Shiphandling

Question 1

Which of the following statements accurately describes the relative properties of water and air?

A) Water is 850 times denser than air and 100 times more viscous than air.
B) Water is 100 times denser than air and 850 times more viscous than air.
C) Water is 100 times denser than air and 100 times more viscous than air.
D) Water is 850 times denser than air and 850 times more viscous than air.

Answer 1

A) Water is 850 times denser than air and 100 times more viscous than air.

Question 2

Which statement accurately reflects the behavior of pressure in a stream?

A) Total pressure decreases as dynamic pressure increases, resulting in a decrease in static pressure.
B) Total pressure remains constant in a stream, and an increase in dynamic pressure corresponds to a decrease in static pressure.
C) Total pressure increases as dynamic pressure increases, leading to an increase in static pressure.
D) Total pressure fluctuates in a stream, regardless of changes in dynamic pressure and static pressure.

Answer 2

Total pressure remains constant in a stream. If dynamic pressure increases, static pressure
decreases.

Question 3

Which principle describes the relationship between static pressure and speed change?

A) Static pressure changes linearly with speed change.
B) Static pressure remains constant regardless of speed change.
C) Static pressure changes exponentially with speed change.
D) The change in static pressure is proportional to the square of the speed change.

Answer 3

D) The change in static pressure is proportional to the square of the speed change.

Question 4

Which statement accurately describes the distribution of static pressure on a ship with headway?

A) A ship with headway experiences low static pressure at the bow and stern, and high static pressure amidships.
B) Static pressure on a ship with headway remains uniform across all sections.
C) A ship with headway experiences high static pressure at the bow and stern, and low static pressure amidships.
D) Static pressure is not affected by the ship’s movement or direction

Answer 4

C. Ship with headway has high static pressure at bow and stern, low static pressure amidships.

Question 5

Which statement accurately compares the characteristics of turbulent and laminar boundary layers?

A) The laminar boundary layer deepens faster and has a steeper velocity gradient than the turbulent boundary layer.
B) Both turbulent and laminar boundary layers deepen at the same rate but have different velocity gradients.
C) The turbulent boundary layer deepens faster and has a steeper velocity gradient than the laminar boundary layer.
D) Turbulent and laminar boundary layers have identical characteristics in terms of depth and velocity gradient.

Answer 5

a. Turbulent boundary layer deepens faster and has steeper velocity gradient than laminar
boundary layer.

Question 6

Which relationship correctly matches a dimensionless number with its corresponding resistance in fluid dynamics?

A) Froude number is indicative of wave resistance, while Reynolds number relates to viscous resistance.
B) Froude number represents viscous resistance, and Reynolds number indicates wave resistance.
C) Froude number correlates with both wave and viscous resistances, while Reynolds number denotes no particular resistance.
D) Reynolds number corresponds to wave resistance, while Froude number indicates viscous resistance.

Answer 6

Froude number = wave resistance.
Reynolds number = viscous resistance.

Question 7

Which statement accurately advises on assessing wind speed onboard?

A) Wind speed should be measured at the highest point on the ship for accuracy.
B) Wind speed should be assessed at sea level to minimize errors.
C) The wind speed reported at 10 meters above sea level is the most reliable onboard measurement.
D) Wind speed should be estimated based on the ship’s speed and direction.

Answer 7

When assessing wind speed, reported 10m wind speed should be used.

Question 8

Which statement accurately describes the relationship between a ship’s displacement and its hydrodynamic mass?

A) The hydrodynamic mass carried by a ship is typically less than 25% of its displacement.
B) Hydrodynamic mass carried is always greater than 100% of a ship’s displacement.
C) The hydrodynamic mass carried by a ship ranges from 25% to 100% of its displacement.
D) Hydrodynamic mass is unrelated to a ship’s displacement.

Answer 8

Hydrodynamic mass carried is 25% to 100% of ship’s displacement.

Question 9

Which statement accurately estimates the virtual mass of a ship?

A) Virtual mass is always less than the ship’s displacement.
B) Virtual mass is approximately equal to the ship’s displacement.
C) The virtual mass of a ship typically ranges from 1.3 times to 2 times its displacement.
D) Virtual mass is irrelevant to the displacement of the ship.

Answer 9

The virtual mass of a ship typically ranges from 1.3 times to 2 times its displacement.

Question 10

Which statement accurately describes the relationship between virtual mass and the ship’s displacement at specific distances from the ship?

A) Virtual mass remains constant regardless of the distance from the ship.
B) Virtual mass increases linearly with the distance from the ship.
C) At a distance of 1.5 times the ship’s diameter (1.5d), virtual mass equals 1.5 times the displacement, and at 1.1 times the diameter (1.1d), it equals 1.8 times the displacement.
D) Virtual mass decreases exponentially as the distance from the ship increases.

Answer 10

C) At a distance of 1.5 times the ship’s diameter (1.5d), virtual mass equals 1.5 times the displacement, and at 1.1 times the diameter (1.1d), it equals 1.8 times the displacement.

Question 11

Which phenomenon is responsible for the turning effect ahead induced by dissimilar drag on propeller blades?

A) Lift force
B) Drag force
C) Torque
D) Thrust

Answer 11

Turning effect ahead caused by dissimilar drag on propeller blades (torque)

Question 12

Which factors contribute to the turning effect astern on a vessel?

A) Propeller torque and the force of water against the hull
B) Wind resistance and hull friction
C) Water currents and wave action
D) Buoyancy and propeller rotation

Answer 12

Turning effect astern caused by dissimilar drag on propeller blades (torque) and force of water
against hull (deadwood effect).

Question 13

What is the primary cause of cavitation in propellers?

A) Formation of bubbles at high-pressure areas and bursting at low-pressure areas.
B) Formation of bubbles at low-pressure areas and bursting at high-pressure areas.
C) Corrosion of the propeller surface due to water exposure.
D) Mechanical failure of the propeller blades.

Answer 13

B) Formation of bubbles at low-pressure areas and bursting at high-pressure

Question 14

What are the primary locations for cavitation occurrence in propellers?

A) At the root of the propeller blades
B) Along the midsection of the propeller blades
C) At points of high water flow, such as blade tips, and blade thickness, such as the leading edge
D) At the trailing edge of the propeller blades

Answer 14

C) At points of high water flow, such as blade tips, and blade thickness, such as the leading edge

Question 15

How does cavitation affect propeller thrust, particularly when rapid pitch changes occur on a Variable Pitch Propeller (VPP)?

A) Cavitation has no effect on propeller thrust during pitch changes.
B) Cavitation leads to a gradual change in propeller thrust during pitch changes.
C) Cavitation may cause an abrupt change in propeller thrust if pitch changes occur quickly on a Variable Pitch Propeller (VPP).
D) Cavitation increases propeller thrust during pitch changes on a Variable Pitch Propeller (VPP).

Answer 15

C) Cavitation may cause an abrupt change in propeller thrust if pitch changes occur quickly on a Variable Pitch Propeller (VPP).

Question 16

What phenomenon describes the occurrence when the upper propeller blade passes close to the water surface?

A) Aeration
B) Cavitation
C) Vibration
D) Erosion

Answer 16

A) Aeration

Question 17

How does aeration affect the performance of a propeller?

A) Aeration increases thrust and decreases drag.
B) Aeration decreases thrust and increases drag.
C) Aeration has no significant effect on thrust or drag.
D) Aeration increases both thrust and drag.

Answer 17

B) Aeration decreases thrust and increases drag.

Question 18

How do high skew propellers contribute to the reduction of harmonic vibration?

A) By increasing harmonic vibration
B) By having no effect on harmonic vibration
C) By exacerbating harmonic vibration
D) By smoothing out harmonic vibration

Answer 18

) By smoothing out harmonic vibration

Question 19

How does increasing the blade area ratio affect vibration and efficiency in propellers?

A) Increasing the blade area ratio decreases vibration and increases efficiency.
B) Increasing the blade area ratio decreases vibration but has no effect on efficiency.
C) Increasing the blade area ratio decreases vibration but decreases efficiency.
D) Increasing the blade area ratio increases vibration and decreases efficiency.

Answer 19

C) Increasing the blade area ratio decreases vibration but decreases efficiency.

Question 20

Which statement accurately describes the effect of increasing the number of propeller blades on vibration?

A) Increasing the number of propeller blades increases vibration.
B) Increasing the number of propeller blades decreases vibration.
C) Increasing the number of propeller blades has no effect on vibration.
D) Increasing the number of propeller blades decreases efficiency but has no effect on vibration.

Answer 20

B) Increasing the number of propeller blades decreases vibration.

Question 21

Which statement accurately describes the effect of reducing the number of propeller blades on efficiency?

A) Reducing the number of propeller blades decreases efficiency.
B) Reducing the number of propeller blades has no effect on efficiency.
C) Reducing the number of propeller blades increases efficiency.
D) Reducing the number of propeller blades increases vibration.

Answer 21

C) Reducing the number of propeller blades increases efficiency.

Question 22

What is a significant factor contributing to the higher efficiency of single screw propellers compared to twin screw propellers?

A) Single screw propellers are smaller in size.
B) Single screw propellers have a simpler design.
C) Single screw propellers are about 20% larger in size.
D) Single screw propellers are about 20% more efficient due to their larger size.

Answer 22

D) Single screw propellers are about 20% more efficient due to their larger size.

Question 23

How does six months of propeller fouling affect propeller efficiency?

A) It increases efficiency by 8%.
B) It decreases efficiency by 8%.
C) It has no effect on efficiency.
D) It reduces vibration but has no effect on efficiency.

Answer 23

B) It decreases efficiency by 8%.

Question 24

How does the power requirement for older ships compare to newer ones to achieve the same delivery condition?

A) Older ships require 30% less power.
B) Older ships require 30% more power.
C) There is no difference in power requirements between older and newer ships.
D) Older ships require double the power.

Answer 24

B) Older ships require 30% more power

Question 25

What is the speed of the flow leaving the rudder relative to the ship's speed? A) The same as the ship's speed B) Half of the ship's speed C) Three times the ship's speed D) One-third of the ship's speed

Answer 25

C) Three times the ship's speed

Question 26

What is the effectiveness of the rudder when propulsion is stopped? A) 100% B) 75% C) 53% D) 25%

Answer 26

C) 53%

Question 27

At what angle is the rudder most effective? A) 10° B) 15° C) 20° D) 25°

Answer 27

D) 25°

Question 28

How is the effectiveness of the rudder distributed between negative and positive pressures? A) 1/2 due to negative pressure, 1/2 due to positive pressure. B) 2/3 due to negative pressure, 1/3 due to positive pressure. C) 1/3 due to negative pressure, 2/3 due to positive pressure. D) Equal distribution between negative and positive pressure.

Answer 28

B) 2/3 due to negative pressure, 1/3 due to positive pressure.

Question 29

Up to what angle does the rudder flow remain laminar with a slim rudder, and up to what angle with a thick rudder? A) Laminar up to 25° with a slim rudder and 15° with a thick rudder. B) Laminar up to 15° with a slim rudder and 25° with a thick rudder. C) Laminar up to 20° with a slim rudder and 30° with a thick rudder. D) Laminar up to 30° with a slim rudder and 20° with a thick rudder.

Answer 29

B) Laminar up to 15° with a slim rudder and 25° with a thick rudder.

Question 30

What is the primary function of Kort nozzles in relation to propeller thrust? A) Reducing propeller thrust B) Redirecting propeller thrust C) Slowing down propeller thrust D) Directing and accelerating propeller thrust

Answer 30

D) Directing and accelerating propeller thrust

Question 31

When does the Kort nozzle effect have the most significant impact on propeller performance? A) High propeller load at high speed B) Low propeller load at low speed C) High propeller load at low speed D) Low propeller load at high speed

Answer 31

C) High propeller load at low speed

Question 32

How do Kort nozzles compare to conventional propulsion in terms of prop walk in reverse, power requirement, and control? A) Kort nozzles have more prop walk in reverse, higher power requirement, and worse control. B) Kort nozzles have less prop walk in reverse, lower power requirement, and worse control. C) Kort nozzles have less prop walk in reverse, lower power requirement, and better control. D) Kort nozzles have more prop walk in reverse, higher power requirement, and better control.

Answer 32

C) Kort nozzles have less prop walk in reverse, lower power requirement, and better control.

Question 33

For which range of speeds are Kort nozzles typically suitable? A) Ships traveling at speeds greater than 12 knots B) Ships traveling at speeds exactly 12 knots C) Ships traveling at speeds less than or equal to 12 knots D) Ships traveling at speeds less than 12 knots

Answer 33

C) Ships traveling at speeds less than or equal to 12 knots

Question 34

What is the typical range of angles for Kort nozzles? A) 15-20° B) 25-30° C) 35-40° D) 40-45°

Answer 34

B) 25-30°

Question 35

How much does a Kort nozzle typically increase thrust in towing and pushing conditions? A) 5-10% B) 10-15% C) 15-25% D) 25-30%

Answer 35

C) 15-25%

Question 36

By what percentage do Kort nozzles typically increase thrust at zero speed? A) 10% B) 20% C) 30% D) 40%

Answer 36

C) 30%

Question 37

What percentage of ahead thrust do modern Kort nozzles typically produce when backing? A) 50% B) 60% C) 70% D) 80%

Answer 37

C) 70%

Question 38

What proportion of the blade surface does the Becker rudder flap typically occupy? A) 1/8 B) 1/4 C) 1/2 D) 3/4

Answer 38

B) 1/4

Question 39

What is the typical relationship between the angle of the Becker rudder flap and the angle of the rudder? A) The same angle B) Half the angle C) Twice the angle D) Three times the angle

Answer 39

C) Twice the angle

Question 40

Under what condition may the Becker rudder flap exceed perpendicular to water flow? A) Speed > 4 knots B) Speed = 4 knots C) Speed < 4 knots D) Speed is irrelevant to this condition

Answer 40

C) Speed < 4 knots

Question 41

What is the maximum angle that a Becker rudder may be angled? A) 50° B) 60° C) 70° D) 80°

Answer 41

C) 70°

Question 42

By what percentage can a Becker rudder increase lift? A) Up to 30% B) Up to 45% C) Up to 60% D) Up to 75%

Answer 42

C) Up to 60%

Question 43

How much of the ahead thrust can be created by the sideways thrust from a Becker rudder? A) Up to 25% B) Up to 35% C) Up to 50% D) Up to 65%

Answer 43

C) Up to 50%

Question 44

At what speed does a Schilling rudder (fish tail rudder) typically create much greater forces than a conventional rudder? A) Over 5 knots B) Over 6 knots C) Over 7 knots D) Over 8 knots

Answer 44

C) Over 7 knots

Question 45

Under what condition are high rudder angles on a Schilling rudder (fish tail rudder) typically practical? A) At high speed B) At medium speed C) At low speed D) At any speed

Answer 45

C) At low speed

Question 46

By what percentage does a Schilling rudder typically have more lift compared to a conventional rudder? A) 10-20% B) 20-30% C) 30-40% D) 40-50%

Answer 46

C) 30-40%

Question 47

At what angle does a Schilling rudder typically have maximum lift, and up to what angle can it be effectively used? A) Maximum lift at 30% angle, can be used up to 60% angle B) Maximum lift at 40% angle, can be used up to 70% angle C) Maximum lift at 50% angle, can be used up to 80% angle D) Maximum lift at 60% angle, can be used up to 90% angle

Answer 47

B) Maximum lift at 40% angle, can be used up to 70% angle

Question 48

What feature does a rotor rudder have on its leading edge, and at what rudder angle does it typically begin turning? A) It has a flap on its leading edge, and it begins turning at about 10° rudder angle. B) It has a cylinder on its leading edge, and it begins turning at about 15° rudder angle. C) It has a fin on its leading edge, and it begins turning at about 20° rudder angle. D) It has a vortex generator on its leading edge, and it begins turning at about 25° rudder angle.

Answer 48

B) It has a cylinder on its leading edge, and it begins turning at about 15° rudder angle.

Question 49

At what rudder angle does the cylinder on a rotor rudder typically reach maximum rotation? A) 20° B) 25° C) 30° D) 35°

Answer 49

B) 25°

Question 50

Under what conditions does a rotor rudder typically stall? A) At high speed and rudder angles up to 45° B) At low speed and rudder angles up to 55° C) At high speed and rudder angles up to 65° D) It rarely stalls, even at low speed and rudder angles up to 65°

Answer 50

D) It rarely stalls, even at low speed and rudder angles up to 65°

Question 51

How does the displacement-to-horsepower ratio typically vary among different types of ships? A) 10x HP for container ships, 1.5x HP for VLCC, 1x HP for passenger ships B) 10x HP for VLCC, 1.5x HP for container ships, 1x HP for passenger ships C) 1x HP for VLCC, 1.5x HP for container ships, 10x HP for passenger ships D) 1x HP for container ships, 1.5x HP for VLCC, 10x HP for passenger ships

Answer 51

B) 10x HP for VLCC, 1.5x HP for container ships, 1x HP for passenger ships

Question 52

What is the typical propulsive force generated per unit of horsepower in forward motion, and what is the corresponding value for reverse motion? A) 1 ton per 100 HP in forward motion, 0.6 ton per 100 HP in reverse motion B) 0.6 ton per 100 HP in forward motion, 1 ton per 100 HP in reverse motion C) 1 ton per 50 HP in forward motion, 0.6 ton per 50 HP in reverse motion D) 0.6 ton per 50 HP in forward motion, 1 ton per 50 HP in reverse motion

Answer 52

A) 1 ton per 100 HP in forward motion, 0.6 ton per 100 HP in reverse motion

Question 53

What is the typical range of transverse force relative to the propeller force? A) 10-20% B) 20-30% C) 30-40% D) 30-50%

Answer 53

D) 30-50%

Question 54

What is the pivot point defined as in the context of ship motion? A) The center of gravity of the ship B) The point where the ship rotates around its longitudinal axis C) The apparent center of the combined motions of drift and turn D) The location where the ship's propeller is situated

Answer 54

C) The apparent center of the combined motions of drift and turn

Question 55

How does the pivot point location typically relate to the bow in a ship with a large block coefficient? A) The pivot point is closer to the stern. B) The pivot point is closer to the midship. C) The pivot point is closer to the bow. D) The pivot point is unaffected by the block coefficient.

Answer 55

C) The pivot point is closer to the bow.

Question 56

What happens to the pivot point when a ship is trimmed by the stern? A) It moves forward. B) It remains stationary. C) It moves aft. D) It depends on other factors and may vary.

Answer 56

C) It moves aft.

Question 57

What happens to the pivot point when a ship is trimmed by the bow? A) It moves forward. B) It remains stationary. C) It moves aft. D) It depends on other factors and may vary.

Answer 57

A) It moves forward.

Question 58

How is the pivot point typically positioned relative to the center of forces (Fc) from the center of gravity (G)? A) They are aligned. B) They are perpendicular to each other. C) They are always in the same direction. D) They are always opposite to each other.

Answer 58

D) They are always opposite to each other.

Question 59

How does the distance between the center of forces (Fc) and the center of gravity (G) affect the position of the pivot point (P)? A) The further Fc is from G, the further P is from G. B) The closer Fc is to G, the closer P is to G. C) The further Fc is from G, the closer P is to Fc. D) The closer Fc is to G, the further P is from Fc.

Answer 59

B) The closer Fc is to G, the closer P is to G.

Question 60

What happens to the pivot point concerning the center of gravity (G) when a ship is turning due to lateral forces? A) The pivot point moves away from G. B) The pivot point remains stationary relative to G. C) The pivot point moves closer to G. D) The pivot point depends on other factors and may vary.

Answer 60

C) The pivot point moves closer to G.

Question 61

How does the position of the pivot point under sternway with engines stopped compare to under sternway with engines operating astern? A) The pivot point is further forward with engines stopped. B) The pivot point is further aft with engines stopped. C) The pivot point is closer to amidships with engines stopped. D) The pivot point is unaffected by engine operation in this scenario.

Answer 61

B) The pivot point is further aft with engines stopped.

Question 62

In a turning vessel with a 35° helm angle, what is the amount of drift observed? A) 5° B) 10° C) 15° D) 20°

Answer 62

B) 10°

Question 63

How does trimming a ship by the head affect its lateral resistance and the time it takes to start or check a swing? A) Lateral resistance is decreased, and the ship will take longer to start a swing and check a swing. B) Lateral resistance is increased, and the ship will take longer to start a swing and check a swing. C) Lateral resistance is decreased, and the ship will take less time to start a swing and check a swing. D) Lateral resistance is increased, and the ship will take less time to start a swing and check a swing.

Answer 63

A) Lateral resistance is decreased, and the ship will take longer to start a swing and check a swing.

Question 64

How does trimming a ship by the head affect its turning ability and the potential risk regarding acceleration? A) Trimming by the head decreases turning ability and poses no risk regarding acceleration. B) Trimming by the head increases turning ability but poses a risk of acceleration exceeding the rudder's turning capacity. C) Trimming by the head increases turning ability and poses no risk regarding acceleration. D) Trimming by the head decreases turning ability but poses a risk of acceleration exceeding the rudder's turning capacity.

Answer 64

B) Trimming by the head increases turning ability but poses a risk of acceleration exceeding the rudder's turning capacity.

Question 65

How does trimming a ship by the head affect the propeller submergence and rudder thrust? A) Trimming by the head increases propeller submergence and rudder thrust. B) Trimming by the head decreases propeller submergence and rudder thrust. C) Trimming by the head has no effect on propeller submergence but decreases rudder thrust. D) Trimming by the head has no effect on propeller submergence but increases rudder thrust.

Answer 65

B) Trimming by the head decreases propeller submergence and rudder thrust.

Question 66

How does trimming a ship by the head and being under sternway affect its lateral resistance? A) It increases lateral resistance. B) It decreases lateral resistance. C) It has no effect on lateral resistance. D) It depends on other factors and may vary.

Answer 66

B) It decreases lateral resistance.

Question 67

How does trimming a ship by the head affect the size of its turning circle compared to when it is on an even keel? A) Trimming by the head results in a larger turning circle. B) Trimming by the head results in a smaller turning circle. C) Trimming by the head has no effect on the turning circle. D) It depends on other factors and may vary.

Answer 67

B) Trimming by the head results in a smaller turning circle.

Question 68

How does trimming a ship by the head affect the phenomenon of bow squat? A) It reduces bow squat due to increased pressure under the bow. B) It has no effect on bow squat. C) It exacerbates bow squat due to low pressure developing under the bow. D) It increases bow squat due to increased pressure developing under the bow.

Answer 68

C) It exacerbates bow squat due to low pressure developing under the bow.

Question 69

How does trimming a ship by the stern affect its lateral resistance when moving ahead or sideways? A) It increases lateral resistance. B) It decreases lateral resistance. C) It has no effect on lateral resistance. D) It depends on other factors and may vary.

Answer 69

B) It decreases lateral resistance.

Question 70

How does trimming a ship by the stern affect the size of its turning circle? A) Trimming by the stern results in a smaller turning circle due to less lateral resistance. B) Trimming by the stern results in a larger turning circle due to less lateral resistance. C) Trimming by the stern has no effect on the size of the turning circle. D) It depends on other factors and may vary.

Answer 70

B) Trimming by the stern results in a larger turning circle due to less lateral resistance.

Question 71

How does trimming a ship by the stern affect the torque experienced when backing? A) Trimming by the stern increases torque when backing. B) Trimming by the stern decreases torque when backing. C) Trimming by the stern has no effect on torque when backing. D) It depends on other factors and may vary.

Answer 71

B) Trimming by the stern decreases torque when backing.

Question 72

What happens to transverse thrust and the position of the pivot point when a ship is making headway with engines astern? A) Transverse thrust decreases, and the pivot point moves forward. B) Transverse thrust increases, and the pivot point moves forward. C) Transverse thrust decreases, and the pivot point moves aft. D) Transverse thrust increases, and the pivot point moves aft.

Answer 72

D) Transverse thrust increases, and the pivot point moves aft.

Question 73

When is transverse thrust at its maximum during ship operations, and how does it change as the ship transitions from making headway to making sternway? A) Transverse thrust is maximum when the ship is making headway, and it decreases as the ship begins to make sternway. B) Transverse thrust is maximum when the ship is making sternway, and it decreases as the ship begins to make headway. C) Transverse thrust is maximum when the ship is making very slow headway, and it decreases as the ship begins to make sternway and the pivot point moves near the stern. D) Transverse thrust is maximum when the ship is making very slow headway, and it decreases as the ship begins to make sternway and the pivot point moves near the bow.

Answer 73

C) Transverse thrust is maximum when the ship is making very slow headway, and it decreases as the ship begins to make sternway and the pivot point moves near the stern.

Question 74

What percentage of the ahead power typically contributes to transverse thrust from kicks ahead? A) 25% B) 35% C) 45% D) 55%

Answer 74

C) 45%

Question 75

What percentage of the astern power typically contributes to transverse thrust from kicks astern, both initially and after sternway is gathered? A) 5% initially, 10% after sternway is gathered B) 10% initially, 5% after sternway is gathered C) 10% initially, 15% after sternway is gathered D) 15% initially, 10% after sternway is gathered

Answer 75

B) 10% initially, 5% after sternway is gathered

Question 76

What percentage of the astern power typically contributes to transverse thrust from continuous operation astern? A) 5% B) 10% C) 15% D) 20%

Answer 76

C) 15%

Question 77

Why is transverse thrust not effective at high speed? A) Because propeller wash does not reach the hull. B) Because the propeller is not rotating fast enough. C) Because the ship is too heavy. D) Because the rudder is not fully engaged.

Answer 77

A) Because propeller wash does not reach the hull.

Question 78

At what speed is transverse thrust typically not effective for turning? A) Over two knots B) Over three knots C) Over four knots D) Over five knots

Answer 78

C) Over four knots

Question 79

What are the consequences of using transverse thrust at speed for turning? A) An increase in the rate of turn and a narrower turning circle. B) A decrease in the rate of turn and a wider turning circle. C) No effect on the rate of turn but a narrower turning circle. D) No effect on the rate of turn but a wider turning circle.

Answer 79

B) A decrease in the rate of turn and a wider turning circle.

Question 80

How should a narrow-beamed ship with propellers close together be operated due to low torque? A) As a single-screw ship B) As a twin-screw ship C) As an outboard-driven ship D) As a trimaran

Answer 80

A) As a single-screw ship

Question 81

Under what condition might a ship with two propellers and one rudder steer better? A) With engines at full power B) With engines stopped C) With one engine running D) With both engines running at half power

Answer 81

B) With engines stopped

Question 82

How should a ship with inboard turning fixed pitch propellers be operated due to transverse torque opposing thrust when one engine is ahead and one is astern? A) As a twin-screw ship B) As a single-screw ship C) As an outboard-driven ship D) As a trimaran

Answer 82

B) As a single-screw ship

Question 83

What is the eccentricity effect related to propellers? A) It is the increase in propeller efficiency at high speeds. B) It is the vibration caused by propeller imbalance. C) It is the torque created by a propeller being off centerline. D) It is the reduction in propeller noise in shallow waters.

Answer 83

C) It is the torque created by a propeller being off centerline.

Question 84

Why are twin fixed-pitch propellers commonly set to outboard turning configuration? A) To reduce propeller efficiency B) To increase wake turbulence C) To decrease twisting ability D) To achieve a smaller, broader wake and increased twisting ability

Answer 84

D) To achieve a smaller, broader wake and increased twisting ability

Question 85

Why are inward turning variable pitch propellers (VPP) considered best for maneuvering? A) Because they reduce the deadwood effect B) Because they increase wake turbulence C) Because they increase twisting ability D) Because the deadwood effect is increased when water is directed inboard against the hull

Answer 85

D) Because the deadwood effect is increased when water is directed inboard against the hull

Question 86

What are the combined effects in a twin-screw configuration with fixed-pitch propellers, outboard turning, and twist? A) Torque effects and eccentricity effects add, deadwood effect cancels out B) Torque effects and eccentricity effects cancel out, deadwood effect adds C) Torque effects and eccentricity effects add, deadwood effect adds D) Torque effects and eccentricity effects cancel out, deadwood effect cancels out

Answer 86

C) Torque effects and eccentricity effects add, deadwood effect adds

Question 87

What happens in a twin-screw configuration with fixed-pitch propellers, inboard turning, and twist? A) Torque effect of both shafts opposes and diminishes eccentricity effect, deadwood effect is increased. B) Torque effect of both shafts opposes and diminishes eccentricity effect, deadwood effect is decreased. C) Torque effect of both shafts adds and increases eccentricity effect, deadwood effect is increased. D) Torque effect of both shafts adds and increases eccentricity effect, deadwood effect is decreased.

Answer 87

B) Torque effect of both shafts opposes and diminishes eccentricity effect, deadwood effect is decreased.

Question 88

What occurs in a twin-screw setup with variable pitch propellers (VPP), outboard turning, and twist? A) Torque effects cancel each other out, and only the eccentricity effect contributes to twist, deadwood effect is increased because the current is directed outboard. B) Torque effects cancel each other out, and only the eccentricity effect contributes to twist, deadwood effect is decreased because the current is directed outboard. C) Torque effects add together, and only the eccentricity effect contributes to twist, deadwood effect is increased because the current is directed outboard. D) Torque effects add together, and only the eccentricity effect contributes to twist, deadwood effect is decreased because the current is directed outboard.

Answer 88

B) Torque effects cancel each other out, and only the eccentricity effect contributes to twist, deadwood effect is decreased because the current is directed outboard.

Question 89

What happens in a twin-screw setup with variable pitch propellers (VPP), inboard turning, and twist? A) Torque effects cancel each other out, and only the eccentricity effect contributes to twist, deadwood effect adds because wash is directed against the hull. B) Torque effects add together, and only the eccentricity effect contributes to twist, deadwood effect adds because wash is directed against the hull. C) Torque effects cancel each other out, and only the eccentricity effect contributes to twist, deadwood effect diminishes because wash is directed against the hull. D) Torque effects add together, and only the eccentricity effect contributes to twist, deadwood effect diminishes because wash is directed against the hull.

Answer 89

A) Torque effects cancel each other out, and only the eccentricity effect contributes to twist, deadwood effect adds because wash is directed against the hull.

Question 90

In a twin-screw setup with fixed inboard propellers, how does the torque affect the eccentricity? A) Torque diminishes eccentricity. B) Torque increases eccentricity. C) Torque cancels out eccentricity. D) Torque has no effect on eccentricity.

Answer 90

A) Torque diminishes eccentricity.

Question 91

In a setup with variable outboard propellers, what occurs with the torque? A) Torque cancels torque. B) Torque increases torque. C) Torque diminishes torque. D) Torque has no effect on torque.

Answer 91

A) Torque cancels torque.

Question 92

What is the characteristic of the wake produced by a ship, in terms of wave directions? A) It produces waves only at 19° to the longitudinal axis. B) It produces waves only at 54° to the longitudinal axis. C) It produces two sets of waves, one at 19° and the other at 54° to the longitudinal axis. D) It produces waves at various angles to the longitudinal axis, depending on the ship's speed and hull design.

Answer 92

C) It produces two sets of waves, one at 19° and the other at 54° to the longitudinal axis.

Question 93

How does frictional resistance typically change over time if a ship's hull is not cleaned? A) It decreases by 15% each year. B) It increases by 15% each year. C) It remains constant over time. D) It varies depending on other factors.

Answer 93

B) It increases by 15% each year.

Question 94

How does an increase in hull roughness of 0.1mm typically affect hull resistance? A) It causes a 5% increase in hull resistance. B) It causes an 8% increase in hull resistance. C) It causes an 11% increase in hull resistance. D) It causes a 15% increase in hull resistance.

Answer 94

C) It causes an 11% increase in hull resistance.

Question 95

What effect do hull appendages typically have on hull resistance? A) They decrease hull resistance by reducing turbulence. B) They have no effect on hull resistance. C) They increase hull resistance by causing turbulence. D) They increase hull resistance by reducing friction.

Answer 95

C) They increase hull resistance by causing turbulence.

Question 96

How does hull resistance typically differ when using multiple propellers and transverse thrusters compared to a single shaft setup? A) It is 15-20% lower. B) It is 15-20% higher. C) It is twice as high. D) It is unaffected.

Answer 96

B) It is 15-20% higher.

Question 97

How does the ship's virtual mass vary with draft (∆)? A) It is 1.5 times the draft at 1.5 times the draft and 1.8 times the draft at 1.1 times the draft. B) It is 1.5 times the draft at 1.1 times the draft and 1.8 times the draft at 1.5 times the draft. C) It is 1.8 times the draft at 1.5 times the draft and 1.5 times the draft at 1.1 times the draft. D) It is 1.8 times the draft at 1.1 times the draft and 1.5 times the draft at 1.5 times the draft.

Answer 97

A) It is 1.5 times the draft at 1.5 times the draft and 1.8 times the draft at 1.1 times the draft.

Question 98

How does the stopping distance of a ship typically change due to the increased inertia from the mass of water following the ship? A) It decreases by 10%. B) It increases by 10%. C) It remains constant. D) It varies depending on other factors.

Answer 98

B) It increases by 10%.

Question 99

How does shallow water, where the ratio of ship draft (P) to water depth (d) is less than 4, typically affect hull resistance? A) It decreases hull resistance. B) It has no effect on hull resistance. C) It increases hull resistance. D) It varies depending on other factors.

Answer 99

C) It increases hull resistance.

Question 100

What typically occurs around the rudders when variable pitch propellers (VPP) are in operation with the engines stopped? A) There is no turbulence. B) There is increased stability. C) There is increased propulsion. D) There is turbulence.

Answer 100

D) There is turbulence.

Question 101

What is the recommended approach for quickly stopping a ship from full speed? A) Using slow astern bell to backload propellers. B) Using full ahead bell to engage propellers. C) Using slow ahead bell to reduce propeller thrust. D) Using full astern bell to reverse propellers.

Answer 101

A) Using slow astern bell to backload propellers.

Question 102

What risk is associated with setting the pitch to zero, even at moderate speeds? A) Reduced fuel consumption B) Increased stability C) Loss of steering control D) Improved maneuverability

Answer 102

C) Loss of steering control

Question 103

What is typically true about the efficiency of blade shape when the ship is moving astern? A) It is as efficient as when moving ahead. B) It is about 40-45% as efficient as maximum astern thrust. C) It is more efficient than when moving ahead. D) It is less efficient than when moving ahead.

Answer 103

B) It is about 40-45% as efficient as maximum astern thrust.

Question 104

How does the efficiency of a variable pitch propeller (VPP) typically compare to that of a fixed-pitch propeller (FPP) with the same pitch and diameter? A) VPP is 50-60% more efficient than FPP. B) VPP is equally as efficient as FPP. C) VPP is 50-60% less efficient than FPP. D) VPP is 50-60% less efficient than FPP in terms of power consumption.

Answer 104

A) VPP is 50-60% more efficient than FPP.

Question 105

For what draft value is the turning circle diagram typically designed? A) Draft of the ship B) Twice the draft of the ship C) 1.2 times the draft of the ship D) 1.5 times the draft of the ship

Answer 105

C) 1.2 times the draft of the ship

Question 105

How is shallow water typically defined in terms of the water depth compared to the draft of the ship? A) Less than the draft of the ship. B) Less than twice the draft of the ship. C) Less than 1.2 times the draft of the ship. D) Less than 2 times the draft of the ship.

Answer 105

D) Less than 2 times the draft of the ship.

Question 106

How does shallow water typically affect the width of the turning circle of a ship? A) It narrows the turning circle. B) It has no effect on the turning circle. C) It widens the turning circle. D) It depends on the shape of the hull.

Answer 106

C) It widens the turning circle.

Question 107

How does stopping distance typically change in shallow water compared to deeper water? A) It remains the same. B) It decreases by 10-20%. C) It increases by 10-20%. D) It increases by more than 20%.

Answer 107

C) It increases by 10-20%.

Question 108

How does the turning circle typically change in shallow water compared to deeper water? A) It remains the same. B) It decreases by 150%. C) It increases by 150%. D) It varies depending on other factors.

Answer 108

C) It increases by 150%.

Question 109

How does shallow water typically affect a ship's directional stability? A) It decreases directional stability. B) It has no effect on directional stability. C) It increases directional stability. D) It varies depending on other factors.

Answer 109

C) It increases directional stability. | When a ship enters shallow water, the hydrodynamic forces acting on its

Question 110

How does squat typically change when a ship is turning in shallow water? A) Squat decreases. B) Squat remains constant. C) Squat increases. D) Squat disappears completely.

Answer 110

C) Squat increases.

Question 111

How does the pivot point typically change in shallow water, affecting steering control, especially for a ship with positive trim? A) The pivot point moves forward, enhancing steering control. B) The pivot point remains stationary, maintaining steering control. C) The pivot point moves aft, reducing steering control. D) The pivot point disappears, resulting in no steering control.

Answer 111

Correct Answer: C) The pivot point moves aft, reducing steering control.

Question 112

Which approach typically yields better control: a heavy rudder and strong kicks ahead, or slowing down? A) Heavy rudder and strong kicks ahead B) Slowing down C) They yield similar levels of control D) It depends on other factors

Answer 112

A) Heavy rudder and strong kicks ahead

Question 113

How does shallow water typically affect a ship's ability to carry its momentum (way)? A) It reduces the time the ship carries her way. B) It increases the time the ship carries her way. C) It has no effect on the time the ship carries her way. D) It depends on other factors.

Answer 113

B) It increases the time the ship carries her way.

Question 114

How does the squat typically manifest in a ship, either by the bow or stern, depending on its hull form? A) Squat is always by the bow. B) Squat is always by the stern. C) Squat can occur by either the bow or stern, depending on the hull form. D) Squat is negligible and does not affect the ship's performance.

Answer 114

C) Squat can occur by either the bow or stern, depending on the hull form.

Question 115

How does the coefficient of block (Cb) typically relate to the squat phenomenon? A) Cb > 0.7 results in squat by the stern, and Cb < 0.7 results in squat by the bow. B) Cb > 0.7 results in squat by the bow, and Cb < 0.7 results in squat by the stern. C) Cb > 0.7 results in no squat, and Cb < 0.7 results in no squat. D) Cb > 0.7 results in squat by the bow, and Cb < 0.7 results in squat by the stern.

Answer 115

B) Cb > 0.7 results in squat by the bow, and Cb < 0.7 results in squat by the stern.

Question 116

How does speed loss typically compare when changing heading in shallow water compared to deep water? A) Speed loss is more significant in shallow water. B) Speed loss is less significant in shallow water. C) Speed loss is the same regardless of water depth. D) Speed loss is negligible in both shallow and deep water.

Answer 116

B) Speed loss is less significant in shallow water.

Question 117

What typically happens to a ship's heading when operating in reverse (astern)? A) The head falls off faster. B) The head falls off slower. C) The stern falls off faster. D) The stern falls off slower.

Answer 117

A) The head falls off faster.

Question 118

How does shallow water typically affect drift when a ship is turning? A) It increases drift. B) It decreases drift. C) It has no effect on drift. D) It depends on other factors.

Answer 118

B) It decreases drift.

Question 119

How does the reduced drift angle in shallow water typically affect the turn radius of a ship? A) It decreases the turn radius. B) It increases the turn radius. C) It has no effect on the turn radius. D) It depends on other factors.

Answer 119

B) It increases the turn radius.

Question 120

How does shallow water typically affect the turn of a ship in terms of forward movement? A) It results in a shorter turn with decreased distance in forward movement. B) It results in a longer turn with increased distance in forward movement. C) It has no effect on the turn in terms of forward movement. D) It depends on other factors.

Answer 120

B) It results in a longer turn with increased distance in forward movement.

Question 121

How does shallow water typically affect the final turning speed of a ship? A) It significantly increases the final turning speed. B) It significantly decreases the final turning speed. C) It slightly modifies the final turning speed. D) It has no effect on the final turning speed.

Answer 121

C) It slightly modifies the final turning speed.

Question 122

How does shallow water typically affect the ability to steer a ship accurately? A) It improves accuracy in steering. B) It has no effect on accuracy in steering. C) It slightly decreases accuracy in steering. D) It significantly decreases accuracy in steering.

Answer 122

D) It significantly decreases accuracy in steering.

Question 123

How does hull resistance typically change when the water depth is 4 times the ship's draft? A) Hull resistance decreases. B) Hull resistance remains constant. C) Hull resistance increases. D) Hull resistance varies depending on other factors.

Answer 123

C) Hull resistance increases.

Question 124

What is the recommended practice when navigating a ship in a channel with current flowing ahead? A) Stay outside the channel. B) Stay inside the channel. C) Speed up to counteract the current. D) Slow down to avoid the current.

Answer 124

B) Stay inside the channel.

Question 125

What is the recommended practice when navigating a ship in a channel with current flowing astern? A) Stay inside the channel. B) Stay outside the channel. C) Increase speed to counteract the current. D) Decrease speed to avoid the current.

Answer 125

B) Stay outside the channel.

Question 126

When are channel effects typically encountered in terms of the width of the channel compared to the ship's beam? A) When the width is less than the ship's beam. B) When the width is about the same as the ship's beam. C) When the width is 8-10 times the ship's beam. D) When the width is greater than 10 times the ship's beam.

Answer 126

C) When the width is 8-10 times the ship's beam.

Question 127

What is the typical effect of channel effects on the rate of turn of a ship? A) It increases the rate of turn. B) It has no effect on the rate of turn. C) It reduces the rate of turn. D) It varies depending on other factors.

Answer 127

C) It reduces the rate of turn.

Question 128

How do channel effects typically affect the directional stability of a ship? A) They increase directional stability. B) They have no effect on directional stability. C) They reduce directional stability. D) They cause erratic changes in directional stability.

Answer 128

C) They reduce directional stability.

Question 129

What is a typical result of channel effects on a ship? A) Increased stability B) Reduced vibration C) Enhanced maneuverability D) Vibration due to water disturbance

Answer 129

D) Vibration due to water disturbance

Question 130

How do channel effects typically affect the stopping distance of a ship? A) They decrease the stopping distance. B) They have no effect on the stopping distance. C) They increase the stopping distance. D) They cause the ship to stop suddenly.

Answer 130

C) They increase the stopping distance.

Question 131

What is a common outcome of channel effects on a ship's hull? A) Reduced hull resistance B) Increased hull resistance C) Improved hull stability D) Decreased hull vibration

Answer 131

B) Increased hull resistance

Question 132

What are examples of channel effects experienced by a ship? A) Increased stability and maneuverability B) Decreased hull resistance C) Bank suction and cushion D) Reduced stopping distance

Answer 132

C) Bank suction and cushion

Question 133

What is a recommended practice for navigating near channel banks? A) Keep close to the channel bank. B) Maintain a distance of at least one ship length from the channel bank. C) Remain at least one ship beam-width off the channel bank. D) Navigate directly against the channel bank.

Answer 133

B) Maintain a distance of at least one ship length from the channel bank.

Question 134

What does the term "bed effect" refer to in ship navigation? A) The tendency of a ship to steer towards the shallowest part of the channel. B) The tendency of a ship to seek the deepest part of the channel. C) The impact of the ship's hull on the riverbed. D) The effect of channel depth on ship stability.

Answer 134

B) The tendency of a ship to seek the deepest part of the channel.

Question 135

How does the ship's stability typically change when the Under Keel Clearance (UKC) is less than 1.5 times the ship's draft (1.5d)? A) The ship becomes much more stable. B) The ship becomes slightly less stable. C) The ship's stability remains constant. D) The ship becomes unstable.

Answer 135

A) The ship becomes much more stable.

Question 136

When evaluating Under Keel Clearance (UKC), which factor is typically considered the most critical? A) Wind direction B) Tide direction C) Speed through the water D) Water depth

Answer 136

C) Speed through the water

Question 137

On wide-beamed ships with a low Metacentric Height (GM), which factor may have a more significant impact on reducing Under Keel Clearance (UKC)? A) Squat B) Heeling C) Pitching D) Rolling

Answer 137

D) Rolling

Question 138

What is the rule of thumb for the speed limit when the Under Keel Clearance (UKC) is 5 feet? A) 10 knots B) 8 knots C) 6 knots D) 4 knots

Answer 138

C) 6 knots

Question 139

How does the Metacentric Height (GMt) typically affect the rolling of a ship during a turn? A) A higher GMt (>3) results in more rolling. B) A higher GMt (>3) results in less rolling. C) GMt has no effect on rolling during a turn. D) GMt can vary depending on other factors.

Answer 139

B) A higher GMt (>3) results in less rolling.

Question 140

How does the Metacentric Height (GMt) typically affect the rolling of a ship during a turn? A) A lower GMt (<2) results in more rolling. B) A lower GMt (<2) results in less rolling. C) GMt has no effect on rolling during a turn. D) GMt can vary depending on other factors.

Answer 140

A) A lower GMt (<2) results in more rolling.

Question 141

How does the location of the pivot point typically affect the directional stability of a ship? A) Directional stability is greater when the pivot point is close to the bow. B) Directional stability is less when the pivot point is close to the bow. C) Directional stability is the same regardless of the pivot point location. D) The pivot point does not affect directional stability.

Answer 141

B) Directional stability is less when the pivot point is close to the bow.

Question 142

How does shallow water typically affect the directional stability of a ship? A) Directional stability decreases in shallow water. B) Directional stability increases in shallow water. C) Directional stability remains the same in shallow water. D) Directional stability is unpredictable in shallow water.

Answer 142

B) Directional stability increases in shallow water.

Question 143

How does the directional stability of a ship typically relate to its turning circle? A) A ship with less directional stability will have a smaller turning circle. B) A ship with less directional stability will have a larger turning circle. C) Directional stability does not affect the turning circle of a ship. D) It depends on other factors.

Answer 143

A) A ship with less directional stability will have a smaller turning circle.

Question 144

How does the length of a ship typically affect its directional stability? A) Directional stability increases as length increases. B) Directional stability decreases as length increases. C) Directional stability remains the same regardless of ship length. D) It depends on other factors.

Answer 144

A) Directional stability increases as length increases.

Question 145

How does the length to beam ratio typically affect the directional stability of a ship? A) Directional stability decreases with higher length to beam ratio. B) Directional stability increases with higher length to beam ratio. C) Directional stability remains the same regardless of the length to beam ratio. D) Directional stability is not influenced by the length to beam ratio.

Answer 145

B) Directional stability increases with higher length to beam ratio.

Question 146

How does increasing trim aft typically affect the directional stability of a ship? A) Directional stability increases. B) Directional stability decreases. C) Directional stability remains constant. D) Directional stability becomes unpredictable.

Answer 146

A) Directional stability increases.

Question 147

How does an increase in block coefficient typically affect the directional stability of a ship? A) Directional stability increases. B) Directional stability decreases. C) Directional stability remains constant. D) Directional stability becomes unpredictable.

Answer 147

B) Directional stability decreases.

Question 148

How does the shift of the pivot point ahead typically affect the directional stability of a ship? A) Directional stability increases. B) Directional stability decreases. C) Directional stability remains constant. D) Directional stability becomes unpredictable.

Answer 148

B) Directional stability decreases.

Question 149

How does a bulbous bow typically affect the directional stability and turning capacity of a ship? A) Increases directional stability and turning capacity B) Decreases directional stability and turning capacity C) Increases directional stability but decreases turning capacity D) Decreases directional stability but increases turning capacity

Answer 149

D) Decreases directional stability but increases turning capacity

Question 150

How does the directional stability of a ship typically relate to its turning circle? A) The turning circle is smaller for a ship with less directional stability. B) The turning circle is larger for a ship with less directional stability. C) The turning circle is the same regardless of the ship's directional stability. D) It depends on other factors.

Answer 150

A) The turning circle is smaller for a ship with less directional stability.

Question 151

How does the width of a ship relative to its length typically affect its turning circle? A) The turning circle is smaller for a ship with a wide beam relative to its length. B) The turning circle is larger for a ship with a wide beam relative to its length. C) The turning circle is the same regardless of the ship's beam-to-length ratio. D) It depends on other factors.

Answer 151

A) The turning circle is smaller for a ship with a wide beam relative to its length.

Question 152

How does the length of a ship typically affect its turning circle? A) The turning circle is smaller for a longer ship. B) The turning circle is larger for a longer ship. C) The turning circle is the same regardless of the ship's length. D) It depends on other factors.

Answer 152

B) The turning circle is larger for a longer ship.

Question 153

How much does the speed typically decrease during a turn of 90º compared to 180º? A) Speed decreases by approximately 30% for 90º and 45% for 180º. B) Speed decreases by approximately 45% for 90º and 60% for 180º. C) Speed decreases by approximately 60% for 90º and 75% for 180º. D) Speed decreases by approximately 75% for 90º and 90% for 180º.

Answer 153

B) Speed decreases by approximately 45% for 90º and 60% for 180º.

Question 154

How does shallow water typically affect the turning circle of a ship? A) The turning circle decreases in shallow water. B) The turning circle remains the same in shallow water. C) The turning circle increases by approximately 50% in shallow water. D) The turning circle increases by approximately 150% in shallow water.

Answer 154

D) The turning circle increases by approximately 150% in shallow water.

Question 155

How does turning in shallow water typically affect squat? A) Squat decreases when turning in shallow water. B) Squat remains the same when turning in shallow water. C) Squat increases when turning in shallow water. D) Squat disappears when turning in shallow water.

Answer 155

C) Squat increases when turning in shallow water.

Question 156

How does increasing trim by the stern typically affect the turning circle of a ship? A) The turning circle decreases as trim by the stern increases. B) The turning circle remains the same regardless of trim by the stern. C) The turning circle increases as trim by the stern increases. D) The turning circle becomes unpredictable with trim by the stern.

Answer 156

C) The turning circle increases as trim by the stern increases.

Question 157

For ships with a length-to-beam ratio between 5 and 9, what is the typical range for the turning circle compared to the Length Between Perpendiculars (LBP)? A) 1-2x LBP B) 2-3x LBP C) 3-4x LBP D) 4-5x LBP

Answer 157

C) 3-4x LBP

Question 158

What is typically true about the turning circle of a ship in loaded condition compared to the ballast condition in deep water? A) The turning circle is smaller in loaded condition than in ballast condition. B) The turning circle is larger in loaded condition than in ballast condition. C) The turning circle is the same in both loaded and ballast conditions. D) The turning circle cannot be accurately determined in these conditions.

Answer 158

C) The turning circle is the same in both loaded and ballast conditions.

Question 159

How does the turning circle in a loaded condition typically compare to the turning circle in ballast condition in shallow water? A) The turning circle is smaller in loaded condition due to higher momentum. B) The turning circle is larger in loaded condition due to higher momentum. C) The turning circle remains the same regardless of the condition or water depth. D) The turning circle becomes unpredictable in these conditions.

Answer 159

B) The turning circle is larger in loaded condition due to higher momentum.

Question 160

Why does the turning circle typically increase in shallow water? A) Due to reduced lateral resistance and larger drift angle. B) Due to reduced lateral resistance and smaller drift angle. C) Due to increased lateral resistance and larger drift angle. D) Due to increased lateral resistance and smaller drift angle.

Answer 160

B) Due to reduced lateral resistance and smaller drift angle.

Question 161

Why does turning away from wind, sea, or swell typically result in a larger turning circle? A) Due to decreased resistance against lever abaft pivot point. B) Due to increased resistance against lever abaft pivot point. C) Due to decreased resistance against lever forward of pivot point. D) Due to increased resistance against lever forward of pivot point.

Answer 161

A) Due to decreased resistance against lever abaft pivot point.

Question 162

How does lowering the Metacentric Height (GM) for a given ship typically affect the diameter of its turning circle? A) The turning circle diameter increases. B) The turning circle diameter decreases. C) The turning circle diameter remains the same. D) The effect on turning circle diameter depends on other factors.

Answer 162

B) The turning circle diameter decreases

Question 163

How does the turning circle typically vary with different rudder angles? A) The turning circle is 33% wider for a 20º rudder and 100% wider for a 10º rudder compared to a 35º rudder. B) The turning circle is 33% narrower for a 20º rudder and 100% narrower for a 10º rudder compared to a 35º rudder. C) The turning circle is the same for all rudder angles. D) The turning circle is unpredictable with different rudder angles.

Answer 163

A) The turning circle is 33% wider for a 20º rudder and 100% wider for a 10º

Question 164

What factors typically influence the size of the drift angle during a turn? A) The size of the drift angle depends on the momentum of the after part of the ship and the lateral resistance of the hull. B) The size of the drift angle depends on the shape of the rudder and the speed of the ship. C) The size of the drift angle depends on the wind and sea conditions. D) The size of the drift angle depends solely on the ship's speed.

Answer 164

A) The size of the drift angle depends on the momentum of the after part of the ship and the lateral resistance of the hul

Question 165

How does the hull shape typically influence the size of the drift angle during a turn? A) Full-bodied ships have larger drift angles. B) Full-bodied ships have smaller drift angles. C) Hull shape does not affect the size of the drift angle. D) The drift angle is unpredictable based on hull shape.

Answer 165

A) Full-bodied ships have larger drift angles.

Question 166

How does the rudder angle typically affect the size of the drift angle during a turn? A) The drift angle is normally 5º for a 10º rudder and 10º for a 35º rudder. B) The drift angle is normally 10º for a 10º rudder and 5º for a 35º rudder. C) The drift angle is normally 10º for both a 10º and a 35º rudder. D) The drift angle is normally 5º for both a 10º and a 35º rudder.

Answer 166

A) The drift angle is normally 5º for a 10º rudder and 10º for a 35º rudder.

Question 167

How does the water depth typically affect the drift angle of a ship with a given hull form? A) The drift angle increases in shallow water. B) The drift angle decreases in shallow water. C) The drift angle remains the same regardless of water depth. D) The drift angle becomes unpredictable in shallow water.

Answer 167

B) The drift angle decreases in shallow water.

Question 168

How does the speed typically affect squat? A) Squat increases linearly with speed. B) Squat decreases linearly with speed. C) Squat increases with the square of the speed. D) Squat decreases with the square of the speed.

Answer 168

C) Squat increases with the square of the speed.

Question 169

Which formula is commonly used to calculate squat in meters? A) Squat = Cb * V / 100 B) Squat = Cb * V^2 / 100 C) Squat = Cb * V^3 / 100 D) Squat = Cb * V^4 / 100

Answer 169

B) Squat = Cb * V^2 / 100

Question 170

Which formula is commonly used to calculate squat in feet? A) Squat = Cb * V / 30 B) Squat = Cb * V^2 / 30 C) Squat = Cb * V^3 / 30 D) Squat = Cb * V^4 / 30

Answer 170

B) Squat = Cb * V^2 / 30

Question 171

How does the speed typically affect squat for a given block coefficient? A) Squat decreases as speed increases. B) Squat remains constant regardless of speed. C) Squat increases as speed increases. D) Squat decreases as speed decreases.

Answer 171

C) Squat increases as speed increases.

Question 172

How does the trim of a vessel typically affect the significance of squat? A) Squat is more significant for vessels trimmed by the stern. B) Squat is more significant for vessels trimmed by the bow. C) Squat is equally significant for vessels regardless of trim. D) Squat is not influenced by the vessel's trim.

Answer 172

B) Squat is more significant for vessels trimmed by the bow.

Question 173

How does the block coefficient typically influence the rate at which squat increases? A) Squat increases at a greater rate for lower block coefficients. B) Squat increases at a greater rate for higher block coefficients. C) Squat increases at the same rate regardless of block coefficient. D) Squat decreases at a greater rate for higher block coefficients.

Answer 173

B) Squat increases at a greater rate for higher block coefficients.

Question 174

What is typically true about the block coefficients of tankers and bulk carriers? A) Tankers and bulk carriers have block coefficients greater than 0.8. B) Tankers and bulk carriers have block coefficients less than 0.8. C) Tankers and bulk carriers have block coefficients equal to 0.8. D) Tankers and bulk carriers have block coefficients that vary widely.

Answer 174

A) Tankers and bulk carriers have block coefficients greater than 0.8.

Question 175

What is typically true about the block coefficients of container ships? A) Container ships have block coefficients greater than 0.65. B) Container ships have block coefficients less than 0.65. C) Container ships have block coefficients equal to 0.65. D) Container ships have block coefficients that vary widely.

Answer 175

B) Container ships have block coefficients less than 0.65.

Question 176

How does sudden changes in speed typically affect squat for high-powered ships? A) Squat remains unchanged during sudden changes in speed. B) Squat increases slightly during sudden changes in speed. C) Squat decreases slightly during sudden changes in speed. D) Squat can double when a high-powered ship increases or decreases speed suddenly.

Answer 176

D) Squat can double when a high-powered ship increases or decreases speed suddenly.

Question 177

How does the passing or overtaking of ships typically affect squat? A) Squat remains constant when ships pass or overtake. B) Squat decreases when ships pass or overtake. C) Squat increases when ships pass or overtake. D) Squat is not influenced by passing or overtaking ships.

Answer 177

C) Squat increases when ships pass or overtake.

Question 178

How does squat typically relate to thrust and torque? A) Squat decreases as thrust and torque increase. B) Squat and thrust/torque are independent of each other. C) Squat and thrust/torque increase in proportion to each other. D) Squat and thrust/torque decrease in proportion to each other.

Answer 178

C) Squat and thrust/torque increase in proportion to each othe

Question 179

Under what conditions is squat typically significant? A) Squat is significant at P/d < 1.5; squat is negligible for P/d > 5. B) Squat is significant at P/d > 1.5; squat is negligible for P/d < 5. C) Squat is significant at P/d < 5; squat is negligible for P/d > 1.5. D) Squat is significant at P/d > 5; squat is negligible for P/d < 1.5.

Answer 179

A) Squat is significant at P/d < 1.5; squat is negligible for P/d > 5.

Question 180

How does the block coefficient (Cb) typically affect the sign of squat? A) Squat is positive for Cb > 0.7; squat is negative for Cb < 0.7. B) Squat is positive for Cb < 0.7; squat is negative for Cb > 0.7. C) Squat is positive regardless of the value of Cb. D) Squat is negative regardless of the value of Cb.

Answer 180

A) Squat is positive for Cb > 0.7; squat is negative for Cb < 0.7.

Question 181

How does the squat typically relate to a vessel moored in a river? A) Squat is based on speed through water, so the vessel moored in a river will experience squat. B) Squat is not influenced by the vessel's mooring status. C) Squat is significantly reduced when a vessel is moored in a river. D) Squat increases when a vessel is moored in a river.

Answer 181

A) Squat is based on speed through water, so the vessel moored in a river will experience squat.

Question 182

Under what wind conditions does a ship typically lose steerageway? A) When wind speed is equal to ship speed. B) When wind speed is less than ship speed. C) When wind speed is 2-3 times ship speed, or even higher (5 times) for deeply-loaded tankers. D) When wind speed is greater than ship speed.

Answer 182

C) When wind speed is 2-3 times ship speed, or even higher (5 times) for deeply-loaded tankers.

Question 183

How does aerodynamic resistance typically compare to the resistance to forward movement in the absence of wind? A) Aerodynamic resistance is equal to the resistance to forward movement. B) Aerodynamic resistance is greater than the resistance to forward movement. C) Aerodynamic resistance is only 3% of the resistance to forward movement. D) Aerodynamic resistance is negligible compared to the resistance to forward movement.

Answer 183

C) Aerodynamic resistance is only 3% of the resistance to forward movement.

Question 184

Which formula represents the calculation for wind force on sail area, where \( s \) is the sail area in m² and \( V \) is the speed in knots? A) Wind force = (s * V) / 50 B) Wind force = (s * V²) / 50 C) Wind force = (s * V) / 100 D) Wind force = (s * V²) / 100

Answer 184

B) Wind force = (s * V²) / 50

Question 185

What is the formula used to calculate wind force on sail area, where \( s \) represents the sail area in square meters and \( v \) is the speed in meters per second? A) Wind force = (s * V) / 18 B) Wind force = (s * V²) / 18 C) Wind force = (s * V) / 50 D) Wind force = (s * V²) / 50

Answer 185

B) Wind force = (s * V²) / 18

Question 186

Under what conditions is the wind force equivalent to beam wind? A) Wind force when the wind is within 30° of the bow. B) Wind force when the wind is within 30° of the stern. C) Wind force when the wind is within 30° of the beam. D) Wind force when the wind is directly astern.

Answer 186

C) Wind force when the wind is within 30° of the beam.

Question 187

What behavior can typically be expected from a loaded tanker in relation to the wind? A) A loaded tanker will always fall off from the wind. B) A loaded tanker will always head directly into the wind. C) A loaded tanker will always luff up into the wind. D) A loaded tanker will always heave to in high winds.

Answer 187

C) A loaded tanker will always luff up into the wind.

Question 188

What is the typical behavior of a tanker in ballast in relation to the wind? A) A tanker in ballast will always luff up into the wind. B) A tanker in ballast will always fall off from the wind. C) A tanker in ballast will fall off wind until the apparent wind is 1 point forward of the beam, then luffs up. D) A tanker in ballast will heave to in high winds.

Answer 188

C) A tanker in ballast will fall off wind until the apparent wind is 1 point forward of the beam, then luffs up.

Question 189

What is the likely outcome for a container ship with deck cargo when experiencing beam wind? A) The container ship will lose headway. B) The container ship will maintain its current speed. C) The container ship will gain slight headway. D) The container ship will heave to in high winds.

Answer 189

C) The container ship will gain slight headway.

Question 190

What is the expected outcome for a container ship without deck cargo when experiencing beam wind? A) The container ship will lose headway. B) The container ship will maintain its current speed. C) The container ship will develop slight headway. D) The container ship will develop slight sternway.

Answer 190

D) The container ship will develop slight sternway.

Question 191

What typically happens to ferries and liners when the wind is between 30 and 60 degrees from the stem? A) They will lose headway. B) They will maintain their current speed. C) They will develop slight headway. D) They will develop slight sternway.

Answer 191

C) They will develop slight headway.

Question 192

What condition results in maximum drift for ferries and liners? A) Winds directly on the bow. B) Winds directly on the stern. C) Winds broad on the bow and stern. D) Winds broad on the beam.

Answer 192

C) Winds broad on the bow and stern.

Question 193

At which wind angles do yaw forces tend to be maximized for all ships? A) 0° and 180° B) 45° and 135° C) 90° and 270° D) 60° and 120°

Answer 193

B) 45° and 135°

Question 194

What is the formula used to calculate the force exerted by the current on a ship, where \( F \) represents the force, \( V \) is the current velocity, \( LBP \) is the length between perpendiculars, and \( D \) is the ship's displacement? A) \( F = c \times V \times LBP \times D \), where \( c \) varies based on the ship's displacement. B) \( F = c \times V^2 \times LBP \times D \), where \( c \) varies based on the ship's displacement. C) \( F = c \times V^2 \times D \), where \( c \) varies based on the ship's length. D) \( F = c \times V \times D \), where \( c \) varies based on the ship's length between perpendiculars.

Answer 194

B) \( F = c \times V^2 \times LBP \times D \), where \( c \) varies based on the ship's displacement.

Question 195

When does the current have a significantly greater effect on an anchored ship? A) When the depth is more than 3 times the draft. B) When the depth is equal to the draft. C) When the depth is less than 3 times the draft. D) When the depth is less than the ship's length.

Answer 195

C) When the depth is less than 3 times the draft.

Question 196

When are pitch and heave at their maximum? A) When pitch or heave is half the wave period. B) When pitch or heave is equal to the wave period. C) When pitch or heave is double the wave period. D) When pitch or heave is triple the wave period.

Answer 196

B) When pitch or heave is equal to the wave period.

Question 197

How does the behavior of a loaded ship differ from that of a light ship in terms of riding and running? A) A loaded ship rides better when hove to, while a light ship runs better before the wind. B) A loaded ship runs better when hove to, while a light ship rides better before the wind. C) Both loaded and light ships run better when hove to. D) Both loaded and light ships ride better before the wind.

Answer 197

A) A loaded ship rides better when hove to, while a light ship runs better before the wind.

Question 198

Why does frictional drag have less effect on larger ships? A) Larger ships have more streamlined hull shapes. B) Larger ships have more powerful engines to overcome drag. C) Larger ships have less surface area relative to their volume. D) Larger ships have deeper drafts, reducing the effect of frictional drag.

Answer 198

C) Larger ships have less surface area relative to their volume.

Question 199

What proportion of the propulsion force at constant speed is typically attributed to longitudinal resistance? A) About 10% B) About 25% C) About 50% D) About 75%

Answer 199

B) About 25%

Question 200

In which direction does a ship typically turn when one side emerges from the water, especially noticeable in twin screw ships? A) Towards the emerged side B) Away from the emerged side C) Towards the submerged side D) It remains straight

Answer 200

A) Towards the emerged side

Question 201

In which direction might ships with a very high block coefficient (Cb > 0.9) turn when one side is submerged? A) Towards the submerged side B) Away from the submerged side C) Towards the emerged side D) It remains straight

Answer 201

A) Towards the submerged side

Question 202

How many kilowatts of power are equivalent to 1 shaft horsepower (SHP)? A) 0.74 kW B) 1.35 kW C) 1.74 kW D) 2.35 kW

Answer 202

A) 0.74 kW

Question 203

How much bollard pull is generated per 100 shaft horsepower (SHP)? A) 0.08 tons B) 0.64 tons C) 0.80 tons D) 8.00 tons

Answer 203

C) 0.80 tons

Question 204

What effect might a bow thruster have on a ship's motion? A) It always induces reverse motion. B) It has no effect on the ship's motion. C) It may induce forward motion. D) It only affects lateral movement.

Answer 204

C) It may induce forward motion.

Question 205

What adjustment must be made to the stern when using a bow thruster to steer a ship under sternway? A) The stern must be aligned parallel to the intended track. B) The stern must be canted relative to the intended track. C) The stern must be trimmed higher than usual. D) The stern must be trimmed lower than usual.

Answer 205

B) The stern must be canted relative to the intended track.

Question 206

What is the recommended procedure for stopping a ship when using a bow thruster under sternway? A) Apply kicks ahead to stop the ship. B) Stop or slow engines to move the pivot point toward the stern and increase steering lever. C) Keep the engines at full speed to maintain control. D) Use reverse thrust to counteract the bow thruster.

Answer 206

B) Stop or slow engines to move the pivot point toward the stern and increase steering lever.

Question 207

How does the thrust of shallow draught thrusters compare to that of tunnel thrusters and azimuth thrusters? A) Shallow draught thrusters have the same thrust as tunnel and azimuth thrusters. B) Shallow draught thrusters have double the thrust of tunnel and azimuth thrusters. C) Thrust of shallow draught thrusters is halved compared to tunnel and azimuth thrusters. D) Thrust of shallow draught thrusters is tripled compared to tunnel and azimuth thrusters.

Answer 207

C) Thrust of shallow draught thrusters is halved compared to tunnel and azimuth thrusters.

Question 208

What advantage do Azipods offer over traditional propellers in terms of power and turning radius? A) Azipods have 10% less power and reduce turning radius by 20%. B) Azipods have 10% more power and increase turning radius by 20%. C) Azipods have 10% more power and reduce turning radius by 20%. D) Azipods have 10% less power and increase turning radius by 20%.

Answer 208

C) Azipods have 10% more power and reduce turning radius by 20%.

Question 209

How does a Contra-Rotating Propeller (CRP) affect thrust? A) Increases thrust by 20%. B) Decreases thrust by 20%. C) Has no effect on thrust. D) Increases thrust by 10%.

Answer 209

A) Increases thrust by 20%.

Question 210

What is a typical size relationship between a Contra-Rotating Propeller (CRP) and the main propeller? A) The CRP is typically 10% smaller than the main propeller. B) The CRP is typically 20% smaller than the main propeller. C) The CRP is typically 20% larger than the main propeller. D) The CRP is typically 10% larger than the main propeller.

Answer 210

B) The CRP is typically 20% smaller than the main propeller.

Question 211

How does the turning radius of a waterjet ship compare to that of a propeller-driven ship? A) The turning radius of a waterjet ship is 40% larger. B) The turning radius of a waterjet ship is 40% smaller. C) The turning radius of a waterjet ship is the same as a propeller-driven ship. D) The turning radius of a waterjet ship is 20% smaller.

Answer 211

B) The turning radius of a waterjet ship is 40% smaller.

Question 212

What is the typical ratio of astern power to ahead power for diesel engines? A) Astern power is 100% of ahead power. B) Astern power is 80% of ahead power. C) Astern power is 50% of ahead power. D) Astern power is 120% of ahead power.

Answer 212

B) Astern power is 80% of ahead power.

Question 213

What is the typical ratio of astern power to ahead power for steam turbine engines? A) Astern power is 60% of ahead power. B) Astern power is 100% of ahead power. C) Astern power is 80% of ahead power. D) Astern power is 50% of ahead power.

Answer 213

A) Astern power is 60% of ahead power.

Question 214

What is the typical ratio of astern power to ahead power for Variable Pitch Propellers (VPP)? A) Astern power is 50% of ahead power. B) Astern power is 100% of ahead power. C) Astern power is 80% of ahead power. D) Astern power is 60% of ahead power.

Answer 214

A) Astern power is 50% of ahead power.

Question 215

What is the typical ratio of astern pull to ahead pull for ASD (Azimuth Stern Drive) tugs? A) Astern pull is 100% of ahead pull. B) Astern pull is 90-95% of ahead pull. C) Astern pull is 80% of ahead pull. D) Astern pull is 50% of ahead pull.

Answer 215

B) Astern pull is 90-95% of ahead pull.

Question 216

When does the rudder typically begin to take effect when going astern? A) Immediately upon turning the wheel. B) When the ship starts moving forward. C) When sternway develops. D) When the ship reaches full speed.

Answer 216

C) When sternway develops.

Question 217

What is the efficiency of the rudder when operating astern with headway? A) 10% B) 15% C) 25% D) 30%

Answer 217

C) 25%

Question 218

How effective is a rudder positioned at 20 degrees when the ship is under sternway, and how does it affect propeller flow? A) It is as effective as a full rudder and impairs propeller flow. B) It is as effective as a full rudder and does not impair propeller flow. C) It is less effective than a full rudder and impairs propeller flow. D) It is less effective than a full rudder and does not impair propeller flow.

Answer 218

B) It is as effective as a full rudder and does not impair propeller flow.

Question 219

What should a vessel do before operating astern? A) Speed up to maximum speed. B) Slow to maneuvering speed. C) Maintain constant speed. D) Stop completely.

Answer 219

B) Slow to maneuvering speed.

Question 220

At what speed does quickwater stream astern? a) One knot b) Two knots c) Three knots d) Four knots

Answer 220

c) Three knots

Question 221

At what speed does the quickwater move at the same speed as the ship? a) One knot b) Two knots c) Three knots d) Four knots

Answer 221

b) Two knots

Question 222

When the ship is stopped, where does the quickwater move? a) Sternward b) Bowward c) Up to midships d) Along the keel

Answer 222

c) Up to midships

Question 223

Which of the following factors can reduce a ship's maneuverability? A) Turbulent flow around the rudder caused by stern seas B) Smooth flow around the rudder caused by calm seas C) Reduced propeller efficiency in calm waters D) Increased stability due to steady seas

Answer 223

A) Turbulent flow around the rudder caused by stern seas

Question 224

How can transverse thrust be utilized effectively? A) Reduce transverse thrust to minimize maneuvering effects B) Ignore transverse thrust as it has minimal impact on ship handling C) Use transverse thrust to advantage in maneuvering D) Avoid transverse thrust to prevent unwanted ship movements

Answer 224

C) Use transverse thrust to advantage in maneuvering

Question 225

What precaution should be taken before letting go of the anchor to ensure effective turning with the assistance of the tide? A) Avoid anchoring in areas with strong tidal currents B) Let go of the anchor without considering the tide C) Ensure the ship is canted correctly to utilize the tide's assistance D) Let go of the anchor and rely solely on propulsion for turning

Answer 225

C) Ensure the ship is canted correctly to utilize the tide's assistance

Question 226

How can a ship be maneuvered sideways using a bow thruster? A) Inboard engine ahead, outboard engine astern, rudder over toward astern engine, bow toward shore B) Inboard engine astern, outboard engine ahead, rudder over toward astern engine, bow toward shore C) Both engines ahead, rudder over toward the bow, bow toward shore D) Both engines astern, rudder over toward the stern, bow away from shore

Answer 226

A) Inboard engine ahead, outboard engine astern, rudder over toward astern engine, bow toward shore

Question 227

How can a ship be maneuvered sideways without a bow thruster? A) Outboard engine ahead, inboard engine astern, rudder toward ahead engine B) Outboard engine astern, inboard engine ahead, rudder toward astern engine C) Both engines ahead, rudder over toward the bow D) Both engines astern, rudder over toward the stern

Answer 227

A) Outboard engine ahead, inboard engine astern, rudder toward ahead engine

Question 228

When maneuvering a ship sideways, what is the initial step to take with the rudder? A) Keep the rudder amidships B) Turn the rudder in the direction you intend the bow to move C) Turn the rudder opposite the direction you intend the stern to move D) Keep the rudder turned in the direction of the intended movement

Answer 228

C) Turn the rudder opposite the direction you intend the stern to move

Question 229

When maneuvering astern with the engine on the same side as the rudder, what is likely to occur? A) Increased stability B) Reduced turning radius C) Increased twist D) Reduced squat

Answer 229

C) Increased twist

Question 230

When maneuvering astern with the engine on the opposite side of the rudder, what is likely to occur? A) Increased stability B) Reduced turning radius C) Increased twist D) Ship walking Note: An exception is when a barge is made up close astern, where the effects are opposite.

Answer 230

D) Ship walking

Question 231

When dropping anchor in adverse weather conditions, where should the anchor be released from? A) Stern B) Leeward bow C) Weather bow D) Midship

Answer 231

C) Weather bow

Question 232

Which of the following conversions is correct for the speed of 1 knot? A) 0.5 m/s B) 1.6 ft/s C) 1.9 km/h D) All of the above

Answer 232

D) All of the above

Question 233

Which of the following conversions is correct for the speed of 1 m/s? A) 3.3 ft/s B) 3.6 km/h C) 1.9 knots D) All of the above

Answer 233

D) All of the above