TRACTOR HAZARDS - Extension

NAGCAT TRACTOR OPERATIONCHARTHOSTA Task Sheet 4.3CoreNATIONAL SAFE TRACTOR AND MACHINERY OPERATION PROGRAMIntroductionFarm families often provide muchof the labor for the operation of thefarm. Farm work may start early ina child’s life as a means of learningresponsibility and contributing tothe productivity of the farm.Tractor operation can come at anearly age for many farm youthbecause tractors are a large part ofhow farm work is done. Tractorwork can range from the simple tothe complex.This task sheet presents a TractorOperation Chart as a guide toappropriate tractor work for youngtractor operators.Youth and TractorsExamples of common jobsperformed by youth operatingtractors include: Mowing pastures, fields, yardsand lanesRaking and baling hay andstrawTowing hay and grain wagonsbetween fields and storagePicking rocks and otherobstacles from fields using afront-end loaderScraping manure from barnfloors with a tractor-mountedbladeUsing the tractor to poweraugers and elevators duringunloading operationsPulling old fence posts and treestumps out of the ground withlog chainsSeveral hazards can arise duringthe course of these and other jobsthat involve tractor use. Manytimes the larger the tractor, themore complex the operation of thattractor becomes. Additionally,large and complex equipment maybe attached to and powered by thetractor.Young tractor operators do notusually have the experience neededto skillfully and safely operatelarge and complex combinations oftractors and machinery.Figure 4.3.a. Oftentimes the youthful farmworker is willing to do more work than his or hermental and physical maturity will safely permit.Youth should never operate a tractor without aROPS and seat belt.North American Guidelines forChildren's Agricultural Tasks(NAGCAT) Tractor OperationChartAre your skills andage matched toFarm injury prevention specialistsfrom the U.S. and Canada havedeveloped consensus opinion that aguide to tractor operations by agegroups is a way of matchingyouthful capabilities with tractoroperation jobs. The NAGCATchart is presented on the reverseside of this task sheet.the appropriatetractor and taskyou are doing?You can use this chart:Learning Goal To see if you have been doingjobs with the size tractor thatmatches your age To guide an employer indetermining what they canreasonably expect a person ofyour age to do with varioustypes and sizes of tractorsTo review safety recommendations inmatching tractor size and tasks withthe age of the tractor operatorRelated Task Sheets:2.11.2Injuries InvolvingTasksYouthAge-Appropriate2.12.4Age Appropriate Tasks2.4It is common for youths to be overconfident in their ability to reactsafely to new or unexpected hazardsituations with tractors. The Pennsylvania State University dInjuriesYouthSafety Involvingand HealthRegulationsCooperation provided by The Ohio State University and National Safety Council.

Page 2References1. www. nagcat.org/Click on Guidelines/Select T1Tractor Operation Chart, December 2002.2. Cooperative Extension Service of your State’sLand Grant University.NAGCAT TRACTOR OPERATION CHARTContact InformationNational Safe Tractor and Machinery Operation ProgramThe Pennsylvania State UniversityAgricultural and Biological Engineering Department246 Agricultural Engineering BuildingUniversity Park, PA 16802Phone: 814-865-7685Fax: 814-863-1031Email: NSTMOP@psu.eduCreditsDeveloped, written and edited by WC Harshman, AM Yoder, JW Hilton and D J Murphy,The Pennsylvania State University. Reviewed by TL Bean and D Jepsen, The Ohio StateUniversity and S Steel, National Safety Council.Version 4/2004This material is based upon work supported by the Cooperative State Research, Education, and ExtensionService, U.S. Department of Agriculture, under Agreement No. 2001-41521-01263. Any opinions, findings,conclusions, or recommendations expressed in this publication are those of the author(s) and do notnecessarily reflect the view of the U.S. Department of Agriculture. The Pennsylvania State University 2004Cooperation provided by The Ohio State University and National Safety Council.

TRACTOR STABILITYHOSTA Task Sheet 4.12CoreNATIONAL SAFE TRACTOR AND MACHINERY OPERATION PROGRAMIntroductionNo other machine is moreidentified with the hazards offarming as the tractor. Nearly 50%of tractor fatalities come fromtractor overturns. Tractors are usedfor many different tasks. Becausethe tractor is a versatile machine,operators sometimes stretch the useof the tractor beyond what themachine can safely do. Forexample, an operator may turn acorner too quickly for the tractor tostay upright. The use of a rolloverprotective structure (ROPS) and aseat belt can save your life if atractor overturns while you aredriving.This task sheet explains the fourmajor reasons and forces that allowtractors to overturn, gives rules forhow to prevent tractors fromoverturning, and discusses the useof tractor ROPS with a seat belt.How Tractors OverturnCenter of gravity (CG). A centerof gravity is the point where allparts of a physical object balanceone another. When you balance apencil on your finger, you havefound the pencil’s CG. This is thepart of the pencil that is resting onyour finger. On a two-wheel drivetractor, CG is about 10 inchesabove and 12 inches in front of therear axle. Figure 4.12.a shows thenormal position of a tractor’s CG.Look at Figure 4.12.b. This showsFigure 4.12.a. Expected position of a tractor’scenter of gravity. Safety Management for Landscapers,Figure 4.12.b. The tractor’s center of gravity isinside the stability baseline.Grounds-Care Businesses, and Golf Courses, John DeerePublishing, 2001. Illustrations reproduced by permission. Allrights reserved.that the CG is inside a tractor’sstability baseline. Drawing a line toconnect all the wheels of thetractor as the wheels set on levelground forms a tractor stabilitybaseline. The line connecting therear tire ground contact points isthe rear stability baseline. The linesconnecting the rear and front tireon the same side are the right andleft side stability baselines. Frontstability baselines exist but havelimited use in tractor overturndiscussions.There are two very importantpoints to remember about tractorCG and stability baselines: The tractor will not overturn ifthe CG stays inside the stabilitybaseline.The CG moves around insidethe baseline area as you operatethe tractor.As you can see in figure 4.12.b, awide front-end tractor providesmore space for the CG to movearound without going outside thestability baseline. The Pennsylvania State University 2004CGCenter ofGravityLearning Goals To explain the role that center ofgravity plays in tractor overturns To list reasons the center ofgravity moves within a stabilitybaseline To explain how to be protectedduring a tractor overturnRelated Task Sheets:Agricultural Tractors4.1Tractor Hazards4.2Moving and Steering the Tractor4.10Using the Tractor Safely4.13Operating the Tractor onPublic Roads4.14Cooperation provided by The Ohio State University and National Safety Council.

Page 2TRACTOR STABILITYReasons the CGMoves AroundThere are five main reasons why atractor’s CG moves outside thestability baseline.1. The tractor is operated on asteep slope.2. The tractor’s CG is raisedhigher from its natural location10 inches above the rear axle.Figure 4.12.c. When a tractor is on a slope, thedistance between the tractor’s CG and stabilitybaseline is reduced.3. The tractor is going too fast forthe sharpness of the turn.4. Power is applied to thetractor’s rear wheels tooquickly.5. The tractor is trying to pull aload that is not hitched to thedrawbar.How Center of Gravityand Centrifugal ForceResult in an OverturnWhen a tractor is on a slope, thedistance between the tractor’s CGand stability baseline is reduced.Figure 4.12.c shows how thisoccurs. On steep slopes, the tractoris already close to an overturn. Asmall bump on the high side, or agroundhog hole on the low side,may be all that is needed for thetractor to overturn.A front-end loader or otherattachment mounted on a tractorcan raise the tractor’s CG. Whenthe bucket is raised high, thebalance point for the whole tractoris also raised. Figure 4.12.d showshow a raised CG makes it easierfor a tractor to turn over sideways.Centrifugal force (CF) is theoutward force nature exerts onobjects moving in a circularfashion. During tractor overturns,CF is that force trying to roll thetractor over whenever the tractoris turning. Centrifugal forceincreases both as the turningangle of the tractor becomessharper (decreases), and as thespeed of the tractor increasesduring a turn. For every degreethe tractor is turned tighter, thereis an equal amount of increasedCF.The relationship between CF andtractor speed, however, isdifferent. Centrifugal force variesin proportion to the square of thetractor’s speed. For example,doubling tractor speed from 3mph to 6 mph increases thestrength of CF four times (22 2x 2 4). Tripling tractor speedfrom 3 mph to 9 mph increasesCF nine times (32 3 x 3 9).Centrifugal force is what usuallypushes a tractor over when thetractor is driven too fast during aturn or during road travel. Duringroad travel, rough roads mayresult in the tractor’s front tires The Pennsylvania State University 2004Figure 4.12.d. A raised CG makes it easier for atractor to turn over sideways. Safety Management forLandscapers, Grounds-Care Businesses, and Golf Courses,John Deere Publishing, 2001. Illustrations reproduced bypermission. All rights reserved.bouncing and landing in a turnedposition. If the tractor starts toveer off the road, over correctionof steering can result in sideoverturns. Centrifugal force isoften a factor in tractor sideoverturns. When the distancebetween the tractor’s CG and sidestability baseline is alreadyreduced from being on a hillside,only a little CF may be needed topush the tractor over.Engaging the clutch of a tractorresults in a twisting force, calledtorque, to the rear axle. Undernormal circumstances, the rear axle(and tires) should rotate and thetractor will move ahead. If thisoccurs, the rear axle is said to berotating about the tractor chassis.If the rear axle cannot rotate, thenthe tractor chassis rotates about theaxle. This reverse action results inthe front end of the tractor liftingoff the ground until the tractor’sCG passes the rear stabilitybaseline. At this point, the tractorwill continue rearward from itsown weight until the tractorcrashes into the ground or otherobstacle. See Figure 4.12.e.Cooperation provided by The Ohio State University and National Safety Council.

Page 3HOSTA TASK SHEET 4.12The CG of a tractor is found closerto the rear axle than the front axle.A tractor may only have to rear toabout 75 degrees from a levelsurface before its CG passes therear stability baseline and thetractor continues flipping over.This position is commonly calledthe “point of no return.” As Figure4.12.e shows, this point can bereached more quickly than anoperator can recognize theproblem.Figure 4.12.e. The point of no return is reachedin 3/4 of a second. Safety Management for Landscapers,Grounds-Care Businesses, and Golf Courses, John DeerePublishing, 2001. Illustrations reproduced by permission. Allrights reserved.Common examples of this type oftractor overturn are: the rear tiresare frozen to the ground; tires stuckin a mud hole; or tires blockedfrom rotating by the operator. Rearoverturns can also happen on aslope if an operator applies toomuch power too quickly to the rearaxle. When a tractor is pointed up aslope, there is less rise needed toreach the point of no returnbecause the CG has already movedcloser to the stability baseline.Figure 4.12.f shows how thisoccurs.Figure 4.12.f. When a tractor is pointed up aslope, the CG is closer to the rear stabilitybaseline.Figure 4.12.g. Only hitch to the drawbar. SafetyManagement for Landscapers, Grounds-Care Businesses, andGolf Courses, John Deere Publishing, 2001. Illustrationsreproduced by permission. All rights reserved.against the forward movement ofthe tractor. The load is describedas pulling down because the loadis resting on the earth’s surface.This backward and downwardpull results in the rear tiresbecoming a pivot point, with theload acting as a force trying to tipthe tractor rearward. An “angleof pull” is created between theground’s surface and the point ofattachment on the tractor.A tractor, including the drawbar,is designed to safely counteractthe rearward tipping action ofpulled loads. When loads areattached to a tractor at any pointother than the drawbar, the safetydesign of the tractor for pullingloads is defeated.Figure 4.12.h. Never hitch to the top link of a3-point hitch. Safety Management for Landscapers,Grounds-Care Businesses, and Golf Courses, John DeerePublishing, 2001. Illustrations reproduced by permission. Allrights reserved.The heavier the load and thehigher the “angle of pull,” themore leverage the load has to tipthe tractor rearward. Figures4.12.g, 4.12.h, and 4.12i. showimportant information about safehitching points.When a two-wheel drive tractor ispulling a load, the rear tires pushagainst the ground. At the sametime, the load attached to thetractor is pulling back and down The Pennsylvania State University 2004Figure 4.12.i. The angle of pull should be keptto a minimum.Cooperation provided by The Ohio State University and National Safety Council.

Page 4Protect Yourself in aTractor OverturnThe rollover protective structure(ROPS) and seat belt, when worn,are the two most important safetydevices to protect operators fromdeath during tractor overturns.Remember the ROPS does notprevent tractor overturns, but canprevent the operator from beingcrushed during an overturn. Theoperator must stay within theprotective frame of the ROPS(Zone of Protection) in order forthe ROPS to work as designed.This means the operator must wearthe seat belt. Not wearing the seatbelt may defeat the primarypurpose of the ROPS.A ROPS often limits the degree ofrollover, which may reduce theprobability of injury to theoperator. A ROPS with anenclosed cab further reduces theTRACTOR STABILITYlikelihood of serious injurybecause the sides and windows ofthe cab protect the operator. Thisassumes that cab doors andwindows are not removed.To prevent tractors fromoverturning in the first place,follow the safety recommendationsthat are illustrated in Task Sheet4.13.Note: ROPS are available infolding and telescoping versionsfor special applications, such asorchards and vineyards and lowclearance buildings. Some ROPSmay be a protective frame onlyand not an enclosed cab.Figure 4.12.j. A rollover protective structure (ROPS) and a seat belt can protect you in the event ofan overturn. If you are in the cab of a ROPS-equipped tractor, fasten the seat belt. Safety Management forLandscapers, Grounds-Care Businesses, and Golf Courses, John Deere Publishing, 2001. Illustrations reproduced by permission. Allrights reserved.Safety Activities1. Use a toy scale model or a full-size tractor to illustrate the five main reasons tractors overturn.2. Invite a farmer whom you know who has survived a tractor rollover to speak to the class about the experience.3. Conduct a survey of area farm people to find out instances of tractor overturns in the last five years. Howmany overturns resulted in a fatality? How many survived an overturn? Did a ROPS play a role in theirReferencesContact Information1.Safety Management for Landscapers, Grounds-CareBusinesses, and Golf Courses, John Deere Publishing,2001. Illustrations reproduced by permission. All rightsreserved.National Safe Tractor and Machinery Operation ProgramThe Pennsylvania State UniversityAgricultural and Biological Engineering Department246 Agricultural Engineering BuildingUniversity Park, PA 16802Phone: 814-865-7685Fax: 814-863-1031Email: NSTMOP@psu.edu2.www.cdc.gov/Type agriculture tractor overturn hazardsin search box/Click on 1 0.67 Tractor OverturnHazards, August 2002.Credits3.Farm and Ranch Management, John DeerePublishing, 1994. The Pennsylvania State University 2004Developed, written and edited by WC Harshman, AM Yoder, JW Hilton and D J Murphy,The Pennsylvania State University. Reviewed by TL Bean and D Jepsen, The Ohio StateUniversity and S Steel, National Safety Council.Version 4/2004This material is based upon work supported by the Cooperative State Research, Education, and ExtensionService, U.S. Department of Agriculture, under Agreement No. 2001-41521-01263. Any opinions, findings,conclusions, or recommendations expressed in this publication are those of the author(s) and do notnecessarily reflect the view of the U.S. Department of Agriculture.Cooperation provided by The Ohio State University and National Safety Council.

USING THE TRACTOR SAFELYHOSTA Task Sheet 4.13CoreNATIONAL SAFE TRACTOR AND MACHINERY OPERATION PROGRAMIntroductionTractors can be operated safely ifthey are used as designed andoperated following recommendedpractices.There are an estimated 300 farmtractor fatalities each year. Readthese short examples. Teenager killed using tractor tospotlight deer in the woods. Man killed when tractor rolledonto him while dragging logsin the woods. Grandfather killed, butpassenger grandson lives whentractor goes over anembankment while going for afun ride. Tractor overturns while towingstalled pickup full of firewood. Tractor upsets sideways whilehigh lift bucket is in a raisedposition while traveling acrossa rough slope.This task sheet will identify severalproper and improper uses oftractors.Proper Use DefinedTractors are made to work, not tobe treated as ATVs, four-wheelers,dune buggies, or as otherrecreational vehicles.Figure 4.13.a. When tractors are operated for their intended purpose, the American farm workerproduces more food than in any other country in the world.A tractor isdesigned todo work.Tractors serve four purposes:1. They are a remote powersource.2. They carry/pull machines.3. They move loads.4. They transport materials.If you are not sure of a specific usefor your tractor, consult theOwner’s Manual. The Pennsylvania State University 2004Learning Goals To recognize proper uses of the tractor To recognize improper uses of thetractorRelated Task Sheets:Agricultural Tractors4.1Cooperation provided by The Ohio State University and National Safety Council.

Page 2USING THE TRACTOR SAFELYProper Use Means Avoiding Improper UseFigure 4.13.b. Tractors are designed for the operatoronly. No passengers allowed!Figure 4.13.c. Tractors provide remote power to machinery. Thisturning shaft, the PTO, must be guarded to prevent entanglementhazards such as this.Recognizewhen adriver isoperatingthe tractorin an unsafemanner.Figure 4.13.d. Hitch loads only to the drawbar. The drawbar has beenengineered to pull heavy loads without risking a rear overturn hazard. SafetyManagement for Landscapers, Grounds-Care Businesses, and Golf Courses, John Deere Publishing,2001. Illustrations reproduced by permission. All rights reserved.Figure 4.13.e. If you are stuck or need to be towed, you will need help from a second tractor. Use the strongest and best tow strap, cable, orchain that is available. Hitch only to the drawbar. The best advice for a young operator is to get adult help to pull the disabled or stuck tractor.Farm and Ranch Safety Management, John Deere Publishing, 1994. Illustrations reproduced by permission. All rights reserved. The Pennsylvania State University 2004Cooperation provided by The Ohio State University and National Safety Council.

HOSTA TASK SHEET 4.13Page 3Figure 4.13.f. Avoid ditch embankments. Trac

Explain how people are run over when they choose to bypass the ignition switch to start the tractor engine. 4. Learn more about the hazards of bypass starting a tractor engine by contacting a tractor salesperson or . JW Hilton and D J Murphy, The Pennsylvania State University. Reviewed by