Test 1 Flashcards
When a vessel starts to sheer across a channel, which of the following would you NOT do?
A. Reduce speed.
B. Let the vessel’s head fall a few degrees off course across the channel.
C. Maintain some rudder angle toward the near bank.
D. Increase speed.
A. Reduce speed.
Which of the following statements is true about the behavior of a ship in a narrow channel?
A. The bow has a tendency to sheer to the nearer bank.
B. The stern has a tendency to move toward the nearer bank.
C. The vessel wants to move laterally towards the far bank.
D. When the ship is slowed, the rudder will gain some effectiveness.
B. The stern has a tendency to move toward the nearer bank.
Which of the following Italians is responsible for the principle that explains the behavior of a ship in a narrow channel?
A. Berlusconi
B. Bellini
C. Benigni
D. Bernoulli
D. Bernoulli
Bank suction, deftly applied, can be put to a shiphandler’s advantage in which of the following situations?
A. When making a turn, a bank can be put close enough to the quarter to cause the ship to sheer in the direction of the turn and thus make a turn she otherwise could not navigate.
B. To assist a ship to pass another vessel in a narrow channel.
C. To locate the center of a channel in times of limited visibility.
D. All of the above
D. All of the above
Which of the following statements is NOT true about the effect of tide and current when navigating in a channel?
A. A fair current helps the stern around a bend when it strikes the quarter so that the stern comes around at a greater rate.
B. A fair current assists the bow in turning because of the eddy currents reflected out of the bend and the lack of current on the bow on the point side of the bend.
C. A head current can be assist to large ships making a turn.
D. All of the above statements are true.
C. A head current can be assist to large ships making a turn.
What is a “freshet”?
A rapid rise in stream flow due to runoff from rain or snowmelt.
A V-shaped ripple with the point of the V pointing upstream in a river may indicate a _____________
A. submerged rock, not dangerous to navigation
B. sunken wreck, not dangerous to navigation
C. towed-under buoy
D. All of the above
C. towed-under buoy
Balanced spade rudders often will not steer when large rudder angles are used.
True
or
False
True
Which of the following statements is NOT true about propeller design?
A. When a right-hand propeller is going astern, the stern tends to walk to port.
B. The diameter of the turning circle for right and left turns is not affected by the direction of the propeller’s rotation.
C. Higher RPMs are required to get a good flow over the rudder at reduced speeds when the ship is fitted with a smaller diameter propeller.
D. All of the above statements are true.
B. The diameter of the turning circle for right and left turns is not affected by the direction of the propeller’s rotation.
A steam turbine ship increases revolutions more slowly than a diesel, and more care is necessary to keep the ship’s speed down while still controlling steering.
True
or
False
True
Which of the following statements is/are true about the relative merits of the handling characteristics of the standard fixed blade propeller and the variable pitch propeller?
A. The variable pitch propeller can go astern indefinitely.
B. Variable pitch propellers can change the direction of propulsion repeatedly without concern for exhausting the supply of starting air.
C. When approaching a berth, lock or pilot station, it is necessary to start slowing a variable pitch propeller sooner than would be necessary for a conventional propeller.
D. All of the above
D. All of the above
When in position and stopped at the berth at zero pitch, the variable pitch propeller is usually turning at high RPM.
True
or
False.
True
Which of the following is NOT an advantage of an omni-directional propulsion system?
A. A propeller is NOT required to transmit power to the propeller.
B. The terminology applicable to this system is not yet standardized.
C. Ships using the system are highly maneuverable.
D. The system is safer than some other propulsion systems because the engine does not have to be stopped and reversed to go astern
B. The terminology applicable to this system is not yet standardized.
Of the many modes available to the omni-directional system, which of the following is/are one of the “standard” modes?
A. Open Sea Mode
B. Harbor Mode
C. Docking Mode
D. All of the above
D. All of the above
Which of the following statements is NOT true about the similarities and differences between the “At Sea” and the other two modes of the omni-directional system?
A. In all modes, the steering and engine commands are given in the same manner as for conventional ships.
B. In the Harbor & Docking modes, the pods are positioned by degrees or clock positions relative to the bow.
C. Engine orders are given in percentage of power ahead or astern in the Harbor and Docking modes.
D. Another description for the Harbor Mode is the “bicycle mode.”
A. In all modes, the steering and engine commands are given in the same manner as for conventional ships.
When the azipod is operating under computer control, the shiphandler is controlling ____________.
A. Revolutions per minute of the pod and thruster and direction of the thruster and pod forces
B. Resultant power, speed, and vessel movement
C. Either of the above
D. None of the above
B. Resultant power, speed, and vessel movement
Experienced mariners limit the use of computer control in omni-directional propulsion systems when maneuvering near docks and fixed objects. A good rule-of-thumb is to change from automatic to manual control when within _________ of a hazard.
A. one ship length
B. three ship lengths
C. 100 feet
D. 500 feet
A. one ship length
To turn an azipod to port, the pod is turned to starboard.
True
Or
False
True
Which of the following statements about the effect of trim is NOT true?
A. As a vessel’s trim by the stern increases, she becomes more directionally stable.
B. As a vessel’s trim by the stern increases, her tactical diameter decreases.
C. A ship with a large block coefficient steers poorly.
D. A ship trimmed by the head is directionally unstable for almost all hull forms.
B. As a vessel’s trim by the stern increases, her tactical diameter decreases.
A ship trimmed by the head, _________________________________.
A. Seems to pivot about a point farther from the bow than normally expected.
B. Wants to continue to swing after the rudder is placed amidships.
C. Both A and B
D. Neither A nor B
B. Wants to continue to swing after the rudder is placed amidships.
Which of the following statements is NOT true?
A. A potentially directionally unstable vessel should not be trimmed by the head.
B. On a directionally unstable vessel, the rudder will have to be used for a longer period of time to start the vessel swinging, after which large amounts of rudder are needed for longer periods of time than normally expected to check a swing.
C. Once the directionally unstable vessel has started to swing, the rudder should be put back amidships since the rate of turn will increase even when the rudder is amidships.
D. A directionally unstable ship requires a relatively large are to turn.
D. A directionally unstable ship requires a relatively large are to turn.
When making a turn in a channel, _____________________________.
A. Begin the turn when the ship’s pivot point is nearly at the turning point at the end of the reach or range.
B. Begin the turn when the ship’s bridge is nearly at the turning point at the end of the reach of range.
C. If in doubt about the amount of rudder required, use a smaller amount than you feel necessary.
D. Starting a turn too late is preferable to starting a turn too early.
A. Begin the turn when the ship’s pivot point is nearly at the turning point at the end of the reach or range.
Which of the following statements is/are NOT true when using an aid to navigation as a rate-of-turn indicator?
A. If the relative bearing of the buoy changes toward the bow, so that the buoy is moving forward relative to the reference point, the ship is turning at a rate that will bring her closer to the buoy. She will be closer to the buoy at the completion of the turn than she is at present.
B. If the bearing is opening away from the bow so the buoy is moving aft relative to the reference point, then the ship’s distance from the buoy is increasing.
C. If the buoy’s bearing is opening away from the bow and the rate at which the buoy is opening is increasing then the rate of turn is increasing.
D. If the buoy is remaining stead relative to the reference point, the ship is turning at a fixed rate.
C. If the buoy’s bearing is opening away from the bow and the rate at which the buoy is opening is increasing then the rate of turn is increasing.
Which of the following steps is incorrect when meeting another vessel in a narrow channel?
A. When approximately one-and-a-half ship lengths apart, put the rudder to starboard
B. When one ship’s bow is abeam the bow of the other, her helm is shifted to move her stern to starboard until she is parallel to the bank.
C. The rudder is put to the right to check the swing.
D. As the other vessel’s quarter passes abeam your bow, increase right rudder.
D. As the other vessel’s quarter passes abeam your bow, increase right rudder.
