Operate tractors

Characteristics of different types of tractors

• Two-wheel drive• Four-wheel drive• Front wheel assist• Articulated tractors• Steering systems• Other variations

TYPES OF TRACTORS

Two wheel drive

Front- wheel assist

Four wheel drive (articulated)

Tracked tractors

Risk assessment

• Identify hazards

• Assess the risks

• Control the risks

Mechanical hazardsMost tractor-related deaths are the result of mechanical hazardsA mechanical hazard is any “machine” factor that may put the operator and bystanders at risk of injury.

The 5 key mechanical hazards are :

• Roll-overs

• Run-overs

• PTO hazards

• Mounting/dismounting

• Noise

Tractor Run OverA major source of injury is falling off and being run over by the tractor and/or the equipment that they are pulling. These accidents can be caused by:

• Being thrown off when running over a hidden hole, ditch or stump

• Passengers falling off

• Starting the tractor while standing beside it on the ground

• Slipping on steps or platform while mounting or dismounting

To prevent tractor run over

Insist that the operator is the only person on the vehicle

ie No passengers

Only ever start the tractor while sitting in the operator’s seat

Never attempt to start or operate the tractor while standing on the ground

Mount and dismount stationary tractors only. Use the safe access platform

Never attempt to mount or dismount a moving tractor. Always shut off the engine and apply the parking brake before dismounting the tractor

Do not jump off the tractor

Wear work boots in good condition with non-slip soles

Keep steps and platform clean and clear of tools, loose parts or general junk

Always check the immediate area for bystanders before starting the tractor.Always wear the seat belt when operating the tractor. Use of the seat belt with an approved ROPS maximises driver protection

Be constantly on the lookout for hazards such as stumps and low hanging branches. They may dislodge the operator form the tractor seat.

Tractor roll oversThe main causes of tractor sideways roll overs

are:• Traversing a steep slope• Cornering too sharply or too fastThe main causes of back flip roll overs are:• Driving off in low gear but with high engine

speed • Rapid acceleration (particularly when driving

uphill or pulling a heavy load)• attempting to drive forward when the wheels

are unable to move forward (bogged)• Rapid engagement of the clutch

To control the risk of tractor roll over – use Roll-over Protection Structures (ROPS)

Two post – standard protection,

for general field work

Four post – standard protection, for general field work

Fold-down – for orchard or confined works, such as undercover parking and glasshouses

Enclose cab – standard protection, for general field work. Controlled environment; controls climate, comfort and noise

The ROPS is designed so that most roll-overs cannot roll over more than 90 °.The safety triangle shown in the picture shows where the driver can be safely protected of the tractor rolls over. If the driver wears a seatbelt and hangs on tightly to the steering wheel, there is a good chance of remaining within the safety triangle if the tractor rolls over.

Sideways rollovers

Tipping axisThe tipping axis is the line that the tractor

pivots about when it tips over. In a trawler tractor this is the outside edges of the track.

Look at the diagram to see the tipping axis of a wheeled tractor

Centre of gravityThis is the point where all parts of the tractor balance.

The position of the centre of gravity changes of any implement as added, removed or changes position.

An overturn resulting from the centre of gravity moving outside the tipping axis

Centrifugal ForceCentrifugal force is

introduced when a tractor corners too fast. It tries to pivot the tractor on its outside wheels during cornering.

Rearward roll overs(back flips)

Rear axle torqueThis is the transfer of energy between the engine and

the rear wheels of the tractor. If the rear wheels can’t move (as when bogged) the tractor can flip over.

Drawbar leverage

This describes the forces trying to pull the tractor rearwards when it is towing or pulling an object. The effects on tractor stability vary according to the weight, draft, hitching point used, resistance to movement and angle of pull

Tractor ballasting

Some implements can impose heavy downward forces on the tractor drawbar. This causes additional weight to be added to the rear of the tractor and increase the weight transfer.Cast iron weight or water in the tyres can act as a tractor ballast to counteract this weight transfer,The main purpose of tractor ballasting is to reduce wheel slip and increase tyre traction. Adding weight to the front increases steering stability.When adding ballast, do not exceed the manufacturer’s recommendation.

PTO hazards

Accidents involving entanglement can occur with the PTO when

• Shields that cover the PTO shaft are missing or damaged.

• attempting to service, adjust or clean a PTO driven implement when the PTO is still engaged

• While attempting to step over an operating PTO shaft

• By operating the PTO at the incorrect speed• When the telescopic portion of the implement

PTO shaft separates and allows the powered end to flail about and injure those nearby

Prevent PTO accidents• Keep all components of PTO

systems shielded and guarded

• Regularly test PTO master guard and shaft guards by spinning and rotating them, to ensure they have not become stuck to the shaft.

• Disengage PTO and shut off engine BEFORE dismounting to clean, repair, service, or adjust machinery.

• Keep universal joints in phase, always use the PTO shaft recommended for your machinery

• Walk around tractors and machinery. Never step over a rotating shaft

• Position the tractor’s draw bar properly for each machine used

• Reduce PTO shaft damage by avoiding tight turns that pinch rotating shafts between the tractor and machine

• Keep excessive telescoping to a minimum

• Engage PTO gradually

Don’t operate the PTO universal joints past 30°because the universal may be damaged or lock.

Get on and off the tractor safely

• Keep steps and platform clean and dry

• Wear heavy tread nonslip type work boots

• Keep three points of contact

Mount and dismount safely

•Always face the tractor when mounting and dismounting

•Never jump from the tractor; you could catch your clothing on pedals, levers or other protruding parts

•use handrails, handholds and steps to pull yourself up to the operator’s platform. Try to keep three points of contact on the machine –either two hands an done foot, or two feet and one hand

Always ensure the tractor is in neutral, clutch depressed and handbrake applied before starting the engine.

Be aware that the use of jumper leads may bypass neutral start switches.

Protect your hearing•Deafness caused by noise if permanent, however it is preventable

•Dangerous noise levels are greater that 85dB over an 8 hour period and any noise levels above 115dB

To prevent ear damage

•Purchase equipment with the lowest noise rating

•Regularly inspect and maintain tractors and farm machinery

•Use personal hearing protection to reduce noise to a safe level

Human factors – the risks

The five human factors that may contribute to hazardous tractor operation are:

• Risk taking behaviour

• Inadequate safety training

• Physical limitations

• Impaired function

• Psychological limitations

Risk taking behaviour•Poor safety attitude

•Excessive speed

•Carrying of passengers

•Taking shortcuts

Insufficient safety training•Unsafe work practices (eg incorrect hitching)

•Poor guarding of machinery (ROPS and PTO guards)

•Lack of awareness of hazards and their control options

Physical limitations•Age

•Reaction time

•Strength

•Body size

•Vision

•Hearing

Impaired body function

•Fatigue

•Effects of drugs, alcohol and tobacco

•Chemicals

•Illness

•Environmental effect on the body (temperature and humidity)

Psychological limitations•Personality

•Temperament

•Anxiety and stress

•Apathy

•Preoccupation

•Anger and frustration

Environmental hazards

During tractor operation, there are three key environmental hazards:

• Broken ground

• Sloping ground

• Climatic influences

Travelling on broken ground•Travel slowly so you can safely negotiate any hazard

•Watch out for creeks and gully banks. They can collapse under the weight of the tractor if you drive too close. As a general rule, never drive any closer to the bank that the gully is deep.

•Have a good look and mark hazards in the paddock: stones, stumps, logs, gullies, wash-outs and creek beds.

Travelling on sloping ground

Tractors have a high centre of gravity and are relatively unstable on sloping ground. High speed combined with slope multiplies the risk.

The risk of overturn is increased when objects are struck when crossing hill slopes.

To control the risk:•Set wheels as wide as possible and carry loads as low as possible

•Always reverse up a steep hill. This positions the tractor in its most stable position.

•Go slowly across slopes

Make turns as gradual and slowly as possible

•Keep off-set implements on the up-hill side of the tractor where possible

•Monitor the ground for obstructions and depressions so you can avoid then when travelling across slopes.

Climatic influences

Hot and humid weather may expose the driver to heat stress, sunburn or heat stroke, leading to an increase in accident rates.

In cold conditions the operator need to wear bulky clothing which may restrict movement and are more likely to become caught in machinery parts.

Controlling climatic risks

• Drink adequate water • In hot weather use a tractor with a

shade canopy or preferably an air conditioned cab

• Cover-up with a long sleeve cotton shirt with collar, broad brim hat, sun screen and sunglasses

• Wear clothing that is close fitting to avoid catching on machinery.

Tractor safety SummaryThe 5 key mechanical hazards are:• Roll-overs• Run-overs• PTO hazards• Mounting/dismounting• NoiseThe 5 key human hazards are:• Risk taking behaviour• Inadequate safety training• Physical limitations• Impaired function• Psychological limitations The 3 key environmental hazards are:• Broken ground• Sloping ground• Climatic influences

Remember!

• Identify the hazard

• Assess the risk

• Control the risk

Work safely