Matching Shovels

©Dr. B. C. Paul 2000 revised 2008Note – Matching procedures depicted in these slides are widely

understood among those schooled in the subject and can be found in many handbooks or manufactures literature. These slides include

reproductions from the Caterpillar Performance Handbook and equipment literature from P+H. Also included are screen shots from

the FPC computer program by CaterpillarEquipment Company.

Match Up a Hydraulic Front Shovel

• As with FELs we want a shovel that• Fills the truck in a logical integer number of

passes• Can get the material over the edge of the truck• Center the load in the truck

• For Material• Easy Load stockpile 1 to 1.1• Average 0.95 to 1• Rather Difficult 0.9 to 0.95• Difficult 0.85 to 0.9

• Note Hydraulic Front Shovel get better fill and have better bucket maneuvering

Zoom in on a Bucket Size

About a 0.93 fill is quite safe to guess

102/0.93*#of passes = bucket size• 3 passes 36.56 yd^3 (pretty big)• 4 passes 27.42 yd^3• 5 passes 21.93 yd^3

Go Shopping for a Front Shovel

Cat’s Front Shovels areSomewhat limited (we willUse them in our example)Hitachi and others have someExcellent offerings.

Only the 5230B is in theSize range we are lookingFor with a 22.2 yd^3 bucket

Buckets Limited in Front Shovel Configuration

Fill Factor = 102/(5*22.2) = 0.9189 – ie about 92%Reasonable for our material and matches the truck with anInteger number of passes

Checking on Loading Height and Reach

Over 36 feet up – ya thatWill load a 16 ft high truckWell over 12 feetExtension definitelyReaches the center of thetruck

Just in case we are notSure it shows the dimensionsOf a 785 truck

Note This

Even a big front end loader struggles with lift and reach

Hydraulic Front Shovels really have almost no challenge if they are sized anywhere close to right

Time to Input into FPC

I will create a 2nd

Fleet for comparisonClick Add New Fleet

Input name anddescription

Input My Same Truck Info

Now we willSelect a loader

Pick My 5230B Front Shovel

Select Cat StandardMachines

Select HydraulicExcavators

Pick the 5230B fromThe list

Click Ok

Check Out Cycle Time

The Cat program defaults to single truck loading• 0.7 for the truck exchange• 0.05 to dump first bucket• 0.48 min for each subsequent pass (4)• Total 2.67 minutes

20 minute truck cycle / 2.67 loader cycle• One loader can handle 7.5 trucks• Pick 2 loaders

Adjust My FPC inputs

2 loaders

85% availability

92% Fill Factor

Try Matching a Cable Shovel

Cable Shovels Favor Larger Sizes Their buckets are called dippers Their Dippers are rated on struck-

not heaped capacity

Fill Factors by Material Constraint

Cable Shovels have more limited motion than a hydraulic front shovel

Easy - Sand and Gravel get about 0.95 to 1 Medium - Unconsolidated - some boulders 0.90

to 0.95 Hard - Well Blasted - has void space

(Limestone) 0.8 to 0.9 Very Hard - Interlocking Chunks 0.7 to 0.8

If We Estimate Fill Factor at 0.93

Size Dipper = Truck Volume/(#passes*fill factor)• 102 cubic yard truck volume limit

3 Passes 36.6 cubic yard 4 Passes 27.4 cubic yard 5 Passes 21.94 cubic yard

Cat Handbook Limitation

Cat Does not make cable shovels• They do put P+H products in their

program

Lets Fish a Little with the Program

I created a 3rd fleetAnd put in my 10 cat785s

When I selected aLoader I picked CatStandard Machines(even though P+H isNot Cat)Picked Power Shovel

List shows 2300 and2800 are my size

Checking Out the Choices

2300XPA has a 27 cubic yard standard dipper• 4 Pass load

• 102/(27*4) = 0.944 still in range of medium material

• 3 Pass load – 2800XP• 102/(39*3)= 0.872 this will probably be

limiting fill by truck size• Lets pick the 2800XP

Information Goes In

Now we need someNumber and availabilityAdjustments

Cable Shovels areRugged and veryAvailable – usually0.9

We also back calculatedOur fill factor at 88%

Input the Easy Pickens

88% Fill

90% availability

Now we need toEstimate how manyLoaders.

Cycle Time For Loading a Truck

0.7 minutes truck change out 0.05 minutes for first dump 0.5 minutes for each of 2

remaining Total = 1.75 minutes Truck Cycle 20/ 1.75 = 11.4 trucks

• Lets go with just 1 loader

What if I Want to Check Loading Height Etc.

Go to My CoursesWeb Site

Pick the ReadingRoom.

In the Reading Room Scroll down to Surface Mining

Scroll Down to Electric Mining Shovels

Pick the PDF file forA P+H2800

Pick off the Manufactures Specs You Need to Check