The boom stops on a pedestal crane prevent the boom from ______.A.being raised too highB.swinging at seaC.overloading when not in useD.being lowered too low
The boom stops on a pedestal crane prevent the boom from ______.
A.being raised too high
B.swinging at sea
C.overloading when not in use
D.being lowered too low
相关考题：
On a crane, the boom indicator tells the operator what angle the boom angle is compared to the ______.A.vertical positionB.horizontal positionC.boom stop angleD.minimum radius angle
The boom stops are installed on an offshore crane to ______.A.prevent the boom from being raised too highB.prevent the boom from swingingC.support the boom when not in useD.prevent the boom from being lowered
With a given load on the cargo hook，the thrust on a cargo boom ______.A.increases as the angle to the horizontal increasesB.increases as the angle to the horizontal decreasesC.is greatest at an angle of 45° and decreases as the boom is raised or loweredD.is least at an angle of 45° and increases as the boom is raised or lowered
The signal man assisting a crane operator has his arm extended with his fingers closed and thumb pointing upward．This is the signal to ______．A.raise the boomB.raise the hookC.raise the boom and hookD.check the boom stop
For any given pedestal crane，when the boom is lengthened，the lifting capacity is ______．A.unchangedB.increasedC.eliminatedD.decreased
What does “evel-luffing” accomplish during crane operations ________．A.It prevents the load from swinging when the boom level is adjustedB.Less power is needed when topping the boom with a load on the hookC.It maintains the height of the load above the deckD.All of the above
What is meant by the term“luffing the boom”of a crane ________．A.Stopping the boomB.Topping or lowering the boomC.Moving the boom left or rightD.All of the above
When a cargo boom or crane is rated at varying capacities，there will be a table at the controls which relates safe working load to ______．A.winch speedB.boom strengthC.load radiusD.cable strength
单选题The （）(笨重货) must be handled by jumbo boom or shore crane.Aawkward cargoBdrummed cargoCcased cargoDheavy cargo
单选题Which action(s) is/are included in crane operations?（）ANormal boom stowage and shutdown operationsBEmergency shutdown operationCRemoving booms from stowageDAll of the above
单选题For any given pedestal crane,when the boom is lengthened, the lifing capacity is（）.AunchangedBincreasedCeliminatedDdecreased
单选题The signal man assisting a crane operator has his arm extended with his fingers closed and thumb pointing upward. This is the signal to（）.Araise the boomBraise the hookCraise the boom and hookDcheck the boom stop
单选题On a ship’s crane，the load chart relates the allowable load to the combination of the boom length and（）.Awinch speedBboom strengthCload radiusDcable strength
单选题The boom stops on a pedestal crane prevent the boom from（）.Abeing raised too highBswinging at seaCoverloading when not in useDbeing lowered too low
单选题What is meant by the term“luffing the boom”of a crane（）．AStopping the boomBTopping or lowering the boomCMoving the boom left or rightDAll of the above
单选题The boom stops are installed on an offshore crane to（）.Aprevent the boom from being raised too highBprevent the boom from swingingCsupport the boom when not in useDprevent the boom from being lowered
单选题When a cargo boom or crane is rated at varying capacities，there will be a table at the controls which relates safe working load to（）.Awinch speedBboom strengthCload radiusDcable strength
单选题A tackle by which the outer end of a boom is raised and lowered is the topping（）.AboomBliftCraiseDtackle
单选题The load chart of a crane enables the operator to combine the load radius with boom length to determine the（）.Amaximum counter weight requiredBminimum horsepower requiredChoist rope strengthDallowable load
单选题Sudden starts or stops of the boom is likely to cause all of the following except（）.Abreaking a cargo runnerBparting guys topping liftsCcarrying away a blockDoverheating the resistors and eventually burning out
单选题The load chart of a ship crane enables the operator to combine the load radius with boom length to determine the（）.Amaximum counter weight requiredBminimum horsepower requiredChoist rope strengthDallowable load
单选题With a given load on the cargo hook，the thrust on a cargo boom（）.Aincreases as the angle to the horizontal increasesBincreases as the angle to the horizontal decreasesCis greatest at an angle of 45° and decreases as the boom is raised or loweredDis least at an angle of 45° and increases as the boom is raised or lowered
单选题When viewed from above，the best position for the guy in relation to the boom is（）.AAt a 45° angleBAt right anglesC4 feet aft of the heel of the boomDParallel to the boom
单选题What does “evel-luffing” accomplish during crane operations（）.AIt prevents the load from swinging when the boom level is adjustedBLess power is needed when topping the boom with a load on the hookCIt maintains the height of the load above the deckDAll of the above
单选题0n a crane ,the boom indicator tells the operator what angle the boom angle is compared to the（）.Avertical positionBhorizontal positionCboom stop angleDminimum radius angle
单选题The boom indicator on a crane will indicate the（）.Alength of the boomBangle of the boomClifting capacity of the boomDdirection of the boom
单选题On a ship crane，the load chart relates the allowable load to the combination of boom length and（）.Aboom angleBboom strengthCload radiusDcable strength