Power Take Off Injuries and Safety

Jon|Mar 27, 2023

A Power Take Off (PTO) transfers mechanical power between tractors and implements. Injuries from improper handling of PTO can end up being very severe. Fast rotation, operator error, and improper guarding make PTOs hazardous farm equipment. Appendages can get caught in an open PTO and result in amputation, severe lacerations, multiple fractures, spine and neck injuries, complete body destruction, or even fatality. Injury can be caused by a person getting entangled in an open PTO, which can be as simple as a string from clothing, a hooded sweater or jacket, or even a loose strand of hair. As the object wraps around the PTO shaft and it starts moving faster the victim can become pulled directly into the PTO unit.

Source: https://ag-safety.extension.org/power-take-off-safety/

The PTO is made up of several parts, all of which can be hazardous.

Source: https://www.researchgate.net/figure/Schematic-diagram-of-engine-with-PTO-drive_fig4_303831747

1) Stub: Most incidents involving the stub result from clothing getting caught by an engaged, unguarded stub. Laces, loose pant legs or coveralls, or jacket or sweater strings are clothing items that can get wrapped around a spinning stub shaft.

2) Drive Shaft: Similar to the stub, this presents a wrapping point hazard when left unshielded and open. When unguarded, the universal joints, connector, and implement input connection are all wrapping point hazards.

3) Machine IID Shaft: This part is coupled to the tractor PTO stub. When rotating this part moves at a speed faster than a person can pull back or take evasive action. Once wrapped, if a person tries to pull back, it will only result in tighter, more binding wrapping. If the IID shaft is coupled to the tractor PTO stub without another hitch between the tractor and the machine, the tractor may pull the IID shaft apart. In this situation, if the PTO is engaged, the shaft will swing wildly around and creates a striking hazard. Additionally, it may break the locking pin which would allow the shaft to become a flying object. This event is one of the less commonly occurring hazards involving PTO. This incident is most likely to happen when 3-point hitched equipment is improperly mounted or aligned or if the hitch accidentally uncouples.

4) Pins and Bolts: Pins and bolts that protrude from the machine can snag clothing. If the clothing does not rip, the clothing becomes a wrapping hazard. In other situations, the PTO part may be tightly compressed by the clothing and the person could get trapped against the shaft.

It is not only PTO parts that can result in injury, equipment handling and other practices present hazards. Practices such as mounting and dismounting, reaching for controls from the rear, and stepping across the shaft instead of walking around are all times that present increased hazard.

There are multiple actions that can be taken to increase the safety of PTO and connected equipment. The first action is to shield the tractor. The master shield is the first shield in the PTO driveline on the rear of the tractor. It prevents the operator from contacting the stub and the front joint of the driveline. The master shield covers three sides of the PTO stub. It is important that before operating PTO machinery the operator checks to ensure the master shield and the front joint are secured properly. In the event that a master shield becomes damaged it should be replaced. A second safety piece to use is a PTO driveline shield. It is plastic or metal and completely covers the PTO shaft and its ends cover the universal joints. It rotates with the shaft but will stop spinning when touched. If the shield is damaged or does not rotate independently it needs to be replaced.

Proper handling practices should be used when working with the PTO. Before conducting any work, always disengage the PTO, shut off the engine, and remove the key before dismounting the tractor. Ensure that no one else can start the tractor while maintenance is being done. The master shield should be kept in place at all times and only removed when necessary for hooking up special equipment. The guards should always remain in place when the equipment is not being used. Regular inspections of the guards should take place to see that they are in good condition. If a guard is not in good condition, it should be replaced.

PTO equipment should be handled properly as it can present a serious hazard. All workers should be informed how to safely work with the equipment and taught proper operating procedures. The information provided above is a brief summary of PTO operating safety. Elite Agri Solutions offers workplace safety training and education on health and safety. We will ensure your workplace is safe and that your workers know how to safely operate PTO equipment. Do not hesitate to contact us for more information on this service.