Cranes are fundamental to various industries, including construction and manufacturing. Operating heavy equipment like cranes involves risks that can seriously impact lives, operations, and costs. According to the United States Bureau of Labor Statistics, there is an average of 42 crane-related fatalities in the U.S. each year. Additionally, 24% of fatal work injuries involving cranes take place in the manufacturing industry.
Understanding what causes crane accidents can help make the work environment more secure and minimize the impact of accidents, injuries and fatalities. This guide by CICB looks at five common causes of crane accidents and explores preventive strategies that can help minimize crane-related risks. That way, you can train your team accordingly and implement the necessary precautions on your construction site to reduce these hazards as much as possible.
5 Common Causes of Crane Accidents
Crane accidents can happen for numerous complex reasons. While there is usually a primary cause one can point to when a crane accident occurs, it is often a series of problems that culminate in the accident. For example, a lack of training may result in poor communication that causes the accident, or a combination of inadequate planning and environmental factors can result in an incident. The five most prevalent causes of crane accidents include:
1. Human Error
Most crane accidents involve human error of some degree. Human error is often the result of improper equipment use, inadequate training, poor communication on-site, and a few other factors:
- Improper operations: Operating the crane outside of its parameters can lead to injuries and fatalities. Improper operations include exceeding the crane's load limits and using incorrect rigging techniques.
- Lack of training: Operating a crane takes incredible skill, but no one can rely solely on skill to get the job done safely. Every worker on-site must be trained extensively to understand the correct safety protocol. Comprehensive training also enhances soft skills that contribute to workplace safety, like communication and teamwork.
- Poor communication: Clear communication is an essential part of workplace safety in construction and manufacturing. Misunderstandings can lead to dangerous errors, as can a lack of effective communication in an emergency situation.
- Distractions: Distractions increase risks on a construction site or a manufacturing plant. In a work environment where serious accidents can happen in a matter of seconds, workers cannot afford to be distracted by their phones or let their minds wander.
- Complacency and routine risk: Complacency, overconfidence, and unlawful or risky behavior can easily result in crane accidents. In these scenarios, a worker may neglect safety protocol due to their overconfidence and act more daringly. This attitude puts them and their co-workers at risk. At times, these actions may be completely unlawful, such as when a worker is under the influence of alcohol or other substances.
2. Mechanical Failure
These types of accidents can result from malfunctions or failures in structural components, mechanical systems, control systems and indicators, and power systems. When structural components fail, the outcomes can be catastrophic and even fatal. The following structural components can experience failure:
- Boom: Boom failure can happen for numerous reasons. The metal could be fatigued or corroded, or there may be weld defects. Exceeding load capacity can also cause the boom to collapse, which can lead to devastating destruction, severe injuries, and fatalities. The boom is a massive and heavy component, and it can fall from elevated heights if not properly secured and maintained.
- Jib and extensions: Compromised points and pins can compromise the structural integrity of the boom extensions and jibs.
- Counterweight system: If the counterweight system fails, the entire crane can tip over, injuring operators and others on-site and destroying surrounding property.
- Outriggers: Outriggers help provide additional stability during lifting operations, and if they fail, the crane can tip.
- Mast section: The mast section also helps provide structural support. If it has faulty spigots or defects, it may fail, increasing the risk of the crane tipping or components collapsing. Improper rigging and overloading can also strain the mast section.
A crane's mechanical system includes the brakes, clutch, gearbox, pulley systems, and hydraulic systems. When these components are compromised, the crane can move uncontrollably. An operator may not be able to slow or stop the crane from colliding with property or people, or they may have trouble safely controlling the load when experiencing mechanical failure.
Control and power system malfunctions and indicator failures can also result in devastating accidents. If any of the electronics or sensors fail, the crane cannot detect potentially hazardous conditions like wind gusts, overloading, and proximity to hazards like overhead power cables. Recognizing the dangers of improper and infrequent maintenance is essential.
3. Environmental Factors
Environmental factors like bad weather and other poor working conditions can make a site unsafe. Safety measures in place, like sensors, can warn of less-than-ideal working conditions. Often, though, working conditions can be ideal and then swiftly change in the middle of operating a crane, sometimes at a crucial moment. Environmental factors that can be a concern include:
- Wind: As a general rule of thumb, workers should halt or postpone operating a crane in winds exceeding 20 miles per hour, or 32 kilometers per hour. However, a safety manager may determine that operations should be halted or postponed in wind speeds lower than 20 miles per hour, especially when other poor conditions factor into the decision.
- Poor visibility: Weather conditions like fog, rain, or snow can make it difficult for operators to see the load and their surroundings. Clear visibility is essential for safe crane operation, so cranes should not operate when visibility is low.
- Unstable ground: Crane stability — and, hence, crane safety — largely depends on the condition and stability of the ground.
Sometimes, the events that cause crane-related accidents seem greatly beyond anyone's control. However, it is crucial to prioritize safe working conditions and emergency response training to help minimize the severity of these types of accidents.
4. Improper Rigging
Proper rigging helps verify that loads are secured and lifted safely. Several factors can lead to rigging-related accidents, primarily involving load instability from miscalculations and using incorrect or damaged slings:
- Improper rigging: Failing to apply correct rigging practices for each load can lead to load instability. These practices include proper load management strategies, clear communication while rigging, and adherence to general safety protocol.
- Using incorrect slings: If the wrong slings are selected and are not rated for the weight of the load, the load can be unstable and drop.
- Improper sling angle: Using improper sling angles that exceed the manufacturer's recommendations can increase the stress on the rigging equipment and reduce lifting capacity. In extreme circumstances, improper sling angle can lead to failed lifts that result in injuries and destruction.
- Damaged slings: Slings that are cut, frayed, worn, and damaged can cause load failure.
- Failure to inspect rigging: Neglecting to inspect rigging equipment before each use may have catastrophic consequences. For greater safety, one should do a thorough visual check of all hardware, including the slings, shackles, and hooks. The load capacity markings must also be legible and verified.
5. Inadequate Planning
Inadequate planning greatly affects operations and can lead to property damage, injuries, and fatalities. Examples and case studies showing the seriousness of improper planning include:
Improper Site Assessment and Setup
Failing to assess a worksite and setup properly led to a fatal incident in November 2003, when a 66-year-old equipment operator was killed on-site. The operator, who was an experienced worker, positioned the crane on unstable ground between two ponds.
The operator allegedly started dredging and attempted side-angle operations without deploying the outriggers. The unstable ground and improper setup caused the crane to tip over. The operator jumped from the cab, and he was sadly crushed by the lattice boom crane.
Improper Use of Cranes
Four workers were killed and six were injured in the collapse of a crane in Texas, on July 18, 2008. The incident involved one of the world's largest cranes at the time, the Versa TC-36000. The crane fell backward when the operator, an unqualified worker operating the massive crane for the first time, lost control of the crane. The collapse also brought down a smaller support crane with it.
Working Through Dangerous Conditions
On February 5, 2016, a 570-foot-high Liebherr crawler crane collapsed in Manhattan, New York. The unfortunate incident resulted in the death of a motorist. The collapse also left two pedestrians injured. The crane was operating in high winds, despite the recommendation to lay the crane down in winds over 20 miles per hour.
This was not the only violation of safety recommendations. The operator had also lowered the boom to 69.4 degrees in these windy conditions, where the recommendation was not to have the boom angle lower than 75 degrees. There may have been a lack of clear instructions contributing to these circumstances.
Inadequate Load Assessment and Miscalculations
A lattice boom mobile crane overturned in 2010, causing over $100,000 in damage. The accident, referred to as the Jay Jay Railroad Draw Bridge Crane Incident, occurred when the crane overturned on a barge while placing pilings with a hydraulic driver.
The loft planner miscalculated the weight of the hydraulic driver, causing the load to exceed the crane's lift capacity. The miscalculation led the operator to believe the load was 9 tons, but it was actually 10.5 tons. The load swung perpendicular to the crane's crawler tracks, and the crane tipped and fell over.
Failure to Plan for Overhead Power Lines
A report by the Occupational Safety and Health Administration (OSHA) shows that in the U.S., the third leading cause of death while working on a construction site is electrocution. Many of these events occur because of contact with overhead power lines.
Even workers on foot who touch or guide crane loads can be injured or killed if a crane comes into contact with power lines. Proper planning and detailed lift plans are essential for a safe working distance from power lines that minimize these risks.
Poor Planning for Assembly and Disassembly
The 2008 NYC Tower Crane Collapse highlighted the need for written procedures and critical processes for “jumping” a tower crane, making it taller as a building grows during construction.
In this incident, the tower crane collapsed while being “jumped,” killing seven people and injuring 24. The devastating accident occurred because temporary restraints were removed before permanent ones were installed, showing a clear lack of planning, training, and supervision by qualified site managers.
The Importance of Prevention Strategies
Some of the statistics for injuries and fatalities related to crane accidents reflect how severe they can be. The World Steel Association published a 2024 data report on safety and health in the industry. One of the datasets in the report examined the ratio between lost-time injuries (LTIs) and fatalities from 2004 to 2023. During this period, overhead crane accidents resulted in 897 LTIs and 103 fatalities.
All crane accidents should be taken seriously, as should preventive measures. Having prevention strategies in place for all construction and manufacturing environments is crucial for minimizing accidents that cause property damage, severe injuries, and loss of life. Crane accident statistics reinforce how vital workplace safety is in these industries. Each construction and manufacturing company and site should prioritize adequate and ongoing training, including crane operator training, overhead crane training, rigger training, crane inspector training, and crane supervisor training.
Awareness and Training Are Essential for Minimizing Crane-Related Accidents
Devastating accidents involving cranes have far-reaching consequences. Workers and bystanders can be injured or lose their lives, and surrounding businesses can also suffer costly damage. These incidents also negatively impact the construction and manufacturing industries — companies risk their reputation and their operations, and the results can sometimes be permanent due to bankruptcy or legal outcomes.
Closely examining the common causes of crane accidents can help businesses proactively address safety concerns, and ongoing training, inspections, and maintenance can make businesses safer and more compliant. Companies that prioritize prevention strategies that minimize crane-related injuries and fatalities help grow crucial sectors in construction and maintenance.
