CHST Crane and Rigging Safety 4 — Questions and Answers
Question 1: What is the primary purpose of a crane's load chart?
- To log maintenance schedules
- To define maximum lifting capacities at various radii and boom angles (Correct answer)
- To record operator certifications
- To specify lubrication intervals
Correct answer: To define maximum lifting capacities at various radii and boom angles
Load charts provide the rated capacity of a crane at specific boom lengths, radii, and configurations to prevent overloading.
Question 2: Which condition requires a crane to be taken out of service immediately?
- Slightly dirty windows in the cab
- A cracked load hook with a visible deformation (Correct answer)
- A load line with minor surface oxidation
- Boom angle within 5 degrees of rated maximum
Correct answer: A cracked load hook with a visible deformation
A cracked or deformed hook is a critical defect that can cause sudden load drop and must be removed from service until repaired or replaced.
Question 3: When must a pre-lift meeting be conducted on a critical lift?
- Only when the load exceeds 100 tons
- Before the lift begins, with all personnel involved in the operation (Correct answer)
- After the load is rigged but before it leaves the ground
- Only when a new operator is performing the lift
Correct answer: Before the lift begins, with all personnel involved in the operation
Pre-lift meetings must occur before the lift to ensure all personnel understand the plan, signals, hazards, and responsibilities.
Question 4: A rigger notices that a wire rope sling has a kink that cannot be straightened. What should the rigger do?
- Use the sling at reduced capacity
- Tag and remove the sling from service (Correct answer)
- Straighten the kink using a pipe for leverage
- Continue use if the kink is not at the choker point
Correct answer: Tag and remove the sling from service
A kinked wire rope sling is permanently damaged and weakened; it must be removed from service and destroyed.
Question 5: What factor determines whether a lift is classified as a 'critical lift' under ASME B30.5?
- The lift requires more than two rigging legs
- The load exceeds 75% of the crane's rated capacity or involves unusual hazards (Correct answer)
- The lift is performed indoors
- The load weighs more than 10,000 lbs
Correct answer: The load exceeds 75% of the crane's rated capacity or involves unusual hazards
ASME B30.5 and most site standards classify a lift as critical when it exceeds 75% of rated capacity or presents exceptional hazards such as lifts over personnel or energized equipment.
Question 6: What is the minimum clearance a crane must maintain from energized power lines rated at 50 kV or below, per OSHA 1926.1408?
- 5 feet
- 10 feet (Correct answer)
- 15 feet
- 20 feet
Correct answer: 10 feet
OSHA 1926.1408 requires a minimum 10-foot clearance from power lines up to 50 kV unless the utility owner de-energizes or insulates the lines.
Question 7: A synthetic web sling is rejected when an inspection reveals what condition?
- Minor surface dirt on the webbing
- Broken or cut load-bearing fibers (Correct answer)
- Slight color fading from UV exposure
- A sewn tag that is difficult to read
Correct answer: Broken or cut load-bearing fibers
Broken or cut load-bearing fibers directly reduce the sling's rated capacity and require immediate removal from service.
CHST Crane and Rigging Safety 4
What is the primary purpose of a crane's load chart?