Mobile Crane Operator Flashcards
7 cards from real NCCCO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Mobile Crane Operator flashcards as text
Under ASME B30.5, at what minimum distance from electrical power lines rated up to 50 kV must a crane boom maintain clearance?
Answer: 10 feet
ASME B30.5 and OSHA 1926.1408 require a minimum 10-foot clearance for power lines rated up to 50 kV.
When traveling a mobile crane with a load suspended, the operator must:
Answer: Follow the manufacturer's procedures and the lift director's direction, keeping the load as low as practical
Traveling with a suspended load requires manufacturer guidance, supervisor oversight, and the load kept low to reduce swing and instability.
A wire rope's discard criteria include finding how many broken wires in one lay length for a running rope?
Answer: 6 broken wires in one lay length or 3 in one strand
Per ASME B30.5, a running wire rope must be removed from service if 6 or more broken wires are found in one lay length, or 3 in a single strand.
What is the primary purpose of an anti-two-block (ATB) device?
Answer: Automatically stops the hoist and boom functions before two-blocking can occur
An ATB device detects when the hook block is dangerously close to the boom tip and automatically disables hoist-up and boom-down functions.
Which factor does NOT directly affect a mobile crane's rated lifting capacity at a specific radius?
Answer: The color of the load being lifted
Rated capacity depends on radius, boom length, reeving, and outrigger configuration—the physical properties of the load, not its color.
When is a crane operator permitted to leave the controls unattended with a suspended load?
Answer: Never, unless the load is safely landed and the crane is secured per manufacturer procedures
OSHA 1926.1417 prohibits leaving a suspended load unattended; the load must be safely landed before the operator leaves the controls.
A radius increase during a pick (boom deflection or crane settlement) will:
Answer: Reduce the crane's rated capacity, potentially causing an overload
As radius increases, rated capacity decreases on the load chart, so any unintended radius growth moves the crane toward an overload condition.