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
Sudden starts or stops of the boom is likely to cause all of the following except（）.
What does “evel-luffing” accomplish during crane operations（）.
Running an electric winch at slow speed over a long period of time causes（）.
Which of the following statements is FALSE concerning cranes being installed on the centerline of vessels（）.
Where is the most probable location of the remote shutdown station for cargo pumps on a tank barge carrying oil（）.
The item（）is not the advantage of the hydraulic winch．
Which part of a conventional cargo gear rig provides for vertical control and positioning of a boom（）.
Official draft measurements should be（）by authorized persons，agreed by both parties involved.
When viewed from above，the best position for the guy in relation to the boom is（）.
On no account（）to be exceeded.