NCCCO Maintenance and Troubleshooting

Question 1

When inspecting wire rope on a lattice boom crane, what condition requires immediate removal from service per ASME B30.5?

Accepted Answer

Six randomly distributed broken wires in one rope lay, or three broken wires in one strand in one lay

Answer

Any single broken wire regardless of location

Answer

More than 12 broken wires in any 10-foot section

Answer

Surface corrosion affecting more than 50% of the rope diameter

Question 2

A hydraulic mobile crane's boom drifts down slowly when holding a suspended load with no commands given. What is the most likely cause?

Accepted Answer

Internal leakage in the boom cylinder or holding valve

Answer

Excessive counterweight

Answer

Overloaded hoist drum brakes

Answer

A faulty anti-two-block switch

Question 3

Which lubrication point on a mobile crane requires consistent attention during maintenance?

Accepted Answer

Wire rope and sheaves, which require lubrication per manufacturer intervals or at minimum monthly under ASME B30.5

Answer

Engine air filter housing O-rings

Answer

Cab door hinges and window seals

Answer

Outrigger pad rubber surfaces

Question 4

During troubleshooting, an operator notices the crane's load moment indicator (LMI) is reading significantly less than the actual calculated load. What hazard does this create?

Accepted Answer

The operator may believe there is more remaining capacity than actually exists, leading to overloading

Answer

The LMI alarm will activate too early, unnecessarily stopping lifts

Answer

The anti-two-block device will be disabled automatically

Answer

Swing speed will increase beyond design limits

Question 5

A crane's swing brake is not holding the load from rotating when power is removed. According to ASME B30.5, what is the correct action?

Accepted Answer

Remove the crane from service immediately — a failed swing brake requires repair before further use

Answer

Continue operations but limit swing to 180 degrees maximum

Answer

Manually hold the swing lever in neutral at all times

Answer

Reduce all lifts to 50% of rated capacity

Question 6

What is the purpose of a periodic inspection on a mobile crane, and how often must it occur per ASME B30.5?

Accepted Answer

A thorough examination of structural and mechanical components performed at 1-to-12 month intervals based on usage severity

Answer

A quick walkaround performed at the start of each shift

Answer

A government-required inspection conducted every 5 years by a licensed inspector

Answer

An operator self-certification submitted to OSHA annually