NCCCO Emergency Procedures & Accident Prevention 4 — Questions and Answers
Question 1: When a crane's hydraulic system fails during a lift, what is the operator's FIRST action?
- Lower the load immediately using the emergency lowering valve
- Activate the emergency stop and secure the load in place (Correct answer)
- Call the supervisor before taking any action
- Increase engine RPM to restore hydraulic pressure
Correct answer: Activate the emergency stop and secure the load in place
The operator must activate the emergency stop and secure the suspended load to prevent uncontrolled movement.
Question 2: A crane operator notices the load line is vibrating excessively during a pick. This most likely indicates:
- The load is properly balanced
- Dynamic loading or resonance that could overload the crane (Correct answer)
- Normal operation in windy conditions
- The hoist brake needs lubrication
Correct answer: Dynamic loading or resonance that could overload the crane
Excessive load line vibration signals dynamic loading or resonance, which can create forces exceeding the crane's rated capacity.
Question 3: What does the term 'two-blocking' refer to in crane operations?
- Using two separate rigging blocks on a single load
- The upper and lower load blocks making contact, potentially causing sudden load drop (Correct answer)
- A two-stage braking procedure for emergency stops
- Blocking outriggers on two sides of the crane
Correct answer: The upper and lower load blocks making contact, potentially causing sudden load drop
Two-blocking occurs when the lower block contacts the upper block or boom tip, which can cause catastrophic rope failure and sudden load drop.
Question 4: If a fire breaks out in the crane cab during operation with a load suspended, the operator should:
- Immediately exit the cab and call 911
- Lower the load to a safe position before exiting if possible without endangering personnel (Correct answer)
- Attempt to extinguish the fire while keeping the load suspended
- Swing the boom away from workers before evacuating
Correct answer: Lower the load to a safe position before exiting if possible without endangering personnel
If conditions allow, the operator should lower the load safely before exiting, but personal safety takes priority if the fire is spreading rapidly.
Question 5: Which condition requires an immediate crane shutdown and should be reported before resuming work?
- A single wire broken in a non-critical section of the rope
- Any structural crack observed in the crane boom or mast (Correct answer)
- Slightly uneven ground under one outrigger pad
- A burned-out cab interior light
Correct answer: Any structural crack observed in the crane boom or mast
Any structural crack in the boom or mast is a critical defect requiring immediate shutdown and inspection by a qualified person before resuming operations.
Question 6: During a pick near an energized power line, the load suddenly swings toward the line. The operator should:
- Jump from the cab immediately
- Lower the load quickly while moving the crane away from the line
- Hold position and warn workers on the ground to stay back (Correct answer)
- Increase hoist speed to lift above the line
Correct answer: Hold position and warn workers on the ground to stay back
The operator should hold position to avoid erratic movements while warning ground personnel to stay clear until the load can be safely controlled.
Question 7: What is the purpose of a crane's anti-two-block (ATB) device?
- It prevents the crane from lifting loads over its rated capacity
- It automatically stops the hoist when the load block approaches the boom tip (Correct answer)
- It locks the swing mechanism during emergency stops
- It monitors hydraulic pressure during lifts
Correct answer: It automatically stops the hoist when the load block approaches the boom tip
The ATB device automatically stops hoist-up and boom-down functions when the load block is within a set distance of the boom tip to prevent two-blocking.
NCCCO Emergency Procedures & Accident Prevention 4
When a crane's hydraulic system fails during a lift, what is the operator's FIRST action?