Relative safety of traditional agricultural tractor power take-off (PTO) drivelines compared to fluid power--a review.

Nearly all tractor PTO arrangements used today consist of a rotating mechanical shaft with two or more universal joints and splined couplings. Although this method of power transfer has been the standard for decades, it continues to be a hazard to farm workers. Commonly, PTO accidents involve the snagging of clothes, resulting in the victim being rapidly and violently drawn into (and around) the rotating shaft. Entanglement injuries are both common and severe in the agricultural workforce, with poor shielding maintenance as a contributing factor. If PTO loads were driven with fluid power, this entanglement hazard would be eliminated. With high-pressure injection injury being the principal hazard, the fluid power alternative appears to pose a lower risk in terms of both frequency of occurrence and severity of injury.