0n a crane ,the boom indicator tells the operator what angle the boom angle is compared to the（）.

相似题目

• What is/are the advantage（s）of cranes over conventional cargo booms（）.

  A . Cranes are able to pick up and drop loads over a greater spotting area B . Increased safety because the deck is clear of running and standing rigging C . Simplicity of operation of the crane by its operator D . All of the above

  查看最佳答案

• During which condition should the operator of a pedestal crane shutdown operations?（）

  A . Bunkering B . High winds C . Potable water spill on deck

  查看最佳答案

• On a ship’s crane，the load chart relates the allowable load to the combination of the boom length and（）.

  A . winch speed B . boom strength C . load radius D . cable strength

  查看最佳答案

• 0n cargo booms,preventers are（）.

  A . auxiliary guys B . extra fair leads C . steel bands D . sto

  查看最佳答案

• The boom indicator tells the operator at what angle the boom is compared to the（）.

  A . horizontal position of the boom B . vertical position of the boom C . horizontal position of the load being lifted D . vertical position of the load being lifted

  查看最佳答案

• A tackle by which the outer end of a boom is raised and lowered is the topping（）.

  A . boom B . lift C . raise D . tackle

  查看最佳答案

• How should you signal the crane operator to raise the boom and lower the load?（）.

  A . Extend arm with the palm down and and hold this position rigidly B . Place both fists in front of the body with the thumbs pointing outward each other C . Clasp hands in front of you body D . Extend arm with the thumb pointing up, and flex the finger s in and out for as long as the load movement is desired

  查看最佳答案

• How should you signal the crane operator to lower the boom and raise the load?（）.

  A . Extend arm and point finger in the direction to move the boom B . Extend arm with the thumb pointing downward and flex fingers in and out C . With f rearm vertical and forefinger pointing up,move hand in small horizond circles D . With arm extended downwards and forefinger pointing down,move hand in small horizontal circle

  查看最佳答案

• 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 speed B . boom strength C . load radius D . cable strength

  查看最佳答案

• Stress on the topping lift of a swinging boom can be reduced by（）.

  A . rigging a back stay B . raising the boom C . increasing the mechanical advantage of the cargo purchase D . taking all slack out of the preventer

  查看最佳答案

• For a given weight of cargo，the stress on the heel block of a cargo boom（）.

  A . increases as the cargo closes the head while hoisting B . increases if the cargo runner is doubled up C . decreases as the boom is topped to a greater angle D . is determined by the thrust stresses on the boom

  查看最佳答案

• The load chart of a crane enables the operator to combine the load radius with boom length to determine the（）.

  A . maximum counter weight required B . minimum horsepower required C . hoist rope strength D . allowable load

  查看最佳答案

• The pivot pin at the base of a sheath-screw boom davit must be（）.

  A . inserted each time before the booms are cranked out B . periodically removed for inspection and lubricated C . replaced at each inspection for certification D . in the locked position after the boat is cradled and griped dow

  查看最佳答案

• How should you signal the crane operator to raise the boom?（）.

  A . Extend arm with the thumb pointing up and flex the fingers in and out B . Place both fists in front of the body with the thumbs pointing upward C . With forearm vertical and forefinger pointing up,move hand in small horizond circles D . Extend arm with the fingers closed and thumb upward

  查看最佳答案

• What is meant by the term“luffing the boom”of a crane（）．

  A . Stopping the boom B . Topping or lowering the boom C . Moving the boom left or right D . All of the above

  查看最佳答案

• What is the purpose of the equalizing beam aboard a crane vessel（）.

  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 crane

  查看最佳答案

• The fitting that allows a boom to move freely both vertically and laterally is called the （）.

  A . swivel B . lizard C . spider band D . gooseneck

  查看最佳答案

• 0n a vessel,multipiying a load’s weight by the distance of the load’s center of gravity above the baseline results in a(n)（）.

  A . transverse moment B . vertical moment C . righting moment D . inclining moment

  查看最佳答案

• For any given pedestal crane，when the boom is lengthened，the lifting capacity is（）.

  A、 unchanged B、 decreased C、 eliminated D、 increased

  查看最佳答案

• The boom indicator on a crane will indicate the（）.

  A . length of the boom B . angle of the boom C . lifting capacity of the boom D . direction of the boom

  查看最佳答案

• On a ship crane，the load chart relates the allowable load to the combination of boom length and（）.

  A . boom angle B . boom strength C . load radius D . cable strength

  查看最佳答案