Overhead cranes and other lifting accessories are an essential part of manufacturing and construction for a lot of companies. Cranes improve business operations from a production standpoint and provide an efficient method of material handling that can help eliminate worker injuries. But, an overhead crane can also be a dangerous piece of equipment if used incorrectly, which can lead to serious injury or even death.A lot of companies have moved away from best safety practices with the use of overhead cranes, particularly since so much emphasis is placed on other forms of safety such as fall protection, safer welding practices, and automated machining. But, each year there are hundreds of injuries and even fatalities as a result of unsafe material handling practices that could have been easily avoided with the use of practical risk assessment measures and pre-start checks.
About Risk Assessment
Overall, risk assessment involves the systematic process of evaluating potential risks involved in a specific project or activity. In regard to overhead cranes, risk assessment is often mixed in with conducting regular crane inspections, many of which do not involve a daily checklist. If in doubt, I believe it’s always a good idea to conduct a daily inspection of any type of heavy machinery. But, there are calculated ways to put safety controls in place, which can and should involve risk assessment.
Assessing Overhead Crane Risks
It’s always a good idea for safety managers, production managers, shop managers, and facility engineers to enforce safer practices for their employees. One way to enforce safer practices with the use of overhead cranes is by asking employees to conduct a risk assessment at the start of each shift or new lifting operation. Each factory may need to compile its own risk assessment list, but the following is a great place to start:
- What is the task at hand? For instance, are you moving steel beams or other heavy metal structures?
- Do I understand the correct way to complete the task at hand? For instance, do I know exactly what needs to be lifted and where?
- Am I using the correct lift system (do I have the right tools and equipment)? This is particularly important in regard to overloading a crane beyond it’s rated capacity, which is extremely dangerous.
- Have I been properly trained and authorized to operate the lifting equipment in question? This may involve the use of appropriate training measures for crane operators or even the implementation of a secondary worker to help the operator move the load safely.
Are the correct controls and procedures in place to ensure safe use of equipment? This may include:
- Warning devices
- Control Units
- Personal Protective Equipment
- Inspection Records
- Safe Working Loads (rated capacities)
- Exclusion Zones
- Potential Obstructions (including other equipment and machinery as well as personnel)
The controls outlined above are important to the overall safety of employees and surrounding equipment and machinery. Furthermore, there are several preliminary checks crane operators should put into place prior to overhead crane use:
Pre-Start Checks: Workers and crane operators need to ensure that no warning signs are attached to the crane or the control unit/main isolation switch. These signs may include warnings that equipment is locked or tagged out and unsafe for operation. If an isolock system is in used, operators should never attempt to remove it. It’s there for a reason.
Control Unit: Depending on the type of control unit used, it will most likely be fitted with a red stop button that requires a key or twist action to release the stop button. Releasing the stop button allows workers to operate the crane OR unlocks the green button, which is then used to energize the crane’s main contactor.
Operators should be instructed to press the red button if they run into any problems during the operation of the crane and follow up by turning off the main isolator immediately.
Pendant Control Unit: Crane control buttons are housed in a box that is connected to the crane using festooned cables. When a button is pressed, the hook will move in the direction indicated; the harder the button is pressed the faster the crane will travel.
Remote Control Unit: A pendant control works by sending a signal to a transmitter on the crane via radio or infrared. The remote is often hand held, but it can also be strapped to the operator to allow free movement during operation. Some remote control units operate twin hoist cranes (as either a singular or double hoist unit). It is important to keep in mind that if operators are required to reposition the slings on a load, they must turn off the control unit to prevent accidental operation.
And, as an extra safety measure, it’s always a good idea for operators to conduct a daily safety inspection checklist prior to each use. This may include (but is not limited to):
Conduct a quick area checkout. This includes knowing where the crane disconnect switch is located and—as mentioned above—verifying that there are no warning signs on or around the push button pendant. Additionally, make sure workers aren’t performing their duties nearby; ensure that the load can travel freely without impediments; ensure that the there are no obstructions in or around the area where the load is traveling and that the area is large enough to move and place materials safely; check that all below-the-hook devices are designed for the crane in use and can safely lift loads; and ensure that the load capacity is less than or equal to the rated capacity of the crane. The general overall condition of the system, including the actual steel beams and enclosed track.
For a Daily Inspection Checklist, see our daily inspection for workstation bridge cranes and monorails blog here.
And, be sure to direct operators to check the following:
- General overall condition of the crane
- Isolation switch and stop
- Pendant or remote control unit
- Hoist rope
- Hook and safety catch
- Enclosed track and steel I-beams/structures
- Upper safety limit switch
- Hoist and travel brakes
- Anti-collision devices
- Ancillary equipment such as chains and web slings, eye bolts, magnets, vacuum lifters, etc.
Lastly, operators can even go as far as to perform a trial lift before moving particularly large or cumbersome loads to ensure total safety of all workers involved:
- Ensure that the load is secure and not fastened in any place before trying to lift or move it
- Lift the load a couple of inches from the ground and stop lifting to ensure ease of movement and travel
- Ensure that the load is stable and has been properly secured before continuing with crane travel checks
- Never snatch the load—this can cause additional loading on the lifting attachments and the crane leading to potential failure
- And, always complete your daily checklist for safe crane operation!