Environmental, Health and Safety Services

Tractor Safety

Tractor Overturns
General Machinery Hazards
Roadway Hazards

Tractor Overturns

No other farm machine is so identified with the hazards of production agriculture as the tractor. According to the Virginia Farm Bureau Federation, tractor overturns are the number one cause of farm fatalities in Virginia. Understanding a few key components of tractor stability and basic procedures can reduce the likelihood of rollover.

Center of Gravity - A tractor's center of gravity is the point where all parts balance one another. On a two-wheel drive tractor (on level ground), the center of gravity is typically 10 inches above and two feet in front of the rear axle (in the center), which is about where the operator's feet are located. The center of gravity on a four-wheel drive and center-articulating tractor is located slightly more towards the front of the tractor. This results in approximately 30 percent of the tractor's weight on the front axle, and 70 percent on the rear axle.

Stability Baseline - The stability baseline of a tractor is made up of imaginary lines drawn between the points where the tractor tires contact the ground. Front, rear, and side stability baselines are established. To avoid turnover, the center of gravity must stay within the tractor's stability baseline. The tractor's center of gravity does not move, but its relationship with stability baselines may change due to:

  • Added weight from attachments and items being hauled (center of gravity will shift to the front or rear of the tractor depending on what is attached or is being hauled),
  • Driving on a slope (center of gravity shifts to the downhill side),
  • Lifting a load (center of gravity shifts towards the load),
  • Turning too fast (center of gravity shifts to the opposite direction you are turning in).

Rear Rollovers - Rear overturns happen fast! It may only take three-fourths of a second to reach the "point of no return". This "point of no return" may only be 75 degrees from a level surface before the tractor will continue to roll over.

  • Many rear rollovers are the result of changing the tractor's center of gravity from hitching above the draw bar. Always hitch low on the tractor and pull slowly!
  • Another cause for rear rollover is driving forward up a steep slope, or backing down a steep slope and applying the brakes. Always back up or drive down a steep slope.
  • Driving forward when stuck in mud, snow, or on ice can result in a rear rollover. This occurs when the rear axle is unable to rotate, resulting in the front end lifting off of the ground, and possibly passing the "point of no return". Always back out or tow to the rear instead.

Side Rollovers - Side rollovers happen even faster! It only takes a half of a second to reach the "point of no return" for side rollovers. Common causes include:

  • Driving across a steep slope or driving on roadways or slopes without locking rear brakes can result in side rollover.
  • Driving too close to a ditch, culvert, or pond/creek.
  • Towing a load that is too heavy.
  • Turning while driving too fast.

Rollover Protective Systems (ROPS)roll over protection

Rollover protective systems (ROPS) and wearing a seat belt are one of the best methods of preventing rollover deaths - they are 95 - 99 percent effective! Seat belts work with the ROPS to keep the operator in a safe zone within the ROPS structure. Many older model tractors can be retro-fitted with such systems. Note: Operators should not wear a seatbelt on tractors not equipped with ROPS!

ROPS do not prevent turnover, but they do limit the degree of rollover to 90 degrees - enough to prevent the operator from being crushed beneath the tractor. Always wear your seatbelt with ROPS! A tractor with an enclosed cab does not mean that it is equipped with ROPS. Check for a label on the ROPS system to verify that it is ROPS certified.

Some tractors are exempt from the ROPS requirement, which became effective on October 25th, 1976.

  • Tractors with 20 horsepower or less,
  • Tractors with mounted equipment that is incompatible with a ROPS cab or frame,
  • Low-profile tractors used in orchards, vineyards, farm buildings, or greenhouses where the clearance of the frame/cab would interfere with normal operations. Note: If the low-profile tractor will be used in other locations, it must be equipped with a ROPS.

General Machinery Hazards

General machinery hazards include pinch points, shear points, hot surfaces, and rotating equipment. Injuries can be quite serious, including amputations or death! The employer must protect employees from coming into contact with hazards created by moving machinery parts. Guards must be capable of withstanding the force that a 250-pound person (leaning or falling against) would exert upon that guard. Guards must also be free of burrs, sharp edges, and sharp corners, and be securely fastened to the equipment (or building). Where the location of the hazard is such that no employee can inadvertently come in contact with the hazard during operation, maintenance, or servicing.

Power Take-Offs (PTO) - Used correctly, PTOs can safely power feed grinders, bales, augers, mowers, chopers, and more. Used incorrectly, PTOs can rip off an arm, crush a skull, or sever a spine! A PTO can operate at around 1,000 rpm, or 16 rotations per second! A person can become entangled in rotating equipment in less than one second - making PTOs very dangerous. A person would barely have time to realize what was happening. Working around PTOs should be done with extreme care.pto

  • Turn off the tractor and PTO before getting off of the tractor. Remove the key.
  • Distance is the best way to avoid accidental entanglement with PTOs - keep at least three feet from the PTO.
  • Never reach over or step over the PTO.
  • Wear snug-fitting clothing without strings or loose ends.
  • Keep long hair tied back and under a cap.
  • Make sure that appropriate shields (guards) are in place, including the master shield, stub shaft shield, shaft shield, and implement shield.

Hydraulic Systems - Leaks in hydraulic hoses form a thin, high-pressure stream that quickly slices through skin, causing a serious injury called hydraulic fluid injection. Surgical removal of the fluid may be necessary, and if not properly cared for, gangrene may result. Always seek medical attention for this type of injury. Hydraulic systems can also fail without warning. Follow these tips:

  • Use a piece of cardboard or paper to search for leaks - not your hand!
  • Relieve pressure before disconnecting a hydraulic line.
  • Never cross hydraulic lines. If the lines are not coupled correctly, the implement will not rise and drop as expected. Tape or color code lines to prevent mistakes.
  • Never stand or work under raised equipment that is not supported by an approved lift support device.
  • Keep ends of hoses and connections free from dirt and debris.

Roadway Hazards

Rural roads can often be more deadly than interstates! Unfortunately, it is often necessary to operate farm machinery on rural roadways. A slow moving vehicle emblem is required for tractors traveling 25 mph or less. Note: Modified vehicles or just driving slowly in a farm truck, for example, is not considered a slow moving vehicle. Often, tractor operators on roadways will motion vehicle traffic to go ahead and pass the tractor. For liability reasons, this should be avoided. Let the vehicle driver make the decision to drive around the tractor. If there is an accident, it will be their responsibility and not yours.

  • Place slow moving vehicle emblems on the very end of the load being pulled. If signno load is being pulled, the emblem should be placed on the tractor in a highly visible location. Emblems should be clean, clear, and not faded.
  • Also recommended are flashing lights and an escort vehicle.
  • Avoid traveling on roadways at night when visibility is poor.