NCCER Crane Maintenance, Inspection & Equipment Setup 4 — Questions and Answers
Question 1: What is the minimum fleet angle allowed for wire rope spooling onto a drum without causing damage?
- No more than 1 degree
- No more than 2 degrees for grooved drums, 1.5 degrees for smooth drums (Correct answer)
- No more than 5 degrees for all drum types
- Fleet angle does not affect spooling quality
Correct answer: No more than 2 degrees for grooved drums, 1.5 degrees for smooth drums
Excessive fleet angles cause wire rope to cross-wind on the drum, leading to uneven spooling, accelerated wear, and potential for rope damage; ASME limits are 2° grooved and 1.5° smooth.
Question 2: A crane's swing bearing shows visible grease purging from the seal area during normal operation. What does this indicate?
- The bearing is receiving too much lubrication
- Normal condition — grease purging confirms the bearing is being properly greased (Correct answer)
- The bearing seals have failed and the crane must be taken out of service
- The bearing needs to be replaced immediately
Correct answer: Normal condition — grease purging confirms the bearing is being properly greased
Grease purging from the swing bearing seal during greasing is normal and actually confirms that the old grease is being pushed out and replaced with fresh lubricant.
Question 3: During crane setup on soft or unstable ground, what is the best practice for outrigger pads?
- Use only the standard-size pads provided with the crane
- Use larger pads or cribbing to distribute load over a greater area, verified by a competent person (Correct answer)
- Pour concrete footings before placing pads
- Avoid using outriggers on soft ground and work on tracks instead
Correct answer: Use larger pads or cribbing to distribute load over a greater area, verified by a competent person
On soft ground, larger or supplemental pads distribute the crane's outrigger loads over a greater area to keep bearing pressure within safe limits for the soil conditions.
Question 4: What is the function of a crane's pawl (ratchet) on the hoist drum?
- It prevents the drum from overheating
- It prevents uncontrolled reverse rotation of the drum under load (Correct answer)
- It controls the speed of lowering operations
- It locks the drum in place during maintenance only
Correct answer: It prevents uncontrolled reverse rotation of the drum under load
The pawl engages the ratchet wheel on the drum to prevent uncontrolled reverse rotation, serving as a secondary mechanical brake to hold loads if the primary hoist brake fails.
Question 5: When inspecting a hydraulic cylinder on a crane, what condition requires immediate repair?
- Slight surface discoloration on the chrome rod
- External leakage at the rod seal or piston seal (Correct answer)
- Minimal dust accumulation on the cylinder body
- A small paint chip on the cylinder barrel
Correct answer: External leakage at the rod seal or piston seal
External hydraulic leakage at seals indicates seal failure that can cause loss of cylinder force and controlled movement, creating a serious safety hazard requiring immediate repair.
Question 6: What must be done to a crane before any maintenance personnel work on or under raised crane components?
- Notify the site supervisor verbally
- Block or crib all raised components and apply lockout/tagout procedures (Correct answer)
- Lower the components to the ground only if convenient
- Post a warning sign and proceed with a second observer
Correct answer: Block or crib all raised components and apply lockout/tagout procedures
OSHA requires that raised crane components be physically blocked or cribbed and that lockout/tagout procedures be applied before any personnel work on or under them.
Question 7: A lattice boom crane's chord member shows a visible bend. What is the correct action?
- Reduce the rated capacity by 25% and continue work
- Take the crane out of service and contact the manufacturer or qualified engineer (Correct answer)
- Straighten the chord using heat application in the field
- Monitor the bend for growth over the next week before acting
Correct answer: Take the crane out of service and contact the manufacturer or qualified engineer
A bent or buckled lattice boom chord is a critical structural defect; the crane must be taken out of service and evaluated by the manufacturer or a qualified structural engineer before returning to work.
NCCER Crane Maintenance, Inspection & Equipment Setup 4
What is the minimum fleet angle allowed for wire rope spooling onto a drum without causing damage?