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H A N D B O O K O F R I P P I N G

Twelfth Edition

HANDBOOKIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 5

Material Hardness and Rippability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 7

Rippability Investigation and Prediction Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 11

Ripping Equipment Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 - 14

Cat® Ripping Tip Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Ripping Equipment Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Ripping Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 - 19

Ripping Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 - 23

Special Ripping Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Estimating Ripper Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 - 26

Ripping vs. Drilling and Blasting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Ripper Compatibility Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 - 29

Caterpillar® Track-Type Tractor Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

H A N D B O O K O F R I P P I N G • T W E L F T H E D I T I O N

F E B R U A R Y 2 0 0 0 • C A T E R P I L L A R I N C . • P E O R I A , I L L I N O I S

w w w . C A T . c o m

Table of ContentsO F R I P P I N G

Production ripping is being used more andmore today as an alternative to drilling

and blasting with explosives. Actually, rippinghas a long history dating back to the RomanEmpire. There is evidence the Romans used aripper mounted on wheels and pulled by oxenwhen they were building the Appian Way.Rippers were also used in the United Statesduring railroad construction from 1860 to 1880.

History of the Ripper

The ripper as we know it today did notappear until approximately 1930. Rippersdrawn by tractors were developed by R.G.LeTourneau in 1931 and used on the HooverDam project. At that time, they weighed about7,500 pounds and were pulled by tractorswith about 75 flywheel horsepower(equivalent to today’s Caterpillar D4C track-type tractor). Their chief shortcomings weretheir clumsiness and poor penetration ability.If enough weight was added to obtain

adequate penetration, the tractors weren’tpowerful enough to pull them. Extra tractorswere often added until as many as threetractors were pushing or pulling a singleripper. These units achieved only limitedsuccess, usually in shale, clay, limestone,hardpan, cemented gravel, and frozenground.

Modern Rippers

Modern tractors of the ’50s and ’60sadvanced ripping capabilities by mounting theripper to the rear of the machine. This design,coupled with advanced hydraulic systems,more machine weight, and greater horsepower, greatly improved rippingperformance and efficiency.

These advances in performance were welcomed as environmental factorsbegan to limit or restrict conventional blastingtechniques. Urban encroachment, safety, andpollution concerns all have placed much

greater demands on customers’ ability to usedrill and blasting as a way to remove material.In the mining world, concern for mixingmaterials, process improvements (leachpads), and similar safety and environmentalconsiderations likewise increased interestin ripping.

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HANDBOOKIntroduction

O F R I P P I N G

Current tractors have become so successful in rippingapplications that 75% of the D8R – D11R are shipped fromthe factory with rippers.

% of tractors %equipped single %

with rippers shank multishank

D11 83% 82% 18%

D10 86% 75% 25%

D9 75% 72% 28%

D8 59% 57% 43%

The Current Cat Ripper

The current line of large Caterpillarelevated sprocket tractors made furtheradvancements with the suspendedundercarriage. The bogie system improvedoperator ride for increased comfort.

The bogie system also increased thetractive capability of the tractor by keepingmore track in contact with the surface. Thisincreased traction allows the machine to putmore usable horsepower into the job, lesstrack spin for less wear, and overallimprovement in cost per hour.

5

SummaryEnvironmental and safety concerns havemade production ripping a popularalternative to drilling and blasting.Design advances, including hydraulicenhancements, increased horsepower,and better traction, continue to improveripping performance and efficiency.

Not all materials or formations can beripped. Others cannot be ripped

economically. Determining whether or not arock formation can be ripped is not a simpleprocess, but today’s technology andexperience can help develop a reasonableprediction for each customer site.

Obviously, the ideal test for determiningrippability is to put a ripping tractor on thejob and see if it can rip the material – test bytrial. But this may not be practical due to thetime and expense involved. Therefore, inorder to determine if ripping is feasible, abasic knowledge of geology and rockcharacteristics affecting ripping is necessary.This knowledge is gained through on-the-jobexperience ripping in various formations.

When classified by origin, rocks fall intoone of three categories, with similarrippability characteristics existing within eachtype. Knowing the correct classification canoften help answer the question: “Can it beripped?”

Igneous Rocks are formed by thecooling of molten masses originating withinthe earth. Igneous rocks never contain fossils,are identified by their mineral content andtexture, and almost never have the stratified,banded, or foliated characteristics of otherrocks. They usually possess high compressiveand tensile strength. Granites, basalts,pegmatites, pitchstone, and pumice areigneous rocks commonly encountered onearthmoving jobs. Formations of these rocksare usually the most difficult to rip becausethey typically lack the stratification andcleavage planes essential to the successfulripping of hard rock. Igneous rocks areusually rippable only where they are deeplyweathered and/or very highly fractured. Theseconditions can readily be detected via fieldseismic surveys.

Metamorphic Rocks result from thetransformation of pre-existing rocks whichhave been changed in mineral composition,texture, or both. The agents causingmetamorphism in rocks are shearing stresses,intense pressure, chemical action fromliquids and gases, and high temperatures.Common metamorphic rocks are gneiss,slate, marble, quartzite, and schist. Theserocks vary in rippability depending on theirdegree of stratification or foliation. All arefound on or near the earth’s surface andusually occur as homogeneous masses.

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Material Hardness and Rippability

Igneous Rock Metamorphic Rock


Sedimentary Rocks consist of materialderived from destruction of previouslyexisting rocks. Water action is responsible forthe largest percentage of sedimentary rocks,although some result from wind or glacialpressure. Their most prominent feature isstratification, i.e., they are built of layersdiffering in texture, material, thickness, color,or a combination of these properties. Thislayering is referred to as bedding, andindividual layers, which are often uniform intexture, color, and composition, are referred to as beds. A single bed may vary inthickness from paper thin to several hundredfeet. Examples of common sedimentary rocksare sandstone, limestone, shale,conglomerate, and caliche. This family ofrocks is generally the most easily ripped.

The material condition of rock affects itsrippability. Although sedimentary formationsgenerally offer the best opportunity forripping, and igneous and metamorphic theleast, decomposed granites and otherweathered igneous and metamorphic rocksoften can be ripped economically.

Little or no trouble is encountered withhardpan, clays, shales, or sandstones.Likewise, any highly stratified or laminatedrocks and formations with extensivefracturing offer good possibilities for ripping.Solid, thickly bedded rock formations mayrequire drilling and blasting. A discussion ofripping vs. blasting, and when each may beconsidered appropriate, is included later inthis handbook.

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Sedimentary Rock

SummaryWhile some materials still cannot beripped or ripped economically, heaviermachines, improvements in horsepower,and advancements in tractor design aremaking ripping possible in moreapplications.

The physical characteristics whichfavor ripping may be summarized by:

1. Frequent planes of weaknessessuch as fractures, faults, andlaminations

2. Weathering3. Moisture-permeated formations4. High degree of stratification5. Brittleness6. Low strengths7. Low field seismic velocity

The list of conditions which make rippingdifficult is not nearly as long as it used tobe. Ripping tends to be more difficult ifthe rock formation is:

1. Massive2. Without planes of weakness3. Crystalline rock4. Non-brittle, energy-absorbing rock

fabrics5. High strengths6. High field seismic velocity

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Rippability Investigation & Prediction Service

Although visible laminations, faults, andfractures may indicate rippability and are

usually helpful, conditions which are notvisible are also important. That’s becausesurface features give only a clue as to what lies underneath. To determine rippability when afield trial is not feasible, a method of estimatingunderlying characteristics is required.

Caterpillar has developed a systematicanalysis procedure to predict the rippability ofa rock formation which combines new

technology with geological and rippingexperience. Our process for gathering theinformation necessary to make a prediction iscalled the Rippability Investigation andPrediction (RIP) service and is availablethrough Caterpillar research. (Contact yourdistrict office.) The service consists of threesteps:

1. Rock analysis2. Site inspection3. Seismic analysis

Rock MechanicsAnalysis

A rock mechanics analysis is the firstphase of the RIP service and requires that afresh rock sample be submitted to our lab foranalysis along with other pertinentinformation about the site. (Minimum samplesize should be 10" x 10" x 10".)

D8R RipperPerformance• Multi or Single

Shank No. 8Series D Ripper

• Estimated bySeismic WaveVelocities

Rippers

Seismic VelocityMeters Per Second x 1000 Feet Per Second x 1000

TOPSOILCLAYGLACIAL TILLIGNEOUS ROCKS GRANITE

BASALT

TRAP ROCK

SEDIMENTARY ROCKS SHALE

SANDSTONE

SILTSTONE

CLAYSTONE

CONGLOMERATE

BRECCIA

CALICHE

LIMESTONE

MET SCHIST

SLATE

MINERAL & ORES COAL

IRON ORE

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

0 1 2 43

RIPPABLE

MARGINAL

NON-RIPPABLE


Geological SiteInspection

The second phase of the RIP serviceconsists of a site visit by Caterpillar personnelwhich includes a geological inspection. Duringthe site inspection, the rock formation inquestion is examined for in-place rock masscharacteristics that may affect a rippingtractor’s performance. These may include rock type, degree of weathering, bedding features,

joint characteristics, and many other pertinentgeological features.

Seismic Evaluation

The third phase of the RIP service includesa seismic evaluation. Caterpillar introducedthe use of the refraction seismograph in 1958as an aid to determine rippability of materials.The instrument functions by measuringseismic velocity, an indicator of the degree ofconsolidation of rock formations. Caterpillarcontinues to offer this service, along withmany independent firms.

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Rippers


Shank Ripper• Estimated by

Seismic WaveVelocities

RIPPABLE

MARGINAL

NON-RIPPABLE



BASALT

TRAP ROCK


SANDSTONE

SILTSTONE

CLAYSTONE

CONGLOMERATE

BRECCIA

CALICHE

LIMESTONE

METAMORPHIC ROCKS SCHIST

SLATE

MINERALS & ORES COAL

IRON ORE

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

0 1 2 43

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Not all material conditions are visiblefrom the surface. To determine therippability of below-the-surface materialand formations, Caterpillar Inc. developed a systematic analysisprocedure based on technology and fieldexperience. The service consists of threesteps:

1. Rock analysis2. Site inspection3. Seismic evaluation

Rippers

Caterpillar Systematic Analysis




RIPPABLE

MARGINAL

NON-RIPPABLE

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15


0 1 2 43


BASALT

TRAP ROCK


SANDSTONE

SILTSTONE

CLAYSTONE

CONGLOMERATE

BRECCIA

CALICHE

LIMESTONE


SLATE


IRON ORE

Rippability Investigation & Prediction Service


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RIPPABLE

MARGINAL

NON-RIPPABLE

Seismic VelocityMeters Per Second x 1000 Feet Per Second x 1000 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

0 1 2 43

GLACIAL TILLIGNEOUS ROCKS GRANITE

BASALT

TRAP ROCK


SANDSTONE

SILTSTONE

CLAYSTONE

CONGLOMERATE

BRECCIA

CALICHE

LIMESTONE


SLATE


IRON ORE

Rippers

Selecting the proper ripping tools canmake the difference between just being

able to rip a material, and being able to reachoptimum efficiency and maximum production(lowest cost/yd3).

For any ripping job, choosing the rightripping tractor for conditions depends on:

1. Tractor flywheel horsepower2. Tractor gross weight3. Downpressure available at the tip

The elevated-sprocket design tractor withmodern resilient undercarriage has proven to

be an excellent ripping tractor because of itssuperior tractive ability. These large tractorsare able to rip many previously unrippablematerials and have greatly increased rippingproduction in existing ripping applications.

Ripper SelectionsThe first step in ripper selection is to

determine the application. Will the job call forproduction ripping or will the tractor be usedas a multipurpose tool? The more productionripping required, the greater the effectivenessof the single shank ripper. If the tractorspends more than 20 percent of its time

ripping, it is considered a production rippingapplication. Material also has an effect onripper selection. The harder or tighter amaterial, the more the application calls forthe single shank ripper.

The multishank design becomes moreeffective in multiple site/multiple useapplications where versatility is an asset. Inthese applications, material may not be ashard and ripping depth not as important. The more varied the job conditions, the greaterthe need for the multishank ripper. The multishank is especially useful in pre-rippingfor scrapers or other loading tools, covering awider area, or ripping close to a high wall orobstruction.

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Proper equipment selection and sound ripping techniques are critical to effective and economic ripping.Following sections will focus on these two important areas.

Ripping Equipment Selection


Hinge-typeRipper

In a Hinge-type ripper, the linkage carryingthe beam and shank pivots about a fixed point atthe rear of the tractor. As the shank enters theground and penetrates to maximum depth, thetooth angle is constantly changing.

Hinge-type rippers offer the advantage of anaggressive entry angle, but cannot be adjusted tocompensate for varying conditions.

A Parallelogram-type ripper allows thelinkage carrying the beam and shank tomaintain an essentially constant tip-groundangle regardless of tooth depth. This type ofripper has advantages over the hinge-type whenripping above maximum depth, but does notprovide the aggressive tooth angle necessary forhard-to-penetrate materials.

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AdjustableParallelogram

Ripper

The Adjustable Parallelogram ripper combines the features of both the hinge-type and parallelogram rippers. It can vary thetip angle beyond vertical for improvedpenetration and can be hydraulically adjustedwhile ripping to provide the optimum rippingangle in most materials.

All Caterpillar large tractors use adjustableparallelogram rippers, available in single shankand multishank arrangements. The single shankmodels are built for the toughest ripping work,where maximum penetration and depth isrequired. The multishank arrangement willaccept three shanks for use in less densematerials.

Figure 1

Figure 3

Figure 2

ParallelogramRipper

Track Shoe WidthWorking on rock requires narrow shoes to

reduce bending or breakage. However, mostripping tractors work in several different kindsof materials. This variety of work environmentsrequires a track width that does the best all-around job, therefore a standard width trackshoe is usually the best choice. A good rule ofthumb is to use the narrowest shoe thatprovides adequate flotation and traction,without excessive track slippage. Shoes of thecorrect width give maximum performance andthe lowest operating costs. Because ripping isoften an abrasive, high impact application,heavy-duty Caterpillar extreme service shoesare usually recommended. These are single-grouser shoes heat-treated to a higher tensilestrength, and provide more wear material thanconventional shoes.

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Summary

To achieve optimum efficiency andmaximum production (lowest cost/yd3),selection of the proper rippingequipment is crucial. Application-specific choices must be made betweensingle shank or multishank rippers.Proper selection of shank protectorsand tips can affect ripping productivityand efficiency.

Ripper ShanksOnly straight ripper shanks are available

for the large track-type tractors. Theseprovide the lifting action needed in tight,laminated materials, plus the ripping abilityrequired in blocky or slabby ripping material.All of the shanks for the large tractors are ofthe one-piece design, eliminating the weldjoint. This increases strength at a critical areaand allows for improved heel clearance. Therolled stock from which a ripper is made isnow cut to length, bent, then fully machined atthe tip end.

Shank protectors are standard for D8and larger Caterpillar shanks. The replaceableprotectors are pinned to the leading edge ofthe shank (see figure 4), protecting it fromwear and greatly extending shank life.

Ripper tips (see Figure 4) are availablein several shapes and sizes designed to meetspecific application requirements. Threequestions should be considered whendetermining the best ripper tip for aparticular job:

1. How difficult is the material to penetrate?

2. What are the fracture characteristics?

3. How abrasive is the material?

Tooth penetration can be the keyto ripping success in many situations,especially in homogeneous materialssuch as mudstone or fine-grainedcaliche, or in tightly cementedconglomerate. These materials arenot difficult to rip if they can bepenetrated. Caterpillar manufactures

short, intermediate, and long penetration tipsrecommended for use in compacted, densematerials where initial penetration is difficult.These alloy steel tips resist tempering (loss ofhardness) at higher operating temperaturesfor long wear life. They are also self-sharpening and provide excellent penetrationcapability.

Ripping Equipment Selection


ShankProtectors

RipperTips

A standard width track shoeperforms a multitude of jobs.

Figure 4

Tip SelectionTip selection is also affected by the

abrasiveness of the material. Centerlineripper tips are designed for abrasiveapplications where increased wear life is aconsideration. Centerline tips are made ofsteel, are self-sharpening, and providereversibility due to the centerline design.Although there are three centerline tiplengths available (short, intermediate, andlong), each is recommended for a specificapplication.

Ripper Tip Designs:• The short tip (see Figures 5 and 6) should

be used in extreme impact conditions only,as it does sacrifice some wear materialcompared to intermediate and long tips.

• The intermediate tip (see Figures 7 and 8)is used for moderate impact and abrasionconditions.

• The long tip (see figures 9 and 10) isdesigned for low impact, highly abrasiveconditions where breakage is not aproblem. This tip has the greatest amountof potential wear material.

For both penetration and centerlineripper tips, always use the longest tip thatwill rip without excessive breakage. Thiswill provide increased wear life, simplybecause the longer the tip, the more wearmaterial available. Using the correct tip iscritical to low-cost ripping, so you may wantto try different tips before making your finalselection. Since longer tips offer more wearmaterial, it’s usually recommended to try alonger tip first and switch to a shorter one ifexcessive breakage occurs.

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Figure 7 -IntermediateCenterline Tip

Figure 8 -IntermediatePenetration Tip

D11R Single Shank

D11R MultishankD10R

D9G, D9H, D9RD8H thru D8R

SummaryCaterpillar manufactures short,intermediate, and longtempering-resistant steel alloypenetration tips for use incompacted, dense materialswhere initial penetration isdifficult; and short, intermediate,and long steel centerline tipsfor increased wear life inabrasive applications. Alwaysuse the longest tip that will ripwithout excessive breakage.

Cat Ripping Tip Options

Figure 5 - Short Centerline Tip

Figure 6 - Short Penetration Tip

Figure 9 - LongCenterline Tip

Figure 10 - LongPenetration Tip

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Use the following chart to aid in solving problems involving ripping equipment.

Problem Causes Action

Excessive tip breakage Tip may be too long for conditions Change to shorter tipShank protector missing Check and replace if neededShank or adapter nose broken, Check and replace if needed

bent, or wornWrong shank angle Adjust shank angleToo many shanks being used Decrease number of shanksOperator backing up or Raise tip before turning or

turning with tip in ground backing up

Shank or adapter breakage Badly worn shank Repair or replace shankOperator side loading shank Rip only in straight line in Operator turning while ripping forward direction

Operator backing up with tip in ground

Difficult tip installation Material buildup on shank nose Remove materialShank nose bent or damaged Repair or replace shank

Lack of penetration Wrong tip in use Try different tip or penetration tipMaterial too dense Use larger tractor, if possible

Make series of very shallow passes to provide improved traction

Pre-blastImproper operator technique Change operators or instruct as to

proper technique (see following section on ripping techniques)

Penetration tip installed the Look for word “bottom” engraved wrong way on tip and install accordingly

Damage to track shoes Track shoes too wide Use narrower extreme service Track shoes not extreme service shoes

Ripping Equipment Troubleshooting Guide


The best ripping procedure depends on ajob’s actual conditions. Likewise, as

conditions vary from job to job, what isappropriate for one situation may not work inthe next. Experience is the best teacher when itcomes to maximizing ripping efficiency. But areview of the following 11 points can helpidentify the necessary procedures.

1. How many shanks should be used?

The multishank ripper is intended as a highproduction ripper in hard-packed soils and forloosened embedded rock. It is intended to beused in material that can be ripped with at leasttwo shanks. It is intended for applicationswhere ripping with a single center shank isrequired less than 20 percent of the time. It isnot intended for high production ripping inrock with a single center shank. One shankshould be used in material which breaks out inlarge slabs – so the slabs either fracture orpass around the single shank. When two ormore shanks are used in this situation, theshank can act as a rake and wedge the largerslabs under the ripper beam. Or, as oftenhappens when using two shanks in difficultmaterials, one of the shanks may becomestalled by a hard spot. This causes off-centerloads to be placed upon the ripper beam andmounting, and thus the tractor.

A single shank can be used in the centerpocket of a multishank ripper in order to gainpenetration in more difficult material. Themultishank frame provides the flexibility toachieve the greatest ripping production invarious strengths of materials.

The use of only one shank centers the loadin the beam and mounting assembly and allowsfull force to be exerted at a single point. Even ifthe material can be handled by two shanks,

production can often be increased by using asingle shank for smoother operation and lessslippage and stalling.

Two shanks can be most effective in softer,easily fractured materials which are going to bescraper loaded. In some cases, two shanks maybe required by job conditions such as rippingalong a high wall or the toe of a slope. Threeshanks should be used only in very easy-to-ripmaterial such as clay hardpan or soft shales.

2. When should a deep rip shank be used?

A deep rip shank should be used wherelaminations or other places of weakness existthat cannot be reached with the standard length

shank. These longer shanks also have thepotential to produce greater volume perripping pass in many materials compared to astandard single shank. Common applicationsinclude relatively easily ripped material such asclay hardpans, coal, and some sandstones andshales. Caution must be applied when usingdeep shanks in harder material, because theextra shank length reduces their ability tohandle ripping loads when compared toconventional shanks.

These shanks are designed for light tomoderate duty and therefore can break whenused in the extended positions in hardmaterial.

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Ripping Basics

18

3. Should tandem ripping everbe considered?

Improvements in tractor design, includingelevated sprocket, bogie suspension, andincreased weight and horsepower, have madetandem ripping obsolete.

4. Should material ever beblasted before ripping?

Rock that is extremely difficult to penetrateand rip can often be lightly blasted (called“preblasting” or “pop” blasting) and thenripped successfully. In many applicationspreblasting can provide cost and environmentalbenefits over complete blasting.

The procedure simply involves light chargeson wide centers to improve initial ripperpenetration. Ripping normally then has theadvantage of fracturing the material intosmaller pieces than blasting. This method hasproduced cost savings in some applications,but must undergo careful cost evaluation.

It is also cost effective in many operationsto rip as much material productively aspossible and then blast the unrippablematerial. This allows the operation to move asmuch material as possible at the lowestpossible cost.

5. What is cross-ripping andwhen is it used?

Cross-ripping involves ripping an area witha series of longitudinal passes (east to west, forexample) and then covering the same areawhile ripping in a transverse direction (north-south).

In general, cross-ripping makes the pitrougher, increases scraper tire wear, andrequires twice as many passes; however, it doeshelp break up “hard spots” or material whichcomes out in large slabs, and will loosen

vertically laminated material in which single-pass ripping produces only deep channels.When material is extremely hard to penetrate,cross-ripping will often separate fractureplanes set up by the first pass and allow ripperuse where blasting would otherwise berequired.

Cross-ripping is often done to reducematerial size to better facilitate scraper loadingof the material, or in order to meet crusherthroat limitations. When considering cross-ripping, careful analysis should determine ifmaterial removal efficiency is increased enoughto offset the increased time and expense.

6. Which direction is best?Generally, ripping direction is dictated by

the job layout. However, there are certainconditions under which ripping direction willgreatly affect results.

When ripping in a scraper cut, it is alwaysbest to rip in the same direction that thescrapers will load. If the rock formation lies insuch a manner that cross-ripping is required,the final pass should always be in the directionof scraper loading. This procedure yieldsseveral advantages. It greatly aids scraperloading, reduces the chances of damaging orspringing the scraper bowl, allows the rippingtractor to double as a pusher in certainsituations, and it permits traffic to flow in thesame direction.

Occasionally, a rock formation will befound containing vertical laminations orfractures that run parallel to the cut, in whichcase, ripping in the direction of the cut mayresult only in deep channels. When this occurs,it may be necessary to rip the material acrossthe cut first to obtain proper fracturing, thenmake the final pass in the direction of the cut.

Material such as caliche tends to break outdifferently than most materials. This“buttercutting” effect lowers productivity anddemands additional ripping passes.

When applied to ripping, buttercutting is aterm used to describe material breakoutsimilar to the slicing of a knife through butter.There is minimal fracturing of the rippedmaterial except in the vicinity of the shank. Thiscan occur in soft or non-brittle materials thatdisplay discontinuous breakout. Discontinuousbreakout occurs in rock because there are nopreferred planes of weakness for a fracture topropagate along. Examples of materials whichcan exhibit this type of breakout are cementedgravels, caliches, and breccias.

It’s also advantageous to rip downhillwhenever possible. Gravity helps the tractortake maximum advantage of its weight andhorsepower. However, uphill ripping isoccasionally used to get more rear-end downpressure or to get under and lift slabbymaterial.

If the material is laminated and the plane ofthe laminations is inclined upward toward thesurface, it’s best to rip from the shallow end(where the laminations reach the surface)toward the deep end. This helps keep theripper tip in the ground. When ripping is donein the opposite direction, the tip tends to “rideover” the laminations and be forced out of theground.

7. What gear is best forripping?

Proper gear and speed selection is critical toobtaining maximum ripper production andefficient tractor operation. Generally speaking,first gear is used in most ripping situationsbecause a speed of 1 to 1-1/2 mph, at about 2/3throttle, gives the most economical production.

Ripping Basics


19

Just a small increase in speed above theoptimum can result in ripper tip wear, excessivetrack slip, and ultimately in lower productionand higher costs. Excessive speed generatesexcessive heat at the ripper tip and greatlyshortens tip life. Therefore, when ripping ineasy-to-rip materials, it is better to rip deeper atregular speed or use two or three shanks thanto use one shank and increase ripping speed.

8. What is the best rippingdepth?

Ripping depth is normally determined byjob requirements, material hardness, beddingthickness and degree of fracturing. Ideally,ripping with standard shanks should be doneat the maximum depth that penetration andtraction allow. This results in maximumproduction per unit of fuel and tip wearmaterial used.

Sometimes, however, it may not bepractical to rip at maximum depth. Whenopening a cut on a very hard or smoothsurface where grouser penetration is limited,making a series of shallow cuts significantlyimproves traction and penetration byproviding a “bed” of loose material for thetrack grousers to grip. Or where considerablestratification is encountered, it is usually bestto rip and remove the material in its naturallayers rather than try to make a full-depthpass. An initial pass at less than full-depth willoften break the material loose so that thesecond pass can be made at the optimumdepth and achieve more completefragmentation.

Ripping depth and the number of shanksto be used should be considered together.While deep ripping with a single shank usuallyyields maximum production, many soft orthinly laminated materials can often be betterhandled by multiple shanks at a more shallowripping depth.

9. Is a difficult first passnormally encountered?

Usually the first pass is the most difficultbecause in consolidated material there are no“voids” for the loosened material to moveinto. Thus, initial penetration can be difficult,and proper technique and penetration angleis a must. On subsequent passes, material canmove into voids created by the previous pass.For this reason, a decision to blast should notbe made based on seemingly poorperformance during the first ripping pass.

10. What pass spacing shouldbe used?

Pass spacing helps determine theproduction rate, because obviously the fewernumber of passes, the shorter the amount oftime required to cover the area. Optimumspacing then is necessary to maximizeproduction and hold down costs. Using themaximum recommended spacing is notalways advisable because material end-useand removal methods must also beconsidered. The closer the spacing, thesmaller the ripped fragments of material willbe. Thus, crusher requirements and loadingmethods can determine the correct spacing.

When full penetration can be obtained,pass spacing of one half the tractor width isusually recommended. This allows one trackto ride over the material just ripped, thusincreasing traction and further crushing thematerial. Using this as a base, pass spacingcan either be increased or decreaseddepending upon the fracturing characteristicsof the material and end-use requirements.

11. What about removing the ripped material?

First of all, for best results, never removeall the ripped material covering an area ifdeeper ripping must be done. Dozers andscrapers should always have one or twoinches of crushed material resting on top ofthe solid formation for increased traction and

to help cushion the tractor. The coefficient oftraction is much greater for a tractor workingon crushed rock than for one working on asmooth, solid bed of rock.

Where scrapers are to be used to removeand haul the material, it’s important toconsistently rip to a uniform depth. Thiseliminates protruding knobs of hard rock andshallow spots which could force the scrapercutting edge out of the ground. This isdamaging to cutting edges and to the scrapersthemselves, possibly reducing the useful life ofthe unit and certainly increasing itsmaintenance costs. A good rule of thumb is torip no deeper than can be ripped on the mostdifficult part of the cut area, and thus nodeeper than the scrapers can readily load.

Summary

With today's advancements in tractordesign – elevated sprocket, bogiesuspension, increased weight andhorsepower – the need for second tractortandem ripping has been eliminated.

Ripping depth and the number ofshanks should be considered together.Deep ripping with a single shank usuallyyields maximum production; but many softor thinly laminated materials can often bebetter handled by multiple shanks at ashallower ripping depth.

20

Until now, this handbook has dealt with thekinds of information necessary before

ripping begins – material rippability, rippingbasics, ripping equipment selection, etc. Thissection will introduce perhaps the mostimportant variable of all in maximizing ripperproduction – effective operator technique.This section provides important techniqueswhich can make the difference betweensuccess or failure. Again, each rippingsituation is different; these techniques arerecommended to increase production,maximize ripper tip life, reduce track wear,and prevent tractor and ripper damage in themajority of ripping applications.

The Decelerator as a Key toRipping

The decelerator is one of the mostimportant controls on the tractor, and properuse of it is a must for efficient ripperoperation. Located to the right of the brake, itshould be used to match drawbar pull toavailable traction and ground conditions, and

to prevent track spin. Too much power whileripping can result in excessive track spin,reduced undercarriage and ripper tip life, andpotential tractor damage. A constant, steadypull when ripping maximizes production andminimizes wear and tear on the operator andthe machine.

Proper use of the decelerator enables theoperator to apply just enough power to be onthe verge of track spin, taking advantage of allusable horsepower. This technique isespecially important when making initial cutson a smooth or hard surface. Use thedecelerator to start out slowly, reduce theaggressiveness of the tracks, and make aseries of light cuts to break up surfacematerial and form a “work pad” for the nextseries of deeper cuts.

Ripping Techniques


Positioning the RipperShank at the Start of the Pass

Achieving initial penetration is critical andmay be the determining factor for whether amaterial is rippable or not. Adjustable rippershave the advantage of allowing the operator to experiment and find the best angle forpenetration.

In most cases, initial penetration for eachpass begins with the ripper shank angled wellback beyond the vertical position (see Figure11), depending on tip selection. If the rock isextremely hard, angling the shank back nearthe maximum angle may enable penetrationand thus permit ripping the material. Whenripping more easily penetrated material suchas soft shale, the shank angle may be onlyslightly back beyond vertical for initialpenetration.

In hard material, the rear of the tractormay be forced up slightly as the ripper tipcontacts the surface and penetration begins.This effect is normal, but if the ripper tip failsto penetrate, and the rear of the tractor staysup, raise the shank enough to set the tracksdown flat again. Then try different shank anglesuntil the best angle for penetration is found,while looking for faults, weak spots, fractures,and weathering to aid initial penetration.

Figure 11

Positioning the RipperShank During the Pass

Using the correct shank angle during thepass is very critical to ripper production. Forbest results in most situations, follow theseguidelines.

Adjust the shank angle forward until thetractor feels “pulled into” or pinned to theground. Due to shank design, a shank anglethat may appear to be too far forward canactually be in the best position for ripping.The ripper tip should be slightly below theheel of the shank, as shown in Figure 12.

This angle is best for ripping because theforce exerted on the small area of the tipinitially fractures and weakens the material.Then as the shank passes through, thematerial is shattered from the bottom to thetip. If the shank pitch angle is too far back(not moved forward enough afterpenetration), it causes the tip to drag acrossthe rock and puts the face of the tip andshank in contact with the material beingripped. This results in excessive wear andincreased resistance, lifting the rear of thetractor, so that traction is lost and rippingeffectiveness reduced. Operating with theshank angle too far back is the most commonerror made by ripping tractor operators.

This condition – shank too far back –raises the rear of the tractor (See Figure13`)and results in: 1. high undercarriagewear rate (track spin); 2. poor shank life(shank impacts rock first); 3. poor tip life(tip is dragged across rock and cannot self-sharpen); 4. reduced production.

For parallelogram rippers, the operatorcan estimate when the shank is in the bestripping position by observing the tilt cylinderrods. After finding the best ripping angle for

the material you are working in, see howmuch of the cylinder rod is extended and usethis as a guide for future reference.

At the proper shank angle, the tip willpenetrate and split the rock much as a wedgeis used to split a log. At the same time, thiswill help keep the tip short by wearing moreon the bottom surface than on the top.

It’s also very important to avoid movingthe shank too far forward. This permits the tipto rise above the shank heel, resulting inrapid heel wear and loss of penetration.

21

Proper Shank LengthSelection

The length of shank extended from theripper frame pocket is determined by twogeneral rules. First, use a length at which thetractor can efficiently pull the shank throughthe material; secondly, maintain sufficientclearance under the lower ripper frame toavoid interference from large chunks or slabsbrought to the surface.

When the material is very hard andpenetration is difficult, the shank should be inthe shortest position. The objective is tooperate the lower ripper frame as parallel tothe material as possible, for even stress

distribution. Occasionally though, the shankmay bring up chunks or slabs that lodgeunder the lower ripper frame. This situationmay lift the rear of the tractor. If this occursrepeatedly, increase the clearance under thelower frame by extending the shank. This maycause the lower frame to operate inclinedupward, rather than parallel to the ground.Although not the ideal frame position, it doesprevent plugging the ripper frame. Avoiddropping the ripper frame so that it inclinesdownward from the tractor.

This traps ripped material under the frameand makes forward travel difficult, while causing excessive wear and potential damageto the underside of the ripper beam.

Figure 12

Figure 13

Figure 14

22

Dozer Position WhileRipping

A dozer carried too high during rippingcan allow the tractor to straddle and hang upon large objects if it fails to push them out ofthe way. There is also danger that a track mayride up on an object, tilting the tractor andrisking damage to the shank or ripper frame.

These problems can be overcome by carryingthe blade low enough to remove obstructions,but high enough to allow smaller fragments topass under. Remember, it’s not practical to tryto rip and doze at the same time.

Ripping DowngradeRipping downgrade can increase

production. If the job layout permits, thedowngrade approach can be helpful whenworking a hard spot or seam.

There are several situations to be avoidedwhen ripping downgrade.

1. Remember that traction on rock is lessthan on dirt.

2. Avoid ripping on or creating slopes thetractor cannot climb.

3. Avoid sideslopes.Even in conditions that appear ideal,

downgrade ripping may not always bepractical. For instance, when the material liesin heavy, longer, level laminations, ripping willbe difficult and production will be reduced. Ifthis situation is encountered, the best solutionwould be to rip upgrade. The degree of theslope and available traction may limit rippingdepth and handling methods.

Using Hydraulic Force toHelp Fracture Rock

An effective technique for ripping hardrock seams or pockets is to combine tractordrawbar power and hydraulic force. When theripper has contacted the hard rock, followthis procedure:

1. Use the decelerator to control trackslip.

2. Use the ripper shank control to adjustshank angle back slightly.

3. Maintain engine speed high enough toallow the tractor to continue movingforward as the ripper shank anglesback.

4. While the tractor moves forward,return the ripper shank to its originalposition (forward), combining ripperhydraulic force with tractor drawbarpull.

This technique can be very effective intough material as well as when attacking hardrock pockets or seams.

In most cases, ripping downgrade is the most productive.

Ripping Techniques


23

Ripping CoalAll methods for ripping rock can be

applied to ripping coal. Even so, rippingcoal requires additional consideration.

If the shank is not angled forwardenough after penetration, the tip will bluntrapidly and may cause the tip tomushroom.

Since ripping characteristics of coal canbe widely varied, the ripper tip should bechecked often for evidence of blunting, orcolor change caused by heat buildup.

Should either of these conditions beobserved, increase the shank angleforward. It may also be advisable to useless down pressure, or rip at a slowerspeed.

Occasional Deposits ofHard Rock or Boulders

Pockets or seams of hard rock orboulders are common in many rippingoperations. Sometimes they may be too hardto be easily broken. There are several ways torip hard spots and boulders. If it is a seam ofextra hard material, try to determine thedirection the seam runs. It may lie diagonally,

perpendicular, or parallel to the direction ofripping. By observing where the hard spotsare found, a pattern will emerge. This patternwill reveal the direction of the hard material.

When the direction of the hard deposit hasbeen determined, rip directly across the hardmaterial. Often the grain will lie crosswise tothe deposit.

In some cases hard deposits are found inthe form of pockets or knots, or they may beboulders. It may be possible to work theripper tip under them and lift them out.

NOTE: When a deposit of hard materialcannot be removed, it may be necessary towork around it until it is exposed enough todoze out.

Correct dozer position during ripping process.

Pockets or seamsof hard rock can beremoved moreeasily if the patternof the material isunderstood.

Summary

There are many variables to ripping.Utilization of the proper operatortechniques will increase production,maximize ripper tip life, reduce trackwear, and prevent tractor and ripperdamage.

24

Most of the discussion in the precedingsections has concerned the ripping of

well-consolidated rocks and minerals.Ripping is also used in other materials andapplications in order to save the user money,do the job faster or more effectively, or evenas a method to convert unusable land into aproductive asset at a lower bottom line cost.

One such application is the use of largetrack-type tractors for deep ripping inagricultural areas. In many cases, breaking uphardpan under the surface permits formerlynon-productive land to be economicallyplanted.

California’s San Joaquin Valley, forexample, holds a virtually impermeable layerof clay and iron oxide hardpan up to six feetbelow the surface. Ranging from an inch totwo feet in thickness, this layer prevents deeproot penetration and traps water at thesurface. By deep ripping, sometimes to adepth of seven feet, this hardpan layer iseffectively shattered.

Diversity of MaterialsThat Can Be Ripped

As demand for tillable land increases,deep ripping may prove a solution todwindling supplies in many areas.

Three of the more common materialsoften ripped besides rock are coal or lignite,concrete, and asphalt or blacktop paving.These materials are somewhat easily ripped,but special considerations are involved inorder to maintain maximum production. Inany case, wherever such materials can beripped, it is usually cheaper to rip them thanto loosen and break them up by other means.

Old concrete, usually six to eight inchesthick, can usually be effectively broken with asingle shank ripper. A ripper in this case isespecially effective in severing steelreinforcing rods or wire which can poseloading and removal problems.

Most asphalt surfacing and other types ofblacktop paving are easily torn up with aripper, usually a multishank. Although thenature of the materials varies, at times thesesurfaces can be ripped with multishankrippers mounted on track-type loaders ormotor graders.

Although procedures and methods forripping rock can also be applied to rippingcoal, additional attention is required due to itsunusual properties.

Some people use very long shanks in coalor lignite ripping and make repetitive passeseach about two feet (0.6m)deeper than thepreceding one. Leach pads have also becomean important ripping tractor opportunity. Deep ripping of the pads loosens materialwhich in turn improves the leaching process.Custom deep rip multishank ripping packages are available on D9 – D11 formaximum production and efficiency.

Frozen Ground RippingAnother application seen increasingly

more often is the ripping of frozen ground.Frozen ground used to bring wintertime jobsto a standstill, especially in the northern U.S.,Canada, and Alaska. With current rippingtractor technology, however, few frozen soilsor subsoils exist which cannot be ripped.Generally, if the material can be ripped inwarm weather it can be ripped when frozen,although at lower production rates.

Leach pads have become an importantripping tractor opportunity.

Summary

Ripping is often used in materials andapplications other than rock to save costand time, and increase efficiency. ContactCustom Products or your local dealer forspecial ripping applications.

Special Ripping Applications


SEISMIC VELOCITY (in feet per second x 1000)1 2

SEISMIC VELOCITY (in meters per second x 1000)

PR

OD

UC

TIO

N (

bm

/ho

ur)

3

PR

OD

UC

TIO

N (

BC

Y/h

ou

r)

2500

3

2000

1750

1500

1250

1000

750

500

250

2000

1500

1000

500

04 5 6 7 8

IDEAL

ADVERSE


3250

3000

2750

2500

2250

2000

1750

1500

1250

1000

750

500

250

2 3 4 5 6 7 8 9


PR

OD

UC

TIO

N (

BC

Y/h

ou

r)

PR

OD

UC

TIO

N (

bm

/ho

ur)

3

IDEAL

ADVERSE

2500

2250

2000

1750

1500

1250

1000

500

250

750

3250

3000

2750

2500

2250

2000

1750

1500

1250

1000

750

500

250

2 3 4 5 6 7 8



PR

OD

UC

TIO

N (

BC

Y/h

ou

r)

PR

OD

UC

TIO

N (

bm

/ho

ur)

3

IDEAL

ADVERSE

2500

2250

2000

1750

1500

1250

1000

500

250

750

5000

2 3 4 5 6 7 8



PR

OD

UC

TIO

N (

BC

Y/h

ou

r)

PR

OD

UC

TIO

N (

bm

/ho

ur)

3

4000

3000

2000

1000

9 10

3750

3000

2250

1500

750

3

IDEAL

ADVERSE

25

D8R with Single Shank




Ripping costs must be compared to othermethods of loosening material – usually

drilling and blasting – on a cost per ton orbank cubic yard (BCY) or bank cubic meter(BCM) basis. (See density chart on page 26 to

transfer between bank cubic yards and tons.)Thus, an accurate estimate of rippingproduction is needed to determine unit rippingcosts.

Estimating Ripper Production

There are three general methods ofestimating ripping production:

1. The most widely used and acceptedmethod is to survey and cross-section the areaand then record the time spent ripping. Afterthe material has been removed, cross-sectionthe area again to determine the volume of rockremoved. The volume divided by the time spentripping gives the ripping rate in terms of bankcubic yards or bank cubic meters per hour.

2. Another method is to record the timespent by scrapers or trucks. Total quantity andtime required can be converted to productionin tons, bank cubic yards, or bank cubicmeters per hour.

3. The third method (if a study isunavailable) is using a production rippingformula for quick estimating on the job. Byknowing the ripping distance, rip spacing,and depth of penetration, volume per cyclecan be calculated. From this, production inBCY (BCM) can be determined. Experiencehas shown results obtained from this methodare about 10 to 20 percent higher than themore accurate methods of weighing or cross-sectioning. See the latest edition of theCaterpillar Performance Handbook for moredetailed information.

Considerations for usingproduction estimatinggraphs

• Machine rips full-time – no dozing• Power shift tractors with single shank

rippers• 100% efficiency (60 min/hour)• Charts are for all classes of material• In igneous rock with seismic velocity of

8000 fps or higher for the D10, and 6000 fps or higher for the D9 and D8, the

production figures shown should bereduced by 25%.

• Upper limit of charts reflect ripping underideal conditions only. If conditions such asthick lamination, vertical lamination or anyfactor which would adversely affectproduction are present, the lower limitshould be used.

Ripping Costs

The required production rate and cost perbank cubic yard (BCY) or bank cubic meter(BCM) are the determining factors as to whatmethod should be used to get solid materialsinto movable form. The advantage of the largeripping tractor over drilling and blasting is itsability to loosen many materials faster and atslower cost per yard (meter). To moreprecisely evaluate this advantage, it’snecessary to know the methods used to figureripping costs on a per unit basis. (SeeDensity Chart to transfer between bank cubic yards and tons.)

The method of determining owning andoperating costs for a ripping tractor issubstantially the same as for any other tractor.There is the purchase price of the tractor andattachments, plus delivery costs to the jobsite.Ripping tractors usually are equipped withextreme service track shoes and additionalguarding. Also include taxes, insurance,depreciation and other fixed owning costs.

The principal difference whenconsidering a ripping tractor versus a dozingtractor is the amount charged for repairs andthe replacement of ground engaging toolssuch as ripper tips, shank protectors, cuttingedges, etc.

Ripping and dozing hard rock isunquestionably one of the most difficult anddemanding jobs a track-type tractor can do.

Consequently, higher repair costs must beexpected. See Performance Handbook forgeneral cost estimating techniques.

Density Chart

26

Approximate Densities TON/YD3 TONNES/YD3

____________________________________________

Limestone 2.0 – 2.2 2.37 – 2.60

Dolomite & marble 2.3 – 2.35 2.72 – 2.78

Chalky lime 1.8 – 2.0 2.13 – 2.60

Coquina (corals) 1.5 – 1.8 1.77 – 2.13

Sandstone (strong) 1.8 – 2.2 2.13 – 2.60

Weak sandstone 1.7 – 1.8 2.01 – 2.13

Tar sands 2.4 – 2.8 2.84 – 3.31

Quartzites 2.2 – 2.3 2.60 – 2.72

Conglomerates 2.1 – 2.2 2.48 – 2.60

Shales 2.2 – 2.3 2.60 – 2.72

Slates 2.3 2.72

Gypsum 1.9 – 1.95 2.25 – 2.30

Anhydrite 2.4 – 2.5 2.84 – 2.95

Gneiss 2.3 – 2.8 2.72 – 3.31

Granite 2.2 – 2.4 2.60 – 2.84

Basalt 2.2 – 2.4 2.60 – 2.84

Dark igneous 2.6 – 2.8 3.07 – 3.31

Coal 1.2 1.42

Conversions:One U.S. Ton = .9 Metric Ton One Yd3 = .765 Meters3

Summary

An accurate estimate of rippingproduction is needed to determine unitripping costs. The most accurate costestimates are obtained by conducting on-site ripping job studies.

Estimating Ripper Production


Because of the improvements in rippingtractor capabilities, a viable alternative

to blasting exists. As mentioned before,environmental factors will undoubtedly playan important role in reaching this decision.

For example, in an urban area there maybe restrictions prohibiting the use ofexplosives, making ripping a necessity.Political factors or the threat of terrorismseverely restrict the use of explosives in somecountries. But in most situations, where thereis equal opportunity for the use of eithermethod, the first consideration is probablyone of cost – will it be cheaper to rip orblast? This initial-cost consideration mustthen be weighed with other influencingfactors: the economics of fully utilizingequipment; the end use of the material; andtransporting and loading methods.

Full utilization of the equipmentavailable or already on the job can helpdetermine the best method of loosening thematerial. This is because many earthmovingjobs already involve track-type tractors andscrapers for a sizable portion of the totalyardage. If this equipment can be used tofinish the job – rather than bring in a rockcrew with drills, explosives, loaders andhauling units – it’s not difficult to appreciatethe savings involved. It’s soon apparent thatconsiderable effort can be expended to ripthe material in order to keep scrapers on thejob.

End-use of the material alsoinfluences the ripping vs. blasting decision.There are few size limitations when the rockis simply moved by a bulldozer and “wasted.”If the material is used to form anembankment, however, very definitelimitations are usually placed upon the size

of the rocks to be accepted. Optimumcompaction cannot be obtained if there arelarge rocks in the fill.

Variations in ripping depth, spacing, anddirection of passes usually can produce thedesired material size. Blasting is at timesunpredictable, as the desired rockfragmentation may be difficult to obtain andeven require expensive secondary blasting(in effect, reblasting). Appreciable increasesin crusher production have been realized bycement plants and aggregate quarries afterswitching from a blasting to a rippingoperation.

The final comparison of ripping vs.blasting can be made in terms of how thematerial is to be moved. As we stated, dozedmaterial presents few problems. Material toploaded into hauling units cannot be largerthan the loading bucket.

Scrapers can inexpensively haul materialswhich are well broken up and loosened.Elevating loaders and conveyors are highcapacity systems. Their greatest advantage –

high production – can be achieved only if thematerial is in small pieces and easy tohandle. Generally, ripping is the most cost-effective method to achieve theserequirements.

A cost analysis will indicate theeconomics of ripping over drilling blasting.This ample comparison indicates how rippertip life is an important factor in decipheringthe production needed for ripping to be costeffective. Ripper tips are the most expensivevariable in the operating costs of rippingtractors, accounting for approximately 30 to40 percent of total operating costs on thelargest tractors.

In the final analysis, a ripping vs. blastingdecision will depend on the total volume ofmaterial to be loosened and moved, on theproduction capabilities and costs of theripping tractor(s) used, and on the size andrelative efficiency of drilling and blastingtechniques.

27

Summary

The initial-cost consideration betweenripping or blasting must be weighted withother factors: the economics of fullyutilizing equipment; the end use of thematerial; and transportation and loadingmethods.

End-use of the material is an importantfactor in determining whether to rip or blast.

Ripping vs. Drilling and Blasting

The topic of ripper compatibility betweenvarious tractors generates questions and

concerns. The following information serves asa basic reference for ripper compatibility.

• The D11R (Serial Number 7PZ) Single Shank and Multishank Ripper Arrangementsare interchangeable with the D11R (Serial Number 9TR).

• The D11R Carrydozer (Serial Number AAF)Single Shank and Multishank Ripper Arrangements are interchangeable with the D11R Carrydozer (Serial Number 9XR).

• The D11R (Serial Number 9TR) Single Shank and Multishank Ripper Arrangementsare not recommended for use on the D11R(Serial Number 8ZR) or the D11N (Serial Number 4HK). The pitch cylinders are different in length and stroke and are pinned to the tractor rather than using trunnion ball mountings.

• The D11R (Serial Number 8ZR) Single Shank and Multishank Ripper Arrangements are interchangeable with the D11N (Serial Number 4HK).

• The D11N Single Shank Ripper Shank does not fit on the D10 Ripper. The size of the D11N shank is 110 by 450 mm (43.0" by 177.2"), while the D10 shank is 100 by 400 mm (39.4" by 157.5").

• The D11N Multishank Ripper Shank will fit on the D10 Ripper. Both use the same shank size.

• The D11N Multishank Ripper Shank Beam Assembly will fit on a D11N Tractor equipped with an impact ripper. A single shank beam assembly will not fit.

• The D10 Single Shank and Multishank Ripper is not compatible to the D11N Tractor. The mounts are different. The D10N Pushblock will fit on the D9N Ripper if excess material is burned off.

• The D1OR Single Shank and Multishank Ripper Arrangements will fit and can be used on the D1ON.

• The D1ON Single Shank and Multishank Ripper Arrangements are not recommended for use on the D1OR. Mounting groups are different, transmission guards are different, and the single shank ripper is a different size cross section. Also the transmission cannot be serviced or removed without removing the ripper frame.

• The D10N Multishank Beam Assembly will fit on a D10N Tractor equipped with an impact ripper. A single shank beam assembly will not fit.

• The D9L Multishank Ripper is not recommended for use on the D10N Tractor. In the carry position, the ripper tipcan contact the track on the D10N Tractor.

• The D9L Single Shank Ripper is not recommended for use on the D10N Tractor. Extensive rework is required.

• The D9R Single Shank and Multishank Ripper Arrangements are not recommended for use on the D9N or vice versa. Pitch and lift cylinders are different, as well as hydraulic pressures, transmission guard, and lines group. If conversion is a necessity, contact your local dealer.

• The D9L Single Shank Ripper Frame is not

compatible with the multishank ripper beam due to different frame requirements.

• The D9L conversion from standard to deep ripping requires one 3G8567 Tooth Group,one 9W3353 Hydraulic Pin Puller, and one 7T4408 Pin Puller Control. The conversion does not work on a D9L Multishank Ripper.

• The D9L Impact Ripper Beam Assembly is not interchangeable with the D10N Tractor Impact Ripper Beam Assembly and vice versa.

• The D9L Multishank Beam Assembly will fiton a D9L Tractor equipped with an impact ripper. A single shank beam assembly will not fit.

• The D9H Ripper is not compatible with any Series N Tractor.

• The D9H Ripper is not recommended for use on the D8L Tractor. Extensive rework isrequired.

• The D8R Single Shank and Multishank Ripper Arrangements are interchangeable with the D8N with slight modifications to the lines group.

• The D8K Ripper will fit the D9N Tractor if 4Z0511 Adapter Arrangement (Custom Product) is used.

• The D8K Ripper is not recommended for use on the D8N Tractor. The ripper mountsare different.

• The D8K Single Shank Ripper fits the D8L Tractor with use of 4Z0511 Adapter Arrangement (Custom Product) and 4Z0519 Pin Puller Modification.

28

Ripper Compatibility Guidelines


29

• The D8K Ripper is not recommended for use on the D7H Tractor. The fuel tank on the D7H Tractor is too low.

• The shank block holders for the D8K, D8L, D8N, and D9N Tractors are the same.

• The single shank and multishank D8L Radial Rippers fit directly on the D9N Tractor. The ripper teeth areapproximately 305 mm (12") closerto the track, possibly trapping more material. Digging depth increases by

25 mm (1") with the multishank ripper. Digging depth decreases 25 mm (1") with the single shank ripper.

30

D11R850 fwhp/634 kW230,100 lb/104 590 kg

D11R Carrydozer850 fwhp/634 kW248,600 lb/113 000 kg

D10R570 fwhp/425 kW144,986 lb/65 764 kg

D8R305 fwhp/228 kW82,880 lb/37 594 kg

D9R405 fwhp/302 kW104,538 lb/47 418 kg

Short center lineShort penetrationShort center line

Short center lineIntermediate penetrationIntermediate penetration

Short center lineIntermediate center lineShort center line

Short center lineIntermediate center lineShort center line

8.9 ft. 2707mm6.4 ft. 1958 mm10.7 ft. 3267 mm

8.2 ft. 2490 mm5.9 ft. 1799 mm9.8 ft. 2977 mm

7.6 ft. 2322 mm5.2 ft. 1600 mm9.0 ft. 2750 mm

6.6 ft. 2010 mm5.2 ft. 1600 mm8.0 ft. 2449 mm

63.5 in. 1612 mm42.1 in. 1070 mm85.7 in. 2178 mm

53.9 in. 1370 mm37.0 in. 941 mm73.1 in. 1857 mm

48.6 in. 1231 mm31.6 in. 798 mm65.3 in. 1658 mm

44.5 in. 1130 mm30.7 in. 780 mm62.0 in. 1574 mm

S/SM/SD/R

S/SM/SD/R

S/SM/SD/R

S/SM/SD/R

D11R & D11R CD

D10R

D9R

D8R

Model Ripper Standard Tip Shank Length Penetration (Depth)*

S/S = Single shank M/S = Multishank D/R = Deep ripping shank* Ripper penetration measured at maximum depth with standard tip and shank pinned in top hole.Note: This chart does not represent all of the possible configurations. Contact your Cat dealer.

Caterpillar® Track-Type Tractor Specifications


AEDK0752-02 (2/00) Printed in U.S.A.

twelfth edition h andbook of r ipping - · pdf filehandbook of ripping • twelfth edition...

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