Winches
Winches
Winches are very similar to hoists in that they are used to pull a load. The distinction is that hoists lift a load vertically whereas winches are used to pull a load horizontally across the ground or another surface. Whether it is being lifted or pulled, anytime material or any load is being moved, there are safety risks associated with the process.
Winches come in many different sizes and are used in a multitude of situations. They are used on construction sites, in emergency situations, and in industrial facilities. Winches are also used extensively on vehicles, both personal and commercial (tow trucks, fishing vessels, etc.).
In general a winch is made of the following components:
- Spool (or Drum). This is what the cable or rope wraps around
- Cable (or Rope). This connects to the load and to the drum and is under constant tension
- Motor. The motor provides the power that turns the spool
- Gearing System. A gear reduction system is generally needed in order to convert the motor’s power into the high pulling forces required for most applications.
- Brake. Used to stop the spool from rotating when it should be steady and the cable is holding the load.
- Mounting Base. The base provides locations for the winch to be securely bolted to a surface.
Winches can be powered using several methods, including; AC motors, DC motors, hydraulic systems, pneumatic systems, and even internal combustion motors. There are certain unique safety risks with each of these types of power sources, but some safety hazards are inherent with every type and size of winch.
The first step to ensuring safe use of a winch is to make sure that it is properly secured before attempting to pull a load. Safety hazards, including being struck by out of control load, that can occur when a winch is improperly mounted or secured could be caused by some of the following component problems:
- Damaged (bent or cracked) tie rods, tie bars, housings.
- Mounting structure not capable of handling the full rated pull of the winch.
- Mounting bolts not tightened to the proper torque.
The main safety hazard with all varieties of winches is the pinch point hazard. Winches can operate with a great force and people can be pulled into the rotating mechanism and be severely injured. This can be caused by improper operation of the winch or by winch failure. Improper operation would include such actions as
- Exceeding the maximum hydraulic pressure or flow for the winch components.
- Using a winch for loads higher than its rated capacity.
Lastly, the ropes or cables used to pull the load can be a source of safety hazards. Ropes and cables are constantly under tension and if the ropes were damaged prior to use or not rated for the size of the load, they could snap and cause severe injuries. Handling of ropes or cables could lead to significant hand injuries and could also lead to a pinch point injury as described above if the operator is unable to let go of a cable in the necessary amount of time to avoid contact with the rotating components.