February 21, 2020
Image credit : Representation image : Crane accident on Indian 2 film making set.
Countless work areas in varied industries (manufacturing units to construction sites to filmmaking sets) rely on overhead cranes to lift, transport materials and for mounting lights/ cameras in case of filmmaking. When installed and used properly, these systems make operations easier and safer. But, overhead crane accidents cause severe injuries and fatalities every year. Preventing these disasters requires workers to recognize certain hazards that occur during operation and follow safety procedures to avoid them.
There are multiple hazards that can arise regarding cranes in general. Many accidents involve large lift systems like tower cranes and mobile cranes. But hazards do exist with all types of cranes—including overhead cranes—and in all facets of crane operation. (Overhead cranes are defined by OSHA 1910.179(a)(8) as a crane with a movable bridge carrying a movable or fixed hoisting mechanism, and traveling on an overhead fixed runway structure.)
Analysis of overhead crane accidents reveals three common safety hazards that every company using overhead lift systems should be aware of to keep their workers safe. It’s important to be familiar with these hazards and learn to recognize them in the workplace in order to avoid them. The three most common hazards involving overhead cranes include electrical hazards, overloading, and materials falling/slipping from overhead hoists.
One commonality that all hazards share is the qualifications of crane operators. It is the responsibility of the crane owner and job supervisor to ensure that crane operators are competent and qualified to do the job.
Common Causes For Crane Accidents & How To Prevent Them:
1. Crane Tipping Due to Improper Outrigger Use:
Any tipping incident can be extremely dangerous for both the crane operator and the other workers in the area surrounding a crane. While thankfully rare, most crane tipping accidents are due to improper outrigger use. This can occur in several different ways but is largely related to unsuitable ground conditions, including depressions, voids, excavations, and uneven grading. When the outrigger pad is positioned on unlevel, wet, or otherwise unstable surfaces, you risk an inability to control crane positioning.
Instead of assuming any area is good enough, use common sense and attention to detail. Fully inspect every area, analyze ground conditions, and manage deflection levels as best as possible. If forced to work in inopportune settings, take extra precautions to improve the load bearing capacity using additional supporting materials.
2. Dropped Loads Due to Improper Rigging:
Cranes are designed to carry heavy, awkward, and oversized items, but when rigging isn’t up to the task, you risk dropping a load and endangering both property and human life. Failed rigging often arises from human error, ranging from improper adherence to procedure to utilizing broken or failing parts. One wrong move can lead a load to slide or fall in a catastrophic manner.
To avoid incident, always rig loads by the book. Do not cut corners or use workarounds. If the proper equipment is not present, do not move forward. Always inspect all elements thoroughly, including chain links and hooks. Any hooks with a broken or bent safety latch or hooks that are stretched or twisted should not be used. Be sure the angle of the load is as close to zero as possible; any load at an angle of 10 degrees or more requires adjustment.
3. Boom Collapsing Due to Improper Weight Calculations:
Not all cranes can carry all loads. All commercial cranes are sold with a strict weight limit and any excess weight, no matter how small, can cause critical failure. In order to avoid boom collapse, dropped loads, and potential tipping, it’s essential to adhere to all posted weight limits.
When preparing a load, make sure no part of what you will be lifting exceeds crane weight limits. When determining total weight, be sure to include the weight of all rigging as well; the chains and hooks used to secure a load obviously must be supported by the crane as well. Once a weight has been determined, do not add any extra materials for any reason. Regular boom inspection should also be a part of your operating procedures as a damaged, warped, rushing, or otherwise compromised boom can reduce noted weight limits.
4. Electrocutions Due to Overhead Power Lines:
Power lines are a necessity for modern life. While more and more cities, towns, and communities are moving toward underground power lines, this is not yet a reality in all areas. Many locations nationwide still use above-ground power lines, and crane operators should pay special attention when this is the case. Unfortunately, electrocutions are responsible for one in 10 deaths.
Before starting a project, heed the location of all power lines. Rather than guessing, teams should always check with utility companies to note the voltage of overhead lines in order to determine minimum distances. Flags should be set to mark boundaries and teams must use spotters with two-way radios to watch for risks before incidents occur.
OSHA Guidelines For Crane Usage:
1. Before using a crane, an inspector should check the machine for any mechanical problem that may result to accidents.
2. The crane machine must undergo a more comprehensive inspection on a regular basis to determine if there is a crack, faulty wiring, worn-out ropes, and any damaged part that could lead to accidents.
3. If there is any damaged part which must be repaired or modified, this should be done by a qualified person.
4. Place the crane in a stable and flat ground which must be at least 10-feet away from electrical
5. Make sure the crane is not carrying a load which is more than its capacity. The load should not be more than 75 percent of the tipping weight.
6. Install fences around the site to prevent outsiders from going near the crane.
7. Make sure the crane’s safety devices such as the level operator are working properly.
8. While operating a crane, there should be a qualified “signal” person who will assist the operator in maneuvering loads.
9. There should be a fall protection equipment for workers who are standing more than 6-feet above the ground.
10. The loads should be set by a qualified “rigger” to make sure that these will not come loose and strike a worker.
11. The foundation for tower crane and other structural supports for this machine should be designed by its manufacturer or a professional engineer.
12. Crane operators should consider the wind as the most important safety concerns. Wind is one of the leading causes of crane accidents (OSHA).
13. Due to stability concerns, cranes mounted on ships and offshore platforms should be used more carefully.
Accidents can happen to anyone, but education is a key part of prevention. When team members work together to inspect equipment, evaluate job sites, and watch for potential threats, it’s possible to minimize or eliminate the possibility of loss of life.
(The author is a Disaster Management Consultant)