NCCCO Mobile Crane Operator Test 1 2

Question 1

What is the first action a mobile crane operator should take upon arriving at a new job site?

Accepted Answer

Conduct a pre-operation site assessment identifying hazards, overhead lines, ground conditions, and obstructions

Answer

A thorough site assessment identifying overhead power lines, underground utilities, ground conditions, restricted areas, and work zone hazards must be completed before any crane setup or operation begins.

Question 2

What information must be in the cab of a mobile crane during operations?

Accepted Answer

Current load charts for the specific crane configuration in use, along with the crane's operating manual

Answer

Current load charts for the specific crane configuration being operated, and the operating manual, must be accessible in the operator's cab during all operations for reference.

Question 3

What is the purpose of the anti-two-block (ATB) device on a mobile crane?

Accepted Answer

To prevent the hook block from rising into contact with the boom tip sheave by cutting off hoist power before contact occurs

Answer

The anti-two-block device monitors the distance between the hook block and the boom tip sheave, cutting off hoist power before contact to prevent two-blocking, which can break wire rope and drop loads.

Question 4

What is a load line hitch and what determines the working load limit of the hitch?

Accepted Answer

A load line hitch is the method of attaching rigging to the load; the WLL is determined by the hitch type (vertical, choker, basket) and the sling's rated capacity

Answer

The working load limit of a rigging hitch depends on both the sling's rated capacity and the hitch configuration: vertical hitches use 100%, choker hitches reduce WLL by at least 25%, and basket hitches can increase WLL up to 200% depending on the load angle.

Question 5

What is the significance of a crane's 'rated capacity' versus its 'tipping load'?

Accepted Answer

Rated capacity is a fraction of tipping load, incorporating a safety factor so the crane remains stable with a margin before actual tipping occurs

Answer

Rated capacity is set at 75% of tipping load (per ASME B30.5), providing a 25% stability safety margin between maximum rated operation and the load that would actually cause tipping.

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO Mobile Crane Operator Test 1 2