NCCCO Mechanical Systems & Maintenance Practices 2 — Questions and Answers
Question 1: How often should a crane receive a 'frequent' inspection according to OSHA?
- Annually
- Daily to monthly, depending on the component and severity of service conditions (Correct answer)
- Every 5 years
- Only after an accident
Correct answer: Daily to monthly, depending on the component and severity of service conditions
OSHA requires 'frequent' inspections ranging from daily pre-shift checks to monthly reviews of critical components. The frequency depends on the crane's usage intensity and operating environment.
Question 2: What is the primary purpose of checking hydraulic fluid levels before operating a crane?
- To maintain the crane's appearance
- Hydraulic fluid powers critical systems; low levels can cause loss of control of boom, hoist, or outriggers (Correct answer)
- To reduce fuel consumption
- Hydraulic fluid is only used for air conditioning
Correct answer: Hydraulic fluid powers critical systems; low levels can cause loss of control of boom, hoist, or outriggers
Hydraulic systems operate the boom, hoist, swing, and outriggers. Insufficient fluid can cause these systems to fail or become sluggish, creating dangerous conditions during lifts.
Question 3: What should an operator look for when inspecting wire rope?
- Only the rope color
- Broken wires, kinks, crushing, birdcaging, corrosion, reduced diameter, and heat damage (Correct answer)
- Only the end termination
- Only visible rust
Correct answer: Broken wires, kinks, crushing, birdcaging, corrosion, reduced diameter, and heat damage
Wire rope inspection covers: broken wires (count per strand), kinking, crushing, birdcaging, corrosion, wear patterns, reduced diameter, heat discoloration, and damage at termination points.
Question 4: What is 'birdcaging' in wire rope?
- When birds nest inside the rope coils
- When the outer strands separate and spread outward from the core, resembling a birdcage (Correct answer)
- A technique for storing rope
- A type of rope splice
Correct answer: When the outer strands separate and spread outward from the core, resembling a birdcage
Birdcaging occurs when outer strands open up from the rope core, typically caused by sudden load release or improper spooling. It permanently weakens the rope and requires immediate replacement.
Question 5: How often should the crane's braking system be tested?
- Only during annual inspection
- Before each shift as part of the pre-operation inspection (Correct answer)
- Once a month
- Only when brakes seem to be slipping
Correct answer: Before each shift as part of the pre-operation inspection
Brake function is tested daily as part of the pre-operation inspection. This includes hoist brakes, swing brakes, and travel brakes. Any brake issues require immediate attention.
Question 6: What does excessive play in the swing mechanism indicate?
- Normal wear — no concern
- Worn swing gear teeth, loose bolts, or bearing failure requiring inspection and potential repair (Correct answer)
- The crane needs more grease
- The operator is using incorrect techniques
Correct answer: Worn swing gear teeth, loose bolts, or bearing failure requiring inspection and potential repair
Excessive play in the swing mechanism can indicate worn gear teeth, loose mounting bolts, or bearing deterioration. These conditions affect precision and can lead to sudden uncontrolled swing.
NCCCO Mechanical Systems & Maintenance Practices 2
How often should a crane receive a 'frequent' inspection according to OSHA?