A.It allows for rotation of the hook in the single mode
B.It is required to“twin-up”30-ton pedestal cranes
C.It is used to pick up light loads
D.It is used to rigidly connect two cranes
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A.Stopping the boom
B.Topping or lowering the boom
C.Moving the boom left or right
D.All of the above
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
最新試題
On no account（）to be exceeded.
Which part provides for transverse control and positioning of a boom in a conventional yard and stay system（）.
When viewed from above，the best position for the guy in relation to the boom is（）.
The item（）is not the advantage of the hydraulic winch．
Which operation may cause the pressure in an inert tank to fall below the prescribed limits（）.
How should you signal the crane operator to lower the boom and raise the load（）.
What does “evel-luffing” accomplish during crane operations（）.
The Master or person in charge of a ship shall ensure the crane record book shows the（）.
Official draft measurements should be（）by authorized persons，agreed by both parties involved.
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（）.