A.Stopping the boom
B.Topping or lowering the boom
C.Moving the boom left or right
D.All of the above
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A.It prevents the load from swinging when the boom level is adjusted
B.Less power is needed when topping the boom with a load on the hook
C.It maintains the height of the load above the deck
D.All of the above
A.started
B.finished
C.completed
D.reported
A.Cranes/derricks
B.Crane/derrick cycles
C.Crane/derrick cycle time
D.Weight per package
A.Date and description of each failure
B.Average load in pounds for each usage
C.Total number of lifts for each usage
D.All of the above
A.less jerky starts
B.less jerky stops
C.overheating worries
D.none of the overheating worries
最新試題
Which of the following statement（s）is/are FALSE regarding a twin pedestal crane set （）.
When discharging an oil cargo，the first consideration is to（）.
The item（）is not the advantage of the hydraulic winch．
What is/are the advantage（s）of cranes over conventional cargo booms（）.
Which part provides for transverse control and positioning of a boom in a conventional yard and stay system（）.
If an attempt is made to hoist a load that exceeds the capacity of an electric winch，an overload safety device causes a circuit breaker to cut off the current to the winch motor（）.
How should you signal the crane operator to lower the boom and raise the load（）.
When viewed from above，the best position for the guy in relation to the boom is（）.
Which part of a conventional cargo gear rig provides for vertical control and positioning of a boom（）.
How should you signal the crane operator to move slowly（）.