Critical Lifts & Hazards
What defines a critical lift?
A lift with increased risk due to weight, complexity, or exposure
What two primary factors reduce crane capacity?
Radius and boom length
What does WLL stand for?
Working load limit
What signal overrides all others?
STOP
What is the most common cause of crane tip-overs?
Improper ground conditions or outrigger support
Name one example of a critical lift
Lifting over occupied areas, tandem lifts, or lifts near power lines
Which is more critical to crane capacity: load weight or radius?
What hitch provides the highest capacity?
Basket Hitch
How many signal persons should direct a crane at one time?
One (unless using relay signaling)
What is the purpose of outrigger mats?
Distribute load and reduce ground bearing pressure
What is the minimum clearance from energized power lines (<= 350kV)?
20 feet
Does a load chart include rigging weight by default?
No — rigging, hook block, headache ball, and attachments must be added.
Why are shackles never side-loaded?
They are not rated for side loading and can fail catastrophically
What must be done before a blind lift?
Designate a qualified signal person and establish communication.
Who is responsible for verifying ground bearing capacity?
The controlling entity, with input from the crane company
What weather condition most commonly stops crane operations?
High wind
Why are load charts based on "gross load"?
Because the crane must lift everything below the boom tip
What inspection frequency is required for rigging?
Before each use and as require by site policy.
When are radios required?
When standard hand signals are not clearly visible
Can asphalt be assumed adequate for crane setup?
No — its capacity varies with temperature and subgrade
Who has authority to stop a lift if unsafe?
What must be done if a lift exceeds 75% of chart capacity?
Treat it as a critical lift and implement enhanced planning and controls.
What must be verified before using lifting lugs?
Capacity, orientation, weld integrity, and design intent
What must be established before the lift begins regarding signals?
Who is the primary signal person and what method will be used
What must be done if underground utilities are present?
Locate, verify depth, and account for them in setup planning