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
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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
A.breaking a cargo runner
B.parting guys topping lifts
C.carrying away a block
D.overheating the resistors and eventually burning out
最新試題
Official draft measurements should be（）by authorized persons，agreed by both parties involved.
Pedestal cranes have limit switches to restrict movement of which function（s）（）.
What does “evel-luffing” accomplish during crane operations（）.
Sudden starts or stops of the boom is likely to cause all of the following except（）.
Which operation may cause the pressure in an inert tank to fall below the prescribed limits（）.
The net productivity per gang-hour can be improved through a decrease of（）.
On no account（）to be exceeded.
Which method should be used to warm up the pump turbines prior to discharge（）.
Which part of a conventional cargo gear rig provides for vertical control and positioning of a boom（）.
When discharging oil from an oil tanker the instantaneous rate（）60 liters per nautical mile.