Posted on: 7 July 2015
If your factory has an overhead crane as part of its material handling equipment, safety should always be the top priority. However, when used every day by workers, some misconceptions about operating the equipment safely could emerge. Below are some of these misconceptions and an explanation of why they are wrong.
Side Pulling Is Safe As Long As Its A Short Distance
Side pulling occurs when the crane is used to pull a load off of a shelf or platform that is next to it. Although some operators believe this is acceptable if the crane is only a short distance from the cargo, it should never be attempted.
Overhead cranes are designed only to lift loads straight up and straight down. When side pulling is done, this throws both the crane and the hoist chain off balance. When this happens, the load starts to sway out of control, possibly knocking into a person or machinery nearby.
Side pulling can also prove hazardous because it puts undue stress on the hoist chain. If there are any weak links in the chain or support wire, the sudden sideways movement could make either one snap, dropping the load and causing a potentially fatal situation if it lands on someone.
Make sure you remind your workers not to use the overhead crane for any type of side pulling. Encourage them to use lifts to remove cargo from platforms or shelves, then place them on the ground for the crane to pick up.
Overloading The Crane Is Okay Because The Hoist Has An Overload Circuit
As a safety feature, many overhead cranes come equipped with an overload circuit that shuts the motor off when the load is too heavy. Because of this, some workers may not worry about weighing the load before attaching it to the crane because the sensor will tell them if the cargo weighs too much.
Although this does help for accidental overloads, it should not be used as an indicator for when the cargo is too heavy. Every time a load is hoisted that exceeds the crane's capacity, it puts a strain on the motor and the hoist wire. The load is lifted a few feet before the sensor shuts it down. During that time, stress has already been placed on the crane.
Remind your workers to carefully weigh each load before attaching it to the hoist. Also, overload tests need to be done to make sure the motor and chain can still withstand the weight listed in the manufacturer's specifications. Regular use and overuse could make this number less over time.
Raising The Crane Further Than Recommended Is Allowable To Clear Tall Objects
Overhead cranes have a limit as to how high they can be raised. This ensures the motor is not overloaded and the chain does not have too much stress on it. However, they do have an override in case of an emergency that allows the operator to temporarily lift it higher.
Some workers use this override to regularly clear tall objects. Doing so puts increased strain on the crane, increasing the likelihood the motor will burn out or the chain will break because of the constant tension.
Tell your workers not to use the override feature, except for when absolutely needed. Instruct them to either move tall obstacles or reroute the path they take transporting loads.
By correcting misconceptions and reminding crew members about the safe operation of overhead cranes, you may be able to avoid serious injury and destruction of property. If you have further questions about operating your particular model or wish to know its specifications, you may want to contact your material handling equipment supplier.Share