Powered winches are in use in a variety of applications, some of the most common include vehicle-mounted electric winches, marine vessel winches, marine recovery winches, industrial winches and chain hoists. Accidents occur in all types of winch uses.
One of the hazards of a powered winch is simple, entanglement in the winch or parts of the winch. Exposed gearing can snag on clothing, pulling the user or bystander into the winch, causing severe injury to the entangled parts.
This simple hazard is known as a pinch point hazard, because of the pinching and crushing action that occurs from the rotation of the winch. Pinch point hazards are well known, and in most situations, are regulated and guarded appropriately. Industrial equipment often has pinch points wherever power transmission occurs. Pulleys, gears, calendar rolls, and a number of other mechanical elements rely on rotation to transfer mechanical energy. Industrial machinery is regulated by standards created by ANSI, ASME, NFPA, and other standard-producing agencies. Most industrial situations involve employees and employers, making OSHA regulations applicable as well. These standards all call for safeguarding against pinch point hazards. Unfortunately, not all applications of power transmission hazards are covered by standards. The lack of a national standard for a product that outlines necessary safety criteria has historically resulted in unsafe products. OSHA standards have the most impact since they are federally mandated, but do not apply unless there is an employer/employee situation. This leaves numerous scenarios unregulated
Figure 2: U.S. Patent number 4,815,756
Vehicle-mounted winches are popular among 4x4 enthusiasts to self-extricate their vehicles, as well as to extricate other vehicles. Vehicle-mounted winches are also used for a variety of tasks not related to vehicles, such as moving heavy objects.
Currently there is little regulation of powered winches for vehicle use. This has resulted in most vehicle-mounted winches being unnecessarily hazardous. It is unclear why little has been done to make these products safe.
People are injured using vehicle-mounted winches when they become entangled in the winching mechanism. The hazardousness of these products is enhanced by the speed of the winches. Winches with high speeds are desirable to vehicle owners. As the speed of a winch increases, the allowable reaction time for human users decreases.
Accidents often occur when the user attempts to hold the cable as it is being retracted. This is presumably done to help guide the cable onto the spool. A moment of inattention can result in the user's hand being pulled into the winch mechanism. Accidents also occur when multiple people are working with a winch. Some winches use remote controls to provide safety for the winch operator. The downside of this intended safety system is that the winch operator may not be in a position where he or she can observe the winch itself.
This creates an additional hazard of bystanders becoming entangled in the winch. The situation is compounded if there are no override controls at the winch itself, making it impossible for an entangled victim to free himself. An emergency stop button should be made available on all vehicle-mounted winches to prevent the severity of these type of accidents.
Some winch manufacturers use remote controls to provide safety to the operator, intending to keep the operator away from the point of operation hazard. This safeguard by itself does not solve the problem since bystanders can be exposed to the hazard. To be effective, a remote control would have to be combined with a barrier that would prevent anyone from reaching the point of operation hazard. Simple fixed guarding is the most cost effective method of accomplishing this. These solutions are all based on established engineering design principles. Other manufacturers use spring loaded switches to help provide a small amount of safety. The theory is that the winch will only operate when the button or switch is depressed, stopping it when the switch is released. This can be a viable safeguarding method in certain situations, and while it may help reduce the severity of injuries in an entanglement situation, the better solution is to neutralize the hazard using guarding technology.
Solutions to vehicle-mounted winch accidents normally involve simply guarding the pinch point of the winch. This can be done with fixed guards that cover the pinch point of the winch while still allowing cable to be retracted and extracted. This keeps hands, fingers, and clothing out of the pinch point. It is also imperative to provide housing over gears and other rotating mechanical components. These do not need to be exposed, and only create additional hazards when they are exposed. An additional safeguard would be to provide the equivalent of a body bar for winches. Body bars are used in industrial operations where an operator may become entangled or pulled into a machine. If an operator or bystander is pulled into a machine, the person's body will be pulled into the body bar, which is wired to a switch that engages an emergency response, either stopping the machine, or stopping and reversing the machine. This same theory could be applied to winches by arranging a bar in front of the winch that would be triggered in the event that a person did become entangled in the device despite the proposed guarding.
Fishing and other marine vessels use powered winches and rollers in a variety of tasks. Fishing vessels rely on powered winches and rollers to pull in fishing nets and pods. Many fishing vessels continue to operate without basic machinery safeguards. This problem may be due in part to the fact that under certain situations, the Occupational Safety and Health Act may not be applicable. This is because the U.S. Coast Guard has authority over vessel safety in certain situations. The Fishing Vessel Safety Act, 46 CFR Section 28 outlines some safety requirements, including safeguarding requirements for exposed machinery hazards like gearing and rotating shafts. Some people argue that the US Coast Guard does not have the resources to adequately patrol and regulate safety of fishing vessels, in addition to their other responsibilities.
Accidents occur frequently when workers become entangled in powered winches and rollers while pulling in fishing gear. Powered rollers are often of a large enough scale to pull a person's entire body into the mechanism, likely resulting in death.
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John L. Ryan, BSME, P.E. is a Mechanical Engineer who provides general Mechanical and Structural Engineering expertise. Mechanical and Safety Engineering (MASE) provides full service analysis and accident reconstruction of products involved in accidents. Mr. Ryan's services have been requested for attorneys and insurance companies needing forensic engineering expert witness testimony to determine whether machinery and products involved in injury cases were adequately designed or whether they have a Design, Manufacturing, or Material Defect. All products are lab-tested on site to determine adherence to industry standards and engineering design protocol. Alternate preventative designs are developed when none exist commercially.
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