Hooyer Flashcards
Behaviour and Handling of Ships - Hooyer
The position of the __________ plays a crucial role in explaining ship behavior.
Pivot point
Behaviour and Handling of Ships - Hooyer
True / False
We can not move a ship sideways without rotational motion.
True
pg 8
Behaviour and Handling of Ships - Hooyer
The moment of a force about a point is the product of that force and ____________________.
The perpendicular on its line of action.
Behaviour and Handling of Ships - Hooyer
Momentum is the quantity of motion measured by the product of mass and __________.
Velocity
Pg 8
Behaviour and Handling of Ships - Hooyer
True / False
Frictional drag has relatively less retarding effect on bigger ships.
True
Big ships sustain speed because of the relatively small wetted area and lower frictional drag.
Pg 9
Behaviour and Handling of Ships - Hooyer
When ship’s momentum acts as a force the ___________ is the pt of impact of that force.
Center of gravity
Behaviour and Handling of Ships - Hooyer
The magnitude of longitudinal and lateral resistance depends on what?
(Two things)
Ships speed and shape
Pg. 11
They are directly proportionate to ship’s prop force at a constant speed.
Behaviour and Handling of Ships - Hooyer
Force exerted a ship will result in motion only after _______ has been overcome.
Inertia
Pg 11
Behaviour and Handling of Ships - Hooyer
True / False
A beam wind meets lateral resistance where a beam current does not.
True
Pg. 11
Behaviour and Handling of Ships - Hooyer
When birthing big tankers the sim is to obtain a singular ___________ motion and prevent __________ motion the moment of making contact on the dock.
Lateral motion
Rotational motion
Pg. 12
Easier to check lateral motion.
Behaviour and Handling of Ships - Hooyer
Rudder and propeller produces a combination of ______ motions. A. 1 B.2
C.3 D. 4
C. 3
Pg.12
Behaviour and Handling of Ships - Hooyer
What are the three motions a propeller and rudder produce?
Lateral, longitudinal and rotational
Pg. 12
Behaviour and Handling of Ships - Hooyer
The direction of ________ motion of the ship determines to a very large extent the position of the pivot pt.
Longitudinal
Pg. 13
Behaviour and Handling of Ships - Hooyer
1 ton of bollard pull = ________ HP
100 HP
Behaviour and Handling of Ships - Hooyer
Longitudinal resistance = _____ % of propulsion force under constant speed.
25 %
Behaviour and Handling of Ships - Hooyer
Transverse force of propeller working astern = _____ % of applied stern power.
5 - 10 % applied stern power.
Behaviour and Handling of Ships - Hooyer
Rotational motion is about a ____________ axis and is influenced by ship’s shape, motion, magnitude and point of impact of various forces.
Vertical the top of the vertical axis can be considered the pivot pt spot.
Behaviour and Handling of Ships - Hooyer
True / False
Frictional drag has no effect on the position of the pivot point.
True
Pg. 17
Behaviour and Handling of Ships - Hooyer
The position of G is indicated by _____________ .
Trim. Only when on even draft is the G at the center.
Pg. 17
Behaviour and Handling of Ships - Hooyer
When a ship makes a turn what happens to the pivot point?
The pressure pushes the pivot point closer to amidships.
Behaviour and Handling of Ships - Hooyer
What does the pressure aft of the pivot point do to the drift angle?
Limits the drift angle.
Behaviour and Handling of Ships - Hooyer
On a directionally stable ship what happens to the turn when the rudder is placed amidships?
The turn will stop or slow down.
Behaviour and Handling of Ships - Hooyer
Two tugs push on a ship under headway (fwd motion) which tug has more leverage?
The aft tug and creates rotational motion.
Behaviour and Handling of Ships - Hooyer
True / False
As long as the center of wind pressure (P) is not above the Center of Underwater Resistance the wind will turn the ship.
True
Behaviour and Handling of Ships - Hooyer
How can transverse winder force be counteracted when forward momentum is causing an angle with intended course?
Use transverse force aft - rudder force.
Pg. 20
Behaviour and Handling of Ships - Hooyer
True / False
Rudder force has no effective leverage when backing.Behaviour and Handling of Ships - Hooyer
True
Pg. 20
True / False
When making Steinway the bow has a tendency to seek the wind.
Behaviour and Handling of Ships - Hooyer
False, the stern seeks the wind.
Pg. 20
True / False
Transverse thrust of a right hand propeller can easily be overcome by a strong wind on the starboard bow.
Behaviour and Handling of Ships - Hooyer
True
Pg. 20
When making a turn underway lateral resistance forward that develops on the exposed bow as the swing sets in acts in the ________ direction as the transverse component of rudder force.
Behaviour and Handling of Ships - Hooyer
Opposite direction .
Pg. 21
When the ship is dead in the water what causes it to resist acceleration?
Behaviour and Handling of Ships - Hooyer
Inertia
Pg. 21
The longitudinal propulsion force is concurrently working to overcome _________ when part of this force is converted into transverse rudder force.
A. Longitudinal Inertia B. Lateral Inertia C. Rotational Inertia D. All of the above.
Behaviour and Handling of Ships - Hooyer
D. All of the above
Pg. 21
True / False
The rudder force overcomes lateral inertia of the vessel sooner than propeller force overcomes longitudinal inertia.
Behaviour and Handling of Ships - Hooyer
True.
Pg. 21
With a ship DIW the pivot point for a L to B ratio of 8 is _____ when initially having fwd motion.
Behaviour and Handling of Ships - Hooyer
1/8 L from the bow.
Pg. 21
The rudder works at max leverage when ____________.
Behaviour and Handling of Ships - Hooyer
Vessel is starting from DIW
When the underwater resistance reaches a magnitude of about 1/4 of the prop force the pp moves away from the fwd position proportionally at _____ x the magnitude of force.
Behaviour and Handling of Ships - Hooyer
1 x magnitude
(Draft to length ratio 8) If the pp initially is 1/8 where does it move back to when the resistance reaches 1/4 of the prop force? When turning at a constant speed?
Behaviour and Handling of Ships - Hooyer
- 1/4 L
- 11/32 L
When on a straight course with no lateral resistance where is the pp? What happens in a turn? What happens to the lever arm?
Behaviour and Handling of Ships - Hooyer
- 1/4L
- It’s pushed back to 11/32L
- It’s shortened
Pg -22
A ship under way under rudder turning has its pp where?
Behaviour and Handling of Ships - Hooyer
1/3 L
Pg 22
The position of the actual pp is determined by
A. L/B ratio
B. Longitudinal motion
C. Trim
D. All of the above
Behaviour and Handling of Ships - Hooyer
D. All of the above
From a position DIW with full rudder it is easier to overcome ________ inertia then ________ inertia.
Behaviour and Handling of Ships - Hooyer
1.Rotational
2. Longitudinal
_______ inertia helps us make a tight turn.
Behaviour and Handling of Ships - Hooyer
Longitudinal pg 23
The magnitude of the rotational momentum introduced upon a ship depends on what?
Behaviour and Handling of Ships - Hooyer
Ships mass
P 23
True or false
Once rotational momentum has developed the influence of a newly introduced force acting on the ship has no immediate affect on pivot point.
Behaviour and Handling of Ships - Hooyer
True
P24
The quickest way to stop a swing of a loaded tanker going astern is ________.
Behaviour and Handling of Ships - Hooyer
Bow thruster or tug due to rotational inertia to overcome by prop force.
P 24
On ships with relatively big propellers a turn in what direction is smaller?
Behaviour and Handling of Ships - Hooyer
Port
P25
Larger diameter propellers of low speed revolutions have more/less transverse thrust when working astern?
Behaviour and Handling of Ships - Hooyer
More p25
What motion of the
Ship plays a role in determing the
leverage of the transverse wind force?
A. transverse
B. rotational
C. longrtvdinal
D, All of the above .
Behaviour and Handling of Ships - Hooyer
C. longitudinal , determines the location of the pivot point
Pg 39
In order to turn the
Vessel short round to stardoard its
best to?
A. Give a Kick ahead full right rudder
B. Give kicks ahead atter backing
(full right rudder)
C. just back and let transverse.
thrust turn to stbd
Hooger
D. None of the above.
Behaviour and Handling of Ships - Hooyer
A. Give a kick ahead full right rudder.
Long inertia will hold the ship back from developing sternway this will max. thansverse thrust leverage.
True or False with a ship still moving ahead it is best Practice to leave the rudder to the side that we wish to turn to , when the ship moves astern it makes sence to shift the rudder.
Behaviour and Handling of Ships - Hooyer
True
pg. 37
On a ship moving ahead and a transverse wind-force of 27 ton when the ship is heading 60° off the wine On the Port Side Which way will tHe bow want to turn? under sternway which way will the how fall ott to?
Hooyer
Behaviour and Handling of Ships - Hooyer
- Port
- Starboard
Pg - 41
truelFalse Ship DIW using a bow thruster the center ot gravity is pushed over in the same direction which the bow is moving .
Behaviour and Handling of Ships - Hooyer
True p
Pg 49
how many times denser
Is water than sea level atmosphere?
Ao 100 times
B. 500 times
C. 800 times
D. None ot the above.
Behaviour and Handling of Ships - Hooyer
800 times
Pg. 61
Force exerted on a ship will
result in motion only after __________ -
A. Inertia has been overcome
B. long resistance has been overcone
C. pivot Pt moves twd
A. None at the above .
Behaviour and Handling of Ships - Hooyer
A. Inertia has been overcome
Pg. 11
When a transverse force on
the bow (bow thruster or tugs) act on a backing
Ship what happens to the pivot pt?
A. It moves fwd
B. It moves aft
c. It stays the same
Behaviour and Handling of Ships - Hooyer
B. It moves aft
This reduces the effect of transverse force
Pg- 26
true false when the engine is stopped on a backing ship the wind will have a greater tendency to turn the ship.
Behaviour and Handling of Ships - Hooyer
True, wind gains Leverage When the pivot pt moves further back .
Pg. 26
True /False 1 Beamy ships have mone underwater resistance fwd of the pivot pt and less lateral resistaree abaft of the pivod pt.
2. narrow Ship’s have longer underwater area abaft the pivot pt and meets greater lateral resistance after of the pivot pt.
Behaviour and Handling of Ships - Hooyer
- True
- True
Pg - 28
True/False Acceleration and Deceleration play a role in positioning of the pivot point.
Behaviour and Handling of Ships - Hooyer
True
True / False for a ship down by the Read if takes time to start a swing but less time to stop it-
True /False ShipS down by the head have large turning circles.
Behaviour and Handling of Ships - Hooyer
- False it tates time to start a swing and even more time to Stop t.
- False Ships down by the head have smaller turning circles.
Pg. 31
What is the best way to check the swing of a vessel going astern with a high beam wind?
A. bowthruster.
B. rudder
C. Coming ahead on the engine
D. None of the above
Behaviour and Handling of Ships - Hooyer
C. Coming ahead on the engine
Pg - 41
true False the bow thnster is most effective when Ship is DIw.
True/false with increase in fwd motion the bow thruster is easily out balanced by rudder torce.
- True
- True
It is best to limit rudder angle to 35º in order to not overpower the thruster
Pg. 50-51 Behaviour and Handling of Ships - Hooyer
What characteristics do ship’s down by the head and wide beam ships have.
A . Short steering lever (Slow Steering response)
B. Strong lateral resistance torce at the bow creating small turning circle
C. Large moment of rotational momentum of the fore ship which creates a difficult to stop swing.
D. All of the above.
D. All of the above.
Pg. 126 Behaviour and Handling of Ships - Hooyer A fast rate of turn.
True or False: The quickest way to stop the swing ot a loaded tanker going astern is opposite rudder wlfull ahead.
False, the ship would have to overcome rotational inertia
Before stopping the swing. A bow thruster or tug on the bow would be better. Behaviour and Handling of Ships - Hooyer
True/false When working astern with the prop working astern the pivot Pt moves farther aft then when the prop is Stopped.
False, False the pivot Point tends
to not go as tar back under the force of transverse thrust and directional resistance, fig 65 pivot point is not as far back as fig7l.
Pg. 25 - 26 Behaviour and Handling of Ships - Hooyer
Which statement is true for narrow ships? For wider ships? .
A. They have a wider dift angle.
B. they have a smaller dritt angle
C. They have a smaller turn
D. they have a wider turn.
/,narrow Ships: B. Smaller drift angle. D. Wider turn
2. larger snips: A . wider dritt angle. C. Smaller turn
Behaviour and Handling of Ships - Hooyer
Which statement is true regarding a ship down by the hend-
A. has more underwater area forward of the pivot Pt ,(IE more lat resistance)
B. A stronger transverse force on the fore ship pushes pivot point back .
C. the Propeller is not as deeply submerged which diminishes steering moment.
D.all of the above.
D. all of the above
Pg. 31 Behaviour and Handling of Ships - Hooyer
What is true concerning the turning circles of ships?
A. A ship down by the head has a smaller turning circle
B. A ship down by the stern has a larger turning circle
C. Both turning circles are the same.
D. A and B above
D. All of the above. large turning circle for a ship down by the stern is because of a weaker lat, resist at the bow and a stronger lat resist abaft the pivot pt, restricting dritt angle. Pg -31 Behaviour and Handling of Ships - Hooyer
under speed where is the pivot point?
A • midsnip
B. between the bow and center of gravity
C. between the stern and center ot gravity
D. None of the above.
B. between the bow and center of gravity. This is where drift angle and lat resistance are minimum
Pg. 122 Behaviour and Handling of Ships - Hooyer
In a turn as the drift angle widens and FR grows what happens to the pivot pt?
A. It gets pusned back.
B. It stays where it is
C. It moves forward
D. None of the above
A. It gets Pushed back until max drift angle has been reached.
AR Limits rudder torce .
Pg 122 Behaviour and Handling of Ships - Hooyer
True False Beamy Ships & Ships down by the head meet stronger FR.
True causes the drift angle to open up
Pg. 122 Behaviour and Handling of Ships - Hooyer
Where is the rate of turn the highest?
A.0-10。
B. 10 - 90°
C.80-100º
D. 100° +
B. 10 - 90º
When the speed das come down to a constant speed and eng. revs running higher the pivot Pt Moves fwd results in a lower rate.
Pg- 122 Behaviour and Handling of Ships - Hooyer
Why is the diameter of full circle smaller than the diameter
Of the first 90º
A. Initial Pivot Pt IS torward
B. First Stage of the turn has greater AR and smaller drift angle.
C. The original momentum carries the ship farther
D. All of the above
D. All of the above. D. all ot the above .
loss ot speed and momentum In the later stage of full turn causes a smaller circle.
Pg. 125 Behaviour and Handling of Ships - Hooyer
When the ship is dead in the water and using a thruster or tug to turn in a circle the pivot point iS where? What needs to be overcome tor transverse rudderforce to have leverage.
A. lb from the stern
B. amidship
C. In trom the bow
D. 1/3L from the bow -
A. Long resistance
B: lat, resistance
C. Inertia
D. None of the above
- A. 1 B from the stern
- C. Inertia
the magnitude ot longitudinal and lateral resistance depends on what?
D. Ship’s shape
B. ship’s speed
C. location ot pivot Pt.
D. A and B only
D. A & B Only
they are directly proportionate to ships prop torce at a constant
Speed.
- I ton of bollard pull = ____ HP
- longitudinal resistance = _______%
propulsion force under constant speed. - transverse torce ot prop working astern = _______% of applied stern power
- 100 HP
- 25%
- 5 - 10%
Pg. 15
Transverse rudder force lifts ______ and the pivot point acts as the fulcrum.
A. Center of Lat resistance
B. Center ot buoyancy
C. center of gravity
D. none of the above.
C. Center of gravity
Рд- 27
True/false The turning circle of a ship at constant higher speed is bigger than at constant lower speed.
True. Trve
Decause of Momentum a relatively longer steering lever and a smaller dritt angle .
Restricted bottom clearance in
Shallow water impedes the flow of water underneath the ship causing restricted _________ motion of the aft ship.
ed -
A. lateral
B. longitvdinaL
C. rotational
D. None of the above
A. lateral motion
a build up of water where the stern is going and less water where the stern is
Moving from creates a smaller drift angle and wider turn.
What does turning into sea
or swell do to the pivot pt and turn?
A. Pivot Pt fwd and smaller turn
B. Pivot pt Aft and big turn
C. Pivot Pt fwd & big turn
D. Pivot pt amidship & small turn.
C. Pivot Pt fwd & big turn
If we want to create lateral
motion with the thruster & Engines what must be careful of?
A. not to over power the thruster with the prop
B. Not to under use the thruster
C. Not to over power the prop with the thruster.
D. All of the above
A. Not to overpower the thruster with the prop, as you gain lat Motion the thruster looses leverage. Might work to use transverse astern motion.
Make Sure they are balanced
Pg - 128.
Lateral resistance in a turn does what do the pivot pt?
A • Moves it forward
B. Pushes it back
C. pivot Pt stays the same.
B. Pushes it back
Pg. 28
Which tanker loses more speed when turning under full speed?
A . Very large tankers
B. Smaller tankers
C. Both lose an equil amount of speed -
A . Very large tankers (they have an extensive underbody)
Pg-32
When entering a Sheltered port on a fully loaded tanker what
Force Must me taken into account as the ship Moves out of the current?
A. lateral resstance
B. Longitudinal momentum
C. Side momentum
D a transvate rudder force
C. Side momentum in direction of the current
Pg. 63
— is directry propottiónal to the speed as well as to the beam of the vessel.
A. Squat
B. velocity
C. Sinkage
D. Trim -
C. Sinkage
Pg. 85
RotationaL effect of a right-handed prop can be countered by keeping the bow to ___________
- Rotational effect of a left -handed prop can be countered by keeping the bow to ____________.
A. Port
B. starboard
C. Neither of the above
D. Either A or B
- Port
- Starboard
Pg. 53
When is the magnitude of the transverse thrust the highest?
When the ship is just starting to move astern.
Moving ahead 5%
Headway comes off 10%
Pg. 36
Two 477,000 dwt tankers one loaded and one in ballast . Which one is more offective at loosing speed by rudder cycling”
A. Loaded (Rudder area ratio 1/60)
B. inballast（rudder area ratio 1/27)
A. In ballast
Pg. 32
The room inside of inner harbor of San Nicolas is limited, loaded tankers employ 3 tugs how do they counter a sheer that may be encountered?
A. Back on the after tractor tug
B. Position two tugs to the side of the ship sheers to
C. One tug pulls on the bow and one tug pushes
D. None of the above
C. One tug pulls on the bow and one tug pushes
Which two levers are interdependent and act as a double lever for the turn? Pick 2
A. Steering lever
B. Rudder force lever
C. long, resistance lover
D. lat resistance lever
A. Steering lever this is the distance from the rudder to the pivot point.
D. lat resistance lever. This is the distance from the pivot point to R’ the Center of forward Lateral resistance. They are both second class levers.
Pg 123
Where in the turn is their a very slow rate of turn. why is it slow there?
A . First 10º
B. Middle 200º
C. Last 10°
D. None of the above
A. transuerse rudder torce has
to overcome long. inerta
B. transverse rudder force has
to overcome Lat Inertia
C. The pivot pt hasnt been pushed back yet
D. All of the above
B. transverse rudder force has
to overcome Lat Inertia
Pg. 122
Light ship that is trying to move the stern up into the wind. What Is the best way to start the swing?
A. back on the engine
B. Use a kick ahead on hard right rudder.
C. use full ahead on hard right rudder o
D. Drop the other anchor.
C. Use full ahead on hard right rudder until the swing starts. This will bring the pivot pt after (with inc. resist on chain) Shorten the lever arm for the wind. Get the stern in to the wind where the transverse Wind force is diminished. As the swing Progresses reduse Engine power, Pg. 131
In Example 3 Tugs/WIND /pivotPt why is it better to have the
Tug on the bow push against a heavy wind then pull the bow into position.
A. The tug could be over powar-ed by the wind and high leverage of the pivot Pt. Tug has more Power pushing & could easily keep the bow in position.
P9 - 58=59
In Example 3 Tugs|WIND PNotPt.
Where is the magnitude the greatest for transverse thrust? why?
A . Fig 47
B. Fig 48
C. Fig 46
D. Transverse thrust is approx the same for all
A . Fig 47 because the pivot point is still fwd and just about to make sternway.
when handling a turbine
tanker & current is aft what is good practice? why?
- A: To Leave some engine rev . astern when the ship is almost in position.
- A: The Engine Room may give some revolutions ahead which will take time to reverse. In a strong beam wind it may be hazardous to move the ship back to recover the distance lost.
True or False: The overall eftect of bank suction and bank cushion is a bodily attraction ot the vessel towards the bank & a yawing effect away.
True The ship can proceed parallel to the bank by applying rudder toward the bank.
Pg. 149
Trve false Bank suction and bow cushion are less pronounced with Smaller underkeel clearances.
False more pronounced by lower UKC.
Pg. 150
How can bank suction * cushion be kept under control?
A. Keeping away trom banks
B. Increasing speed
C. decreasing speed
D. A & C only .
D. A & C only
Bank suction and bow cushion effect increase proportionately with ship’s speed.
Pg. 150
what is the best way to conteract a sheer & caused by
bank suction or cushion.
Kick ahead (full power) and hard rudder to counteract
True /talse the lower a ship’s speed in negotiating a bend in shallow water the more reserve power to control Mavement .
True
Also the more effective tugs can be.
Pg 150
True /false when UKC reduces to 20%
Of the dratt more astern power and consequently more tug power is needed to stop a ship then in deep water.
True, Ship drags large amount of water with it sometimes as much as 40% displacement which is virtual mass.
Pg 150
True/false Pressura fields caused by
Bernoulli ettect are the main cause of the wave pattern around a ship at low speeds .
True
Pg. 151
When steam lines of water movement converge water ______ when stream lines diverge _______.
A. Slows down / speeds up
B. Speeds up / slows down
C. Pressure increases / pressure decreases
D. None of the above
B. Speeds up / slows down
When water converges pressure goes down when diverges pressure goes up.
Pg 151
How does Shallow water
Effect the pressure fields around the ship?
A. Everything is magnified more high pressure and less low pressure
B. Does not effect the pressure fields
C. Everything is nullified less high pressure and low pressure
D. None of the above
A. Everything is magnified more high pressure and less low pressure. Lower low pressure. Speed along the mid body of the ship is accelerated
Pg. 151
True /false due to the boundary layer the space between the bank & Ship narrows towards the ships stern giving the
Ship a Yaw moment away from the bank.
True, in addition the high pressure near the bow gives the cushion.
Pg 152
True / False it is important not a to overuse the bow thruster in many cases it is better to wait for the on final stage of docking to use it to keep parallel to the dock.
True it can be used to balance forces fore and aft.
Pg. 56
Docking Starboard side to with current coming from starboard quarter remaining in the same position, two tugs one fwd and one aft on the Pls push at the same powers which way does the Ship turn? why?
Talia kristm
A. Ship turns to stbd because the center ot lat resistance is aft and the pivot pt is aft making Att tug have to use more eftort.
Pg. 63
In case 4 PA where the stern is Striking the quarter. What Is the desired lateral motion to lift the stern out?
A. With the current on the stbd quarter
B. with the current on the port quarter
C. directly in line with the current
C. directly in line with the current or parallel
Pg. 120
True /False It backing trying to use trasverse stern way to move laterally It Is possible to overpower the the engine if a Port thrust cants the Stern to stbd.
True you will be no closer to the dock kills later motion.
Pg. 129
The bigger the ship ________.
A. The more a lateral approach makes way for a longitudinal one
B. The more power required from the engines to dock.
C. the less tugs required.
D. the more a longitudinal approach makes way for a lateral one.
D. the more a longitudinal approach makes way for a lateral one.
Impact load on contact must be spread over as much as possible and area. One pt landings must be avoided.
Pg. 114
It is easier to maintain a balance of transverse forces when the ship is not under _______ motion.
Ao longitudinal
B. lateral
C. Rotational
D. None ot the above
A. Longitudinal In a head current when the ship is drifting back or moving forward w/a following current. In the final stage of docking.
Pg. 117
Ret CASE# I
In both senercos which spring line was used to assist in coming off the dock.
D. Fwd springs only
B. After springs only
C. The spring to the side which no which no way could be made .
D. None of the above.
C. The spring to the side which no way could be made.
Pg. 99
When assisted ship teB was assisted where was the tug placed? why was it placed there?
As far forward as possible to push and not depend on the breaking strength of the line. Also to counter the rudder and engine.
When can the ship start
the swing to stbd and how should we use the engines to start the swing .
A. When the ship stern will clear start swing with the rudder and Engine. Take all fwd motion and use astern bell. use the tug to Pull be the bow off when the PP Moves att.
Pg. 98
How much turning effect does the after tug have? Why? How do you get the stern in?
p. while under sternway the PP Is aft No turning motion. Back on the fwd tug to get it in. Aft tug is compensating tor the ottshoe wind.
which tug needs to be stronger? Once the steinway comes ott which tug has more fevergge.
NOTE: Case 2
The aft tug needs to compensate tor wind & lack at leverage when backing. It the PP Moves fwd the aft tug will have more.
Pg 100
What makes it ditticult to
Swing to port what makes it ditticult to stop the sternway,
A. Longitudinal momentum
B. Rotational momentum
C. transverse Momentum
D. lateral momentum
- B. Rotational momentum
- A. Longitudinal momentum
More of an effect on a loaded ship.
Pg. 103 - 104
Ret. Note: PA Case 8
When the ship initiates a turn to stbd after being pulled out Why does the doppler stern read zero?
Where is the pivot pt?
- A: The bow is Showing the lateral momentum of being Pulled out plus .2 it increase in rotational Motion. The stern is showing the same but the other way. lateral Speed to stbd on the stern has been nullitied by the Prop. PP Is between the COG and the prop closer do midship.
Ref. Note 8 What has Kept the PP back so long. What needs to stop in order for the PP to move fwd.
“ As long as ______ speed of the stern to Port is not at least _________ the bow to stbd their is still ________ momentum.
- A= the magnitude ot lateral
momentum .
2A: lateral momentum - A: Lateral spd.
- A: twice
5• A: lateral momentum
Pg. 111
The Stern has a leiteral
Speed ot 1.2 to Port & bow • 2 to Stbd
What is the net motion?
- 1.0 kt to port
Pg. 111
Note Case 8. .5 kt current swinging the bow to stbd Doppler shows .2 stbd bow, 1.2 port stern. Where is the pivot point?How do we create a tighter swing to stbd using the tugs. It we use propulsion what does it do.
- A: Pivot point is midships. .5 from stern and add .5 to the bow.
- Let the stern tug push on the Part bow allow the bow tug to continue to pull. Also come astern on the Engine to increase leverage. Also have the tug Push stbd Quarter or Pull Port Quarter.
- A: Add fwd Propulsion widens the turn.
Pg. 113
with a reading of zero on the stern and 1 kt on the bow to stbd
Where is the pivot pt?
How is a ship with 45° of rudder at an advantage?
- A : PivOt Pt IS on the stern
2.A: It is helptul to turn a Ship by making a tight swing within the limitations at its use. (under 8KtS, Rpm Under 50)
Fig 103 Case #5. why is it a good I dea to release the fwd tug?
A. Fwd tug has too much leverage when backing
B. Fwd tug must keep position so must keep some strain on.
C. The next command will be to assist in the turn so send him to start setting up.
D. All of the above.
D. All of the above. He seems to ignore the order to stop but is trying to stay in position.
Pg. 119
The ship is moving twd with three tugs 2 equadistant from the pp. 3rd tug has been stopped - what
10 the lateral ettect?
A. 1x tons
B. 2 x tons
C. 3 x tons
D. 1/3 x tons
B. 2 x tons
Pg. 119
When two tugs push opposite sides ot a ship with equal force what is true?
A . pivat Pt is amidships
B. max underwater resistance is at the ends ot the ship.
C. max underwater resistance is amidships
D. A and B only
D. A and B only
Pg. 125
As power trom a tug decreases and Engine power over takes where doos the pivot pt move?
A. Moves fwd as you decrease tug power to eng power
B. Moves aft as you decrease tug power to engine power
C. Stays the same
D. None of the above
A. Moves forward as you decrease tug power and engine power increases
Pg. 126
When turning with one tug where is the pivot point when a tugs (tug on the bow) power and Engue power are equal?
When the tug exerts zero power?
A. 1/3L from stern
B. amidships
C. 1/3L from the bow
D. 1/8L from the bow
B. Amidships
D. 1/3L from the bow
Pg. 126 - 127
In a turn with one tug on the bow: Where does the pivot pt go when a tug apposes the swing ot the engine but doesn’t over Power it.
When the tug aposes and has equal force to the prop force what force is left?
1.
A. Far forward
B. Amidships
C. Remains the same
D. Far aft
- A. Longitudinal force
B. Propulsion force
C. Transverse force
D. None of the above
- A. Far Forward
- Transverse force
Pg. 127
True |False Head in dockng is generally considered safer than
Stern docking?
False Stern docking is considered safer it is easier to kill sternway than headway.
Pg. 53
On the ship turning toward the dock, _________ momentum sweeps the stern away trom the dock & will a be hard do stop.
A. lateral
B. Rotational
C. longitudinal
D. None of the above
B. Rotational, transverse thrust will counter but not strong enough to stop the ship from moving away laterally.
Pg. 54
When pushing on the bow with a thruster or tug, transverse force brings the bow in and counter-acts lateral motion away from the dock. If continued to push on the bow where does the pivot Pt go.
A. to the pt of force
B. Stays fwd with fwd motion
C. Moves aft
D. None ot the above .
C. Moves aft, transverse thrust of the prop will push it fwd and reduce leverage.
Pg. 54
What is a good way to check the stern lateral motion when going
Port side to the dock.
A. Hard Right Rudder Kick Ahead.
B. Hard Lett Rudder Kick ahead
C. midship Kick astern
D. StoP Engines .
B. Hard Lett Rudder Kick ahead
Also use a thrust to port to convert rotational motion to lateral motion.
Pg. 54-55
When docking Port side to Full rudder angle is very important when we want to stop rotational motion because:
A. At slow speeds it is mporand to use full rudder:
B, Full rudder has more to an effect with stern
C. The more longitudinal prop force is deflected into transverse rudder force the better
D. All of the above.
C. The more longitudinal prop force is deflected into transverse rudder force the better, the sooner we stop the swing without appreciable acceleration of fwd motion of the ship.
Pg. 55
When bringing out a ballasted tanker (lott) having a tug alongside will work because the pivot pt is
A. Positioned well after
B. not move as far aft
C. Positioned fwd.
D. none ot the above .
B. not move as far aft
Also can use the engine on astern without being afffected as much by transverse thrust.
Pg. 58
What is the advantage of taking speed off with a tug after (of assisted ship)?
A. Pivot Pt stays fwd.
B. You get a quicker response time.
c. you get better directional contral.
D. B & C only.
D. B & C only
During the final stage of docking tug can pull out on the beam to control lateral motion in.
Pg. 60
Case 3: Which current would be easier to control? Why?
- A. The flood current would be better with not as much moving through the water. An Ebb tide current would be harder as the pivot pt would stay after longer.
Pg. 100
True/False wave Making around the Ship is increased in shallow water due to restriction in the flow of water under the ship.
True.
Pg. 85
The wave profile alongside the ship shows a _______ wave ahead of the ship, a ___________ trough along the sides and a _________ wave following the ship.
A. Increased
B. Decreased
C. Deeper
D. Shallower
- A. Increased
- C. Deeper
- A. Increased
Pg. 85
True /False Increase in trough in shallow water makes the ship come closer to the bottom (squat) and contributes to speed loss.
True
Pg. 85
True /False The closer to the bank the ship gets the more rudder Is needed to compensate tor bank eftect .
True
Pg. 86
True False Bank suction suffers to a lesser extent from loss in strength when the bank is submerged.
True
Pg. 88-89
True/False suction has a greater tolerance for angle between ship & bank
True
Pg. 88-89
True/ False Trim by the head accentuates bow cushon ettect .
True
Pg 88-89
True /False Over taking in narrow channels is more dangerous than meeting or passing?
True
Pg. 95
When overtaking is necessary
what is the key to doing it sately?
A. Stay to respective sides as far over as possible
B. Stay in the middle of the channels
C. Both ship’s Keep the speed down as much as possible.
D. none ot the above .
C. Both ship’s Keep the speed down as much as possible.
Pg. 95
What Statement is true concerning bank suction?.
A. Suction pushes the bow off toward the center of the channel.
B. Suction acts as a first class lever when the pivot point moves forward.
C. suction draws the ship toward the bank and weakens the strength of the rudder.
D. B and C
C. Suction draws the ship toward the bank and weakens the strength of the rudder.
Pg. 87
The increase in ___________ resistance in shallow water causes a speed loss.
A. lateral
B. longitudinal
C. rotational
D. transverse
B. Longitudinal
Pg. 85
Bernoulli effect is the souree of lateral force acting on the Ship in the direction of the bank called ____________.
A. bank cushion
8. Squat
C. bank suction
D.Sinkage
C. Bank Suction
Pg. 85
The Pt of impact for bank suction iS the __________ of the ship. The magnitude of the resulting transverse force acting on the ship is directly proportionate to the ditterence in water level and is directly related to the ship’s ___________
1.
A. Pivot pt
B. Center of mass
C. Center of gravity
D. Stern
2.
A. Draft
B. Squat
C. Speed
D. Trim
- C. Center of gravity
- C. Speed
Pg. 86
Which way does the ship turn faster & with the presence ot wind. (normal trim)
A • Into the wind (bow sternaway )
B. into the the wind (Stern. (bow away
a. Into the Sind with the bow and stern away from the wind.
Pg. 35 Stern into the wind moves slow especially with the lower eng power.
True false when we want to move the ship laterally we should increase transverse rudder force at the extente of longitudinal force.
True pg 51
How may a vessel be affected when entering into a Sheltered port where part of the vessel is exposed.
A. An unexpected increase in long motion
B. Turning effect as current hits exposed quarter
C. An unexpected increase in lateral Motion -
D. None of the above
B. Turning effect as current hits exposed quarter
Pg. 62
Ship with a following current two tugs (one fwd & one aft) the aft tug provides what motion, what Should We do with the fwd tug?
A. Rotational motion
B. Lateral mation
Co Longitudinal Motion
D. A÷B only .
B. Lateral mation
Stop the fwd tug. The aft tug is closer to the pivot point moving the ship laterally.
Starting a swing on a fully loaded Ship takes time; it takes even more time to stop a swing because of
A. Rotational Momontum
B. longitudinal Momentum
C. Lateral momentum
D. Rotational inertia
A. Rotational momentum
Pg. 93
On big tankers we can expect strong suction effect in narraw Channels because -
A. wide beam causes extra sinkage
B. UKC is generally smaller causing bow wave & deeper trough (increased Bernoulli effect)
C. large ships create more leverage for suction
D. All of the above
D. All of the above
Pg. 87
What does the heightened Bow wave in a narow channel do for
longitudinal Resistance & Pivot pt?
A • Increases Long ReS. & MoveS PiVot Pt fwd.
B. Decreases Long Res & Moves PivotPt back
C. Increases long ReS MOveS PIVoT Pt back
D. Decreases Long Res & Moves PivotPt fwd
C. Increases long ReS MOveS PIVoT Pt back
Pg. 88
What Statement is true concerning the pivot Pt when a ship is effected by bow effect?
A. A bow wave in shallow water pushes the pivat Pt back.
B. Once a sheer sets in the Pivot pt gets pushed back
C. Most ships have a comparatively small lateral underwater area fwd of their pivot point.
D. All of the above
D. All of the above
Pg. 89
When is the most likely time tor a ship to take a sheer?:
1• In a Narrow Channel with the Ship center and equal pressure on bothsides
B. In a Narrow Channel Ship off of center pressure is counterbalanced by a couple
degrees at rudder.
C. in a narrow channel when a ship passes a branch canal
D. In deep ocean water with too much rudder applied
C. In a narrow channel when a ship passes a branch canal. The build up of water will all of a sudden disperse & cause a sheer
Pg. 89 - 90
After correcting for a sheer when the Ship is Straightened up, what is the First thing to do?
A. Midship the rudder
B. return engine speed back to original.
C. Increase engine speed.
D. reduse rudder to the same side
B. return engine speed back to original. It is important to keep a low speed while in a narrow channel.
Pg. 91
When two ships pass in a narrow channel each other, they should:
A. As fast as possible.
B. Move over to their respective sides as soon as possible
C. Stay close to the middle of the channel as long as possible.
D. Be stopped engines as they pass.
C. Stay close to the middle of the channel as long as possible.
Pg. 93
When two ships pass in a narrow channel they should avoid this!
A. Going starboard to starboard.
B. Moving to the side too quickly.
C. Stopping Engines during the interaction
D. Using Port rudder if going Port to Polt.
B. Moving to the side too quickly. Avoiding an uncontrollable sheer toward the other vessel.
Pg. 93
True/False when two ship’s pass each other their bow waves will push them apart and once they are to succosstully passed each other their Stern suction will take their Sterns back to the center of the channel.
True
Pg. 93
Reference Note reeship’s Meeting in a Narrow Channel. Where should Ship speed be for ships about to meet in a narrow channel.
A • Stop Engines
B. Reduced Eng. Revs but sufficient tor steering control
C. full ahead
D. None ot the above .
B. Reduced Eng. Revs but sufficient tor steering control
Pg. 93
True/False Both ships gave Lett rudder to counter bow waves pushing off and right rudder to compensate tor midship suction.
Ref ships meeting in a narrow channel
True
page 94
Ref Ship’s meeting in a
narrow channel
What did Ship A do to get in trouble?
In Shallow Water A InceaTes n
Ship A used left rudder in attempt to swing the stern clear this brought him too close to the Channel edge. Ship B used no rudder and allowed stern suction to bring him back in the channel.
Page 94
In shallow water, AR increases faster and causes ____________.
A. A large drift angle and a larger turning circle.
B. A smaller drift angle and a larger turning circle.
C. A larger drift angle and a smaller turning circle.
D. Smaller drift angle and smaller turning circle.
B. A smaller drift angle and a larger turning circle.
Page 1 21–1 22
Ret. Note overtaking in a narrow channel
What is the most dangerous part of the overtating interaction?
A. Upon approach of Ship B to ship A
B. when the two Ships are even
C. The final stage when ship A is being sped up by ship B
D. None of the above
C. The final stage when ship A is being sped up by ship B. Ship A will feel the suction of Ship Bs prop and the suction of the bank which form a couple turning Ship B.
Pg. 96
water flow restricted between Ship and the nearest bank results in increased flow rate and lower water level
Is called ____________.
A • Bank Suction
B. Bank cushion
C. Bernoulli effect
D. squat
C. Bernoulli effect
Pg. 85-86
Ref. Ship’s overtaking
At what stage will ship B Cause Ship A to Slow down.
A. When Ship A feels Shipe Bs bow Wave
B. When the two ship’s are even.
C. When Ship B is in the final Stage and almost by ship A.
D. None of the above
B. When the two ship’s are even. Mutual suction draws the sterns together. Ship A is swinging to the bank but should not over react.
Pg. 96
Ref ships overtaking in a narrow channel
At what Stage does Ship A speed up. At What Stage does Ship A have a tendency to swing to the bank?
A. 1st stage
B. 2nd stage
C. 3rd stage
D. 4th stage
E. A & D only
F. B & C only
- E. A & D only
- F. B & C only
Pg. 96
What 4 conditions must be achieved to experience bow effect?
One. Proximity to Bank.
Two. Ship must be parallel course to Bank.
Three. Ship must reach a certain speed to build up a bow wave.
Four. The ship must have a large underwater area fwd of the pivot point
Page 88
On a loaded tanker, trimmed by the head, we should be alert to any turning motion by putting on preemptive rudder if Rutter has no effect what should be the next action?
A. Increase engine revolutions to half full.
B. Decrease engine revolutions
C. Drop and anchor.
D. Use astern bell.
A. Increase engine revolutions to half or full.
Pg. 91
True false transverse thrust is stronger on ships with large and slow turning propellers than on ships with small and fast turning props,
True
Pg. 37
Twe/ False when it is nearly slack ballasted ships will be more affected by wind and loaded tankers still remain headed into the tide.
True
Pg. 62
A Ship proceeding against a current of 2 kits making 3kts through the water is making how many kts over the ground?
1 kt
Pg. 67
The build up of water at the bow that results in a difference of pressure between the onshore bow and offshore bow
Is called ___________.
A. bant cushion
B. bank suction
C. Squat
D. Bernoulli effect
A. Bank cushion
pg. 86
True False Because we must use More rudder closer to the bank ettectiveness
Is relatively less at large angles of rudder It is best to stay closer to the center of the channel.
True
Pg. 86
True False the build up of water near a bank is greater than other side pushing the bow away from the bank.
True
Pg. 88
True or False bow cushion has the same rotational direction as the stern suction.
True , its effect to deep draft ships is strong.
Pg. 88
When should the use of anchors to stop a sheer be avoided?
A. On a tanker inballast
B. When the Anchor is to the Bank side of the vessel.
C. On a deeply loaded tanker with little UKC.
D. Anchors should always be an option to stop a sheer.
C. On a deeply loaded tanker with little UKC.
Pg. 91
When an anchor is down, engine is ahead, but vessel is stopped. What does this mean?
A. Engine power is greater than anchor force.
B. Anchor force is greater than power.
C. Achor force is equal to engine force.
D. B & C
D. B & C
Pg. 129
what describes a time delay due to human factos.
A - time betwen order & execution at order
D. Time between responce by the engine room due to No bridge control
C. Order from the bridge wing about steering to the helmsman
D. all ot the above
D. All of the above
Pg. 7
To assess angle of approach _______ is useful from the bridge wing :
A . Doppler Speed log
B. compass repeater
C. rudder angle indicator
D. All ot the above -
B. compass repeater
Pg. 14
Two tugs pushing on either end of the snip on the same side, which Statement Is true?
A. Ship DIw results in rotational motion.
B. Fwd motion results in more leverage for the aft tug & rotational motion.
C. Astern motion results in less leverage tor the fwd tug
D. Fwd motion results in more leverage for the fwd tug
B. Fwd motion results in more leverage for the aft tug & rotational motion.
Pg. 18 - 19
True / False When two tugs pushing equal distance from amidships and a swing sets in it can be concluded that the Ship is under longitudinal motion.
True
Pg. 19
What is the best way to increase steering effect?
A, Increase engine rev.
B. Increase rudder angle
C. decrease engine rev
D, decrease rudder angle-
B. Increase rudder angle
Pg. 37
True /False under sternway with the prop stopped there is some rotational effect of the full rudder.
True it is very slight and easily nullified by a breeze.
Pg. 37
What is the advantage of having bow thruster indication on the bridge wing?
A. The ship handler knows exactly what he is getting.
Pg. 51
When a Ship that is Stemming the tide swings beam to the tide it will Shoot ahead even with stopped engines because of __________ of the current. If the current is two kts how much will be picked up?
A. Lateral momentum
B. Rotational momentum
C. Longitudinal momentum
D. None of the above
C. Longitudinal momentum
2 kts
Pg. 66
How can big loaded tankers compensate tor sluggish turns in the Aruba turn?
A. More Engine RevolutionS
B. Less Engue revolutions
C. turn sooner
D. None ot te above .
A. More Engine RevolutionS
Pg. 69
When entering the Port of san Nicolas, Aruba which side of the loading lIne should a deeply loaded tanker be On to assist in the turn I/B.
A. North of the leading line
B. south ot the leading Line
C. On the Leading Line.
A. North of the leading line It too tar south the ship Could take a sheer to Part and take a long time to stop with full ahead and statboard rudder Port tug pushing & Stbd tug pulling backing full.
Pg. 92
The position of the actual pivot Point is determined by -
A. L/B ratio
B. Longitudinal Motion
C. trim
D. All ot the above
D. All of the above.
Pg. 23
True or False: vessels fitted with propeller ducts produce strong transverse thrust when working astern.
False. They produce less transverse thrust.
Pg. 25
True False transverse thrust loses leverage & ettectiveness when the pivot Pt Moves aft .
True
Pg. 25
The position of the pivot Pt on a ship under stern way depends on __________.
A. Trim
B. leverage ot transverse torce which causes the ship to rotate
C. speed through the water
D. All of the above
D. All of the above.
Influence of the other forces acting on the ship simultaneously.
Pg. 25
True False A vessel trimmed down by the head will have a pivot point that is farther back under sternway.
True, the effect of the pivot point under headway for trim is reversed under sternway.
Pg. 25
What is the best way to slow down without using engine astern?
A. Cycle the rudder
B. round turn
C. Go aground
D. None of the above
A. Cycle the rudder
Pg. 27
True false the speed of the ship will not come to the indicated spead on the information sheet.
True. True, propulsion torce is diverted into transverse rudder torce and the Ship 1s meeting more underwater resistance while turning -
Pg. 30
What 1s a negative result of leaving a kick ahead on too long?
A. A reduced steering lever
B. A slower stw
C An increased steerng Lever
D. None of the above
A. A reduced steering lever. Causes an increase in speed through the water and higher resistance on the bow.
Pg. 30
True/false A Ship down by the stern has a pivot pt farther fwd than down by the head.
True, the fore ship meets less underwater resist when moving ahend. the propeller is deeper and has a better steering moment.
Pg. 31
True/False 1. A Ship working at full speed, a prop. working at 20°% capacity meets more resistance to water than Stopped prop .
True
Pg. 33
- Dead slow ahead on the prop after full speed ahead gives better Braking Power than stopped.
True
Pg. 33
Working full astern gives a quicker stop than working 20% astern after full ahead.
- False 20°% ot capacity gives a quicker stop when most of the effect is lost to cavitation.
Rate of turn peaks between ______ and _______- degrees and settles
at a lower rade when proceeding at a constant speed.
A. 0º - 30º
B. 10º - 90º
C. 30º - 110º
B. 10º - 90º
Pg. 33
Is the turning circle tor a loaded tanker bigger /smaller / the same than a tanker in ballast in shallow water?
In deep water?
- Bigger due to relatively smaller rudder area ratio and greater momentum
- The same trim brings most tankers on an even keel resulted in stronger lat resistance.
Pg. 34-35
True or false under stern motion when the center ot lateral resistance moves aft and settles close to the pt of impact there
Is no longer much rotational effect from transverse thrust .
True
Pg. 36
True False A rudder being used when going astern is most efficient with
15-20 degrees and not hard over .
True
pg. 37
What factor is most important when determing the effect of wind?
A. Ratio of draft / freeboard
B. deadweight of ship
C. magnitude of wind force
D- all at the above .
D. All of the above
Pg. 39
When a ship is under sternway and a transverse wind force develops What would be best to keep the ship under control?
A. Fwd tug / bow thruster
B. Stern tug
C. Midship tug
D. Ship’s rudder
A. Fwd tug / bow thruster
Wind has a lot of leverage
Pg. 40
Where is the pivot pt DIW using the bow thruster to turn with no other forces?
A. midships
B. 1B aft of the Bow
C. 1B fwd of the Stern
D. 1/4 L fwd of the stern.
C. 1B fwd of the Stern
When rotational motion is the same direction as lateral motion __________ opposes the swing.
A. Inertia
B. transverse resistance
C. longitudinal resistance
D. lateral resistance.
D. Lateral resistance
Pg. 49 - 50
under fwd Motion of the Ship the useful effect of the ___________ decreases whereas the __________
Is not ettected by fwd motion .
A . Transverse rudder force
B. Lateral rudder force
C. bow thruster
D. Transverse propeller force
- C. bow thruster
- A . Transverse rudder force
Pg. 50
True False on full astern there is practically no effect of the transverse thrust of the propeller .
True, The pivot pt has moved stern ward under the effect of the transverse force exerted on the bow.
Pg. 55
A balance must be struck between the rudder force and __________ to
Keep the ship steady near the bank.
A. Bow cushion
B. Stern suction
C. Mid Ship suction
D. A and B only
D. A and B only
Pg. 86
The height of the bow waves depends on what factor?.
A. bottom clearance
B. distance to the bank
C. ship’s dratt, beam and speed.
D. all ot the above.
D. All of the above.
Pg. 88
What statements are true concerning using Bank effect to assist in the return?
A. Just before the bend, let the ship come off center.
B. In the bend let the ship turn with the rudder mid ships or a few degrees.
C. Suction makes the ship turn and all Rutter is available to control the swing.
D. All the above
D. All of the above
Pg. 92
What does ship handling Theory focus on & hinge on. What is the hub of all rotational motion?
A. the center of gravity
B. the pivot Pt.
C. the center of Mass
D. Center of long. Pressure.
B. The pivot pt.
Its position depends upon the interaction among several forces acting on the ship.
Pg. 113
What is the main difference between handling big tankers vs, SMall tankers? (As it pertains to ship handling)
A. the windage area
B. The pivot Pts location
C. The momentum to horse Power.
D. The amount of bollards.
C. The momentum to horse Power. The momentum of the big one is tremendous where the horsepower is relatively low.
Pg. 114
On big Ships since the exposed broadside area is so much larger, the wind forces & current are so Much greater. Our Satety margin must be
A. wider
B, Smaller
C. the same
A. Wider
Lateral & rotational motion must be kept to a minimum.
Pg. 114
True or False: we must try & prevent getting into a situation where we have to take forceful measures - on the big ones patience will in most cases, achieve more than force .
True.
Pg 115
True or false lateral resistance depends on lateral underwater area at deeper draft gives a greater resistance.
True
Pg. 116
True or false a point of impact of transverse force that coincides with the center of gravity, as well as center of lateral resistance can be replaced with two forces half the size and equidistant from amidship (fore/aft)
True
Pg. 116
the ratio of ___________ and propulsion force has an important role in position at pivot Pt.
A. longitudinal Resistance
B. lateral resistance
C. Rotational resistance
0. None of the above
A. longitudinal Resistance
Pg. 17
When is the magnitude of transverse thrust at it greatest ?
A. When moving astern @2-3 kts
B. When the ship is Moving ahead or DIW
C. When the Ship just starts making stern way
D. All of the above.
B. When the ship is Moving ahead or DIW. The pivot point is forward.
Pg. 25
True or false the effect of lateral resistance on a turn is assistance because it has the same rotational direction as the transverse force
True
Pg. 28
When a bow thruster is used._____________ inertia has to be overcome before the swing sets in.
A. Longitudinal
B. lateral
C. RotationaL
D. None of dhe above
C. RotationaL
Pg. 50
When the bow thruster is used to swing lateral resistance ____________
the swing.
A. opposes
B. contributes to the swing
C. Neither ot the above.
A. Opposes the swing
Pg. 51 - 52
True or false a bow thruster at full speed may have an opposite ettect on the center ot gravity moving it away trom the swing.
True, When the pivot point moves between the center of gravity and the bow thruster this is true.
Pg. 52
with a ship under sternway the bow thruster has a very effective Lever w/pp after. The lateral resistance on the exposed quarter ________ the swing.
A. Counters the swing
B. Contributes to the swing
C. Neither of the above.
B. Contributes to the swing
Pg. 53
the rotational effect of the transverse thrust of the propeller can be easily overcome by ________ when
making sternway •
A. bow thruster or tug on the bow
B. stern thruster or tug on the stern
C. Wind on the Quarter
D. None of the above
A. bow thruster or tug on the bow
Pg. 53
The affect of wind on a ship has to be considered with respect to the ______________.
A . Center at Mass
B. Center at gravity
C. pivot point
D. Trim
C. Pivot point
Pg. 61-62
ship’s not freely moving are subject to pressure exerted by current this pressure is directly proportionate to _____________
And to the ____________.
to
1.
A. Draft ot vessel
B. trim ot vessel
C. exposed underwater area
D. freeboard of the vessel
2.
A. Velocity of current
B. Square of current velocity
C. Average velocity of current
D. STW
- C. exposed underwater area
- B. Square of current velocity
Pg. 62
When using a narrow channel on a large ship, suction and Rudder force act as __________ class levers and both forces gain leverage as the pivot point moves fwd.
A. 1st
B. 2nd
C. 3rd
D. 4th
B. 2nd class levers the slower the speed the better.
Pg. 87
The _______ has leverage with respect to the pivot pt and can be the point of impact of a rotational force when the ships mass manitests itself as ____________.
1. 2.
A. Center of Mass. A. Motion
B. Center of resistance. B. Resistance
C. Center of gravity. C. Momentum
D- None of the above. D. None of the above
- C. Center of gravity.
- C. Momentum
Pg. 114
True or false FR (lateral resistance for of the pivot point) has a direct rotational effect and is one of the principal forces that determines the pivot point
True
Where is the center of FR?
A. Between The pivot point and bow.
B. Between the pivot point and center of gravity.
C. Between the pivot point and mid ships.
D. Between the pivot point and center of longitude resistance.
A. Between The pivot point and bow.
Pg. 121
AR (lateraL resistance abaft Of the pivot pt) does what to the turn?
A. AssIstS the turn.
B. Increases dritt angle
C. opposes dritt angle.
D. All of the above -
C. opposes dritt angle. Works against rudder force
Pg. 121
True False the diameter ot the full speed, full rudder, turning circle is directly proportional to the steering lever and inversely proportionate to the lateral resistance lever.
True
Pg. 123 - 124
When is longitudinal resistance met?
A . When pressure bullds along the side o the Ship.
B. when pressure builds ahead ot the ship.
C. When pressure dissopates from ahead of the ship
D. None of the above
B. When the pressure builds up ahead of the ship.
Pg 10
When a ship working ahead turns the Rudder the result is a transverse force and longitudinal force. Which do we need to steer? Which causes a reduction in speed?
- Transverse force
- Longitudinal force
The turning moment is made up of the steering Moment and _________ moment.
A . Moment of lateral resistance
B. transverse Moment
C. Longitudinal moment
D. None of the above
A . Moment of lateral resistance
Pg. 28
What two forces form a couple to regenerate a swing if
unchected by the rudder .
A. Longitudinal force & Lateral force
B. lateral force and Rotational force
C. Lateral resistance & Rotational momentum
D - lateraL resistance & lateral Momentum
D - lateraL resistance & lateral Moment
As lat momentum decreases we can take off counter rudder to keep the ship steady.
Pg. 29
If not perpendicularly applied the tug’s force loses out in ________ force which further reduces the net _________ effect.
A. longtudinal
B. lateral
C. transverse
D. Rotational
- C. Transverse force
- B. Lateral
Pg. 53
the lever for rotational Motion when X is the pt of impact and y is the distance from the pivot pt?
- A: xy ft/tons
Pg. 117
Under full ahead and full Rudder, when the ship is momentarily at zero longitudinal speed, where is the pivot point?
A. 1B from the bow
B. 1/4 L
C. 3/4 L
D. None of the above
A. 1B from the bow
Steering levers can be calculated by 1/4 to 3/4 (L-B) when under speed.
Lat resistance lever is 1/2 (L-steering lever)
Pg. 123
A. Define Longitudinal Momentum?
B. Define Lateral Momentum?
A. Mass x fwd velocity
B. Mass x sideways velocity
Pg. 10
true False Transverce force pushing the stern to stbd coming ahead is at it’s maxImuM when the vessel is Moving ahead at 2 kts.
False, it is when the ship is DIW and the initial PP is fwd
Pg. 24
when using the rudder to swing to port the center ot gravity moves __________
When using the bow thruster to swing to Port the center ot gravity moves _________.
- Starboard
- Port
Pg. 51
The effect of wind has to be considered with respect to _______ and Current effects a ship’s _______ the most.
A. pivot pt
B. Center of gravity
C. Center ot buoyancy
D. longitudinal motion.
- Pivot point
2.B. Center of gravity
Pg. 61-62
In the Example of Fig 81 what class lever does the rudder act? What Class does the bank suction act? Does this slow the turn?
A. Ist Class
B. 2nd Class
C. 3rd Class.
D. None of the above
- A Ist class turns the bow to Starboard.
- C. 3rd class holds the tanker Captive by the attraction of the reef.
- yes the ship turns at half tha rate as a same dratt Ship in deep water
Pg. 87
In example san Nicolas, Aruba 1 outbound what class lever does the bow cushion act like? If we are taken unawares a Strong bow cushion force may turn it into a _________ lever.
A. Ist Class
B. 2nd class
C. 3rd Class
What is the objective of a 1st class lever?
- A. 1st class
- B. 2nd class this will shorten the steering lever.
- To gain in speed rather than force.
Pg. 90
When the Ship is under longitudinal motion ther center of lat resistance moves forward and serves as a _________
rotational motion.
A. hard tulcion
B. Soft fulcrom
C. Pivot Pt
B. Soft fulcrum
Pg. 116
A Ship under speed will meet lat resistance under rudder effect.
The center of lateral resistance serves the rudder as a ______ for the swing.
A . Soft fulcrom.
B. Pivot Point
C. hard fulcrom
A. Soft fulcrom
Pg. 121
Rudder force depends on what? (2 things)
Lateral resistance depends on what? (2 things)
1. A. Rudder angle. 2. A. Longitudinal resistance
B. Lateral resistance. B. Lateral inertia
C. Propeller thruster. C. Drift angle
D. Transverse resistance D. Speed through the water
- A. Rudder angle and C. Propeller thrust
- C. Drift angle and D. Speed through the water
True /False steering lever and lateral resistance lever remain constant when a ship is turning under constant speed.
True
Pg. 123
- Steering lever is rated as a ___________.2. What is the lever of lat resistance?
A. 1st class Lever
B. 2nd class lever
C. 3rd class lever
D. None ot the above.
- B. 2nd class lever
Steering moment = rudder force x steering lever
Steering lever is the distance from rudder to pivot point - B. 2nd class lever
Lever of lateral resistance is from R1 to pivot point
Pg. 123
What is the reason it takes more time to straighten up then to start a swing?
A. Because lat resistance remains acting on the opposite bow
B. Because lateral momentum has built up
C. Because the rudder force is working with more leverage
D. All of the above.
A. Because lateral resistance is working on the opposite bow and opposite direction to the rudder.
Pg. 29
Loss of speed does what to pivot point and drift angle
A. widens drift angle pushes point back
B. Narrows drift tangle pushes pivot point back.
C. Widens drift angle moves pivot point forward.
D. narrows drift angle pushes pivot point back
C. Widens drift angle moves pivot point forward.
Pg. 123
Holding power of an anchor depends on what? (3 things)
A. Nature of the bottom, the weight and shape of the anchor and the amount of chain out.
Pg. 70
For max holding Power of
an anchor What Should happen?.
A• Anchor is dug in and fetched
B. Anchor should be at on bottom w/ sutticient chain.
C. Anchor should be dropped with sternway.
D. all ot the above.
B. Anchor should be at on bottom w/ sutticient chain and be paid out.
Pg. 70
At best what is the holding power of an anchor? When shaft is lifted 5º? @ 15°?
1. 2./3.
A. 2 times it’s own weight A. 25%oless
B. 4 times its own weight B. 35% less
C. 6 times itS own weight C. 50% less
D. 8 fimes it’s awn weight D. 75% less
- B. 4 times its own weight
A. 25% less holding power
C. 50% less holding power
True/False when a 15-ton anchor is lifted 5° it’s still enough holding power to keep a 10,000 ton tanker in a 60 kt head wind
True, however in reality yawing and weaving create jerks that cause the chain to start dragging.
Pg. 70-71
When will an anchor start to drag?
A. When holding power of the anchor is less than force exerted.
B. When holding power of the chain is less than force exerted.
C. When holding power of the anchor & chains less than force exerted.
D. None of the above.
C. When holding power of the anchor & chains less than force exerted.
Pg. 71
If the bottom allows dredging an archor is a safe and practical way to ____________.
A. turn a Ship away from the dock.
B. swing the bow.
c. back out without losing control of the bow.
D. Stop the ship at full speed.
C. Back out without losing control of the bow.
Pg. 71
what is the secret to successfully dredging the anchor?
A. Keep a heavy Strain & Mod. speed
B. Keep a light strain & very slow speed.
C. Keep no strain & slow speed
D. None of the abave.
B. Keep a light strain & very slow speed.
Pivot point stays forward with a a low speed very little underwater resistance.
Pg. 71
What scope of chain should Be used when dredging Anchor?
A. 1½ times the depth ot water
B. 1 1/2 times dist trom hawsepipe to bottom
C. 2 times depth at water
D. 2 times distance from the hawsepipe to the bottom
B. 1 1/2 times dist trom hawsepipe to bottom
Hooyer
Pg. 71
True/False in order to dredge an anchor ettectively the flukes must dig in .
False you do not want the flukes to dig in.
Pg. 71
When dredging an anchor the pivot pt stays foward at min speed which results in _________ which makes the rudder very ettective.
A. a small swinging moment
B. a large swinging moment
C. low lateral resistance
D. High long. Resistance
B. a large swinging moment
Pg. 71
True or False Dredging an anchor makes It possible to hold the stern up In a beam wind when the anchor holds the bow.
True
Pg. 71 / 72
Force exerted by the anchor windlass gives mainly _________ motion.
A. rotational
B. longitudinal
C. lateral
D. A & B only
D. A & B only. Lateral motion ceases to have an effect as soon as the ship starts moving fwd.
True/False Heaving of the anchor brings the pivot Pt fwd of the center of gravity .
True
Pg. 78
In case of an emergency where we need to drop the anchor we should:
A. Swing to the side where we intend to drop it first.
B. Swing to the opposite side we intend to drop the anchor
C. Do not swing at all.
D. Lower the anchor under power.
A. Swing to the side where we intend to drop it first.
Pg. 83 -84
In the case of the 47,000 dwt tanker that lost power how was the master able to turn to stbd.
A. dropping the Port Anchor
B. dropping the stbd anchor & holding @ 1 shot.
C. dropping & veering |checking the stbd
D. Dropping both anchors.
C. dropping & veering & checking the stbd
True /False A loaded VLCC 250,000 DwT tanker can maneuver with very little strain on the anchor chain. even at DSA.
True
Pg. 130
True or False Shock load breaks chain free but constant strain holds.
True
Pg. 130
Where does the pivot Pt go when manoevuring on the anchor.
A . Aft
B. very far toward
C. midship.
D. None ot the above.
B. very far toward, No speed through the water no weight pushes the pivot point aft, no underwater resistance.
Pg. 130
When maneuvring on an anchor the ____________ and the _____________ Of the ship absorbs the
Part ot the kinetic energy gen, by prop Force.
A. Lateral inertia
B. Weight of the chain
C. Rotational inertia
D. Long inertia
- B. Weight of the chain
- D. Long inertia
On a big ship the long inertia is a benefit
Pg. 130 - 131
what is a disadvantage ot having a tug for assistance?
A. tugs may push on the side prior to be made fast
B. Tugs may give additional unwanted longitudinal motion when trying to assist a ship underheadway
C. If their is not enough room to work the tug may shove ahead as well as push to the dock
D. All of the above
D. All of the above. Part of the tugs time might be spent increasing headway.
Pg. 56
What is the advantage of using a tug tor assist work?
A. Tugs can fit into many small spaces alongside the dock
B. You get immediate reaction for a command
C. Can be used to limit or reduce speed as well as push and pull to the dock
D. All of the above
C. Can be used to limit or reduce speed as well as push and pull to the dock
Pg. 56
What is the advantages of a tug out fitted with a nozzle?
A. Increases tugs directional Stability.
B. Increases tugs towing lever.
C. Increases output (bollard pull) on ahead up to 130%
D. all ot the above.
C. Increases output (bollard pull) on ahead up to 130%.
However loses half that pull on astern. There may be further wash with the wash directed at the sides.
Pg. 57
True False the advantage of having a tug alongside is that it is good for pushing.
True. On a ballasted tanker lines give bad loads for pulling and is impossible to work in poor weather.
Pg. 60
When two tugs equadistant from amidships, Ship DIW where center of gravity and lateral resistance coincide the lateral attect is:
A . 2x tons
B. 1 x tons
C. 3x tons
D. None of the above
A . 2x tons
pg 118
Two tugs working equidistant trom amidships, Ship is moving ahead in the water what is the lateral ettect .
A. Ix tons
B. 2 x tons
C• 3x tons
D. 1/2 x tons
A. Ix tons
The aft tug needs to be stopped completely with no strain on the line
Pg. 118
True / False under head motion ot the assist ship the fwd tug finds the most leverage when its line is made as
far fwd as possible .
True
Pg 119
Where may tugs find the most trouble finding bits?
A working twd .
B. Working Att
C. working Alongside or Amidship
D. None of the abore.
C. working Alongside or Amidship. May need to find a cross bit near the manifold.
Pg 119
When the ship is moving astern through the water with three tugs
2 aft tugs equidistant trom the pivot pt the fwd tug is stopped. what
Is the lateral ettect?
A。1X tons
B. 2x fons
C. 3x tons
D ½xtons
B. 2x tons
The after tug is made fast as far aft as possible as shown in fig 104.
Pg. 120
When turning into a finger Pier for backing using only Rudder & Prop what motion is created?
A. Rotational
B. Longitudinal
C. Lateral
D. All of the above
D. All of the above.
Pg. 54
True False The rudder force plays an insigniticant role when the ship Is under sternway
True
Force produced by underwater resistance is small, pivot pt is aft.
Pg. 35
True or False Bow thruster use has been observered to cause a slight creep ahead motion of the ship.
True could be caused by initial flow of water from ahead of the ship into the tunnel
Pg. 50
True/False there is tendency to over use the bow thruster, probably because ot the direct control trom the bridge.
True
Pg. 50
True/ False during the time lapse betweer the RPM that has been called for and the speed it produces a build up of resistance forward is not yet proportionate to the increase of propulsion force causing the pivot pt to move torward.
True If the rudder is put hard over it will be working on a momentarily increased leverage with the ship at a comparatively low speed through the water.
Pg. 30
A complete turn under full rudder and full speed takes ______ the room when initially stopped than with full speed through the water.
A. Same amount
B. twice
C. Half the room
D. Three times
C. Half the room. Momentum causes wide turn inertia enables a short turn and resists long acceleration
Pg. 33
True or False As longtudlinal motion increases lateral resistance increases and opposes a turn by the bow thruster which decreases the thrusters effectiveness .
True, Leverage also decreases as PP moves forward.
Pg. 52
True/False A tug pushing in the same direction and same position as the Bow thruster has the same diminishing effect with increase of fwd motion of the Ship •
True
Pg. 52
True / False lateral motion comes off sooner than rotational motion.
True, results in a flat landing.
Pg. 55
In order to stop side momentum of a loaded Ship stemming the current you must can’t the vessel and put the current on the opposite side of the hull. In order to accomplish this we must move the ________ over.
A. Pivot pt
B. Center of gravity
C. Center of lat resistance
D. All of the above
B. Center of gravity must be moved over with respect to the pivot pt.
Pg. 66
The center of rotational motion when a ship is under longitudinal motion is?
A. Center ot lateral resistance
B. Center ot gravity
C. Center ot longitudinal resistance
D. Pivot point
D. The pivot point
Pg. 116
As drift angle opens up _________ develops against the exposed ship’s side .
A. longitudinal resistance
B. lateral resistance
C. Rotational resistance
D. transverse resistance
B. Lateral resistance
Pg. 121
True False The diameter of the full speed turning circle is larger than the diameter of the completed turning circle.
True
Pg 125
When using rudder for a port turn and ship’s moving ahead lateral resistance increases in direct proportion to __________ and contributes to the swing.
A . propeller force
B. rudder torce
C. transverse force
D. None of the above-
B. Rudder force
Pg 51
What is the lateral force coefficient for cross currents in deep water? What is deepwater considered?
1. 2.
A. .4. A. 1 1/2 x draft
B. .8. B. 2 x draft
C. .6. C. 5 x draft
D. .1. D. 6 x draft
- C. .6
- Deep water = 6 x draft
Pg 138
Tug Use In Port - Hensen
