Spot andLoadtime


= 1879.70 x 0.92

37.62 x 60 x 0.85

= 0.90



= 0.98 ≈ 1 shovel


= Truck CycleTimeSpot∧load time

= 13.960.92 = 15.17

= 15.17 x 0.98 = 14.87 trucks = 15 trucks

CHAPTER FOUR

4.1 Observations



Table 4.1.1 Data on ShovelModel 5110 5130Bucket CapacityOperating WeightFlywheel KilowattAvailability Economic life (hr)Cycle Time (min)

7.8m 3

120000kg (264500 lbs)447KW (600 hp)0.91250000.43

9.5m3

179000kg (390000 lbs)563KW (755hp)0.92400000.46

Table 4.1.2 Data on TrucksTruck Type EUR 100C EUR 50C

Manoeuvre and Dump time 1.2 1.0Spot time (min) 0.55 0.45Availability 0.87 0.87Economic life (hr) 30000 30000

It is observed from table 4.1.2 that the Economic Life of Shovel Model 5130 (40000hr) is

slightly above the anticipated years of operation (30000hr); while that for Shovel Model 5110

(25000) is less than the anticipated years of operation of Tarkwa Rocky Gold Mining Company.

Shovel Model 5130 again has a high Bucket Capacity and Flywheel Kilowatt than that for

Shovel Model 5110.

From Table 4.1.2, we realized that both Truck Model EUR100C and EUR50C have the same

Economic Life of 30000hr which matches with the anticipated years of operation.

Shovel Model 5110 is not suitable for the problem in question due to its limitation in capacity

and economic life.

Table 4.1.3 Calculated result on Truck EUR 100CType of Shovel Number of passes Tonnage per hour Number of

ShovelsNumber of truck to Shovel


MATERIAL HANDLING 2011Model 5110 6 15.44 1 7Model 5130 5 18.81 1 6

Table 4.1.4 Calculated result on Truck EUR 50CType of Shovel Number of passes Tonnage per hour Number of shovels Number of truck to shovelModel 5110 3 164.62 1 11Model 5130 2 137.44 1 15

It is also observed that both Shovels satisfy the recommendation that three to six (3 to 6) passes

should fill truck except for Shovel Model 5110 when matched with Truck Model EUR100C.

From Table 4.1.3 and Table 4.1.4, Truck Model EUR100C is observed to check well with Shovel

Model 5130 and Truck Model EUR50C is observed to check well with Shovel Model 5130

respectively.

Table 4.1.5 Comparing EUR100C & 5130 with EUR50C & 5110

Selection FactorsNumber of

Passes

Tonnage per

Hour (t/hr)

Number of

Trucks

Number of

trucks to

Shovel

Shovel Capacity

And Economic

Life

EUR100C with

51305 287.05 8 6

9.5m3

40,000hrs

EUR50C with

51302 137.44 16 15

9.5m3

40,000hrs

From Table 4.1.5, it can be observed that considering the various selection factors considered

Shovel Model 5130 offers the highest hourly tonnage matched with Truck Model EUR100C with

a lower truck fleet (8 trucks) and this also checks well.

Since both trucks and shovels have the same shovel capacity, same number of shovels, the same

dipper volumes, then we consider the number of trucks for economic reasons.


MATERIAL HANDLING 20114.2 Conclusion

Based on the above observation, Shovel Model 5130 and Truck Model EUR100C have been

selected since this match gives;

Higher tonnage rate per hour

Reduced logistic trouble (less truck fleet)

4.3 Recommendations Berms and escape lanes should be provided to improved safety. Traffic signs should be postal for velocity limits stops and intersection warnings. To avoid road damage, appropriate drainage ditches should be constructed,

a curve, the necessary super – elevation should be constructed to counteract the effect of centrifugal forces.

FIG 4.1 A Picture of a truck loading under a shovel

References


MATERIAL HANDLING 2011Cummins A. & Given I. (1973): SME Mining Engineering Handbook, Vol. 1. Port City Press,

New York.

Temeng, V.A. (2010): Lecture Notes on Material Handling (Unpublished). University of Mines

and Technology, Tarkwa.

Anon (2010) http://www.metric-conversions.org


http://www.metric-conversions.org/

SHOVEL TRUCK HAULAGE

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