Mobile Crane Operator Fundamentals Flashcards

When a mobile crane is traveling on a public road, the boom must typically be:

Answer: Lowered and secured in the travel position

During road travel, the boom must be lowered and secured to keep the crane within legal height limits and maintain stability.

Which factor is NOT typically considered when selecting outrigger pad size?

Answer: Color of the pad material

Pad color is irrelevant; pad size is determined by crane load, outrigger float area, and ground bearing capacity.

The term 'two-blocking' refers to:

Answer: The upper and lower block making contact

Two-blocking occurs when the lower load block contacts the upper sheave block, which can cause the hoist rope to part.

A load chart for a lattice boom crane shows a note 'on outriggers fully extended.' This means:

Answer: The rated capacities only apply when outriggers are fully extended

Load chart configurations must be matched exactly; using partially extended outriggers voids the rated capacities shown.

What is the primary purpose of a crane's anti-two-block (ATB) device?

Answer: Automatically stop hoist motion before two-blocking occurs

The ATB device detects when the load block approaches the boom tip sheaves and automatically cuts power to the hoist before contact occurs.

When operating a mobile crane near energized power lines, OSHA requires a minimum clearance of ___ for lines up to 50 kV:

Answer: 10 feet

OSHA 1926.1408 requires a minimum 10-foot clearance from energized lines up to 50 kV unless the utility owner de-energizes the line.

Before beginning a lift, the operator should verify the load weight against the load chart using:

Answer: The net load plus all rigging, attachments, and below-hook devices

The total load on the crane hook includes the load itself, all rigging hardware, spreader bars, and the hook block weight.