Understanding Crane Rigging: Types of Loads and Proper Techniques

Key Takeaways

Different load types require specific rigging configurations – matching the right technique to the load is crucial for safety and efficiency
Even routine lifts can be deadly – 74% of crane incidents occur during everyday operations that workers considered “standard” procedures
Improper rigging accounts for 27% of all load drops – making it the single most common cause of crane accidents
Complete pre-lift assessments that evaluate the load’s shape, weight distribution, and attachment points are non-negotiable safety steps
Investing in proper training can reduce crane-related accidents by up to 50%, offering significant return on investment beyond regulatory compliance

When a crane hoists a multi-ton load above a busy construction site, the only thing preventing catastrophe is the rigging that connects that load to the crane. Between 2011 and 2017, 297 crane-related deaths occurred in the United States, according to the National Safety Council. More alarming is that the majority of these incidents didn’t happen during complex, unusual lifts but during everyday operations that workers considered routine.

The difference between a successful lift and disaster often comes down to two critical factors: understanding the specific type of load being lifted and applying the appropriate rigging techniques for that load. Yet many crews apply a one-size-fits-all approach to rigging, failing to account for the unique characteristics of different materials and shapes.

This comprehensive guide dives into the critical relationship between load types and rigging techniques. Whether you’re a crane operator, site supervisor, rigger, or safety manager, you’ll find practical, actionable information to make your lifting operations both safer and more efficient – especially for those “”routine”” lifts that statistics show are surprisingly dangerous.

Crane Rigging Basics: Foundation for Safe Lifting

What Is Crane Rigging?

Crane rigging refers to the process of preparing and securing loads to a crane for lifting operations. It encompasses the equipment, techniques, and procedures used to attach, stabilize, and control materials during a lift. Proper rigging creates the critical connection between the crane and its load, directly impacting the safety and success of every lift.

The rigging system typically includes:

Slings (wire rope, synthetic, chain, or web)
Hardware (shackles, eyebolts, hooks)
Below-the-hook devices (spreader beams, lifting beams)
Attachment points on the load itself

Each component plays a vital role in distributing forces and maintaining stability throughout the lifting process.

Key Principles of Safe Rigging

Safe rigging begins with understanding several fundamental concepts:

Load balance and center of gravity: Every load has a center of gravity that must be properly aligned with the crane’s lifting point to prevent dangerous tilting or rotation.
Sling angles: The angle at which slings connect to the load significantly affects the force placed on each sling. Wider angles create greater stress on rigging components.
Dynamic forces: A static load becomes dynamic once in motion, creating additional forces that must be accounted for in rigging calculations.
Load rating and capacity: All rigging equipment has specific load ratings that must never be exceeded.
Load securing: Different materials and shapes require specific securing methods to prevent slippage during lifts.

Beyond technical knowledge, successful rigging demands effective teamwork between riggers, operators, and signalpersons. Clear communication protocols and thorough pre-lift planning are non-negotiable elements of safe rigging operations.

Hazard Overview: Why Getting Rigging Right Matters

The consequences of rigging failures are immediate and often catastrophic. According to a 2024 Konecranes Training Institute study, improper rigging practices cause 27% of load drops, making it the single most common cause of crane incidents. When a load shifts unexpectedly or slips from its rigging, workers below have little time to react.

More than half of workplace deaths in the crane industry involve workers being struck by objects or equipment, with an additional 27% resulting from falls and transportation incidents, according to the National Safety Council. The physics of these incidents are unforgiving – even relatively small loads can become lethal when falling from height.

For more foundational knowledge on operator safety, see our post on industrial crane safety key training points for carry deck operators.

Classifying Loads: Understanding Load Types in Crane Lifting

Common Load Types

Every lift presents unique challenges based on the load’s characteristics. Understanding these differences is crucial for selecting appropriate rigging techniques.

Load Type	Description	Special Rigging Considerations
Regular/Uniform	Balanced weight distribution with predictable center of gravity (e.g., crates, containers)	Typically requires simpler rigging setups with equal-length slings
Irregular	Uneven shape or weight distribution with complex center of gravity (e.g., machinery, structural components)	Needs careful weight calculation and multiple attachment points to maintain balance
Fragile	Materials that can be damaged by pressure from rigging (e.g., finished products, glass panels)	Requires protective measures like softeners and specialized attachment methods
Long/Flexible	Items that may bend or flex during lifting (e.g., pipes, beams, rebar)	Needs multiple lift points and often spreader beams to prevent bending
Bundled	Multiple similar items grouped together (e.g., lumber, pipes)	Requires secure bundling and assessment of potential shifting within the bundle
Live/Dynamic	Loads containing liquids or movable parts that shift during lifting	Demands accounting for potential movement and center of gravity changes
Heavy/Concentrated	Extremely heavy loads with weight concentrated in small areas	May require specialized heavy-lift rigging and precise balancing

Special Considerations for Each Load Type

The complexity of a load extends beyond just its shape and weight. Successful rigging must account for:

Attachment Points: Different materials offer varying options for secure attachment. Steel beams might have pre-drilled holes for shackles, while concrete elements may require specially designed lifting anchors cast into the material.

Weight Distribution: Irregular loads present particular challenges. A piece of equipment with most of its weight concentrated on one end requires rigging that accommodates this imbalance to maintain a level lift.

Material Characteristics: The material itself affects rigging choices. Fragile materials need padding at contact points, while rough-surfaced loads might require edge protectors to prevent sling damage.

Movement Potential: Loads containing liquids, loose materials, or movable parts present the hazard of shifting center of gravity during lifts. These require specialized rigging configurations and lifting plans that anticipate potential movement.

The Danger of Complacency in Routine Loads

Perhaps the most overlooked aspect of load types is the danger of familiarity. When crews lift similar items repeatedly, complacency can set in. This explains the troubling statistic that 74% of crane incidents occur during routine activities, according to Konecranes data.

Even standardized loads can present dangers if:

Their condition has changed (corrosion, damage)
Environmental factors differ (wind, precipitation)
Slight variations exist between seemingly identical items
Previous “successful” lifts used inadequate methods that haven’t yet resulted in failure

To learn more about advanced techniques for handling complex loads, check out our guide to advanced load handling and positioning with telescopic boom cranes.

Rigging Techniques: Tools, Methods, and Best Practices

Essential Rigging Tools and Hardware

The foundation of effective rigging begins with selecting the appropriate equipment for the specific load type:

Slings: Available in various materials, each with distinct properties:

Wire rope slings: High strength and heat resistance, good for abrasive environments
Synthetic slings: Lighter weight, won’t damage delicate loads, but vulnerable to cuts and chemicals
Chain slings: Extremely durable and heat-resistant, ideal for harsh conditions and heavy loads
Web slings: Flexible and conforms to load shapes, but limited weight capacity

Hardware Components:

Shackles: Connect slings to loads and other rigging components
Hooks: Available with various safety features like latches to prevent disengagement
Eyebolts and hoist rings: Provide attachment points on loads
Turnbuckles: Allow adjustment of sling tension
Master links: Connect multiple sling legs to the crane hook

Below-the-Hook Devices:

Spreader bars: Maintain specific sling angles and create horizontal force distribution
Lifting beams: Provide multiple lifting points for long or flexible loads
Plate clamps: Specifically designed for metal plate material handling
Vacuum lifters: Use suction for smooth, non-porous materials like glass or metal sheets

Selecting the right combination of these tools depends entirely on the load characteristics identified during assessment.

Common Rigging Techniques

The way slings and hardware attach to a load dramatically impacts lifting safety. Here are the fundamental techniques and their applications:

Vertical Hitch:

Description: Direct connection between hook and load, with sling running straight up and down
Best for: Loads with built-in lifting points directly above the center of gravity
Capacity: Maintains 100% of the sling’s rated capacity
Caution: Provides no load control during lifting; attachment can slip if not secure

Choker Hitch:

Description: Sling wraps around the load and passes through itself or an attachment
Best for: Cylindrical objects or bundles where a secure grip is needed
Capacity: Reduces to approximately 75-80% of the sling’s rated capacity due to the bend
Caution: Creates a pinch point that can damage fragile materials

Basket Hitch:

Description: Sling cradles the load from beneath, with both ends connected to the lifting device
Best for: Loads without specific attachment points that need support from below
Capacity: Can utilize up to 200% of the sling’s rated capacity when vertical
Caution: Load can slide or roll if not properly secured against horizontal movement

Double Wrap Choker:

Description: Similar to choker hitch but with an additional wrap around the load
Best for: Smooth or slippery materials that might slide in a standard choker
Capacity: Similar to standard choker but with enhanced grip
Caution: Additional rigging time required; potential for increased wear on slings

Bridle Hitch:

Description: Multiple slings connected to a single lifting point, distributing the load
Best for: Large, irregularly shaped loads requiring multiple attachment points
Capacity: Varies based on sling angles; wider angles reduce overall capacity
Caution: Requires careful calculation of forces on each leg based on angles

Matching Rigging Methods to Load Type

Choosing the appropriate rigging technique for specific load types can mean the difference between safe operation and catastrophic failure:

For Regular/Uniform Loads:

Vertical hitches with evenly spaced attachment points work well
Basket hitches provide stable support for crates and containers
Focus on balanced attachment directly above the center of gravity

For Irregular Loads:

Bridle hitches with multiple legs accommodate uneven weight distribution
May require custom-designed lifting fixtures for complex shapes
Test lifts (raising slightly off ground to check balance) are essential

For Fragile Loads:

Use synthetic slings with corner protectors at contact points
Consider specialized below-the-hook devices like vacuum lifters for glass
Avoid choker hitches that create pressure points

For Long/Flexible Loads:

Spreader bars prevent slings from squeezing and damaging the load
Multiple attachment points distribute stress and prevent bending
Consider the load’s rigidity when planning lift points

For Bundled Materials:

Double-wrap choker hitches prevent slippage
Verify bundle integrity before lifting
Consider how the bundle might shift during the lift

For Live/Dynamic Loads:

Use rigging configurations that limit movement potential
Plan for the worst-case center of gravity shift
Consider specialized containers for liquids

The Consequence of Improper Rigging

The stakes of mismatched rigging techniques are high. As mentioned earlier, improper rigging practices cause 27% of load drops. These incidents don’t just endanger workers—they carry significant business impacts.

According to Konecranes data, the average major injury from a crane accident costs over $200,000, while the average fatality costs over $4 million. These figures don’t include project delays, equipment damage, and reputation harm.

For professional development in this critical area, consider the comprehensive rigging and signalperson training program offered at Operator School, which provides hands-on experience with diverse load types and rigging techniques.

Lifting Safety Protocols: From Planning to Execution

Pre-Lift Safety Checks and Planning

Every safe lift begins long before the crane moves. A thorough pre-lift protocol includes:

Load Assessment:

Calculate precise weight and dimensions
Identify center of gravity
Note special characteristics (fragility, liquid content, irregular shape)
Determine appropriate attachment points

Equipment Inspection:

Verify crane capacity for the planned lift
Inspect all rigging gear for damage or wear
Check certification and load rating of all components
Ensure compatibility between rigging components

Environmental Evaluation:

Assess ground conditions for crane stability
Check weather conditions, especially wind speed
Identify overhead obstructions in the lift path
Survey the area for potential hazards

Lift Planning:

Create a detailed lift plan for complex or heavy loads
Establish clear communication protocols
Define personnel roles and positions
Identify emergency procedures

Documentation:

Complete required paperwork (permits, checklists)
Record equipment inspection results
Document the lift plan for reference
Brief all team members on the plan

Safe Lifting Operations

Once planning is complete, execution requires:

Communication Systems:

Establish clear hand signals or radio protocols
Designate a single person to communicate with the operator
Use standardized signals understood by all team members
Maintain continuous visual or verbal contact during the lift

Personnel Positioning:

Keep all workers outside the load’s fall zone when possible
Position the signalperson where both the load and operator are visible
Assign spotters for blind spots or complex movements
Establish exclusion zones for non-essential personnel

Controlled Movement:

Begin with a test lift a few inches off the ground to verify balance
Lift, swing, and lower at appropriate speeds for the load type
Avoid sudden movements that create dynamic loading
Maintain constant awareness of the load’s position and stability

Troubleshooting:

Stop the lift if anything seems wrong
Have a plan for common scenarios (load shift, rigging slippage)
Maintain clear pathways for emergency exit
Keep emergency contact information readily available

Role of Training and Certifications

Despite the critical nature of rigging operations, a concerning training gap exists. Eight out of ten crane industry workers believe they have access to appropriate safety training, yet lack of proper training still accounted for 7% of personal injuries and 8% of on-site injuries, according to the National Safety Council.

This discrepancy highlights the difference between basic awareness and comprehensive skill development. Effective training programs must include:

Hands-on practice with various load types
Scenario-based problem-solving
Regular refresher courses
Evaluation in real-world conditions
Documentation of competency

Formal certification through organizations like NCCCO (National Commission for the Certification of Crane Operators) provides standardized evaluation of rigging knowledge and skills. Many job sites now require certified riggers, especially for complex or high-risk lifts.

For those seeking to develop or enhance their crane operation skills, mobile crane operator training provides the foundation needed to work effectively with rigging crews.

Common Hazards and How to Prevent Them

Top Hazards in Crane Rigging

Understanding the most common hazards allows teams to implement targeted preventive measures:

Struck-by Incidents:
More than half of workplace deaths in the crane industry involve workers being struck by objects or equipment. These occur when:

Loads detach from rigging due to improper attachment
Rigging equipment fails under stress
Loads swing unexpectedly into workers
Materials shift within the load during lifting

Equipment Failure:

Slings weakened by cuts, abrasion, or chemical exposure
Hardware damaged by shock loading or improper use
Connection points that fail under stress
Crane components that malfunction during operations

Environmental Factors:

High winds that cause loads to swing uncontrollably
Rain or ice that makes loads slippery
Lightning that endangers elevated personnel
Temperature extremes that affect equipment performance

Human Factors:

Complacency during routine operations
Inadequate communication between team members
Pressure to work quickly at the expense of safety
Fatigue that impairs decision-making

Preventive Strategies and Continuous Vigilance

Effective hazard prevention combines technical measures with cultural approaches:

Technical Prevention:

Implement formal equipment inspection protocols
Use appropriate safety factors in lift calculations
Install safety features like hook latches and overload indicators
Employ technology like load moment indicators when available

Procedural Prevention:

Develop and enforce standard operating procedures
Require written lift plans for all non-routine lifts
Implement robust pre-use inspection processes
Establish clear weather guidelines for suspending operations

Training-Based Prevention:

Provide comprehensive initial training
Conduct regular refresher courses
Share lessons from incidents across the organization
Use simulators or controlled environments for skill development

Cultural Prevention:

Empower all workers to stop unsafe operations
Reward safety observations and near-miss reporting
Emphasize that safety takes priority over production speed
Learn from incidents through non-punitive investigations

Business Impact of Hazards

The financial case for investing in proper rigging safety is compelling:

Crane-related incidents resulted in $2.3 million in OSHA fines over a ten-year period
The average major injury from a crane accident costs over $200,000
Project delays from accidents typically cost thousands per day
Insurance premiums increase dramatically after major incidents
Reputation damage can affect future contract opportunities

According to industry data, crane accidents can be reduced by up to 50% when cranes and rigging equipment are operated by trained personnel, inspected regularly, and used following strict safety protocols. This represents a significant return on investment for training and equipment costs.

The Value of Training, Inspections, and a Safety-First Mindset

Ongoing Training: Staying Up To Date

Effective rigging knowledge isn’t static—it requires continuous development:

Formal Certification and Recertification:

Initial qualification establishes baseline knowledge
Periodic recertification ensures skills remain current
Specialized training addresses unique operations
Documentation provides verification of competency

Knowledge Expansion:

Cross-training in related skills enhances overall awareness
Understanding load engineering principles improves decision-making
Learning from incidents across the industry prevents repeat occurrences
Keeping up with new equipment and techniques improves efficiency

Practical Skill Development:

Supervised practice with increasingly complex loads
Scenario-based training for emergency situations
Manufacturer-specific training for specialized equipment
Mentorship from experienced riggers

Addressing the Knowledge Gap:

Regular assessment of actual vs. perceived knowledge
Targeted training to address specific weaknesses
Creating an environment where questions are encouraged
Building a learning culture that values continuous improvement

Regular Inspections and Equipment Maintenance

The integrity of rigging equipment directly impacts safety:

Inspection Types and Frequency:

Pre-use visual inspection before each lift
Frequent inspection (daily to monthly) for actively used equipment
Periodic inspection (annually or semi-annually) with formal documentation
Special inspections following incidents or extreme conditions

What to Look For:

Wire rope: broken wires, kinks, core protrusion, diameter reduction
Synthetic slings: cuts, tears, chemical damage, UV degradation
Chain slings: stretched links, gouges, twists, excessive wear
Hardware: cracks, deformation, thread damage, excessive wear

Documentation and Tracking:

Maintain detailed inspection records
Implement equipment identification systems
Establish clear criteria for retirement
Create equipment history files

Implementing a robust inspection program can dramatically reduce incidents. When combined with proper training and protocols, accidents can be reduced by up to 50%.

Fostering a Safety-First Culture

Technical knowledge and equipment integrity must be supported by an organizational culture that prioritizes safety:

Leadership Commitment:

Management visibly prioritizes safety over production
Resources are allocated for training and proper equipment
Safety performance is recognized and rewarded
Accountability exists at all levels

Open Communication:

Workers feel comfortable reporting hazards
Near-misses are treated as learning opportunities
Safety concerns receive prompt attention
Regular safety meetings address current issues

Continuous Improvement:

Safety procedures evolve based on experience
Incidents trigger thorough root cause analysis
Industry best practices are actively sought out
Metrics track safety performance over time

Personal Responsibility:

Each worker understands their safety obligations
Teams look out for each other’s wellbeing
Stop-work authority exists for unsafe conditions
Pride in safety performance is cultivated

For more on developing the professional skills that contribute to safety culture, see “”Beyond the Seat: Essential Soft Skills Every Heavy Equipment Operator Needs“”.

Conclusion

Understanding the relationship between load types and proper rigging techniques forms the foundation of safe and efficient crane operations. As we’ve seen, even routine lifts demand careful attention to detail, as the statistics show they account for the majority of serious incidents.

The stakes couldn’t be higher – proper rigging practices directly impact worker safety, project timelines, and business profitability. With improper rigging causing more than a quarter of all load drops, the investment in training, equipment, and cultural development offers clear returns.

Remember these essential principles:

Every load has unique characteristics requiring specific rigging approaches
Complacency during routine operations is a significant risk factor
Proper training and inspection protocols can cut accident rates in half
A culture of safety reinforces technical knowledge and equipment integrity

By combining technical expertise with a commitment to safety at every level, crane operations can avoid becoming another statistic in the industry’s troubling safety record.

For those seeking to develop or enhance their rigging skills, contact Operator School to learn about our professional crane and rigging training programs.

FAQs

What is the most common cause of rigging accidents and how can it be prevented?
The most common cause of rigging accidents is improper rigging techniques, accounting for 27% of all load drops. Prevention starts with thorough load assessment to understand the center of gravity and weight distribution, followed by selecting appropriate rigging gear rated for the load. Using the correct hitch type for the specific load characteristics is crucial, as is conducting thorough equipment inspections before each use. Finally, comprehensive training ensures riggers understand both the “”how”” and “”why”” behind proper techniques.

How do you determine the correct sling angle for a lift, and why does it matter?
The correct sling angle is determined using trigonometric calculations based on the horizontal distance between attachment points and the height to the crane hook. Angles less than 30 degrees from horizontal should generally be avoided. Sling angle matters tremendously because as the angle decreases (becomes more horizontal), the stress on each sling increases dramatically. A 30-degree sling angle doubles the force on each sling compared to a vertical lift of the same weight. Most rigging charts provide load ratings at specific angles to ensure safe operation.

What specific precautions should be taken when rigging irregular or asymmetrical loads?
Irregular loads require special attention to center of gravity identification, often through engineering calculations or manufacturers’ specifications. Multiple attachment points with load-rated rigging gear should be used, with careful consideration of the force distribution among all rigging points. A test lift a few inches off the ground is essential to verify balance before proceeding with the full lift. For highly complex loads, consider using spreader bars or custom lifting fixtures to maintain stability, and always have taglines attached to control rotation.

How often should rigging equipment be inspected, and what are the key signs of damage?
Rigging equipment requires inspection before each use (visual check), frequent formal inspections (daily to monthly depending on use intensity), and periodic documented inspections (annually at minimum). Key damage signs vary by equipment type: wire rope slings may show broken wires, kinks, bird-caging, or diameter reduction; synthetic slings might have cuts, tears, punctures, or heat damage; chain slings could exhibit stretched links, gouges, or twists; hardware might show cracks, deformation, excessive wear, or damaged threads. Any equipment with questionable integrity should be immediately removed from service.

What role does communication play in safe rigging operations, and what systems work best?
Communication is critical in rigging operations, connecting the rigger, signalperson, operator, and other crew members. Standardized hand signals recognized by all team members provide the foundation, with the designated signalperson positioned to see both the load and operator. For complex lifts or when visual contact is limited, radio communication with dedicated channels and clear protocols offers an effective solution. The key to any system is clarity, consistency, and redundancy—important messages should be acknowledged and confirmed. Pre-lift briefings ensure everyone understands the plan, communication methods, and emergency procedures before operations begin.