How Does a Winch Work?by Derek Odom
Mechanics of a Winch
A winch can be used in many different ways, but they are primarily found on the front bumper of off-road vehicles such as four-wheel-drive trucks and SUVs. They might also be found on trailers to help load boats or ATVs. It is a motor-driven unit that contains a spool of wire or rope. Some winches use a 12-volt motor to power them, while others use hydraulic fluid from the power steering unit. The latter is mostly found on military applications. Their biggest downfall is that the vehicle has to actually be running for the winch to work, while an electric unit will work as long as the battery has power. When the winch is turning, it rotates the spool, which either sends the winch cable in or out, depending on the direction chosen.
The primary reason to have a winch on a vehicle is to aid in recovering it should it become stuck such as in mud or sand. The winch line is spooled out of the winch, and connected to another vehicle or something solid via a large clevis hook on the end of the cable. The winch is then put into gear using a switch on the body; once power is applied, the cable is brought back toward the vehicle and spooled onto the winch, effectively getting the vehicle unstuck.
Safety and Things to Know
It is good when purchasing a winch to know the weight of the vehicle it will be installed on, because different winches are rated for specific weight limits. For instance, it is not a good idea to put a winch with a 5,000-pound maximum pull rating on a 5,000-pound vehicle because if the vehicle is stranded in mud or sand, it can effectively weigh much more. A good rule of thumb is to aim for 1½ the vehicle weight for the pull rating of the winch. A 5,000 pound vehicle should be fine with an 8,000-pound winch. Always wear gloves when grabbing steel winch cable because it tends to fray and can easily cut a hand. It is a good idea to place a heavy jacket or other soft weight in the middle of the winch line when pulling, because if the cable snaps, it can release a lot of energy at once and snap violently. A weight will transfer that energy to the ground and make it safer for everyone around it. Also, it is a good idea to pull for only 30 seconds at a time with an electric model winch, so the motor does not get hot and burn up. A hydraulic winch will not experience this and have a 100 percent pull cycle. With an electric model, pull for 30 seconds and wait for a minute, then repeat until the vehicle is free.