Types of Cranes on Construction Sites
Mobile Cranes
- Mounted on wheeled or tracked carriers
- Include hydraulic boom, lattice boom, and rough terrain types
- Can move around the jobsite
- Require outriggers for stability
- Typically operated by a single person
Tower Cranes
- Fixed to the ground or attached to a building
- Include hammerhead, luffing jib, and self-erecting types
- Used for tall buildings and large projects
- Require careful assembly and disassembly
- Often operated from elevated cab
Overhead Cranes
- Run on fixed rails
- Include bridge cranes, gantry cranes
- Used in fabrication shops, warehouses
- Move in straight lines on fixed paths
- Controlled by pendant or remote
Articulating Cranes (Knuckleboom)
- Mounted on trucks or other vehicles
- Fold up when not in use
- Used for delivery of materials
- Have variable reach and lifting capacity
- Often include materials handling attachments
Crane-Related Hazards
Struck-By Hazards
- Loads swinging or falling
- Crane components during assembly/disassembly
- Counterweights during crane movement
- Crane boom during operation or collapse
- Materials being moved
Crushing/Pinch Point Hazards
- Between rotating superstructure and fixed objects
- During assembly and disassembly
- Between outriggers and ground obstacles
- In access areas to operator cab
- Between load and fixed structures
Electrical Hazards
- Contact with overhead power lines
- Arcing electricity (no direct contact needed)
- Energized crane components after contact
- Lightning during storms
- Damaged electrical components on crane
Tip-Over Hazards
- Exceeding load capacity
- Improper outrigger deployment
- Soft or unstable ground
- High winds
- Side loading the boom
Other Hazards
- Falls during access/egress
- Mechanical failure
- Two-blocking (hook block contacts boom tip)
- Dropped loads from rigging failure
- Weather conditions (wind, ice, lightning)
Safe Work Around Cranes
General Safety Guidelines
- Never walk under suspended loads
- Stay out of the swing radius of the crane
- Make eye contact with the operator before approaching
- Stay visible to the operator at all times
- Know and use correct hand signals
- Wear high-visibility clothing
- Be aware of pinch points and crush zones
Danger Zones
- Within swing radius of counterweight
- Below any suspended load
- Areas where the load might swing
- Between loads and fixed objects
- Within reach of power lines (minimum 20 feet)
- Near outriggers during setup
Communication
- Designate one signal person at a time
- Use standard hand signals
- Use radios in noisy environments or when the operator can't see the signal person
- Verify signals are understood
- Stop operations if communication is unclear
- Use audible warnings when moving loads over workers
Crane Operator Responsibilities
Before Operation
- Perform pre-operation inspection
- Review load chart for planned lifts
- Check operating area for hazards
- Verify outrigger deployment on stable ground
- Test all controls
- Ensure all safety devices are functioning
During Operation
- Never exceed load chart capacities
- Maintain awareness of boom location
- Watch for power lines and obstacles
- Respond only to designated signal person (except emergency stop)
- Never leave the controls with a load suspended
- Avoid sudden movements or stops
After Operation
- Secure the crane according to manufacturer guidelines
- Place boom in designated position
- Set all brakes and locks
- Shut down according to procedures
- Document any operational issues
Signal Person Responsibilities
Qualifications
- Knowledge of standard hand signals
- Understanding of crane operations
- Ability to communicate clearly
- Awareness of site-specific hazards
- Authorized by site management
Before Signaling
- Establish communication method with operator
- Position yourself where visible to operator
- Clear unnecessary personnel from lift area
- Review the lift plan
- Understand the path of the load
During Signaling
- Give clear, deliberate signals
- Watch the load at all times
- Warn workers of approaching loads
- Stay focused on the task
- Signal "emergency stop" if necessary
Rigger Responsibilities
Selection of Rigging
- Choose appropriate slings, shackles, etc.
- Verify working load limits
- Inspect all rigging before use
- Consider load weight, shape, and balance
- Use proper hitch types for the load
Rigging the Load
- Protect slings from sharp edges
- Balance the load properly
- Use tag lines to control load movement
- Ensure all connections are secure
- Keep hands clear of pinch points
During the Lift
- Stand clear of the suspended load
- Guide the load using tag lines, not hands
- Watch for shifting or unstable loads
- Signal any rigging problems immediately
- Never ride on the load
Crane Setup Safety
Site Assessment
- Verify ground conditions can support the crane
- Check for underground utilities or voids
- Identify overhead hazards, especially power lines
- Ensure adequate space for crane movement
- Plan for changing weather conditions
Outrigger Deployment
- Extend outriggers fully when possible
- Use adequate cribbing under outrigger pads
- Set up on compacted, level ground
- Check for proper outrigger float
- Barricade outrigger area
Assembly/Disassembly
- Follow manufacturer procedures
- Use qualified assembly/disassembly director
- Ensure crew understands their roles
- Control hazardous energy (hydraulic, pneumatic, etc.)
- Secure components before disconnecting
Critical Lift Considerations
What Is a Critical Lift?
- Exceeds 75% of crane capacity
- Involves multiple cranes
- Unusual or complex rigging
- Lift over occupied facilities
- Lift near power lines or critical equipment
Planning Requirements
- Written lift plan
- Pre-lift meeting
- Verification of crane and rigging capacity
- Designated signal person and lift director
- Inspection of all equipment
- Weather considerations
Emergency Procedures
Power Line Contact
- Operator should stay in cab if possible
- All ground personnel must stay away (at least 30 feet)
- Call emergency services and utility company
- If operator must exit (fire), jump clear of crane without touching crane and ground simultaneously
- Hop with feet together away from crane
Tip-Over
- Warn all personnel to clear the area
- Operator should stay in cab if possible
- Secure the area
- Report the incident
- Do not attempt to use crane until inspected
Load Failure
- Clear drop zone immediately
- Secure the area
- Lower any remaining load safely
- Determine cause before resuming operations
- Document the incident