Mobile Crane Operator Test 1 Flashcards

When operating a mobile crane near an unguarded energized power line of unknown voltage, the minimum safe approach distance is:

Answer: 20 feet

OSHA 1926.1408 requires a minimum 20-foot clearance from energized lines when voltage is unknown.

A load chart rating for a mobile crane is based on which structural condition of the crane?

Answer: Crane on level, firm ground with all outriggers fully extended

Load charts assume the crane is on firm, level ground with all outriggers fully extended and set on pads.

Which of the following conditions requires an operator to immediately cease crane operations?

Answer: The load line becomes slightly slack during a pick

A slack load line can cause sudden uncontrolled load movement or two-blocking, requiring immediate stoppage.

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

Answer: To alert the operator when the crane approaches its rated capacity

An LMI (also called a rated capacity indicator) warns the operator as the crane nears its load limit for the current configuration.

During a lift, the operator notices the load is slowly swinging uncontrollably. The FIRST action should be to:

Answer: Lower the load to the ground as smoothly as possible

An uncontrolled swinging load should be landed as safely and smoothly as possible to eliminate the hazard.

On a mobile crane, the 'working area' or 'working range' is defined as:

Answer: The arc through which the crane can swing while carrying a load within rated capacity

The working area is the specific arc and radius within which the crane can safely operate a rated load in its current configuration.

Which factor does NOT reduce a mobile crane's rated lift capacity?

Answer: Reducing the operating radius

Reducing the operating radius (working closer to the crane) generally increases available capacity, not decreases it.