Safety Practices for a Tractor Mounted Post-Hole Digger

Tractor mounted post-hole diggers can be extremely efficient for setting posts, building fence or planting trees. However, like other pieces of heavy machinery, if not used properly post-hole diggers can cause injuries or fatalities. The three most common incidents involve entanglement of the power take-off (PTO) driveline, entanglement with the rotating auger, and injury to bystanders by objects being thrown from the rotating auger when digging. Injuries sustained from post-hole diggers can be avoided with a little forethought and by following a standard set of guidelines.

Equipment Safety

There are generally two types of tractor mounted post-hole diggers. The most common is power take-off driven. A power take-off driveline connected from the tractor to the post-hole digger gearbox delivers power to run the auger.  The second type of post-hole digger is hydraulic driven. Hydraulic lines from the tractor connect to a hydraulic motor that provides power to the auger.

Figure 1. Recognize and follow all safety labels before using the equipment.

Potential hazards with each type of post-hole digger can vary. Before operating the piece of equipment follow these guidelines:

• Read and understand the owner’s manual and safety labels that are on the digger before using the equipment (Figure 1). If you do not have an owner’s manual, one may be available from the dealer.
• Use the equipment only if all the shields and guards are in place and are in good condition. Priority areas to guard include at each end and around the power take-off shaft, and the output guard of the gearbox.
• Inspect the digger before each use to ensure it is in good working order. Items to check include the auger point, cutting edges and shielding around PTO rotating parts.
• Check for fluid leaks of hydraulic lines or the gearbox and repair before use. Never use hands or fingers to check for pinhole leaks. Hydraulic fluid within the lines can be under high pressure, causing the fluid to be injected into the skin.
• Relieve pressure from the hydraulic system before repairing, adjusting or disconnecting a hydraulic driven post-hole digger.
• Use only the shear bolts or auger retaining bolts supplied/specified by the manufacturer. Larger size augers can increase the stresses put on the driveline assemblies, increasing the need to frequently check and replace worn sheer bolts.

Operator Safety

Safely using a tractor mounted post-hole digger starts with the operator. The operator is responsible for maintaining control of the equipment and safe completion of the work. Guidelines for the operator include:

Figure 2. All operations should be performed from the tractor seat, with bystanders 20 feet from the equipment.

• Before digging, check with local utility authorities about underground utility, cable and sewer lines. Call 811 in the United States.
• Clear digging area of stones, branches or debris that might be thrown or entangled in the post-hole digger, causing injury or damage.
• Be especially observant to overhead obstructions or low hanging tree limbs.
• Only one person should operate the post-hole digger and operation should be performed from the tractor’s seat, not from the ground. (Figure 2).
• Avoid engaging power to the implement while anyone is in contact with any part of the implement, PTO driveline or auger.
• Engage the PTO with the engine RPM at idle speed. Make sure the PTO speed matches the implement’s recommended speed during operation.
• Do not lift the auger point more than 12 inches off the ground when the PTO is running. It can lead to possible driveline failure or other damage.
• Know the controls and how to stop the tractor, engine and post-hole digger quickly in the event of an emergency.
• Follow safe shutdown procedures and wait for all moving parts to stop before dismounting the tractor.

Worker Safety

Individuals working with the operator or around the post-hole digger are recommended to follow these safety guidelines:

Figure 3: Keep 20 feet away from the drive-line, gearbox and auger when the equipment is in operation.

• All bystanders should be at least 20 feet from equipment while it’s in operation (Figure 3).  
• Use caution to avoid flying debris when the auger is rotating at higher speeds.
• Maintain visibility and communication with the operator when the tractor or post-hole digger is in operation.
• Watch for pinch points that are common with pivoting parts.
• Do not wear loose-fitting clothing near a rotating PTO. Make sure shoelaces are tied and secure long hair. Remove strings from sweatshirts and jackets to prevent entanglement.
• Do not step over a rotating PTO shaft.
• Do not place your hands on the auger, gearbox, boom or driveline when positioning the post-hole digger.
• Never position the auger by hand or with a tool when the auger is running.
• Wear appropriate personal protective equipment (PPE) for the work being completed (safety glasses, hearing protection, safety shoes, and gloves).
• Do not walk or work under a raised auger unless it is securely blocked or held in position.
• Never stand or sit on the frame to increase digging capability when the soil is hard. Persons and additional objects attached to the frame can be thrown or entangled in the equipment.
• Do not shovel dirt away from the hole during the digging process. The hand tool can catch on the auger, pulling the hand tool or the person into the moving parts of the equipment.

Tractor mounted post-hole diggers are subject to certain hazards that cannot be eliminated by mechanical means or product design. Therefore, use the equipment only for the manufacturer’s intended purpose. Many injuries occur due to negligence, carelessness or complacency. Observing owner’s manual recommendations, training workers and planning for safety when using a post-hole digger can reduce the risk of serious injury.

Acknowledgments

This fact sheet was reviewed by Erdal Ozkan, PhD, Professor and Extension Specialist, Food, Agricultural and Biological Engineering.

References

• ASABE Standards. 2013. S619: Safety for Tractor Mounted, Boom-Type Post-Hole Diggers. St. Joseph, MI: American Society of Agricultural and Biological Engineers.
• ASABE Standards. 2017. S318.18: Safety for Agricultural Field Equipment. St. Joseph, MI: American Society of Agricultural and Biological Engineers.
• Post-Hole Diggers Operator’s Manual: 317-048M. Land Pride. September, 2017. 
• Woolf, Lynn M. “Safe Operation of Post-Hole Diggers.” Rural Lifestyle Dealer (2009): 41-42.