Mobile Crane Operator Flashcards

When operating a mobile crane on a slope, the load chart ratings are based on which condition?

Answer: Level ground within 1% grade

NCCCO load charts are based on the crane being level within 1% grade; operating on slopes beyond that requires deration.

Which document must the operator review before each shift to understand site-specific hazards?

Answer: The lift director's pre-lift meeting notes or site safety plan

A pre-lift meeting and site safety plan identify hazards, utilities, ground conditions, and emergency procedures specific to that lift.

What is the purpose of a load moment indicator (LMI) on a mobile crane?

Answer: To provide the operator a continuous warning when approaching or exceeding rated capacity

An LMI monitors the combination of load and radius and alerts the operator when rated capacity is being approached or exceeded.

A mobile crane's maximum rated capacity at a given radius is reduced when the load is handled:

Answer: Over the side vs. over the front or rear, depending on crane design

Many mobile cranes have lower rated capacities when lifting over the side compared to front or rear due to structural and stability differences.

Before making a pick, the operator must verify ground bearing pressure does NOT exceed:

Answer: The ground's or mat's bearing capacity at the outrigger pad locations

Ground bearing capacity at each outrigger pad must be confirmed adequate to prevent settlement or crane tip-over.

Which condition requires an operator to immediately cease operations and notify the competent person?

Answer: A load line becomes kinked or birdcaged

A kinked or birdcaged wire rope is damaged and must be removed from service immediately to prevent failure.

What does 'two-blocking' mean in crane operations?

Answer: The load block contacts the boom tip sheave, causing rope or component failure

Two-blocking occurs when the hook block is hoisted until it contacts the boom tip sheave, potentially causing catastrophic rope failure.