Ship Handling Flashcards
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
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
(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
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
The magnitude of the rotational momentum introduced upon a ship depends on what?
Behaviour and Handling of Ships - Hooyer
Ships mass
P 23
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.
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
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
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
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
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
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
- 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
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
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
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
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
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
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.
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.
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
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)
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
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 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
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
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
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
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
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
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 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 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
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
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
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
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 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
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
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
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
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
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/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
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
What is a single greatest influence upon the magnitude of the title force?
A. Draft
B. Depth ot water
C. UkC
D. Trim
C. UkC
This is due to the blocking effect of a vessel as UK see reduces .
Pg 81 Shiphandler’s Guide - Rowe
What is the conversion trom KW to Shaft horse power (SHP)?
Shaft HP to tones force?
.74 =1 SHP
100 SHP = 1 T
Pg 89 Shiphandler’s Guide - Rowe
If their is a choice when entering a bend in a river which part of the turn would be prudent to take:
A. The inside of the bend
B. The outside of the bend
C. Middle Channel.
D, It mates no ditterence
B. The outside of the bend. The flow of the current is the strongest
Pg 77 Shiphandler’s Guide - Rowe
To slow down a persistently high-speed with a following current, you will put the engines of stern. What will this do to the pivot point and control over the situation?
A pivot point moves after and are at the whim of transverse thrust
B. Pivot point remains forward and have complete control.
C. Pivot point moves after you have Control.
B. The outside of the bend. The flow of the current is the strongest
Pg 77 Shiphandler’s Guide - Rowe
What technique can be used to keep speed low, controll heading with kicks ahead virtually drive to a desired position and remain there.
SHG- Rowe
Dredging two anchors
Pg 53
What speed Should the vessel be going when approaching the swing area and instant of letting go
the anchor? (turning short round)
A. Minimum for steerageway and SOG as low as possible as stern before applying brake on windless.
B. slow had engines and a stern
C. 2 knot speed through the water and one knot speed through the water.
Dredging two anchors
Pg 53 Shiphandler’s Guide - Rowe
Which direction should the bow be canted when turning short round?
A. Towards the deepest swatter in the channel.
B. So that the tide is on the correct quarter to the turn.
C. To starboard.
D. None of the above.
B. So that the tide is on the correct quarter to the turn.
Pg 74 Shiphandler’s Guide - Rowe
What is the e downside to a diesel - powered Ship with a fixed propeller when utilising the kick ahead method?
The number of starts of the engine
Page 20 Shiphandler’s Guide - Rowe
True or false the difference between the modern conventional bulbous bow, and the more traditional rounded bow has no significant influence on title flow
True, This should be taken into account in the interest of accuracy
page 81 Shiphandler’s Guide - Rowe
When twin screws are design too close together the ability to torque or turn is quite poor. What is the best option for maneuvering?
A. Or stop one and use as a single screw.
B. Use them together as one like a single screw.
C. None of the above.
B. Use them together as one like a single screw.
Page 121 SHG – Rowe
How much does the location of the pivot point change when twin screw vessels are used?
A. Pivot point while backing is 1/4 length stern
B. Pivot point making headway 1/8 L to 1/3 L from forward
C. The fundamental concepts remain the same for pivot point.
D. All of the above.
All of the above. An exception would be immensely powerful ships that can turn on the spot.
Page 125 sHG – Rowe
When the tow line is slacked and the tug is making way, where is the pivot point?
A. Where the tow line contacts the tug.
B. 1/8 L from the bow.
C. 1/4 L from the bow
C. 1/4 L from the bow
Pg 131 Shiphandler’s Guide - Rowe
True or false unless there are excessive, Highwinds or maximum current should be able to negotiate any turn in a river or channel without tug assistance
False the ships size, shallow, water, tides, or any combination would require tug assistance
Page 150 to 153 Shiphandler’s Guide - Rowe
True or false when installed on larger, single screw shifts the nozzles are usually rid rigidly attached to the ship’s stern.
True in other cases, the shroud moves as one unit with the propeller becoming a nozzle or azimuth drive.
Page 110 Shiphandler’s Guide - Rowe
Propellers in shrouds tend to have how much transverse thrust?
Very little. flow of water is concentrated on both sides of the whole equally
Page 26 Shiphandler’s Guide - Rowe
When is Rudder force optimum for vessel?
When the ship is dead in the water and Ford movement is initiated with hard rudder
Page 27 Shiphandler’s Guide - Rowe
The turning lever for a ship, making sternway is ________ than that of a ship making slight headway.
Smaller. This situation is not helped by the center of when moving aft as the wind comes to the quarter.
Page 41
Trim by the stern with sternway will have which effect on a ship?
A. Intensify wind effect.
B. Nullify wind effect.
C. None of the above.
A. Intensify wind effect. With a pivot point and waypoint further away, you create a larger turning lever.
Pg - 41
What forces may be used on the turning lever of a ship?
Rutter force transverse force, bowthrust force, tug force, and forces of the wind and tide.
Page 12 and 13
What two factors determine how much power should be applied for a kick ahead?
The size of the ship and the needs of the ship handler at the time.
Pg 18
What design may cause a reduction of transverse thrust to the extent that the bow may fall off in either direction?
Hull design
PG – 26
These three factors are the same to create the same turning circle?
RPM, Rudder force, and lateral resistance
Pg 27 - 30
When tidal force is exerted 19 tons of pressure on a 50,000 DWT tanker at anchor with a 3.0 draft ratio what is the force when the draft ratio is 1.1?
64 tons. Longitudinal title force increases by three times
Page 8164
when the tide goes out and a ship is left with a 1.1 draft to depth ratio, the __________ forces of the current have the greatest effect on a ship at anchor.
Lateral forces
Page 83
The force on the beam of a 280,000 DWT ship with a 1.05 depth to draft ratio is 328 tons at .5 kn what is it at 1.5 kn?
700 tons
PG 83
The force of the tide is directly proportional to the _________ of the tidal force?
Square
PG 83
From a dead stop to turning with the ships propulsion in conjunction with the Bow thruster where does the pivot point move when the ship picks up speed?
Moves half ships length from forward. 1/2 L
Page 94
What is a Combinator in reference to CPP systems?
A. Gives the ability to the helmsman to change pitch or engine speed.
B. Built in control that balances a reduction of revolutions at slow speeds.
C. Built in control that balances an increase in revolutions at high speeds.
D. B and C are correct.
B. Built in control that balances a reduction of revolutions at slow speeds.
Helps with fuel economy
PG – 106
How does the stern power of a ship with a shrouded propeller compare to the same size ship with an unshrouded propeller?
The stern power of the shrouded propeller is very poor in comparison
Pg 112
True or false Twin shilling, Rutters are the same in concept of design and operation to single flap or shaped rudders.
False the system is totally different in design and operation
PG 116
True or false twin schilling, rudders act independent of one another to achieve maximum efficiency
False these writers are synchronized to work in harmony with each other in response to a single joystick control
PG – 116
With a single rudder and a twin screw response time is __________ and realize on what?
Exceptionally poor and vessel speed
Pg 119
When the starboard prop to an O /B turning fixed pitch twin screw prop is put a stern. How does it behave?
A. Like a left-handed prop.
B. Like a right handed prop.
C. No transverse thrust is noted.
D. None of the above
B. Like a right handed prop.
Prop heal discharge goes to the starboard quarter bow goes to starboard
PG – 122
True or false backing one engine is the best way to turn a twin screw vessel no matter what speed.
False this is fine at low maneuvering speeds. It is unwise at moderate speeds. Transverse thrust is a poor force.
Page 127
Where should the towing hook be to increase maneuverability of a tug as much as possible?
A. As forward as possible.
B. Aft close to the prop.
C. It does not matter
A. As forward as possible, this has a tendency to place a conventional tug at risk for interaction or gifting
Pg. 131
What does it mean to bows down or gob down when referring to tug operations?
A. Adjust the length of the gob line.
B. Work hard againt gob line.
C. Turn downstream.
D. To release the gob line.
A. Adjust the gob line
Pg. 138
What option to traditional tugs can be used to assist a turn when Ballard poll cannot be used?
A. Find a bigger more maneuverable tug.
B. Use the power of the tug to maintain position and tugs weight to lay on the tow.
C. Use a gob rope.
D. None of the above.
B. Use the power of the tug to maintain position and tugs weight to lay on the tow.
This can be done on the bow at higher speeds to assist, swinging the bow
Pg 138
When using the tugs weight to assist in return with a traditional tug, which tug is more restricted? Bow/Stern
The stern tug usually resorts to the following on a slack line until speed is reduced to get imposition
PG 138
Where are the two towing positions that an ASD tug is located?
One Forward and one mid ships propulsion is two aid units located after similar to traditional twin screw tag positions
PG – 144
Which tug position should be used with caution because of the healing angle with full side, thrust and backwash and turbulence?
Lashed up alongside backwash and turbulence is due to the close proximity of the hull
PG 147
Which tug position is best when moving a dead ship where the tug can work as a Rutter and propeller?
A. Lashed up tug aft
B. On a hawser forward
C. On a hawser aft
D. Lashed up forward
A. Lashed up tug aft. Should be as far after as possible.
PG Dash 149
When an ASD tug is working position, one it can paravane out as long as the tow line is coming off the bow it does not generate the same force as a tractor tug because of what?
A. ASD lack the BP of a tractor tug
B. ASd has propulsion aft
C. Tractor tug have a larger skeg.
D. None of the above
C. Tractor tug have a larger skeg.
Pg 150
True or false a ship with a good bow thruster can replace a tug up forward.
True. A ship without a bow thruster should have the tug placed close to where the bath thruster should be.
Pg 158
A 1000 KW baluster generates how much force?
1341 SHP or 13 tonnes
Pg 47
.74 kw = 1 shp
True or false It is often more expedient to use backing into a birth as a method for docking star side, two as opposed to bow in
Using a large reserve, power for positioning and control helps much more to control position of the stern and speed
Pg 104
What effect can be used to lift the ship bodily off the dock when backing out?
Wedge effect
Pg 24
CPP clockwise rotation acts like a traditional ______________ handed propeller. CPP counterclockwise acts like a traditional __________ handed propeller.
- Left-handed. Cut the bow to port.
- Right handed cuts the bow to starboard
PG 26
In general, where can the weakest current in a bend be found and what is the drawback to using this side during a turn?
A. Outside of the bend and too shallow for most ships.
B. Inside the bend and to shallow.
C. The middle of the channel in subject to rotary currents.
B. The inside of the band has the weakest current generally is shallow..
PG 77 all right
When may a ship lose the influence of the current in one part of the ship and cause an unexpected turning lever?
A. Passing close to the end of a jetty or shallow area.
B. Passing from shallow water to deep water.
C. Passing the ship at close quarters
D. None of the above
A. Passing the end of a yeti or shallow water, this can be remedied with a healthy kick ahead.
Pg 77 - 80
True or False: If a bow thruster is equal in power to a dead, slow ahead, kick dead, slow ahead should be the only thing used in working a ship laterally
False. More powerful kicks may be useful a compromise at lower power power may be used.
Pg 94 - 96
If the ship is allowed to creep ahead, where does the pivot point move the instant it begins to make headway?
1/8 length from the bow
Pg 104
What 2 forces come in to play when making headway? Where does the pivot point go when making steady speed forward?
- Forward momentum and longitudinal resistance to forward momentum.
- 1/4 L from fwd
Pg 12 - 13
What is SHP?
What is BHP?
Shaft horsepower: the power generated to turn the prop
Break Horsepower: the actual power developed by the engine
Pg 20
An 80,000 deadweight ton ship with full ahead power of 20,000 SHP how much force is applied to the starboard when backing assuming 50% of is applied a stern and transverse thrust 5% to 10%
1,000 SHP or 10 tonnes
100 SHP = 1 ton
Pg 23
Shaft horse power is an important factor in determining the magnitude of transverse thrust. What must also be considered when going astern?
Location of pivot point
Pg 23
When does transverse thrust start to create a turn moment on a vessel?
When it is moving slow enough for the propeller wash to meet the hull
Pg 24
When does the magnitude of transverse force reach its peak when making headway?
What will maximize transverse force?
- Just prior to the ship being completely stopped.
- When stern power is applied it’s at its maximum.
Pg 24
What is the only thing that changes with changes in speed in regards to turning?
Rate of turn
Pg 30
During a turn the exposed side experiences increase in water resistance which acts as a brake. A ship may see _______ % to _______% speed loss during a turn.
30% to 50%
Pg 30
Standing turns and kicks ahead can reduce a turn radius this is because a reduction in _________.
Lateral resistance
Pg 30
When the stern is sweeping to port during a turn in shallow water where does the water pressure build up?
A. Fwd of the pivot point
B. At the pivot point
C. Abaft of the pivot point
C. Abaft of the pivot point. Due to restricted UKC
Pg 33
True or False: If the wind is on the port beam, transverse thrust from a fixed right hand prop may be nullified, depending on the strength of the wind/prop power will determine which way the stern swings (while backing).
False a port beam wind will intensify bow swing to stbd stern to port. Starboard beam wind will be unpredictable
Pg. 41.
At best how much power percentage is used with a kick ahead at full power?
A. 50%
B. 35%
C. 45%
D. 80%
C. 45%
Pg 43
When using lateral motion to walk a crossed the tide this is called?
A. Crab
B. Poor man’s tugboat
C. All of the above.
C. All of the above.
A kick ahead at full power will produce approximately what percentage of sideways thrust?
A. 70% - 80%
B. 10% - 20%
C. 40% - 50%
D. 20%-30%
C. 40% - 50%
If the Main Engine produces 12,000 SHP - 120 T that’s 48 - 60 tonnes of thrust.
Pg 94
What is the weakest link on the ground tackle assembly?
A. The anchor chain
B. The anchor
C. The windlass
D. The Jews harp
C. The windlass
Pg 49
Where would the windlass most commonly fail?
The brake
Pg 49
Safety parameters for dredging anchors include:
A. Cable length not to exceed 1.5 x depth of water
B. Windlass gypsy head speed of 30 ft/min
C. Windlasss designed to lift deadweight of anchor + 4 shackles
D. All of the above
D. All of the above
30 ft / min is .3 kts ship speed over the ground
Pg 50
What is the optimal speed for dredging anchor so that it does not dig in and holds?
A. .3 kts
Pg 50
Dredging anchors is very effective for controlling what two major problems when berthing?
A. Control of heading & speed
B. Control of heading & drift
C. Control of speed & drift
A. Control of heading & speed
Pg. 50
When dredging two anchors where does this bring the pivot point?
Between the two anchors
Pg 50
True or False: even if the vessel with two anchors down may slow or stop the pivot point stays forward and Lateral resistance remains low.
True
Pg 50
What are the three rules of thumb when dredging two anchors?
- Speed must be low
- Max cable depth x 2
- UKS must be 20% of max draft
Pg 51
True or False: Dredging one anchor is easier to control speed then dredging 2 anchors.
False
pg. 53 - 54
When dredging with one anchor where does the pivot point go?
The hawse pipe of the anchor being dredged. And effectively acts like a back spring.
Pg 54
True or False: excessive swings can develop if a helmsman allows too much of the swing in either direction. Sluggish rudders may cause violent sheering and grounding.
True longitudinal pressure forces can be easily brought to an exposed side due to shallow water effect.
Pg 59
What can develop from prolonged use of kick ahead?
A violent sheer or unwanted build up of speed.
Pg 18
Which way does a right hand prop swing coming ahead?
Slight swing to port
Pg 23
True or False the effect of wind making sternway is generally more complex and less predicatable.
True
Pg. 41
Assuming HP is a little over half of the ahead power, how much power will be used for transverse thrust?
10%
Pg 47
When a ship is running with a 1.5 kt current from astern where is teh pivot point if it is running at a considerably higher speed over the ground then the current is running?
Forward, in order to keep the pivot point forward the ship will have to run at a considerable higher speed than the current.
Pg 72
A gop rope clearly limits the maneuverability of tugs stern under the towline to a relatively small arc. What advantage does it provide?
A. Keeps the stern up to the ship
B. It allows the tug to dig in at suitable slow speeds
C. It moves the pivot point over the Propellers
D. A and B only.
D A and B only. The tug master can slack the rope to reposition and come back on again.
Pg 138
With a ship making way what kind of turning lever does a tug have on the bow?
(Ship 160 m long) (tug 20 T)
A. 40 x 20 = 800 tm
Pg 153
Where is the best position for a tug in an emergency when you need to slow down?
A. On the stern digging in and braking
B. On the bow pushing
C. On the quarter lashed up
D. All of the above
A. On the stern digging in and braking.
Pg 153
A 160 M ship has a tug on the bow and stern (20 T tugs). What is the turning lever for the tugs when the ship is DIW?
Making headway? Making sternway?
A. Stopped FT 80 m x 20 t = 1600 tm
AT 80 m x 20 t = 1600 tm
B. Headway FT 40 m x 20 t = 800 tm
AT 120 m x 20 t = 2400 tm
C. Sternway FT 120 m x 20 t = 2,400 tm
AT 40 m x 20 t = 800 tm
Pg 154
Where is the pivot point when a vessel is stemming the tide moving at a very little speed over the ground but making headway through the water?
Pivot point is forward
Pg 72
When operating against the current and the ship is allowed to drift back where is the pivot point?
Midships
Pg 72
True or False: Crabbing or using the current to create sideways motion can be accomplished by bringing the ships SOG to zero and directing the tide to the appropriate bow with the rudder along.
True. A short kick ahead can be used to ease the tide to stop bring the head back towards the tide.
Pg 72
What may be encountered by using the bow thruster?
A small amount of headway. A buildup of positive water pressure along the ship’s side which creates water flow around the bow causing low pressure ahead of the ship
Pg 93
What is true concerning twin schilling rudders?
A. This system is incredibly complicated and hard to learn.
B. This system is a little strange at first but after some instruction it’s picked up relatively quickly.
C. This system is the same as a conventional rudder system.
B. This system is a little strange at first but after some instruction it’s picked up relatively quickly.
Pg 118
True or False some twin screw props are designed well beyond the fore and aft line of a ship if this is the case the master may have to stop the inboard propeller while coming close to the dockside.
True
pg 121
True or False:
The effect of inward turning fixed pitch propellers upon a ship is extremely severe and unmanageable from a shiphandling prospective. Often one engine is stopped and maneuvered like a single screw.
True.
Pg 124
Transverse thrust is more noticeable with _____________.
A. Ahead movement
B. Astern movement
C. Equally noticeable
B. Astern movement
Pg 23
Which movement of the ship is of greater significance to teh ship handler when considering transverse thrust?
Astern movement
Pg 23
True or False: The large superstructure and funnel of a vessel is the only thing to consider when estimating the effect of wind on a ship.
False. The freeboard forward of the house to the bridge should also be considered
Pg 38.
True or False: The center of wind is sometimes much farther forward than expected.
True
Pg 38
True or False. Small increases in wind speed mean small increases in wind strength.
False. They can mean large increases in wind strength. Gusting can have an enourmous strain on a ship.
Pg . 43
Large full bodied ships have ___________ turning circles. (Poor or good)
Good, mall lined ships have poor turning circles
Pg 36
True or False the same ship doing a full ahead and slow ahead turn will create virtually the same turning circle for 20º and 35º turns.
True. Pg 27
When a vessel is backing down and intending to work the ship to starboard and checking the swing on the bow with the thruster what can be an unintended consequence?
The ship sets itself to port with the bow operating bow thruster and the stern transverse thrust.
Pg 96
When is the bow thruster most efficient?
A. When working astern
B. When the ship is stopped
C. When working ahead
D. A and B only
D. A and B only
Pg 96
What is the maximum angle a Becker rudder will give you when the helm is put hard over?
70º
This adds much more turning ability over the conventional rudder.
Pg 115
The maximum rudder angle for twin schilling rudders is what?
110º
Pg 116
By splitting the engines of a twin screw propeller system in a turn where does the pivot point go? What happens as the vessel gets headway or sternway?
- 1/8 L of the bow permanently.
- The pivot point moves aft
Pg 125
What is the best way to turn a twin prop vessel at moderate speeds?
A. Put one engine astern and one engine ahead w/hard over rudder.
B. Hard over rudder with sufficient power kicks ahead.
C. Hard over rudder.
D. Both engines astern.
B. Hard over rudder with sufficient power kicks ahead.
This results in a much tighter turning circle.
Pg 127
When a tug takes the weight of the tow where does the pivot point go? What happens to the turning moment?
A. After and is reduced
B. Stays the same and stays the same
C. After and increases
D. Fwd and increases
A. Aft and is reduced
Pg 131
What is the safest practice for tug approaching a ship from the stern?
A. Approach at full speed
B. Have the vessel slow down
C. Have the vessel stop engines
D. Approach at slow speed
C. Have the vessel stop engines. The tug mast should be fully informed as to the status of the ship’s propulsion.
Pg 134
Where is the best place for a tug to be to prevent gifting?
A. 1
B. 2
C. 3
A. 1
Regardless of the ship speed it has a small angle on the bow position 2 may be out run with too much speed or stbd helm position 3 is the worst it is pulled along the radius of the towing line.
Pg 136
Which position is the best for a conventional tug on the stern? What is the worst most risk in girting?
A. 1
B. 2
C. 3
A. 1 is the best and most effecient for a conventional tug with max bollard pull in all directions
Position 2. The tug keeps in the heading and has a tendency to get the tow line on the bow.
Position 3 is the worst position tug dragged around the radius.
Pg 136
These two things should be remembered if a conventional tug is working forward.
- The risk of girting is increased and the tug master must keep a close eye on ship’s speed.
- Tugs may imapart an insidious increase in speed to the ship which needs to be monitored
Pg 140
What are the advantages of tractor tugs? 10 things
- Full thrust 360º
- Rapid power on response
- Outstanding maneuverability
- Able to reposition quickly
- Simple control systems
6.very low risk to girting - Can more effectively overcome interactive forces
- Improved operational capability in a restricted area such as enclosed dock
- May decrease the turn around time of port movements that use tug assist
- Reliable robust prop units
Pg 142
What are the disadvantages of tractor tugs? 8 things
- High capital investment costs
- Less bollard pull per KW power
- Repair and maintenance of complex underwater units may be expensive
- Handling in open seaway might be poor with the short distance between pivot point and thrust creating a short turning lever
- Heeling angle with full thrust may be up to 21º with some tugs. There fore risk of damage can exist when laying alongside a ship
- Sophisticated underwater units may damaged or grounded
- Draft may be up to 5 meters, which is large in comparison to conventional tugs
- The re-training of conventional tug masters in order to fully max a tractor tugs potential
Pg 144
What are the advantages of ASD tugs? 6 things
- Better directional stability at speed
- More suitable hull form for open waters and working in a seaway
- Improved bollard pull per KW power
- Azimuth units easy to withdraw for maintenance and repair
- Maximum heel with side thrust less than 15º
- Shallower average draft of 3m
Pg 144
What are the disadvantages of ASD tugs? 6 things
- Side stepping ability not as good
- Squat at the stern and flooding of the aft deck has been known to occur with certain design types when backing full power
- Still susceptible to girting from effects of interaction
- It is not uncommon for 99% of all towing to be limited to fwd position
- Complex control systems
- More susceptible to rubbish damage in propellers.
Pg 144
Note on Tractor Tugs
Position 1 and 2 if the ship’s speed is sensible it can assist in swinging and positioning this is similar to a conventional tug.
Position 3 shorten but retaining the tow line, this will give it more push pull position during breasting.
Note tractor tugs working tug fwd
Position 1 is good for lifting off from the berth and can move in to push or check ship’s speed.
Position 2 is lashed up alongside is used in lifting off with a lot of power.
Pg 147
What is paravane effect?
A. Tug on a hawser aft uses its weight and water pressure to assist in swinging and steadying
B. Tug on a hawser aft direction pull aft
C. Tug aft quarter pushes or pulls
D. Tug on the bow shoulder uses its weight and drag to turn the vessel.
A. Tug on a hawser aft uses its weight and water pressure to assist in swinging and steadying.
Also known as indirect towing.
Pg 149
When in indirect towing mode the pull on the tow line can increase by a factor of ________ to ________ times the bollard pull.
1.5 to 2 times
Pg 149
These are questions you should ask when positioning a tug. 5 things
- What is the intended movement or maneuver?
- Will the ship be predominantly with headway?
- Where will the ship’s pivot point be?
- Where will the tug be in relation to the ship’s pivot point?
- What type of tug being used?
Pg 150
What are some reasons to require a tug escort?
A. Wind, current, ship size or shallow water or a combination exceeds the ship’s normal turning ability
B. Legislation requires it based on previous accidents or pollution
C. Serious equipment failure of ship
D. All of the above
D. All of the above
Pg 153
What is the benefit of having a tug forward when the vessel has fwd momentum?
A. Best place to assist in swinging the vessel
B. This is an ideal place to help brake and stop up
C. Most effective spot to create lateral movement
D. All of the above
C. Most effective spot to create lateral movement
Coupled with hard over rudder and kicks ahead.
Pg 156
When using an anchor to turn short round and it doesn’t seem to have the desired effect what should the first move be?
Let out more chain
Pg 76
Where does the pivot point go when going astern?
1/4 L from the stern
Pg 12 - 13
Trim in which direction will change a vessels wind handling characteristics? (While moving fwd with headway)
Trim by the stern with a pivot point close to the wind point wind effects the turning lever is reduced.
Pg 41
Rudders that include flaps, rotors or rotors with flaps are called what?
Becker rudders also jastram rudders
Pg 115
A rudder where the top and bottom is constructed with flanges which helps channel water flow across the rudder face as it run into the concave section before being deflected at a sharp angle at the end is what?
C. Single schilling rudder
Pg 115
Single schilling rudders and Becker rudders that are capable of 70º are used like conventional rudders they have one advantage which is?
A. Excellent turning ability
B. Excellent fuel economy
C. Excellent response time
D. Excellent backing power
A. Excellent turning ability when used in combination with the bow thruster the lateral motion with kick ahead can be even too excessive.
Pg 115
When handling a twin screw ship at moderate speeds the following is true?
A. Transverse thrust is a good turning force
B. Transverse thrust wash will not reach the hull if the speed is too high
C. Rudder force generated with ahead power is a poor turning force.
D. Correctly applied kicks ahead will not be the most effective way to tighten a turn.
B. Transverse thrust wash will not reach the hull if the speed is too high.
Every thing else is opposite
A. Transverse thrust is a poor turning force
C. Rudder force generated with ahead power is a good turning force
D. Correctly applied kicks ahead is the most effective way to tighten a turn.
Pg 127
What is the formula for calculating wind speed in meters / second from knots? What is the formula for calculating wind force in tonnes?
V = wind speed in meters/second
V = wind speed in knots / 2
Force (tonnes) per 1000 m2 = V2 / 18
Pg 43
What might a tug experience when approaching from the stern?
A. An increase in speed
B. A sudden sheer toward the stern of the ship.
C. Less water resistance ahead
D. All of the above
D. All of the above.
Pg 134
Where is the riskiest place for a conventional tug to work?
On the stern
It is frequently obliged to lay with the tow line much more inclined toward the beam.
Pg 136
What are five things that a traditional tug may be at a disadvantage compared to a tractor or ASD?
- Interaction
- Girting
- Excessive ship speed
- Confined locks and dock areas
- Traditional maneuverability
Pg 138
The directional stability of a tractor tug can be improved by what feature?
A large skeg
Pg 142
What best describes a combination or combi tug?
A. A combination of tractor tug and ASd tug
B. Traditional tug retrofitted with a thruster system forward
C. An ASd stern drive tug with a thruster fwd
D. Two thrusters forward like a tractor and one aft centerline
B. Traditional tug retrofitted with a thruster system forward
This could be anything from a thruster system fwd or a tunnel thruster to an azimuth thruster unit that will improve handling characteristics.
Pg 144
When placing a tug for maneuvering what is the most important factor to consider?
A. Where the tug will be in relation to the ship’s pivot point
B. How powerful the tug is
C. Where the pivot point of the tug is
D. What kind of tug is available
A. Where the tug will be in relation to the ship’s pivot point
Pg 150
Which statement is true concerning a bow thruster?
A. Thruster is always fast coming to full power
B. The ship will steer sluggishly with a tendency to flop to either side
C. The thruster will be quick to correct ROT
D. Looking astern ROT is easily perceived
B. The ship will steer sluggishly with a tendency to flop to either side
The thruster may be slow coming to full power.
The thruster may be slow to correct ROT
Looking astern ROT is not easily perceived
Pg 99
A 200 m ship with a 12,000 shp main engine will use how much of this to go astern power? How much will be transverse thrust?
60% ahead and 10% transverse thrust
720 shp or 7 tonnes
Pg 99
True or False shrouds are especially effective at low speeds and high loads at zero fwd speed and full power about 50% of thrust comes from the duct.
True
pg 110
What happens to the water flow a crossed the rudder when angles that exceed 45º are put on the rudder?
It is progressively turbulent until the rudder stalls out is much less effective
Pg 115
How does a joystick control work with twin schilling rudders? Full ahead? Bow to port? Full astern? Stop engine? Astern?
Full ahead: joystick fully forward as eased back open outwards to reduce speed.
Bow to port: joystick forward and to port one rudder 70º and one is 35º
Full astern: joystick is pulled back until rudder rotates to 110º closing gap between
Stop Engine: achieved by adjusting the joystick to appropriate intermediate neutral setting
Astern: stern to port when operating full aster backing or slowing joystick is eased to port quarter control bow with kicks ahead.
Pg 118
If the wind is on the port beam how much does this effect transverse thrust when backing with a fixed right hand prop? What is the best way to overcome it?
- It will be nullified.
- Overcome with kicks ahead
If the winds over ride the power of the bow thruster and attempting to back down what should be done?
Do not attempt to back down
Pg 103
What can be done when backing down to limit transverse thrust?
Take every opportunity to stop the engine and keep the pivot point aft.
Pg 103
What are two advantages to backing a ship to a berth and using engine power?
- You can correctly position the stern
- You can check the stern speed and keep it to a minimum.
Pg 104
When going stbd side to with a left hand cp propeller which direction will the natural flow of water go when approaching or departing?
Along the stbd side pushing off the dock. This is coming ahead.
What is true about a tug aft when backing into a berth?
A. It is best placed to help develop bodily lateral motion
B. It will be useful in lifting the ship off the dock
C. It is not the best position to turning
D. All of the above
D. All of the above
Pg 158
True or False when approaching a berth with the wind dead ahead it is much easier to control vs. wind on the beam.
True
Pg 41
What is the best way to back into a berth when going starboard side to when considering stern placement?
Keep the stern close to the berth. Keep the heading so that it leaves sufficient distance to work alongside this tendency can then be used to swing the ship forward of the pivot point towards the berth and keeps the pivot point back when using the thruster.
Pg 103
When going starboard side to a berth and approaching with the bow what may be the best way to dock?
A. Run past the berth and back in
B. Continue straight into the berth
C. Dredge the port bow anchor as you approach
D. None of the above
A. Run past the berth and back in.
Pg 104
True or false when turning at a steady speed the rudder becomes progressively less efficient.
True the turning lever is reduced.
Pg 27
If a relatively large ship is turning in the bend of a tidal river where should the stern be positioned and where should the bow be positioned to take advantage of the best turning lever?
Stern positioned in the strong current
Bow positioned in the weak current
Pg 77
If a vessel is in a situation with a large turning lever in a tidal river what actions can be taken to aid in the turn?
Kicks ahead with full power.
Pg 77
Propeller wash from tugs can enhance the ________ pressure area between a jetty and ship causing even more _________ that can result in the vessel going aground.
- Low
- Suction
Pg 80
If the ship is allowed to wonder off the intended course what is the first action to take when working astern?
A. Use a bold and vigorous bow thruster power
B. Use a kick astern
C. Use a kick ahead
D. Stop the engine and use small bow thruster corrections
A. Use a bold and vigorous bow thruster power
Consider the effect of transverse thrust
Pg 99
True or False if on a CP prop ship the sod is not reduced slowly and progressively the rudder will be shielded and steering may become erratic and poor.
True
Pg 107
What is true concerning the shroud on a propeller?
A. It will improve the quality of steering
B. It will improve response to kicks
C. It may give better directional stability
D. All of the above
D. All of the above
Pg 112
How much transverse thrust will a shrouded propeller see when backing?
Very little or no transverse thrust. The ship will run in a relatively straight line.
Pg 112
How is lateral motion used to maneuver to a berth with the tidal current from ahead?
It is put fine on the bow and wait to see if it takes the desired effect. If a big angle is taken it may take too much time and room to maneuver back into the tide.
Pg 72
True or False
With stern power, hull design and transverse thrust varying from ship to ship. Transverse thrust is still considered a relatively poor force.
True. Because of the short turning lever.
Pg 99
True or false the kinetic energy that develops with a ship threat is allowed to drift sideways when backing down the channel is more pronounced on vessels with larger tonnage.
True
Pg 100
The basic rudder is not hydrodynamic efficient beyond what rudder angle?
35º
Pg 112
What is the greatest enemy to work against you when turning a twin screw vessel?
A. Excessive speed
B. Squat
C. Bank effect
D. Transverse thrust
A. Excessive speed
Pg 127
What is drift angle?
The angle between the ship’s head and the direction the bridge (aft) is traveling.
Pg 36
True or False it is likely that transverse thrust power will be overcome by most wind speeds.
True. Transverse thrust is a weak force against most wind.
Pg 47
In calm conditions and still water what point does the pivot point coincide with and where?
- Center of Gravity
- Midships
Pg 12
With a 26, 000 DWT ship with 6,000 SHP astern what is the transverse force working on the starboard quarter going astern? What is the turning moment with fwd movement (pp 110 m away)?
Transverse thrust 10% of 6,000 is 6 tonnes
Turning moment 6 tonnes x 110 = 660 tm
Pg 24-25
At a steady speed while turning the pivot point is here?
1/2 L from the bow
Pg 27
The balance between __________ force and _________ plays a crucial part in shaping all turning circles.
- Rudder force
- Lateral resistance
Pg - 27
Rudder Force try’s to do two things what are they?
- Turn the ship
- Drive the ship forward
Pg 27
When a ship starts a turn from DIW what initially resists the ships tendency to come ahead?
Ship’s inertia
Pg 27
The large build up of water along the ship’s side which apposes rudder force in a turn is called what?
Lateral resistance
pg 27
After ______º of a turn care should be given as the ship may start to build up again as rudder force and lateral resistance return to normal.
90º
Pg 30
Where is the best turning moment achieved while using the bow thruster?
A. When stopped
B. When coming ahead
C. When a coming astern
D. When in a constant RPM turn
A. When stopped
Any headway or stern way will move the pivot point and shorten the lever.
(Pp is at 1 W from the stern when stopped)
Pg 90
In shallow water where does the pivot point moved due to the build up of longitudinal resistance?
A. Back towards the center
B. Fwd to the bow
C. Back to the stern
A. Back towards the center due to an upset in the imbalance of fwd momentum and longitudinal resistance
Pg 33
Ship’s with the ability to have large drift angles have _______ turning circles.
Good , finer lined ships do not have large drift angles and have poor turning circles.
Pg 36
Even in a weak tide if a ship blocks the tide between it and a jetty it causes what? Resulting in what?
- Low pressure
- Resulting in more suction toward the jetty.
Pg 80
You should always avoid ________ angles when passing jetties to avoid suction to the bank.
Acute
Pg 80
A depth to draft ratio of 1.05 the tidal force is _______ times stronger than a draft ratio of 3.0.
3 times
Pg 81
Except for a few powerful units performance of the bow thruster will fall off quite rapidly after the ship’s speed rises above _______ kts.
2 kts , high speed turbulence through the entrance tunnel impairing performance externally water flow deflects thrust output.
Pg 93
Twin CPP handed propellers refers to what?
I/B turning props.
O/B turning cp props are very uncommon and be used like a single screw ship.
Pg 124
True or False: Full bodied ship’s like bulk carriers are difficult to ship handle because of their inability to generate lateral motion.
False, these ships have large drift angles and the lateral motion they generate can be used to advantage.
Pg 36
With a ship initially stopped where is the center of a beam wind in comparison to the pivot point?
Amidships
Pg 38
In general which is more effective against a wide range of wind strengths, kicks ahead with full power or bow thruster power.
Kicks ahead with full power
Pg 47
If it takes 15 min to turn a ship short round in a 2 kt current, how far will it have moved over the ground in that time?
.5 nm
Pg 70
If a ship finds itself rounding a bend where the bow is in a stronger current and stern is in a weaker current what action should be taken?
A. Use appropriate helm and power
B. Hard rudder only
C. Stop engines
D. Drop the appropriate anchor
A. Use appropriate helm and power
Pg 77
The force of the tide upon a ship is directly proportional to the _________ of the ________ of the tide.
- Square
- Velocity
Any smaller increase in velocity has a much larger increase in force.
Pg 81
What are the two aspects that need to be monitored when using a thruster while stopped?
- Unexpected movement ahead
- Position of the pivot point
Pg 90
When interacting with a bank which has a larger turning lever?
A. Bow cushion
B. Stern suction
B. Stern suction
On the greatest turning lever with the pivot point closer to the bow.
Pg 55
What causes low buoyancy in a vessel moving into shallow water?
A. High pressure created by high speed water moving under the bow
B. Low pressure created by high speed water moving under the bow
C. Low pressure created by high speed water moving along the side of the ship
D. None of the above
B. Low pressure created by high speed water moving under the bow.
Pg 55
When a vessel squats in shallow water what happens to the steering lever and pivot point?
Pivot point moves back and steering lever is reduced
This is because of the build up of water on the bow and increase in longitudinal resistance.
Pg 55 - 59
General ship’s squat by the __________ when moving into shallow water.
Head
Pg 59
True or False: The ship’s wave system catching a ship up as it slows in shallow water, may affect trim for a short time and enhance sinkage at the bow.
True
Pg 59
Why does a ship lose rudder efficiency in shallow water?
A. Rudder force has to overcome a larger amount of lateral resistance
B. A larger amount of pressure builds up on the bow because of reduced UKC
C. The pivot point gets pushed back
D. All of the above
D. All of the above
Pg 33
True or False a ship maneuvering through a large turn in shallow water may experience an increase in draft due to list.
True . Due to an increase pressure along the side which the ship is turning this results in an increase flow of water under the ship this produces a low pressure under the ship.
Pg 33
True or False: When meeting in a narrow channel it is essential to move over to your side of teh channel as close to the edge as soon as possible.
False, working over too soon may cause an unexpected sheer acrossed the path of an approaching ship.
Pg 60
What are two possible causes for a ship under sternway cutting the wrong direction in close proximity of solid jetties, banks or shallow water?
- Wedge effect - excessive stern power creates was between the ship and obstruction this may be enough to swing the bow to port.
- Shallow water effect flow of water is being deflected.
Pg 24
At what depth of water is considered shallow water?
2 x the draft or less.
Pg 55
Shallow water may be experienced when the depth of water is less than _______ the ship’s draft.
2 times
Pg 33
True or False: when two ship’s are interacting in an overtaking situation and are abeam of one another a strong turning lever exist. In the low pressure midship and high pressure bows turning away from each other, powerful force and correction is needed to overcome.
True
Pg 64
As two ship’s pass abeam when one is overtaking the other, a powerful suction exists and will draw the ship’s together the overtaken ship may be dragged with the overtaking ship. How do you break the suction?
A. Both ship’s increase speed
B. Bother ships turn away from each other
C. Both ship’s slow down
C. Both ship’s slow down.
Pg 64
What two forces will a ship being overtaken in a narrow channel experience when the two ships are abeam of each other?
A. Squat and bank suction
B. Bank effect and low pressure area of the overtaking vessel
C. Bank effect and high pressure area of the overtaking vessel
Bank effect and low pressure in the area of the overtaking vessel. Creates a turning force.
Pg 64
What actions should be done when two ships are going to interact in a narrow channel?
- Prior to the maneuver bother ships should stay in center for as long as possible
- Speed should be reduced to reduce interactive forces
Pg 68
True or False
When ship’s are about to interact engines should be brought to dead slow ahead so that power is instantly available to control with kicks ahead.
True, this is especially important with turbine or fixed pitch propeller ships.
Pg. 68
END of Shiphandler’s Guide - Rowe and Start of Ship Handling for the Mariner - Macelrevey
- When a VLCC is being brought alongside a berth, mooring lines must be used to heave the vessel into final position. (Page 250) a. True b. False
B. False
Shiphandling for the Mariner - Macelrevey
At what depth of water should the Master conduct trials to best know the vessels response to shallow water effects?
A. 1 x vessel draft
B. 1.5 x vessel draft
C. 2 x vessel draft
D. 2.5 x vessel draft
B. 1.5 times vessel draft
Pg 7 Shiphandling for the Mariner - Macelrevey
At what depth of water does a vessel start to feel shallow water effect? What depth of water is a full effect felt? (In relation to draft)
- 1.5 x draft
- 1.2 x draft
Pg 9 Shiphandling for the Mariner - Macelrevey
True or False: Most ships will turn at about half the tactical diameter for a hard right turn with acceleration than one at constant speed at 6 kts.
True
Pg 11 Shiphandling for the Mariner - Macelrevey
As required a vessel can turn around in ______ times her length when reducing the amount of a head and astern speed she develops.
1.5 times her length
Shiphandling for the Mariner - Macelrevey
True or False: when in a narrow channel a vessel may back the wrong way if the starboard quarter is in proximity of a bank or shoal area.
True
Pg. 14 Shiphandling for the Mariner - Macelrevey
When backing what should be done with the rudder?
A. Start amidship and then steer with the rudder once sternway develops’
B. Keep rudder amidships
C. Keep the rudder hard right or left
D. None of the above
A. Start amidships and then steer with the rudder once sternway develops.
Pg. 15 Shiphandling for the Mariner - Macelrevey
True or false in shallow water a directionally unstable ship becomes easier to steer or less unstable.
True
Pg 17 Shiphandling for the Mariner - Macelrevey
What are considered shallow water depths in relation to draft of the vessel?
1.2 times the draft
Pg 17 Shiphandling for the Mariner - Macelrevey
What statement describes positive, negative and neutral directional stability?
A. Swing increases rate of turn when rudder is put amidships
B. Tends to steady up when rudder is put amidships
C. Continues to swing when rudder is put amidships with no ROT increase or decrease
- Positive B. Tends to steady up when rudder is put amidships
- Negative A. Swing increases rate of turn when rudder is put amidships
- Neutral C. Continues to swing when rudder is put amidships with no ROT increase or decrease
Pg 18 Shiphandling for the Mariner - Macelrevey
True or False Bank cushion is more strongly felt than bank suction.
False, bank suction is more strongly felt.
Pg 21 Shiphandling for the Mariner - Macelrevey
When a reference to “smelling shallow water” is made what is it referring to?
A. Bank suction
B. Bank Cushion
C. Bernoulli Effect
D. All of the above
B. Bank Cushion
Pg 21 Shiphandling for the Mariner - Macelrevey
Which of the following could a round turn be used for?
A. To slow a ship before arrival at a pilot station.
B. To make a lee for a pilot.
C. To stop a ship after losing the engine.
D. All of the above.
D. All of the above
Pg 25 Shiphandling for the Mariner - Macelrevey
Ships swing a lee by doing what?
A. Swinging the ship’s quarter away from the pilot boat
B. Swinging the ship’s quarter toward the pilot boat
C. Swinging the ship’s bow away from the pilot boat
D. Swinging the the ship’s bow toward the pilot boat
A. Swinging the ship’s quarter away from the pilot boat. This is helpful when there is a cross sea and swell.
Pg 27 Shiphandling for the Mariner - Macelrevey
At very low maneuvering speeds a high sided ship, such as a passenger ship or containership will feel the wind significantly at a wind speed of _______ times the ship’s speed. While a loaded tanker will require ______ times the ship speed before being affected to the same degree.
- 3
- 5
Pg 32 Shiphandling for the Mariner - Macelrevey
What is an example of what not to do if your vessel takes a sheer off the bank?
A. Apply rudder towards the bank
B. Apply rudder away from the bank
C. Increase engine speed
D. Reduce engine speed
D. Reduce engine speed
Pg 47 Shiphandling for the Mariner - Macelrevey
Bank suction can be used for which of the following?
A. Pass another vessel in a narrow channel
B. Locate the center of the channel in times of limited Visibility
C. Make routine maneuvers
D. All of the above
D. All of the above. Speed must be restricted so the ship can come ahead if the sheer should become greater than desired.
Pg 48 Shiphandling for the Mariner - Macelrevey
It is a good idea to check the actual current against that which has been predicted by looking at piling, buoys and other fixed items for what reason:
A. To verify the validity of your prediction platforms
B. To report to the Coast guard
C. Because freshets resulting from heavy rains upriver and strong off or onshore winds may significantly changed the prediction of currents.
D. None of the above
C. Because freshets resulting from heavy rains upriver and strong off or onshore winds may significantly changed the prediction of currents.
Pg 49 Shiphandling for the Mariner - Macelrevey
Speed in narrow channels should be kept to a minimum for what reason?
A. To minimize unwanted hydrodynamic effects
B. To have sufficient engine speed in reserve to increase rudder effectiveness when required
C. To keep to min speed restrictions
D. A and B only
D. A and B only
Pg 50 Shiphandling for the Mariner - Macelrevey
True or False Ships fitted with balanced spade rudders often will not steer when large rudder angles are used.
True, turbulent flow develops over the rudder’s surface so its lifting effect is lost or stalls.
Pg 51 Shiphandling for the Mariner - Macelrevey
True or False: A variable pitch propeller is less effective going astern than a conventional propeller.
True It often takes longer periods of time to stop her.
Pg 52 Shiphandling for the Mariner - Macelrevey
For the azipod system at sea mode which is true?
A. The rotation of the pod is limited to 35 degrees to port and starboard off the centerline
B. Full power is available
C. Pod movement is synchronized so pods move in unison
D. All of the above
D. All of the above
Pg 60 Shiphandling for the Mariner - Macelrevey
Power in At Sea is about ________ the horse power available when maneuvering.
A. The same as
B. Double
C. Triple
D. Quadruple
B. Double
Pg 60 Shiphandling for the Mariner - Macelrevey
In which mode in an azipod system can the pods be rotated 360º?
A. At Sea Mode
B. Harbor Mode
C. All of the above
B. Harbor Mode
Pg 60 Shiphandling for the Mariner - Macelrevey
What is steering with Azipods similar to in At Sea Mode?
A. Steering a bicycle
B. Steering a twin screw vessel
C. Steering with a tiller
D. None of the above
C. Steering with a tiller
Pg 61 Shiphandling for the Mariner - Macelrevey
In At Sea Mode with an Azipod System when turning the pod to port which way does the stern move?
To port and the ship’s head goes to starboard
Pg 61 Shiphandling for the Mariner - Macelrevey
What is harbor mode also known as? Why?
Bicycle mode, because it steers like a bicycle. When the Starboard control is pulled back to turn the head to starboard.
Pg 62 Shiphandling for the Mariner - Macelrevey
What statement is true concerning azipod system communication?
A. Engine commands use percentage of power from zero to 100 in forward or reverse in At Sea mode only.
B. Conventional rudder commands are used in degrees to port and starboard in At Sea and Harbor Mode.
C. Pod configurations uses clock settings relative to the ship’s bow in harbor mode.
D. All of the above
C. Pod configurations uses clock settings relative to the ship’s bow in harbor mode.
Pg 65 Shiphandling for the Mariner - Macelrevey
What statement is true concerning azipod system communication?
A. Engine commands use percentage of power from zero to 100 in forward or reverse in At Sea mode only.
B. Conventional rudder commands are used in degrees to port and starboard in At Sea Mode.
C. Pod configurations uses clock settings relative to the ship’s bow in At Sea mode.
D. All of the above
B. Conventional rudder commands are used in degrees to port and starboard in At Sea Mode.
Pg 65 Shiphandling for the Mariner - Macelrevey
What statement is true concerning azipod system communication?
A. Engine commands use percentage of power from zero to 100 in forward or reverse in At Sea mode and Harbor modes.
B. Conventional rudder commands are used in degrees to port and starboard in At Sea and Harbor Mode.
C. Pod configurations uses clock settings relative to the ship’s bow in At Sea Mode.
D. All of the above
A. Engine commands use percentage of power from zero to 100 in forward or reverse in At Sea mode and Harbor modes.
Pg 64 Shiphandling for the Mariner - Macelrevey
True or False: Approximately 90 percent of all marine accidents occur in restricted waters.
True because that is when ships are exposed to the greatest hazards.
Pg 67 Shiphandling for the Mariner - Macelrevey
A ship with a large block co-efficient steers poorly and tends to be directionally unstable, This condition ________.
A. Is amplified when she trims by the head as she enters shallow water.
B. Ins improved when she trims down by the stern as she enters shallow water
C. Is unchanged as she enters shallow water.
D. None of the above.
A. Is amplified when she trims by the head as she enters shallow water.
Pg 71 Shiphandling for the Mariner - Macelrevey
True or False: A ship trimmed down by the head requires large amounts of rudder for excessive periods of time to check her swing.
True
Pg 71 Shiphandling for the Mariner - Macelrevey
As a ship turns there is an increase of pressure below the waterline on the __________________ the resultant imbalance forces in that location forward and outside of the center of gravity causing the ship to be directionally unstable.
A. Stern toward the center of gravity
B. Bow toward the center of gravity
C. Stern away from the center of gravity
D. Bow away from the center of gravity
D. Bow away from the center of gravity
Pg 72 Shiphandling for the Mariner - Macelrevey
With a ship that is trimmed _________ (aft, fwd or even) pressure shift in a turn is further aft and as the ship stabilizes in the turn the pressure drop on the quarter on the inboard side of the turn continues to increase. The resultant couple has then shifted aft of the center of gravity so the ship is directionally ____________.
- Aft
- Stable
Pg. 72 Shiphandling for the Mariner - Macelrevey
When a ship is trimmed by the _________ There is an increase in pressure in the submerged area forward with a reduction in pressure aft. This couple remains _________ of the center of gravity which makes the ship continue to be directionally __________.
- Bow
- Forward
- Unstable
Pg 73 Shiphandling for the Mariner - Macelrevey
On a vessel with marginal directional stability how may a Shiphandler make a turn to prevent the ship from swinging out of control.
When the ship starts to swing immediately put the rudder amidship if the rudder is kept on too long it may swing out of control.
Pg 74 Shiphandling for the Mariner - Macelrevey
When should the turn of a ship be started when in a channel?
A. When the ship’s pivot point is nearly at the turning point at the end of the reach or range.
B. When the ship’s bow is nearly at the turning point at the end of the reach or range.
C. When the ship’s bridge is nearly at the turning point at the end of the reach or range.
D. None of the above
A. When the ship’s pivot point is nearly at the turning point at the end of the reach or range.
Pg 74 Shiphandling for the Mariner - Macelrevey
If the relative bearing of a buoy changes toward the bow so the buoy is moving forward of the reference point the ship turning rate will _________.
A. Bring it closer to the buoy
B. Bring it farther away from the buoy
C. None of the above
A. Bring it closer to the bouy
Pg 77 Shiphandling for the Mariner - Macelrevey
If the relative bearing of a buoy changes toward the bow so the buoy is moving forward of the reference point. The rate at which the buoy is moving ahead of the reference point is increasing then the ship’s ROT is ________.
Increasing
Shiphandling for the Mariner - Macelrevey
If the relative bearing of a buoy changes away from the bow so the buoy is moving aft of the reference point. The rate at which the buoy is moving ahead of the reference point is decreasing then the ship’s ROT is ________.
Decreasing
Pg 77 Shiphandling for the Mariner - Macelrevey
If the relative bearing of a buoy does not change toward the bow so the buoy is fixed on the reference point. The rate at which the buoy is moving ahead of the reference point is not changing how far from the buoy will the ship end up?
It will maintain the present distance all the way around the buoy.
Pg 77 Shiphandling for the Mariner - Macelrevey
Why is using a buoy as a reference point in current of interest to the ship handler?
Because it is the resultant net movement from the combination of the vessel momentum, swing and current effects. And the resultant motion is immediately apparent when the ship is turned using fixed references.
Pg 78 Shiphandling for the Mariner - Macelrevey
When two ships are meeting in a narrow channel what is a good rule of thumb for when they should put their rudders to starboard to move to their respective sides.
A. 1 ship length
B. 2 ship lengths
C. 1.5 ship lengths
D. None of the above
C. 1.5 ship lengths
Pg 78 Shiphandling for the Mariner - Macelrevey
What makes the vessel want to swing in stage 3 of the two ships meeting in a narrow channel? Two things
- Bank suction
- Suction of the other ship’s stern as it is abeam of your bow.
Pg 80 Shiphandling for the Mariner - Macelrevey
What is an essential piece of bridge equipment when dealing with an unstable ship making a turn?
ROT indicator
Pg 84 Shiphandling for the Mariner - Macelrevey
What is a good rule of thumb for a maximum rate of turn for an ordinary turn?
A. 25 degrees per minute
B. 36 degrees per minute
C. 42 degrees per minute
D. 50 degrees per minute
B. 36 degrees per minute
Pg 83 Shiphandling for the Mariner - Macelrevey
This is the bodily increase in draft, increase in mean draft due to effects of moving in a restricted channel?
Sinkage,
Pg 85 Shiphandling for the Mariner - Macelrevey
this is the rotation about the transverse axis due to the change in pressure and the resulting change in draft along the length of the ship.
Trim
Pg 85 Shiphandling for the Mariner - Macelrevey
This is the largest change and location of that change along the ship’s hull depending on the location of maximum change in trim.
Squat
Pg 85 Shiphandling for the Mariner - Macelrevey
True or False the ship displaces an amount of water equal to her own weight.
True
Shiphandling for the Mariner - Macelrevey
What are 6 variables blockage factor depends on?
X
- The speed of the ship through the water.
- Ratio of the ship’s draft to the depth of water.
- Ratio of the ship’s cross-sectional area to the cross-sectional area of the channel (fig. 2-17).
- The ship’s block coefficient. (The previously explained effects on draft and handling characteristics of a high block coefficient are amplified in shallow water.)
- The ship’s displacement, which determines the amount of water that must pass around and under the ship’s hull at a given speed.
- The rate and period of acceleration as the ship increases speed
Pg 87 Shiphandling for the Mariner - Macelrevey
Squat varies in proportion to the ___________ of the ship’s speed.
Square
If the ship’s speed is doubled squat is increased by 4.
Pg 88 Shiphandling for the Mariner - Macelrevey
When referring to speed with squat what is referred to?
Speed through the water
Pg 88 Shiphandling for the Mariner - Macelrevey
What is the equation for squat in meters? In feet?
S (meters) = Cb x V2/100
S (feet) = Cb x V2 / 30
Cb = block coefficient
S = squat
V = speed in knots
Pg 88 Shiphandling for the Mariner - Macelrevey
What is the wake of a ship that is feeling shallow water effect?
A. Wake is long and shallow
B. Wake is short and steep
C. Wake is long and steep
D. None of the above
B. The wake is short and steep
Pg 91 Shiphandling for the Mariner - Macelrevey
True or False when under keel clearance is less than .5 of the ship’s draft the ship will become more stable.
True and difficult to steer.
Pg 91 Shiphandling for the Mariner - Macelrevey
_________ is the most critical factor when determine and maximizing UKC.
Speed through the water
Pg 95 Shiphandling for the Mariner - Macelrevey
True or False: The effects crabbing which causes the ship to proceed at some angle to the axis of the channel increases squat by 10%.
False, it does not increase squat.
Pg 96 Shiphandling for the Mariner - Macelrevey
As a rule of thumb what speed is a practical speed limit for ships in channels where UKC is 5 ft or less?
6 kts
Pg 96 Shiphandling for the Mariner - Macelrevey
True or false: wide beam, full-hull ships, like tankers and bulk carriers are expected to experience a greater increase in draft.
True squat is greater for ships with greater block co-efficient
Pg 97 Shiphandling for the Mariner - Macelrevey
Car carriers, container ships and passenger ships with lower block coefficients (less than .8) are more likely to squat by _________ (the stern or the head) and accelerate more quickly.
The stern
Pg 97 Shiphandling for the Mariner - Macelrevey
When a tug is to assist in a routine docking or undocking and is made fast on the bow or quarter she generally puts two lines up the first one is __________.
A. The backing line
B. The quarter line
C. The spring line
D. None of the above
A. The backing line
Pg 103 Shiphandling for the Mariner - Macelrevey
When a tug is to assist in a routine docking or undocking and is made fast on the bow or quarter she generally puts two lines up the second one is __________.
A. Backing line
B. Stern line
C. Come ahead line
D. None of the above
C. Come ahead line, this is used to help the tug keep in position.
Pg 103 Shiphandling for the Mariner - Macelrevey
What is rule number one in using a tug?
A. Always use multiple tugs
B. Always use a stern tug
C. Plan a job as if you do not need the tug and minimize their use
D. All of the above
C. Plan a job as if you do not need the tug and minimize their use
Do not use the tug.
Pg 106 Shiphandling for the Mariner - Macelrevey
The tugs power when working alongside is primarily to move the ship _________.
Laterally
Pg 107 Shiphandling for the Mariner - Macelrevey
What are two occasions when a conventional tug can be put on a hawser?
- When handling a dead ship
- When handling a ship with such a light draft it is impossible to make up alongside.
Pg 112 Shiphandling for the Mariner - Macelrevey
If a tug is lashed on the quarter the ship can be handled like what?
A twin screw
Pg 112 Shiphandling for the Mariner - Macelrevey
When only one tug is lashed up, the off center location of the tug will be felt until what?
A. The ship gets sternway
b. The ship gets headway
C. The tug is released
D. None of the above
B. The ship gets headway on. This will Morten’s to move the ship initially away from the tug.
Pg. 114 Shiphandling for the Mariner - Macelrevey
This is a common position for the tug to be lashed up to move a ship astern past another ship docked astern.
Tug lashed up forward looking aft . Also used to back up a dead ship from a berth.
Pg 114 Shiphandling for the Mariner - Macelrevey
What are three good shiphandling practices when piloting a vessel upon approach to the dock?
- Staying in the same spot on the bridge
- Using hand signals in addition to helm orders
- Remaining calm and unexcited throughout the docking
Pg. 115 Shiphandling for the Mariner - Macelrevey
What are four ways for mariners to Judge speed?
- Doppler log or GPS
- Fixes by radar or visual bearings
- Position of ship’s quick water
- Observation of passing objects and comparisons with known distances
Pg 119 Shiphandling for the Mariner - Macelrevey
If the quick water falls behind the ship when the engine is put astern how fast is the vessel going? When the quick water starts moving with the ship? When the ship is DIW? What is a comfortable approach speed to the berth?
- 3 kts
- 2 kts
- Midships
- 2 kts
Pg 119 Shiphandling for the Mariner - Macelrevey
At what objects should the shiphandler look upon approach to the dock to judge speed?
A. Objects abaft
B. Objects ahead
C. Objects abeam or a little abaft the beam
D. All of the above
C. Objects abeam or a little abaft the beam. An optical allusion occurs when looking ahead.
Pg 120 Shiphandling for the Mariner - Macelrevey
True or False speed through the water should be used when judging the ships response to her rudder.
True
Pg 121 Shiphandling for the Mariner - Macelrevey
When approaching a dock at night Shiphandler’s make it good practice to stop the vessel __________ off the berth to estimate the vessel’s speed.
1 ship length
Pg 121 Shiphandling for the Mariner - Macelrevey
Quick water effects which side docking the most by pushing the stern away as quick water gets wedged between the ship and dock.
Starboard side, deeply loaded ships often require a tug to keep the stern in.
Pg. 122 Shiphandling for the Mariner - Macelrevey
How many degrees of approach should a vessel approaching a Port Side to berth with a right hand prop? Where should the ship aim initially?
- 10 -15ºs
- Where the ship will be amidships when finally alongside.
Shiphandling for the Mariner - Macelrevey
True or False: a ship docking bow in should turn and line up at the greatest possible distance from the pier.
True. Allow leeway toward or away from the pier for current or wind.
Pg 123 Shiphandling for the Mariner - Macelrevey
When backing into a slip what reference point should be used for when you turn away from the pier and begin lining up for the slip.
The pivot point
Pg 124 Shiphandling for the Mariner - Macelrevey
At what angle toward the pier should be made when backing into a slip when going starboard side to?
A small angle toward the dock
Pg 124 Shiphandling for the Mariner - Macelrevey
What should be avoided when using tugs docking into a slip?
A. Using a bow tug on a hawser
B. Using tug lashed up on the quarter
C. Having the tugs push so long that excessive lateral motion is given to the ship
D. None of the above
C. Having the tugs push so long that excessive lateral motion is given to the ship. It will cause the ship to land heavy on the string piece.
Pg 125 Shiphandling for the Mariner - Macelrevey
The stern tug when used for docking a ship into a slip with a stern in approach must not be made fast until what?
The ship has turned to bring her stern toward the slip and is dead in the water.
Pg. 125 Shiphandling for the Mariner - Macelrevey
When backing into the slip using a bow tug which line should be best to make the tug up with?
A backing line and trailing the ship in to the slip.
Pg 126 Shiphandling for the Mariner - Macelrevey
What should be planned for when stemming the current and docking the vessel with a solid pier face?
A. Suction on to the pier
B. Set off the pier by cushion of water between the pier and ship
C. Slack water at the pier
D. All of the above
B. Set off the pier by cushion of water between the pier and ship. Often an Eddie moving in the opposite direction as the current is experienced.
Pg 126 Shiphandling for the Mariner - Macelrevey
What should be used to move the ship laterally toward the wharf when the current is coming from the stern and the vessel is docking?
The current
Pg 126 Shiphandling for the Mariner - Macelrevey
When docking stern toward the current where do problems usually arise?
A. Angling the stern to far off the dock and getting set away
B. Angling the stern too close to the dock and getting set on to the dock
C. Using tugs to push the ship alongside the dock.
D. None of the above
C. Using tugs to push the ship alongside the dock.
Pg 127 Shiphandling for the Mariner - Macelrevey
Air is how many times less dense than water?
900 times
Pg 129 Shiphandling for the Mariner - Macelrevey
Which of the following ways does wind and current assist a ship?
A. Wind blowing off the berth can be used to overcome a ship’s lateral motion toward the berth
B. Wind blowing on the berth can ease a ship alongside if the shiphandler stops her a few feet off the berth
C. Current that runs across the end of the berth acting on the ship’s quarter can assist the ship in turning into a slip the ship is landed and pivoted on a cluster of pilings or a canal rather than being steamed into the slip while fighting the current.
D. All of the above
D. All of the above
Pg. 131 Shiphandling for the Mariner - Macelrevey
When docking the a ship against a strong wind coming off the dock what is the best tactic to take?
Use a larger angle of approach and as the ship comes alongside use a kick ahead with hard rudder to add more lateral motion. As the ship slows the wind will overtake the lateral motion. In stronger winds an anchor can be dredged to check up the bow and amplify the lateral motion.
Pg 131 Shiphandling for the Mariner - Macelrevey
If the wind is blowing the ship on the dock what is the best way to dock?
A. Use a smaller angle and aim for the end bow position
B. Use a greater angle and drop the inboard anchor to slow the bow down
C. Land the ship earlier and move along the dock with the string piece until in position
D. None of the above
C. Land the ship earlier and move along the dock with the string piece until in position
If the ship is already alongside it can’t be blown heavily on the dock.
Pg 132 Shiphandling for the Mariner - Macelrevey
If 10 revolutions equals 2 kts how many does 60 revolutions equal?
12 kts
Pg 132 Shiphandling for the Mariner - Macelrevey
True or False: lateral motion is easier to detect when working from the centerline of the ship.
True, you have a better view of the vessel and her heading watch objects ashore located astern or ahead.
Pg. 133 Shiphandling for the Mariner - Macelrevey
True or False: when docking Port side to the quick water will partially check the swing of the vessel so the ship lands easier.
True, it will partially stop the swing to starboard when it gets past the pivot point.
Pg 134 Shiphandling for the Mariner - Macelrevey
True or False quick water will eventually move up the full length of the ship so she is affected equally forever and aft when docking.
True. It can be used to reduce lateral motion or move the ship away from the dock.
Shiphandling for the Mariner - Macelrevey
Quick water effect is strongest when ______________. It helps push the vessel _________ the dock.
A. There is shoaling or a solid bulkhead at the dock
B. It is an open dock
C. On an ebb tide
D. At slack water
- A. There is shoaling or a solid bulkhead at the dock
- Away from
Pg 135 Shiphandling for the Mariner - Macelrevey
What are five reasons it is important to land flat alongside the dock?
1.The frames through the entire midbody of the ship can absorb the impact of landing, rather than having the inapace contentee within a small area of the hull.
2. A parallel landing traps the maximum quantity of water between the hull and the pier or wharf, thus developing the maximum cushioning effect.
3. The eddy current acts equally along the entire length of the ship, slowing her lateral motion and easing the landing.
4. If the ship is docking with any current, having the ship’s upstream end hard alongside keeps the current from getting inside the ship and forcing her back off the berth.
5. The maximum cushioning effect is gained from the ship’s quickwater when the ship is parallel to the berth.
Pg 137 Shiphandling for the Mariner - Macelrevey
True or False when the impact of a landing is spread over the entire length of the flat parallel midbody the ship can go alongside with surprising force without damage.
True
Pg 137 Shiphandling for the Mariner - Macelrevey
Ship’s usually run sufficient head, spring and stern lines to keep the ship from moving fore and aft. Which lines are the most effective to keeping the ship alongside?
Breast lines, they should be doubled like any other line.
Pg 138 Shiphandling for the Mariner - Macelrevey
What is true about ballasting a vessel for transit?
A.the ship has excellent directional stability with good drag
B. The propeller and rudder are most effective with excellent drag.
C. It is preferable that the bow also be ballasted to at least give a moderate draft to reduce wind age and submerge the bow thruster so it is effective.
D. All of the above
D. All of the above
Pg 40 Shiphandling for the Mariner - Macelrevey
What is the perferrred way to single up?
A. Leave spring lines only
B. Leave a longer bow and stern line and a spring
C. Leave short lines, a short stern, short head line, short spring or short breast line
D. None of the above
C. Leave short lines, a short stern, short head line, short spring or short breast line
Pg 141 Shiphandling for the Mariner - Macelrevey
What is the reason for leaving short lines when singling up?
A. They hold the ship alongside the dock more effectively
B. They can be brought in quicker
C. They will clear the propeller as soon as possible so the engine can be used
D. All of the above
D. All of the above
Pg 141 Shiphandling for the Mariner - Macelrevey
What is true about undocking leaving starboard side to?
A. The quick water will help the ship move laterally off the pier because it has better flow and strikes forward of the pivot point.
B. The quick water has minimal effect in moving the ship off the dock laterally but does reduce the angle to the berth as it strikes the fore part of the hull.
C. The quick water will cause an eddy that will hold the ship to the dock and should be used with caution.
D. None of the above
A. The quick water will help the ship move laterally off the pier because it has better flow and strikes forward of the pivot point.
Pg 142 Shiphandling for the Mariner - Macelrevey
What is true about undocking leaving Port Side to?
A. The quick water will help the ship move laterally off the pier because it has better flow and strikes forward of the pivot point.
B. The quick water has minimal effect in moving the ship off the dock laterally but does reduce the angle to the berth as it strikes the fore part of the hull.
C. The quick water will cause an eddy that will hold the ship to the dock and should be used with caution.
D. None of the above
B. The quick water has minimal effect in moving the ship off the dock laterally but does reduce the angle to the berth as it strikes the fore part of the hull.
Pg 142 Shiphandling for the Mariner - Macelrevey
When undocking how can the quick water be used to advantage?
A. By backing off of the dock the quick water will raise the ship laterally
B. Start backing off the dock and stop the engines to allow the quick water to check the swing and then back out straight astern.
C. Use a series of kick aheads with hard rudder toward the dock and backing to move laterally off the pier.
D. All of the above
B. Start backing off the dock and stop the engines to allow the quick water to check the swing and then back out straight astern.
Pg 142 Shiphandling for the Mariner - Macelrevey
How should a ship undock with current coming from astern?
Work the bow toward the dock and back into the stream. Maintain a speed through the water that matches the current so you can back out laterally.
Pg 143 Shiphandling for the Mariner - Macelrevey
True or False: Starboard Side to vessels backing out from a berth need no angle from the dock when backing out.
True
Pg 144 Shiphandling for the Mariner - Macelrevey
When backing out of a finger pier what should be kept in mind with regards to when to turn out?
A. Turn out when you have the speed astern to clear the pier
B. Turn out when the pivot point is beyond the pier so you will clear the pier
C. When you are port side to you can use hard starboard rudder and a kick ahead to walk the ship off the dock.
D. All of the above
B. Turn out when the pivot point is beyond the pier so you will clear the pier
Pg 144 Shiphandling for the Mariner - Macelrevey
When backing from a pier starboard side to with the wind coming off the dock what should be kept in mind?
A. The bow will turn into the wind when coming astern
B. The stern will turn into the dock when coming astern
C. The ship should move bodily off the dock and back straight out
D. All of the above
B. The stern will turn into the dock when coming astern. The wind will overcome transverse thrust.
Pg 146 Shiphandling for the Mariner - Macelrevey
What is the best option for undocking with out tugs and backing from the pier with the wind on the pier?
A. Working against a spring to get the stern out and back at an angle
B. Sliding along the stringpiece until the stern clears teh outboard corner of the pier and can turn fair into the channel.
C. Working the bow out with the after spring and backing out
D. All of the above
B. Sliding along the stringpiece until the stern clears teh outboard corner of the pier and can turn fair into the channel.
Pg 147 Shiphandling for the Mariner - Macelrevey
When docked stern in and undocking with the wind against the dock the ship can be slowly moved out along the string piece. What angle of rudder toward the dock should be given to keep the ship lightly against the dock? When the pivot point clears the pier it can be turned and an increase of speed to clear the stern at what speed should be sufficient to clear the stern?
- 10º
- 2 - 3 kts
Pg 148 Shiphandling for the Mariner - Macelrevey
How are left hand fixed propeller ships handled?
The opposite of right hand fixed propellers
Pg 151 Shiphandling for the Mariner - Macelrevey
To use the rudder when under sternway which direction should you put it in relation to where you want the stern to go?
Put the rudder to the side opposite you want the stern to go.
Pg 151 Shiphandling for the Mariner - Macelrevey
These are 7 things to keep in mind when turning in a basin.
- Turn in the direction that keeps the stern in the best water.
- Take nearly all sternway off the ship before starting to swing her.
- All factors being equal, turn the ship to the right to take advantage of the ship’s better turning characteristics backing and filling direction.
- Position the ship’s pivot point so the stern swings clear
- Fix the diameter of the basin in your mind before starting to turn
- When possible put the end of the ship to be swung in the area of maximum favorable current
- Put the ship at the end of the basin from which the current is flowing when starting the maneuver
Pg 153 Shiphandling for the Mariner - Macelrevey
In a river where is the deepest water as it flows from one bend to the next? When mid way between turns?
- The nearest path of the ebb tide as it flows from one bend to the next.
- Middle of the channel
Pg 154 Shiphandling for the Mariner - Macelrevey
At approximately what amount of anchor chain should be used when turning the vessel short round with an anchor?
2 x depth of water
Pg 154 Shiphandling for the Mariner - Macelrevey
At what speed are bow thrusters not effective?
2 kts
Pg 166 Shiphandling for the Mariner - Macelrevey
When anchoring and choosing an anchorage what are 9 things to consider?
- Direction and strength of current
- Depth of water.
- Type of bottom.
- Location of lee shore, shoals, or other hazards.
- Maneuvering room for approach.
- Number and location of ships already at anchor.
- Conditions affecting visibility, weather, and currents.
- Local customs and practices of the port.
- Swinging room after anchoring.
Pg 167 Shiphandling for the Mariner - Macelrevey
What may be a bail out plan if conditions in an anchorage are not conducive to a safe anchorage?
A. Dropping an anchor at short stay while you sort things out
B. Leaving the anchorage and returning when things get better
C. All of the above
C. All of the above
Pg 167 Shiphandling for the Mariner - Macelrevey
Are no circumstances should you pass close upstream or to windward of?
A. Buoys
B. Obstacles
C. Ships at anchor
D. All of the above
D. All of the above
Pg. 168 Shiphandling for the Mariner - Macelrevey
With ships with large sail areas and light drafts that turn in a strong wind may find it easiest to:
A. Turn into the wind with the bow going through the wind
B. Back and fill around the long way by bringing the stern into the wind
C. Stop and turn with the bow thruster
D. None of the above
B. Back and fill around the long way by bringing the stern into the wind
Pg 169 Shiphandling for the Mariner - Macelrevey
As depth of water decreases the ship’s tactical diameter increases so it is necessary to approach a shallow anchorage under a __________ speed.
Slow
Pg. 170 Shiphandling for the Mariner - Macelrevey
True or False: In depths greater than about 100 ft the brake may not be able to stop the chain when an anchor is let go from the hawse.
True. It may be necessary to lower the anchor nearly to the bottom before disengaging the wildcat and let the anchor fall the last few fathoms to the bottom.
Pg 171 Shiphandling for the Mariner - Macelrevey
What are 8 things to discuss with the bridge team prior to anchoring?
- When area anchors to use.
- Whether the ship will turn to the final heading before letting go.
- How much chain will be put out initially.
- Direction, ahead or astern, and approximate speed of the ship over the bottom when the anchor is let go.
- Whether the ship will be turned on the anchor.
- Whether the anchor should be held at short stay for maneuvering.
- If more than one anchor is used, how those anchors will be laid out.
- Final amount of chain to be used.
Shiphandling for the Mariner - Macelrevey
How many shots of chain should be used to assist a ship in turning into the anchorage on her final heading?
2 x the depth of water.
Pg 175 Shiphandling for the Mariner - Macelrevey
When letting go an anchor on a nearly recipricol heading which anchor should be let go and which way should be turned?
Starboard anchor for a starboard turn to take advantage of the ships twisting motion.
Pg 176 Shiphandling for the Mariner - Macelrevey
Which anchor should be used when turning to port or starboard on to the final heading?
A. The upstream or windward anchor after turning.
B. The downstream or down wind anchor after turning
C. Either anchor can be used.
A. The upstream or windward anchor after turning.
Pg. 176 Shiphandling for the Mariner - Macelrevey
What is the deep water considered in relation to ship’s draft?
Greater than 1.5 times
Pg 178 Shiphandling for the Mariner - Macelrevey
With a ship turning in deep water with a constant rpm how far ahead will the advance be from the starting position?
3 1/2 times the ship length, in shallow water these are approximately doubled
Pg 178 Shiphandling for the Mariner - Macelrevey
With a ship turning in deep water with a constant rpm how many lengths will the ship take to turn 90ºs from original course?
1 1/2 ship length, in shallow water these are approximately doubled
Pg 178 Shiphandling for the Mariner - Macelrevey
With a ship turning in deep water with a constant rpm how many ship lengths will it take to turn on the reciprocal course 180º from original course?
3 1/2 ship lengths, in shallow water these are approximately doubled
Pg 178 Shiphandling for the Mariner - Macelrevey
When on or near the final heading and about to drop anchor you should _________.
A. Continue straight to the anchorage position
B. Kick the bow to port prior to letting go the anchor
C. Kick the bow to starboard prior to letting go the anchor
D. None of the above
B. Kick the bow to port prior to letting go the anchor. When backing the bow will turn back to starboard to the final heading.
Pg 181 Shiphandling for the Mariner - Macelrevey
When laying out the anchor chain why is important not to set the anchor too soon?
A. If the shank is not parallel to the bottom it may not dig in and ball up with mud causing difficulty to dig in again.
Pg 182 Shiphandling for the Mariner - Macelrevey
If there is a 1 kt current from ahead and you back until the quick water is amidships what speed will you be going? Is this an appropriate speed for laying out the anchor?
- 1 kt astern over the bottom
- Yes
Pg 182 Shiphandling for the Mariner - Macelrevey
True or False: the ship should not be stopped completely when anchoring.
True, just enough to slow sternway
Pg. 183 Shiphandling for the Mariner - Macelrevey
True or False the ship should have a little bit of sternway on to work against the anchor when setting.
True
Pg 182 Shiphandling for the Mariner - Macelrevey
Which type of moor: The ship is brought to her final, heading stemming, the current and wind, and the first anchor is let go, and then slacked as the ship continues to move slowly ahead to drop the second anchor the first chain is then he as the second chain is slacked so the ship drops back to ride between both anchors?
A. Standing moor
B. Running moor
C. Mediterranean moor
D. None of the above.
A. Running moor
Paige 185 Shiphandling for the Mariner - Macelrevey
This is a type of moor where the ship is on her final heading and backs dropping the first anchor, slacks the chain and maneuvers astern to drop the second anchor, the first anchor is heaved while slacking the second anchor until the ship rides between the two anchors. This is the best moor to lay anchors perpendicular to wind and current.
A. Standing moor
B. Running moor
C. Mediterranean moor
D. None of the above.
A. Standing moor
Pg 187 Shiphandling for the Mariner - Macelrevey
True or False: Mooring to two anchors may be the best way to anchor under some circumstances, despite potential problems.
True
Pg 188 Shiphandling for the Mariner - Macelrevey
When dredging an anchor how much chain should be used to be effective?
Twice the depth of water
Pg 195 Shiphandling for the Mariner - Macelrevey
Where should the anchor be dropped when dredging an anchor to assist in berthing? What should the reaction be to the ship when using?
Before arriving at the berth and dragged into position. At low revolutions the anchor should stop the ship in higher revolutions it should drag it and move forward.
Pg 197 Shiphandling for the Mariner - Macelrevey
True or False when dredging an anchor the engine should not be put astern.
False. There is no reason the engine can not be put astern.
Pg 197 Shiphandling for the Mariner - Macelrevey
What is true about using an anchor to hold a vessel in position?
A. Use minimum amount of chain until the ship has lost nearly all her way.
B. Holding effect is increased as speed is lost.
C. If a single anchor is not sufficient use a second anchor.
D. All of the above.
D. All of the above.
Pg 198 Shiphandling for the Mariner - Macelrevey
True or False: when using an anchor to assist in steering the amount of chain is not critical as long as the anchor does not fetch up.
True
Pg 199
Shiphandling for the Mariner - Macelrevey
True or False: when using an anchor to break a sheer it should always dig in.
False, it should not dig in so minimize the amount of chain slack.
Pg 200 Shiphandling for the Mariner - Macelrevey
True or False: the same effect used to break a sheer with the anchor is used to negotiate a bend whose radius is less than the ship’s normal turning radius.
True
Pg 200 Shiphandling for the Mariner - Macelrevey
What is the worst response when steering is lost?
A. Putting the Engine Full Astern
B. Using two anchors to stop
C. Putting the Engine Slow Astern
D. None of the above
A. Putting the Engine Full Astern
Pg 201 Shiphandling for the Mariner - Macelrevey
True or False if the bank has a steep gradient and is soft material the ship can be put alongside and held with the anchor regardless of the direction of wind or current.
True
Pg 203 Shiphandling for the Mariner - Macelrevey
When lying alongside a bank what should you avoid doing?
A. Using the outboard anchor
B. Using chain equal to 2 x the depth of water
C. Putting out so much chain that the vessel stops before she is alongside the bank
D. All of the above
C. Putting out so much chain that the vessel stops before she is alongside the bank
Pg 203 Shiphandling for the Mariner - Macelrevey
Using an anchor to back down keeps the stern from walking to port as much. When it does start to walk to port what should be done?
A. Come ahead on the engine with full port rudder
B. Stop the engine
C. Increase sternway
D. None of the above
B. Stop the engine
Pg 203 Shiphandling for the Mariner - Macelrevey
If the anchor is allowed to fetch up when using it to back down what happens?
The stern walks only to Port
Pg 204 Shiphandling for the Mariner - Macelrevey
When approaching a single point mooring after being at anchor close by how should the approach be?
The same direction she sat at anchor.
Pg 215 Shiphandling for the Mariner - Macelrevey
When is the heading adjusted when approaching a single point mooring and what speed is appropriate?
A. During initial stages
B. Mid way through the evolution of approach
C. In the final stages when the vessel slows down
D. None of the above
- C. In the final stages when the vessel slows down
- 1 kt
Pg 216 Shiphandling for the Mariner - Macelrevey
One large course change should be planned during the final stages of the approach to a single point mooring, why?
So you can knock off speed with a turn rather than making the full final approach at 1-2 kts you can go 3-4 and know off two knots quicker.
Pg 217 Shiphandling for the Mariner - Macelrevey
Where are hoses and the buoy kept when approaching a SPM? Why?
On the port bow because when the ship comes astern the bow will move to starboard.
Pg 218 Shiphandling for the Mariner - Macelrevey
When hooking up to a SPM what is the primary limiting factor to consider during make up?
A. The wind speed and direction
B. The Sea State
C. The current velocity
D. None of the above
B. The Sea State. A moderate sea can make it impossible to hook up.
Pg 220 Shiphandling for the Mariner - Macelrevey
So long as these two things are accomplished the make up to a SPM is a safe and straightforward task.
- Speed is kept down to bare steerageway in the final stages.
- The ship is put on a heading close to that at which she will lie after mooring.
Pg 220 Shiphandling for the Mariner - Macelrevey
What is the approach to a multiple buoy mooring?
A. Into the sea and swell
B. Perpendicular to the line at which the anchors will be dropped
C. 90º to the axis of the berth along the line the buoys will be dropped.
D. None of the above
C. 90º to the axis of the berth along the line the buoys will be dropped.
Pg 229 Shiphandling for the Mariner - Macelrevey
True or False: When hooking up to multiple point mooring and the first anchor is dropped all seven shots are allowed to be let out on the way to the location of the second anchor drop spot.
True
Pg 229 Shiphandling for the Mariner - Macelrevey
True or False when setting up for a multi point mooring the ship proceeds past the axis of the berth and back and fills until in position to drop the second anchor.
False the ship is swung into position allowing for the natural twisting motion of the ship when backing to be accounted for.
Pg 230 Shiphandling for the Mariner - Macelrevey
What should be avoided when lines are going out in a multipoint mooring?
Do not let the propeller to turn.
Pg 230 Shiphandling for the Mariner - Macelrevey
When in a multiple point mooring operation is the strain in both anchors taken?
A. Never
B. When maneuvering back into the berth
C. When all lines are out
D. None of the above
C. When all lines are out
Pg 230 Shiphandling for the Mariner - Macelrevey
The procedure for setting up for a Mediterranean more is most similar to:
A. A running moor
B. A standing moor
C. A five point moor
D. None of the above
C. A five point moor
Pg 232 Shiphandling for the Mariner - Macelrevey
What angle do the anchors make from the ships heading to the drop point?
60 degrees
Pg 232 Shiphandling for the Mariner - Macelrevey
How much chain should be used with a Mediterranean moor?
A. 7 shots both anchors
B. 1 shot more than would be used for the depth of water off the berth
C. The amount that would be used for the depth of water off the berth.
D. None of the above
B. 1 shot more than would be used for the depth of water off the berth.
Pg 232 Shiphandling for the Mariner - Macelrevey
True or False in a meditterranean moor the engines should be stopped when running stern lines.
False, engines will be needed to keep the ship in position the stern lines must be kept clear of the props.
Pg 232
Shiphandling for the Mariner - Macelrevey
What piece of equipment is essential when maneuvering for a Mediterranean Moor?
Bow thruster
Pg 234 Shiphandling for the Mariner - Macelrevey
Which anchor (windward or leeward) do you heave first when letting go from a Mediterranean Moor? How many shots do you leave out when starting to heave the other anchor?
Windward you heave it to 2 shots then heave the leeward anchor.
Pg 235 Shiphandling for the Mariner - Macelrevey
True or False: twin screw twin rudder ships are inherently more responsive at low speeds than ships with single rudders.
True
Pg 238 Shiphandling for the Mariner - Macelrevey
When docking a twin screw vessel at the pier what is done to assist in a soft landing alongside the pier?
The direction of rotation of the propellers is reversed.
Pg 239 Shiphandling for the Mariner - Macelrevey
With twin propellers which (outboard turning or Inboard turning) is more efficient a moving the stern laterally?
Outboard turning
Pg 240 Shiphandling for the Mariner - Macelrevey
True or False: while operating in shallow water a twin screw vessel is more likely to take a sheer than a single screw vessel.
True, outboard prop is closer to the bank.
Pg 241 Shiphandling for the Mariner - Macelrevey
When docking a twin screw vessel and the stern starts setting in faster than the bow what can be done to correct this? Why does this resolve the situation?
A. The Outboard engine can be put ahead
B. The Inboard engine can be put astern
C. Both engines put astern
D. Both engines put ahead
- B. The Inboard engine can be put astern.
- The quick water will move up the side and lift the ship off the pier
Pg 242 Shiphandling for the Mariner - Macelrevey
The pilot comes aboard to take charge of the navigation of the vessel and brings with him at least these 6 pieces of expert knowledge?
- Local tides and currents
- Bottom and channel depths and configurations.
- Courses, distances, aids to navigation, and significant geographic features en route.
- Local customs and practices for ship movements.
- Local weather patterns.
- The shiphandling skills necessary to move vessels in the waters employed.
TBCCWS
Pg 293 Shiphandling for the Mariner - Macelrevey
What is the most common problem when turning a vessel around a bend or corner?
Starting the turn too early
Pg 74 Shiphandling for the Mariner
True or False: When it is possible to determine where to start a turn using channel widths and the theoretical turning radius of the ship it is much better to learn the vessel by instincts and feel.
True
Pg 75 Shiphandling for the Mariner
Where should you start a turn?
A. When the bow is even with a buoy of reference at the start of the turn.
B. When the pivot point is even with a buoy of reference at the start of the turn.
C. When the pivot point is near to abeam of the center of the turning circle
D. When the stern crosses abeam of a buoy of reference.
C. When the pivot point is near to abeam of the center of the turning circle
Pg 75 Shiphandling for the Mariner
When in doubt about how much rudder to give in a turn which statement is true?
A. Use more than you think is necessary
B. Use less than you think is necessary
C. Consult the ship maneuvering board for details on the ship’s turning circle.
D. None of the above
A. Use more than you think is necessary. You can always reduce rudder if necessary.
Pg 75 Shiphandling for the mariner
Shiphandling with Tugs - Slesinger
What are the hazards of starting a turn too early?
A. You may turn out of the channel.
B. You may not be able to stop the swing of the ship.
C. You may not be able to start the turn again once checked because of bank suction.
D. None of the above
C. You may not be able to start the turn again once checked because of bank suction.
Pg 75 Shiphandling for the Mariner
What is the towing point? START: Shiphandling with Tugs - Slesinger
The point on the tug where the tow line is attached.
3. The last physical point on the tug that fairleads its line; or the contact point between tug and ship when the tug is pushing.
Shiphandling with Tugs - Slesinger
What is the propulsion point?
The point where the tug generates thrust. 4. The focal point of the tug’s application of horsepower under the water.
Shiphandling with Tugs - Slesinger
What is the maneuvering lever?
The distance between the towing point and the propulsion point. 5. The distance between the towing point and the propulsion point.
What advantage does a twin-screw tug have?
Improved maneuverability and redundancy. 10. Excellent maneuverability, ability to maintain position when backing (if ship is stopped), and ability to steer astern.
What are the disadvantages of the twin-screw tug? (5 things)
Increased complexity and maintenance costs. 11. May require a stern line when backing, is less efficient than a single screw tug. Backing power is less than ahead.
What advantages does a tractor tug have over a conventional tug? (6 things)
Better control, stability, and ability to push or pull effectively. Can steer when going astern. Has Omni-directional thrust. Does not have the same risk of capsizing as a conventional tug.
What advantages does an ASD have over a tractor tug? ( 5 things)
Enhanced maneuverability and versatility in operations. Better sea keeping ability , shallower draft, more efficient in converting horse power to bollard pull and can perform transverse arrest (Tractor tug can not)
What three factors determine a rudder’s efficiency?
- Velocity of water flow, quality of water flow and rudder shape.
- Shape and area
- Angle of attack
- Speed of the vessel
These factors influence how effectively a rudder can steer a vessel.
What is the difference between an unbalanced and balanced rudder?
- Balanced or semi-balanced rudders are constructed so that the leading edge of the rudder extends forward of the rudder post.
This is done to provide more effective steering and a mechanical advantage to the steering gear.
Unbalanced rudders have a greater area behind the pivot point, while balanced rudders have equal area on both sides
This design difference affects the force required to turn the rudder.
What are the disadvantages of a VSP? (5 things)
- VSP horsepower to bollard pull ratio is lower than conventional or steerable propeller tugs; VSP tug will have a deeper draft than a conventional or ASD tug, VSP systems are expensive compared to a steerable propeller or conventionally propelled tug.
- Complexity in design
- Higher maintenance demands
VSPs can be more challenging to manage compared to conventional systems.
Ducted propellers can produce ______ to _____ percent more thrust than unducted propellers.
15 - 60%
Hydrodynamic interaction between ship and tug are a function of which three factors?
- Ship Speed, displacement, and hull shape
Speed, distance, and angle of approach
Understanding these factors helps in predicting the tug’s behavior.
What is stemming?
- Stemming” can occur when a tug takes a towline from the bow of a moving ship. If the tug comes in contact with the ship’s side it may lose steerage, in which case the tug may be caught by the ship’s bow and rolled over.
The process of maintaining the tug’s position against the ship’s movement
Stemming is crucial for effective tug operations, especially in strong currents.
What are two common cases of stemming?
- Misjudgment of the tug’s set in towards the ship’s bow or oversteering as the tug transits through the ship’s pressure zones at the its bow. When the tug is overtaking the ship by the bow the bow wave could push the bow of the tug off and if the operator over corrects and continues to overtake he could have the same positive pressure continue to make the tug turn into by pushing the stern of the tug off.
Alongside a moving ship and in strong currents
These scenarios often require careful tug handling to ensure safety.
What are the four hazards a tug operator needs to be aware of when approaching the stern of a vessel?
- Suction towards the stern.
- Rake or tumble home of the ship is a structural hazard.
- The ship’s turning propeller.
- The ship changing course.
What tug has a distinct advantage over conventional tug when it comes to passing a tow line to the bow of a vessel underway?
A. ASD tug operating stern first
B. ASD tug operating bow first
C. All of the above
D. None of the above
B. ASD tug operating stern first
They can extricate themselves from a potential stemming situation by steering away from the vessel.
True or False: An ASD tug operating bow first near the bow of a vessel underway shares the same risks as a conventional tug.
True
Ship’s interactive forces ________ with the ship’s speed.
A. Stay the same
B. Reduce exponentially
C. Grow exponentially
D. Grow slightly
C. Grow exponentially
Ideally the ship speed is ______ kts or less and the ship’s propeller is stopped when a tug is making fast.
7 kts or less
If the pilot must make a change in __________ he should communicate with the tug operator.
A. Rudder
B. Engines
C. Speed
D. A and B only
D. A and B only
What is an additional advantage of tractor and ASD tugs over Conventional tugs?
A. They can both perform transverse arrest
B. They are both capable of indirect towing
C. They can both transition from towing to push/pull mode without disconnecting the tow line.
D. All of the above
C. They can both transition from push to pull mode without disconnecting the two line.
At what speed should a tug transition to a push/pull position?
A. 7-8 kts
B. 5-6 kts
C. 3-4 kts
D. 1-2 kts
D. 1-2 kts 2 kts or less.
Once the tug operator has safely maneuvered a tug into position and made fast to the ship, he can declare to the pilot what?
A. In position
B. In position and ready to work
C. Standing bye to work
D. None of the above
B. In position and ready to work
What are the two components of the Center of Hydrodynamic Pressure?
- Lift and Drag
Lift and drag
The two components are vertical and horizontal forces.
The Center of Hydrodynamic Pressure is critical for understanding how forces interact with vessels in water.
Why is towline work on a conventional tug dangerous?
- The tug’s towing point is forward of the propulsion point which can make the tug susceptible to tripping or girting.
Because of the risk of tripping or girting.
These actions can cause loss of control and accidents.
Explain how a conventional tug trips or girts.
- Tripping or girting the tug can be caused by the ship overtaking the tug, or when the tug’s thrust and maneuvering lever cannot counteract the force of the tug’s center of hydrodynamic pressure acting on the tugs turning lever.
A tug trips or girts when it loses stability due to an unexpected shift in forces.
This can occur during maneuvers or when the towline is not managed properly.
How can the ship handler best avoid tripping or girting?
By employing tractor or reverse tractor tugs or requiring that the ship go at slow-to-moderate speeds. This risk can be managed by mechanical means moving the towing point through the use of hold downs and a gob rope.
By maintaining proper tension on the towline and adjusting to vessel movements.
Awareness of the surrounding conditions is crucial.
What is the advantage of using a tug alongside?
- It takes less time for the ship to respond to the tug’s efforts, and working the tug alongside is safer than towline work.
It provides better control and stability during maneuvers.
This technique is often used in tight spaces or when precision is necessary.
Explain a wrap line.
- A wrap line is line used by a tug to steer the bow of a ship moving stern first. It is led from one side of the ship’s bow to the bullnose on the tug located on the opposite side of the ship’s bow. This allows the tug to steer the bow in either direction.
A wrap line is a line that wraps around a vessel to provide additional towing support.
This technique can enhance stability and control.
Can a tug work a wrap line on all vessels?
- No. Bulbous bows, severely raked stems, and ships with flare may prevent a tug from working in this position.
No, it cannot work a wrap line on all vessels due to size and shape limitations.
The effectiveness of this method depends on the specific vessel configuration.
What is meant by the term snapping a tow?
- This occurs when a tug with a ship or barge in tow astern makes a hard turn and at the same time applies more power.
Since the tug’s rudder will set the stern of the tug in the opposite direction, the bow of the towed vessel will often also be set in the opposite direction of the turn at first.
Snapping a tow refers to the sudden release of tension in the towline.
This can lead to dangerous situations if not managed properly.
Why is indirect towing so powerful?
- Indirect towing uses the tug’s hydrodynamic resistance to add force to the towline.
Because it allows for greater leverage and control over the towed vessel.
This method is particularly effective in challenging conditions.
How is indirect towing used to advantage?
- Indirect towing can be used to provide steering and braking forces at ship speeds that are too high for effective direct towing.
It is used to maneuver larger vessels more effectively.
Indirect towing can provide better handling in tight situations.
Assist tugs use what four basic positions in shipwork?
- Leading tug towing on a line
- Tug alongside the ship pulling on a line or pushing
- Tug alongside the ship breasted or “on the the hip”
- Trailing tug, pulling on a line or pushing
What term describes a tug working a head of the ship moving forward? Astern of a ship moving forward?
- Lead tug
- Tail tug
True or False:
Effective application of a tug pushing, pulling, or working a towline can be achieved only if both pilot and tug operator understand the dynamic balance between a tug’s center of hydrodynamic pressure, lift-and-drag forces, maneuvering and turning resistance levers, and applied horsepower (fig. 9-1).
True
The amount of force applied to the towline is a function of the tug’s thrust and steering forces combined with __________ forces.
A. Hydrodynamic Lift
B. Hydrodynamic Drag
C. Hydrodynamic Velocity
D. A and B only
D. A and B only
What are the two forces that come into play where a tug has moved to a position where its towline angle approaches the desired angle?
A. Turning Lever and Maneuvering Lever
B. Turning Lever and Hydrodynamic Lever
C. Maneuvering Lever and Steering Lever
D. None of the above
A. Turning Lever and Maneuvering Lever
The turning Lever is the distance between ________ and ________.
Center of Hydrodynamic Pressure and Towing Point
The Maneuvering Lever is the distance between the tug’s _________ point and _______ point.
Propulsion Point and Towing Point
On a conventional tug it counters a turn by moving the tugs stern and towing point away from the ship, what does this do?
Adds the tugs pull on the towline in the opposite direction to the tow.
A sign that the hull’s hydrodynamic forces are strengthening is what?
The sensation of “digging” in
What is a clear sign that the tug is on or past the precipice of losing its maneuverability?
When it reaches the point of deck edge immersion
Conventional tugs are very effective in the position of __________________
Lead tug on a tow line it can apply forces equally in both the port and starboard directions.
When a conventional tug on a towline begins a turn the bow of the ship may be set in what direction initially?
Directly opposite the intended turn direction
True or False: tractor tugs as lead on a tow line do not have the same hydrodynamic advantage as a conventional tug in the same position.
True, this is because the tractor tug must use more of its power to stay in position and pull its own hull through the water there by reducing actual pull on the tow line.
An ASD tug working bow to bow has the advantage of what? But the disadvantage of what?
- Longer maneuvering lever
- Operating skeg first
When working as a lead tug on a line both tractor and ASD (reverse tractor) have distinct ______ advantages over a conventional tug.
Safety because of their Omni-directional thrust capability and prop first orientation it makes them less likely to trip or girt.
The effectiveness of all tugs working as a lead tug diminishes as ship _________ increases.
Speed
The head line is also referred to as what?
Backing line
Stern lines and ______ are interchangeable terms.
Quarter lines
The magnitude of a tug’s pushing force against a ship’s side is a result of the aggregate effect of what four factors?
- Pushing angle of the tug in relation to the fore and aft line of the ship
- Amount of the tug’s hydrodynamic lift
- Amount of the tug’s thrust allocated for steering
- Efficiency of the tug’s maneuvering leverage
The key determinant to the required allocation of steering force is the proportional relationship between what two levers?
- Maneuvering Lever distance between tow point and prop point
- Turning Lever: distance between towing point and the center of hydrodynamic pressure.
When a tug is pushing on a ship DIW where is the towing point and where is the center of hydrodynamic pressure?
Both at the bow of the tug
As the ship begins to move forward what happens to the Center of hydrodynamic pressure?
It moves aft
Where is the center of hydrodynamic pressure on a conventional tug compared to a tractor tug or ASD?
Further aft. This increases the turning lever making it harder to overcome
True or False: it is important that the tug be secured parallel to the ship’s centerline with its propulsion units as close to the end of the ship as possible when towing on the hip.
True, this gives better leverage in applying steering forces to the ship.
What are two reasons most tugs can only make up alongside the flat of the ship’s hull?
- They avoid contact between superstructure of the tug and hull of the ship.
- The tug is more secure and less likely to yawn on the lines if more surface area near the tugs propulsion end is in contact with the ship.
What are the two ways a conventional tug can work as a trailing tug?
- Off its stern with a towline
- Off its bow with 1 or 2 headlines
When is it safer to shift the towing point all the way aft to a position over the prop as a conventional tug on a tow line?
A. When it is providing only steering forces
B. When it is providing only braking forces
C. When it is indirect towing
D. None of the above
B. When it is providing only braking forces
When towing circumstances call for more ship speed a conventional tug is safer ________ as a trailing tug.
A. Acting as a rudder tug going bow first
B. Indirect towing
C. Going stern to stern with a gob line
D. None of the above
A. Acting as a rudder tug going bow first
True or False: A conventional tug can be very effective functioning as a trailing tug off the bow of a ship with stern way.
True
What orientation do ASD and tractor tugs operate when acting as a trailing tug or rudder tug?
ASD: Bow to stern of vessel
Tractor: Stern to stern of vessel
At what ship speeds can an ASD and Tractor tug provide steering forces when Direct towing?
A. 3-4 kts
B. 4-5 kts
C. 5-6 kts
D. 6-7 kts
C. 5-6 kts
This is the technique that the tug operator adds to indirect towing line forces by moving the tugs towing point farther off to the ship’s side and applying full power.
Power indirect
In power indirect mode the towline angle approaches _____ºs and has the potential of applying up to _____% of the tugs rated bollard pull to the tow line.
- 90º
- 120% (between 75% and 120%)
What are determining factors in establishing safe limits of indirect towing at maximum ship speed?
A. Tug stability
B. Tug freeboard
C. Tug bollard pull
D. All of the above
D. All of the above also skeg design, towing and propulsion point locations.
Forces generated by indirect towing are a result of what factors? (4 things)
- Towline angle in relation to the ship
- Tug angle in relation to the towline
- Speed through the water
- Allocation of the tugs thrust to steering
what option does a tug operator have if the tow line force becomes too much during indirect towing?
A. Steer back toward the pulling force
B. Reduce the angle to water flow and hydrodynamic resistance
C. Reduce power and slow down
D. All of the above
D. All of the above
A maneuver allowing a quick repositioning of the tug from indirect to direct towing in which the tug operator can use combination of towline tension, render the recovery feature of the winch and the tug’s lateral maneuverability to swing around into the direct towing position is what?
Jackknifing
At what speed does jackknifing start to be an appropriate maneuver?
A. 1-2 kts
B. 2-3 kts
C. 3-4 kts
D. 5-6 kts
C. 3-4 kts
What three fundamental principles of shiphandling are essential to a shiphandler’s eye?
- Center of Lateral Resistance 2. Pivot Point 3. Maneuvering levers
The Center of Lateral Resistance determines the resultant proportion of _____________ vs. _______________ force of an applied lateral force to the ship.
Lateral vs. rotational
Where is the pivot point located for a ship that is stopped?
Amidships at the CLR depending on the draft and trim
Where is the pivot point located for a ship that is moving laterally?
Amidships at the CLR depending on draft and trim
Where is the pivot point located for a ship that is moving ahead?
Approximately one quarter ship length aft of the bow
Where is the pivot point located for a ship that is moving astern?
Approximately one quarter ship length forward of the stern
Where is the pivot point located for a ship that is turning?
Approximately one third ship length aft of the bow
The pivot point functions as the _______ of the ship’s maneuvering lever.
fulcrum
If a tug is meant to turn a vessel where is the best placement for it?
A. Positioned on the fulcrum
B. Positioned a ship width forward of the fulcrum
C. Positioned a ship width aft of the fulcrum
D. As far away from the fulcrum as possible
D. Positioned as far away from the fulcrum as possible.
If a tug is meant to turn a vessel where is the best placement for it?
A. Positioned on the fulcrum
B. Positioned a ship width forward of the fulcrum
C. Positioned a ship width aft of the fulcrum
D. As far away from the fulcrum as possible
D. Positioned as far away from the fulcrum as possible.
If a tug is meant to move a vessel laterally where is the best placement for it?
A. Positioned on the fulcrum
B. Positioned a ship width forward of the fulcrum
C. Positioned a ship width aft of the fulcrum
D. As far away from the fulcrum as possible
A. Positioned on the fulcrum
This is the point on a ship where the application of a lateral force results in the ship moving sideways with no rotation.
The center of lateral resistance
The CLR is not fixed and reflects the balance pint of what factors? (3 factors)
- Hull shape
- Direction of the ship’s motion
- Draft and Trim
Where does the CLR move when the ship gains headway? Stern way?
- Moves forward
- Moves aft
True or False: the Center of Lateral Resistance of a ship down by the stern is farther aft than one trimmed forward.
True
True or False: the location of the center of lateral resistance is often the same location as the pivot point.
False. It is often not in the same location
This is the point appears on the ship as an axis of rotation with reference to the water’s surface.
The pivot point
True or False: the pivot point is the result of applied forces and the subsequent motion of the ship.
True
Where does the pivot point move in relation to the vessels movement? In relation to applied lateral force?
- Toward the direction of vessels movement.
- Away from applied lateral force.
What are the five basic ship movements?
- Stopped
- Lateral
- Headway
- Stern way
- Turning
Where is the pivot point of a ship in relation to the center of lateral resistance on a ship with lateral but no rotational motion?
At the same location
Where is the pivot point after a ship first starts to come ahead?
A. 1/2 L from bow
B. 1/4 L from Bow
C. Far forward
D. Amidships
C. Far forward
Where is the pivot point after a ship gains headway?
A. 1/2 L from bow
B. 1/4 L from Bow
C. Far forward
D. Amidships
B. 1/4 L from bow
When a ship initiates are turn and lateral resistance builds on the ship’s side what happens to the pivot point?
A. Stays at the same spot
B. Moves aft of its usual spot
C. Moves forward of its usual spot
D. None of the above
B. Moves after of its usual spot. Usually 1/3 L from the bow.
The ship’s maneuvering lever is defined by the relationship between what two factors?
- Pivot point location
- Ship propulsion forces
The Maneuvering lever of a ship may either lengthen or short in accordance with the ship’s motion and what?
The magnitude of the force being applied to the end of the lever
The art of ship handling with tugs is teh ability to apply the power of tugs within the context of the ship’s pivot point and in conjunction with ______________.
The ship’s maneuvering lever.
Define a tug’s assist lever.
- The distance between the location of the tug’s applied force and the ship’s pivot point.
. The
A lever that helps a tug apply force to a ship while maneuvering
The assist lever is crucial for enhancing the tug’s effectiveness in towing and positioning.
Why is it easy for a ship with headway to overwhelm a lead tug on a towline?
- The ship has greater power and can apply that power on a longer and more efficient maneuvering lever. This can easily overpower the tug.
Because the ship’s forward momentum can exceed the tug’s pulling capacity
This phenomenon can lead to loss of control over the towline.
What are the three means a tug has to apply force when working?
- Push, act as a drogue or pull on a line.
- Direct pull
- Side pull
- Push
Each method has its advantages depending on the situation and desired maneuver.
What are the four factors that affect a tug’s effectiveness when working alongside?
Angle of the tug, offset position of the tug, drag force and tug’s applied horsepower.
- Tug size
- Tug power
- Ship size
- Environmental conditions
These factors determine how well a tug can assist in maneuvering the ship.
Why is a conventional tug backing on the stern quarter, on the outboard side of a turn, ineffective in turning the ship?
- At all but the lowest speeds the conventional tug allocates almost all its horsepower to maintain position at, or close to, 90.
There is minimal lateral pull applied to the tug’s headline tug’s angle, offset position, drag, and horsepower are all working on a long assist lever to counter the turn.
ll.
Because it cannot generate sufficient force to change the ship’s direction
This position often leads to a loss of control over the ship’s movement.
In breasted towing, a tug made up on the ship’s stern creates, in effect, a _______.
Twin screw
[pushing force]
This configuration helps in maintaining the ship’s heading and stability.
In breasted towing, a tug made up on the bow functions as a _______.
- Steerable bow thruster.
[pulling force]
This setup assists in steering the ship and controlling its speed.
What is negative water flow?
- Negative flow considerably increases the torque loadings on the propeller and engine. High negative water flow may increase the load enough to stall, or damage, the tug’s engine, clutch, or couplings.
Water flow that moves against the direction of the ship’s movement
Negative water flow can complicate the tug’s efforts in maneuvering.
How is negative water flow a factor in conventional tug performance?
- Negative flow considerably increases the torque loadings on the propeller and engine. High negative water flow may increase the load enough to stall, or damage, the tug’s engine clutch, or couplings.
This situation may require adjustments in tug positioning and strategy.
Why is a trailing tug the most effective position for steering a ship?
- A trailing tug creates the longest assist lever and allows the tug to apply equal forces to both starboard and port. The tug can enhance the effect of the ship’s rudder on a ship with headway and can also control the bow and steer a ship with sternway
Because it can exert force in the direction of the ship’s movement
This position allows for better control and responsiveness.
What precautions should the shiphandler exercise when employing a conventional tug as a trailing tug on a towline?
- The shiphandler must execute careful management of ship speed and propulsion wash.
Ensure proper communication and coordination with the tug
This helps to prevent accidents and ensure effective maneuvering.
What two methods can tractor and ASD tugs use to steer a ship as a trailing tug?
- A tractor or ASD tug can utilize direct towing at ship speeds of five knots or less, and indirect towing at higher speeds
- Pivoting
- Side pulling
These methods enhance the tug’s ability to control the ship’s heading.
What is the essence of effectively using tugs to steer and propel ships?
- Steering and propelling ships with tugs is a matter of creating and using the tug force as an effective lever in conjunction with the ship’s maneuvering lever.
Coordinated force application and positioning
Effective tug operations rely on teamwork and strategic maneuvering.
A shiphandler’s effective use of tugs to steer and propel ships requires an awareness and appreciation of three maneuvering factors what are they?
First, the pilot must understand the relationship between tug location and the ship’s pivot point.
Second, he must be cognizant of the orientation of both the tug’s position and the ship’s propulsion point in reference to the ship’s pivot point.
Third, he must account for the strengths and weaknesses associated with the four basic tug positions in ship assist.
What tug position is the optimal position to steer a ship with headway?
A. Tug on a tow line on the bow
B. Tug at or near the stern
C. Tug on the hip midship
D. Tug on the shoulder of the bow
B. Tug at or near the stern
What determines the length of the assistance lever of the tug and maneuvering lever of the ship?
A. Ship speed
B. Ship direction
C. Tug location
D. All of the above
D. All of the above
With a leading tug towing on a line the tug always has a force component that adds to ship ________.
Speed
What is the assistance lever of a tug towing on a line compared to the maneuvering lever?
Assistance lever is much shorter
True or False: With prudent use of the ship’s rudder and propulsion, the ship pilot can use a tug on a towline to control the ship’s bow and regulate the turn rate of the ship.
True
True or False: with a lead tug with a vessel with stern way it is difficult if not impossible for one tug to effectively steer the ship.
True, the pilot must steer judiciously using rudder and small kicks ahead.
With a lead tug along with a trailing tug with a vessel that has sternway what does the ship use its rudder and propulsion to do?
A. Nothing it is not effective while under sternway
B. Provides sternway
C. Shift and position the stern
D. None of the above
C. Shift and position the stern
With a tug alongside the ship pulling on a line or pushing what is critical?
A. The length of the quarter line
B. The length of the head line
C. The length of both lines
D. None of the above
B. The length of the headline to allow the tug to lie flat alongside and be more effective.
With a tug alongside the ship pushing if the tug is not at a 90º angle what component will the tug add to?
A. Ship speed
B. Rotational momentum
C. Lateral motion
D. All of the above
A. Ship’s speed or rate of advance.
When a tug lays passively on it line with engines stopped, the line is under tension created by the tugs weigh and hydrodynamic resistance. What is this called and in which direction may it turn the vessel?
Drogue effect and toward the tug
True or false: a tug alongside generally is not as effective pulling on its line as it is pushing into the ship.
True
Tug performance alongside depends on what?
A. Location of pivot point
B. Ship draft
C. Ship speed
D. None of the above
C. Ship speed
What is true about a tug alongside the bow shoulder on a ship with head way?
A. This position gives a small to negligible assist lever to turn the ship
B. This position can steady and apply lateral forces to the ship’s pivot point
C. This tug can function as a dynamic spring line.
D. All of the above
D. All of the above
True or False a tug alongside the bow shoulder on a ship with head way when the tug is on the outboard side of a turn it can push to assist the ship’s maneuvering lever.
True
a tug alongside the bow shoulder on a ship with head way when the tug is on the outboard side which factor detracts from the vessel’s rate of turn?
A. Angle of the tug
B. Offset position of the tug
C. Drag force
D. Tug’s applied horse power
C. Drag Force
A tug alongside the bow shoulder on a ship with head way when the tug is on the inboard side and backing which factor detracts from the vessel’s rate of turn?
A. Angle of the tug
B. Offset position of the tug
C. Drag force and Tug’s applied horse power
D. None of the above
D. None of the above they all contribute to the rate of turn. Additionally the tug acts as a dynamic spring line.
A tug alongside the bow shoulder on a ship with head way when the tug is on the inboard side and backing on a line what is the weak link ?
The tug’s line. Always be mindful of speed.
When a tug is alongside the stern quarter what side is the best placement? Why?
The inboard side of the turn because if it pushes it accentuates the ship’s steering and propulsion.
What position is a conventional tug practically useless?
After quarter on the outboard side of a turn. Unless the ship is bare steerageway the tug will oppose the turn even when backing full.
When tractor or ASD tugs are alongside the ship’s quarter which way should they position their propulsion end? If they are required to pull how can they avoid loss of effectiveness?
- Propulsion end first
- Direct pull at about 45º to prevent wash hitting the ship’s hull.
If a tug is alongside the ship’s bow shoulder it has an excellent Assist lever when the vessel has sternway, how can the pilot steer the ship with the Rudder and propulsion?
By giving kicks ahead and using the tug to steady the bow.
True or False with a conventional tug alongside the ship’s bow shoulder it has the same limited or contrary effect as it does alongside the stern quarter of a ship with headway.
True
A tug alongside the ship’s stern quarter with sternway the tug can assist in moving the ship’s pivot point ________.
Laterally
What is the correct nautical terminology for a tug on the hip or hipped up?
Breasted or alongside towing
What happens to the vessel if a tug on the hip of the bow comes ahead or comes astern of a vessel with headway?
- The vessel will rotate away and gain speed.
- The vessel will rotate toward the tug and lose speed.
What statement is true concerning a conventional tug when breasted towing?
A. It is most effective when it propels or steers by coming ahead on its engines.
B. It is most effective when its bow if facing the direction of ship advance.
C. When it is made up with its stern facing the ships way it is limited in bollard pull and maneuverability.
D. All of the above.
D. All of the above.
Conventional tugs at what speeds can lay broadside to the general direction of ship’s advance as a trailing tug?
A. 1 - 3 kts
B. 2 - 4 kts
C. 4 - 5 kts
D. 5 - 6 kts
A. 1 - 3 kts with the use of a gob line
What is the effect on the ship’s pivot point of one tug pushing at the bow?
The pivot point moves from mid ships to the ship end opposite of the tug.
How many ship lengths will it take to turn a ship with one tug pushing at the bow?
Two ship lengths. When the tug starts pushing the ship gains momentum and begins to creep ahead.
What is the effect on the ship’s pivot point of two tugs pushing with equal force, one on the port bow and one on the starboard stern of a stopped ship?
They can turn the ship within one ship length and the pivot point stays in line with the Center of lateral resistance.
In order to move a stopped ship laterally, the external forces applied must have _______ on either side of the ship’s pivot point.
equal magnitude
What is drift angle?
The angle between the ship’s centerline and the direction in which the ship’s bridge is actually traveling in a turn.
Why is knowledge of drift angle useful to the pilot?
Drift angle serves as a visual cue for the pilot to estimate the degree of lateral motion or slide that a ship has as it executes a turn . It helps in navigating and maneuvering the ship effectively
The interrelation between the ship’s center of lateral resistance and its pivot point is most apparent when the tug pushes or pulls laterally on a ship that _____________.
A. Is moving ahead
B. Is moving Astern
C. Is stopped
D. Any of the above
C. Is stopped
True or False: if one force is stronger the pivot point of a vessel shifts toward the weaker force.
True
Moving a ship laterally requires the absence of ___________ consequences of forces applied to the ship’s turning lever.
Rotational
The ship’s pilot should be familiar with what principle of ship movement?
A. Pivot point movement
B. Drift Angle
C. Lateral motion
D. All of the above
D. All of the above
On a ship DIW when the pilot turns the rudder hard over and orders ship’s engines ahead the ship’s stationary inertia resists the ship’s forward motion. Where does the pivot point go?
1/8 ship Length from the bow
On a ship DIW when the pilot turns the rudder hard over and orders ship’s engines ahead the ship’s stationary inertia resists the ship’s forward motion. If the ship continues to turn where does the pivot point eventually go?
1/3 ship length from the bow
When the bridge of the ship is aft and the pilot makes a large turn what will the sense be from the bridge?
The stern skidding sideways in the turn
Full bodied ships such as bulk carriers usually have _______ drift angles?
Large drift angles
Finer narrower hulled ships have _______ drift angles.
Small
the tug can initiate the tum by pushing or pulling on the bow. The tug does this to take advantage of the long assist lever to the ship’s pivot point aft. As the ship comes read with the rudder hard over, the ship loses its aft momentum and tra pivot point migrates toward midships. At this point both ship and tug are working together to spin the ship within its own length. This presents another CDP. If the pilot allows the ship to gather headway, the pivot point rial moves very close to the bow, enhancing the effect of the ship’s rudder. As a result the ship’s maneuvering lever is rotating the body of the ship around its bow and the tug is no longer aftectively turning the ship. Here is yet another CDP.. This allows the ship to continue turning with minimal headway. If the tug lacks sufficient capability, the ship continues to gather headway and the tug may be overrun by the ship unless released. What are the three CDPs mentioned above?
One CDP when to apply the ship’s power and rudder.
The pilot can allow either the ship to gather headway or by giving short kicks ahead, keep the way off, allowing the ship to continue turning around its midships turning axis.
If the tug has enough maneuverability and power it can offer sufficient resistance to the ship’s headway to hold the ship’s pivot point in a position well forward
The interrelation between the ship’s forward inertia and the amount and location of the tug’s lateral force determines this?
The ship’s pivot point
When a ship gives a kick ahead with the rudder hard over, the ship’s inertia sustains a residual lateral motion after the propeller is stopped where on the vessel is this lateral motion more pronounced?
The Ship’s stern
When a ship is being pulled off the dock laterally by two tugs equal distance apart. The ship propulsion starts to engage ahead the ________ tug will lose leverage what are the two ways the tugs can regain balance?
- Forward
- A. If the stern tug reduces thrust
B. If the stern tug shifts to a position closer to the ship’s pivot point
What are the three principle techniques used by tugs to apply braking force to the ship?
- Tug’s weight
- Lateral resistance
- Bollard Pull
Or a combination of these three.
What is the prime function of tugs in shipwork?
A. To provide steering effect
B. To provide lateral movement
C. To provide longitudinal movement
D. To create braking effect
D. To create braking effect
The ship’s rudder requires a minimum amount of water flow. The velocity of this flow is the combined result of ship’s __________ and ___________.
- speed
- Propeller wash
As ship speed and propeller wash drop so does control of the ship.
What are the two ways a pilot uses the tug’s braking force?
- To bring the ship to a stop
- To provide sufficient drag to keep the ship speed down without actually bringing it to a stop.
What is the primary tools pilots use to manage speed?
Tugs
What are the two positions a tug can apply braking force to a ship?
- Alongside
- In-line aft
If a tug is alongside and using breaking force it will tend to can’t the ship in which direction?
The side the tug is on
How do tractor tugs or ASD tugs use bollard pull to create sufficient braking forces? (Two positions)
- Inline
- Reverse arrest
An ASD tug has the ability to use this position to apply breaking force that the other tugs do not. What is it?
Transverse Arrest
What factor or factors effect tug’s braking capability?
A. Ship Speed
B. Negative water flow
C. Ship’s propeller wash
D. All of the above
D. All of the above
When a tug reverses its thrust to slow a ship, the tug’s propulsion machinery must contend with the effects of ___________. Which may overload and stall engines of conventional tugs or tractor tugs using too much pitch.
Negative Water Flow
How can ASD tugs and tractor tugs with independently controlled thrusters manage negative water flow?
Turning its units at an angle to the tug’s center line.
ASD tugs can align their units anywhere between ______ position to __________ position to avoid the effects of negative water flow.
Reverse arrest to transverse arrest
Conventional and VSP tractor tugs may find it difficult to apply consistent, direct pull on the two line while keeping the tug inline aft because of the eddies associated with this area what technique can an ASD tug apply to that works well in these situations?
Transverse Arrest
True or False: To ensure they are effective in critical times where ship propulsion may malfunction the pilot must have prepositioned the tug in a manner that enables the tug to employ its most effective braking factors associated with the design and propulsion features of the tug.
True
What are the factors in choosing the placement of tugs in Shipwork ?
Sequence of maneuvering events, safety of tug, limits of tug design, skill level of tug operator, need and location of highest horsepower tug, required allocation of tug’s horsepower to maintain or achieve assist position
True or False: A pilot’s ability to quickly sense changes (the gust of wind, the drift of the ship’s bow, and make quick and accurate adjustments is the mark of a skilled and experienced pilot.
True
If a ship is being turned through the wind and is light where may the ship handler consider moving the leeward tug?
A. To the lee quarter
B. Center lead aft
C. To the windward bow
D. To the windward quarter
C. To the windward bow to check the swing of the ship before it has too much momentum.
What should the ship handler avoid when a tug is moving from one quarter to another?
Backing hard until the tug is fast
During a maneuver it helps to break it up into sections 4 parts of a maneuver which a ship handler can think of for placement of tugs are?
- Stop the ship
- Turn the ship
- Shift tugs
- Breast vessel to the dock
When making a bend with a tug it helps for the tug on the inside of the bend backs this does two things which are?
- Starts the swing
- Retards the speed making the prop and rudder more effective on the ship.
If the bend is sharp what will a tug on the inboard quarter do to help facilitate a turn?
A. Back to use a twin screw effect in conjunction with the ships prop.
B. Push if it has a head line up.
C. Act as a drogue
D. None of the above
B. Push if it has a head line up and can get to a 45º angle vessel speed must be kept low.
Why is an anchor called a poor man’s tugboat?
1, Because when a ves Theres is anchors, it can dispense with the services of a tue. There are also occasions when the use of the anchors is preferred.
An anchor is considered a poor man’s tugboat because it serves a similar purpose of holding a vessel in position without the cost of hiring a tug.
How does using an anchor differ from using a tug?
- The anchor is esse ules it assie” device that cannot push nor pull like a tug unless it has been “spotted” beforehand and is used as a “deadman” to heave against, or is used as a “brake” to check a vessel’s way.
Using an anchor relies on holding a vessel in place, while a tug actively maneuvers and positions a vessel.
What are the three functions of an anchor when a ship is maneuvering?
- Restrain but not stop the ship, fix or hold the anchored end of the ship, or provide a deadman to heave against.
- Holding the vessel in position
- Preventing drift
- Assisting in control during maneuvering
What are the two primary purposes of tugs in ship escort?
- Emergency Stopping
Emergency Steering
What are the three tug response modes?
- Retard
Assist
Oppose - 2 tugs, aft of the ship’s bridge
• 4. What is the least effective tug response position?
- Forward shoulder of ship
• 5. What is the most effective tug response position?
- Rudder tug tethered to ship’s stern
• 6. What are the three maneuvering options for a tethered ASD or tractor tug?
. Direct, indirect, in-line arrest
• 7. Why is ship speed critical to a ship escort response?
- Determines advance and carry
Compounds effect of time delay
Determines effectiveness of response positions
- What is the danger of the new line and winch technology used in ship escort?
- The line may not break or release if the tug is in peril
- What are the three qualities of good verbal communication?
- Simple, clear, easily understood not misunderstood
- Why did the verbal radio communication replace whistle signals?
2 More complex tugs and maneuvers required a bigger vocabulary than whistle signals could provide.
- What terminology must be clear for effective command and response communication? (5 things)
- Communication that:
• Identifies the tugs
• Indicates the direction of force to be applied
• Indicates the amount of force to be applied
• Indicates the desired push or pull angle
• Verifies the receipt, understanding, and implementation of the command by the tug
- Why should the terms “full,” “on,” and “off” be avoided?
- They can be mistaken for other words
- How does the tug acknowledge an order?
- The tug operator’s response includes the tug’s name and repeating the order back to the pilot
- What is a means of non-verbal communication in shipwork?
- Action of the tug
Which statement is true about good communication?
A. It has no universal protocol or vocabulary
B. It has no universal principles
C. It must be verbal and spoken in English
D. All of the above
A. It has no universal protocol or vocabulary
It has universal principles that attempt to ensure an accurate exchange of information.
what do the following whistle signals mean by an assist tug?
1. One short blast if stopped
2. One short blast if you are going ahead or astern
3. Two short blasts
4. 3 very short blasts
5. One prolonged blast
6. One long blast followed by two short blasts
One short blast means “come ahead on your engines” if stopped.
One short blast means stop if you are going ahead or astern on your engines.
Two short blasts mean back your engine.
Three very short blasts is a signal for more speed.
One prolonged blast is a signal for slow speed.
One long blast followed by two short blasts is a signal to let go or shift the tug.
What statement is true concerning communication with the tug?
A. The tug should be identified first
B. Ambiguous words with multiple meanings should be avoided
C. Orders should be given as brief and direct as possible
D. All of the above
D. All of the above
Changing in pushing angles can be communicated with terminology that refers to the tug’s aspect to what?
The ship’s hull or other easily understood reference point
Tug response to a command must include what?
A. Tugs name and repeat order given
B. Tugs name only and “roger” or “affirmative”
C. just an affirmation of what was said “roger or affirmative” will do
D. None of the above
A. Tugs name and repeat the order given.
An average-size ship’s turning circle is usually slightly when the ship turns to the right than to the left 1. Larger 2. Smaller 3. The same
MacElrevey 10-11 The correct answer is: Number 1 Larger
For a given rudder angle and engine speed, the rate of turn as the depth of water increases 1. increases 2. decreases 3. does not change
MacElrevey 10 & 18 The correct answer is: Number 3 does not change
You are aboard an average-sized, loaded, house-aft tanker proceeding through an open roadstead. The wind is blowing hard enough to overcome the normal twisting effect when your ship’s engine goes astern. When you back your ship you would expect her to? 1. Head into the wind when she has headway and back into the wind when she has sternway. 2. Head away from the wind while she has headway and back away from the wind when she has sternway.
MacElrevey 14 The correct answer is: Number 1 Head into the wind when she has headway and back into the wind when she has sternway.
Assuming there are no extraordinary wind, current, or bank effects, a ship should be swinging moderately to before her engine is put astern. 1. Port 2. Starboard
MacElrevey 14-15 The correct answer is: Number one Port
When a ship moves from deep to shallow water; twisting effect when backed 1. increases 2. decreases 3. no significant change
MacElrevey 17-20 The correct answer is: Number 1 increases
When a ship moves from deep to shallow water; the rate of turn 1. increases 2. decreases 3. no significant change
MacElrevey 17-20 The correct answer is: Number 3 no significant change
When a ship moves from deep to shallow water; speed loss during a large course change 1. increases 2. decreases 3. no significant change
MacElrevey 17-20 The correct answer is: Number 2 decreases
When a ship moves from deep to shallow water; the speed loss when the engine is stopped 1. increases 2. decreases 3. no significant change
MacElrevey 17-20 The correct answer is: Number 2 decreases
When a ship moves from deep to shallow water; the directional stability. 1. increases 2. decreases 3. no significant change
MacElrevey 17-20 The correct answer is: Number 1 increases
How would you expect the following to affect directional stability: Increased length 1. more positive (or less negative) 2. less positive (or more negative) 3. no significant change
MacElrevey 18-20 The correct answer is: Number 1 more positive (or less negative)
How would you expect the following to affect directional stability: Increased beam. 1. more positive (or less negative) 2. less positive (or more negative) 3. no significant change
MacElrevey 18-20 The correct answer is: Number 2 less positive (or more negative)
How would you expect the following to affect directional stability: Increased drag. 1. more positive (or less negative) 2. less positive (or more negative) 3. no significant change
MacElrevey 18-20 The correct answer is: Number 1 more positive (or less negative)
How would you expect the following to affect directional stability: Decreased UKC. 1. more positive (or less negative) 2. less positive (or more negative) 3. no significant change
MacElrevey 18-20 The correct answer is: Number 1 more positive (or less negative)
How would you expect the following to affect directional stability: Increased Cb. 1. more positive (or less negative) 2. less positive (or more negative) 3. no significant change
MacElrevey 18-20 The correct answer is: Number 2 less positive (or more negative)
How would you expect the following to affect directional stability: More full sections forward. 1. more positive (or less negative) 2. less positive (or more negative) 3. no significant change
MacElrevey 18-20 The correct answer is: Number 2 less positive (or more negative)
How would you expect the following to affect directional stability: Increased Rudder Angle. 1. more positive (or less negative) 2. less positive (or more negative) 3. no significant change
MacElrevey 18-20 The correct answer is: Number 3 no significant change
Ships with large block coefficients are more likely to trim by the head in shallow water.
MacElrevey 19 The correct answer is: True
Which of the following statements is/are true for ships with negative directional stability. 1. A larger rudder angle is needed for a longer period of time to start a turn 2. A larger rudder angle is needed for a longer period of time to steady up after a turn 3. The ship’s rate of turn increases when the rudder is put amidships during a turn
MacElrevey 18-20 The correct answer is: Number 2 A larger rudder angle is needed for a longer period of time to steady up after a turn and Number 3 The ship’s rate of turn increases when the rudder is put amidships during a turn
A VLCC makes a hard-over turn. You would expect her to lose nearly percent of her headway when her heading changes by 90 degrees. 1. 10 2. 20 3. 25 4. 50
MacElrevey 25 The correct answer is: Number 3 25
The ship’s call letters should be transmitted frequently when communicating by VHF and, in any case, at intervals of 1. before and after every transmission during a series of transmissions with another ship 2. at ten minute intervals 3. before the first transmission and after the last transmission of a VHF converstaion regardless of length
MacElrevey 36-37 The correct answer is: Number 2 at ten minute intervals and Number 3 before the first transmission and after the last transmission of a VHF converstaion regardless of length
Ships with variable pitch propellers steer best if speed is reduced quickly.
MacElrevey 52 The correct answer is: False
Advantages of omnidirectional propulsion systems over conventional systems include 1. Greater safety 2. increased maneuverability 3. reduced reliance on traditional shiphandling skills
MacElrevey 53 The correct answer is: Number 1 Greater safety and Number 2 increased maneuverability
When steering using azipods in the At Sea mode the pod is turned to port to turn the ship to starboard.
MacElrevey 61 The correct answer is: True
Using azipods, when is the at sea mode is used? What is their orientation?
MacElrevey 61-63 In open waters. Units parallel to the centerline of the vessel.
Using azipods, when is the Harbor mode is used? What is their orientation?
MacElrevey 61-63 In narrow channels. The units set at a 45 degree angle away from the centerline.
Using azipods, when is the Docking mode is used? What is their orientation?
MacElrevey 61-63 Used in approaching berths. The inboard unit is parallel to the dock, the outboard unit athwartships.
When operating in the Harbor Mode the pods are placed at 45 degrees in opposition to each other. The vessel is turned to port by moving the control ahead and pulling back on the control.
MacElrevey 62 Starboard, Port
When in Docking Mode and going port side to the berth, the pod is placed parallel to the centerline, and the pod is placed in the 3 o’clock position with the propeller .
MacElrevey 62-63 Port, Starboard, Outboard
When researching various methods for standardizing azipod commands, some pilot groups found it worked well to use… 1. Standard steering and engine commands in the At Sea mode 2. standard steering and engine commands in the Harbor and Docking modes 3. clock positions and percentage of power for all modes 4. clock positions and percentage of power for Harbor and Docking modes
MacElrevey 63-64 The correct answer is: Number 1 Standard steering and engine commands in the At Sea mode and Number 4 clock positions and percentage of power for Harbor and Docking modes
When operating under computer control, the shiphandler is controlling? 1. revolutions per minute of the pod and thruster and direction of the thruster and pod forces 2. resultant power, speed, and vessel movement
MacElrevey 65 The correct answer is: Number 2 resultant power, speed, and vessel movement
Experienced mariners limit the use of computer control when maneuvering near docks and fixed objects. A good rule of thumb is to change from automatic to manual control when within of a hazard 1. three ship lengths 2. 100 feet 3. one ship length
MacElrevey 66 The correct answer is: Number 3 one ship length
The tactical diameter is when the object moves ahead relative to the shipboard reference point. 1. increasing 2. decreasing
MacElrevey 75-77 The correct answer is: Number 2 decreasing
It is best to overtake and pass close by another ship in a narrow channel at very slow speed, while the overtaken ship should increase her speed before being passed.
MacElrevey 80 The correct answer is: False
The change in mean draft is know as? 1. Sinkage 2. Squat 3. Trim
MacElrevey 85 The correct answer is: Number 1 Sinkage
Hull rotation about the transverse axis and resulting change in draft forward or aft is known as? 1. Sinkage 2. Squat 3. Trim
MacElrevey 83 The correct answer is: Number 3 Trim
The increase in deep draft forward or aft is called? 1. Sinkage 2. Squat 3. Trim
MacElrevey 83 The correct answer is: Number 2 Squat
The increasing pressure drop under a hull and the corresponding increase in squat caused by water flowing under the hull at increased velocity as the ship’s speed increases is due to what principle?
MacElrevey 85 Bernoulli’s
The pilot or ship’s officer can reduce sinkage and squat by reducing the…. 1. block coefficient 2. speed 3. blockage factor 4. the rate and period of acceleration
MacElrevey 96-97 The correct answer is: Number 2 speed and Number 4 the rate and period of acceleration
Squat for a given speed and hull condition in confined water is that in open water. 1. half 2. twice
MacElrevey 87-88 The correct answer is: Number 2 twice
What is the standard formula for Squat
MacElrevey 87-88 S = Cb x V2 / 30 Where: S = Speed Cb = Block Coefficient V2 = Knots
What is the standard formula for Squat
MacElrevey 87-88 S = Cb x V2 / 30 Where: S = Speed Cb = Block Coefficient V2 = Knots
UKC is influenced by several factors including. 1. Vessel Speed 2. Channel Dimensions 3. Changes in Engine Revolutions 4. Vessel Interaction
MacElrevey 95 The correct answer is: All Of The Above
How much is UKC is reduced when two ships pass in a narrow channel because squat increasing dependant on ship speed and distance of separation?
MacElrevey 95-98 50 - 100 or more%
UKC is reduced significantly as a ship accelerates and squat increases as much as %.
MacElrevey 95-97 You could have answered with any of the following: 1. 100 2. one hundred
Changes in the shape of the channel have no effect on squat so long as the blockage factor does not change.
MacElrevey 95-98 The correct answer is: False
You are docking a ship using two tugs. You have the quarter tug stand off until just before the ship enters the slip. Give two reasons for this.
MacElrevey 108 1. The after tug acts as drag, reducing the effectiveness of the rudder, especially at slow speeds when the shiphandler is trying to move the stern laterally without any increase in speed. 2. The stern tug tends to set the stern away from the side on which she is made fast. This effect increases the angle at which the tug lies to the ship increases, since the tug is acting as a rudder of the dimentions of the tug’s underwater profile.
What is the signal for increase to full power?
MacElrevey 105 Series of short, rapid blasts.
What is the signal for tug dismissed. Let go?
MacElrevey 105 On long, two short.
What is the signal for if working, stop?
MacElrevey 105 One blast.
What is the signal for if pushing, increase power.
MacElrevey 105 Series of short, rapid blasts.
What is the signal for come ahead, dead slow.
MacElrevey 105 One long blast.
What is the signal for back the tug, normal power?
MacElrevey 105 Two blasts
What is the signal for if stopped, come ahead?
MacElrevey 105 One blast.
What is the signal for if backing, increase power.
MacElrevey 105 Series of short, rapid blasts.
A bow thruster if used correctly has the same effects on a ship as a tug made fast on the bow?
MacElrevey 106 The correct answer is: False
There are several techniques a shiphandler can use to hold a ship in position in a channel or other confined area including… I. steam on the anchor at slow engine speeds II. anchor on a short scope of chain with the current from ahead III. simply back and fill in the channel 1. I only 2. II only 3. III only 4. all of the above
MacElrevey 118 The correct answer is: Number 4 all of the above
Quickwater begins to move forward, up the ship’s side when the ship is making a speed of approximately _____ knots, and the quickwater reaches the ship’s midsection when the ship is moving at a speed of ____ knots. 1. 1/0 2. 2/1 3. 3/2
MacElrevey 119-120 The correct answer is: Number 1 1/0
Why is it better to approach the berth with less angle when docking a ship with a right hand propeller starboard side to the dock?
MacElrevey 122 Becasue the quickwater moving up from the stern when backing down acts as a cushion, or wedge effect.
Ships docking at a wharf in a strong current can expect to be set off the berth just as they come alongside becasue of the ____ and the ____, especially when ther is a bank or solid face below the wharf. 1. hydraulic cushsion / Bernoulli effect 2. Bernoulli effect / eddy current 3. hydraulic cushion / eddy current
MacElrevey 126-127 The correct answer is: Number 3 hydraulic cushion / eddy current
When docking at a wharf with the current from astern, the _____ is used to move her laterally the last few feet from the berth. 1. current 2. engine
MacElrevey 111 The correct answer is: Number 1 current
Your ship is docking port side to a wharf parallel to the channel. There is a strong ebb current as you come alongside, and the tugs are made fast at the bow and stern. I. the tugs should come full ahead at a 90-degree angle to the ship to pin the ship tight alongside and prevent movement while the ship’s lines are run. II. the tugs should work at an angle towards the ship, into the current, to hold the ship both alongside and into the current III. the tugs should come ahead parallel to the ship’s side, against the current, to hold the ship in position while lines are run to keep the ship alongside. 1. I only 2. II only 3. III only 4. either I or III
MacElrevey 127 The correct answer is: Number 2 II only
A ship moving at 2 knots moves approximately _____ in one minute. 1. 50 feet 2. 100 feet 3. 200 feet 4. 200 yards
MacElrevey 132 The correct answer is: Number 3 200 feet
You are docking a ship with a right-hand propeller and she is about to come alongside and be stopped, in position, at the berth. The ship should be set up for backing to allow for, and use to advantage, the normal twisting effect as the ship goes astern. This is most commonly done… I. when docking starboard side to, by kicking the engine ahead with hard port rudder before going astern. II. when docking port side to, by kicking the engine ahead with hard starboard rudder before going astern. III. when docking port side to, by going astern to take off headway and bring the ship alongside. 1. both I and II 2. both I and III 3. III only 4. none of the above
MacElrevey 133-134 The correct answer is: Number 2 both I and III
It’s important to always put the rudder amidships before the engine starts turning astern.
MacElrevey 134 The correct answer is: False
In a ballasted condition, it’s usually better to have too much drag than not enough, if such trim is necessary to get the propeller and rudder well submerged.
MacElrevey 140-141 The correct answer is: True
You are about to undock a ship berthed port side to at a wharf. Ships are berthed close ahead and astern, so the ship must be moved laterally to starboard, away from the berth, to clear those ships. Only one tug is available. Describe one way to accomplish this. The tug _____ at a 45-degree angle towards the stern, while the ship’s engine turn’s ahead and her rudder is put hard to _____. 1. comes ahead/starboard 2. backs/starboard 3. comes ahead/port 4. backs/port
MacElrevey 142-144 The correct answer is: Number 4 backs/port
A ship’s bow can be moved or canted towards a pier before undocking by… I. Pushing with a tug II. Letting go the forward spring, then heaving on the headline III. Coming ahead dead slow against the sping line with rudder hard over towards the dock. 1. I only 2. I and II 3. I and III 4. all of the above
MacElrevey 145 The correct answer is: Number 4 all of the above
Variable pitch propellers should be fitted with _____ propellers. 1. right-hand 2. left-hand
MacElrevey 151 The correct answer is: Number 2 left-hand
Safe speed at departure is to a large extent determined by… I. The shiphandler’s experince and confidence in his shiphandling ability. II. The depth of water, the speed of departing traffic, and the weather conditions. 1. I only 2. II only 3. all of the above 4. none of the above
MacElrevey 157 The correct answer is: Number 2 II only
Allowance should be made one degree at a time for set and leeway when maneuvering at slow speeds in an anchorage.
MacElrevey 168 The correct answer is: False
- A ship 600 feet long, moving at 3 knots, would require about ____ minutes for her entire hull, bow to stern, to pass a fixed point. 2. And a one knot current on the beam sets a 600 foot ship about ____ feet in that amount of time. 1. one 2. two 3. three 4. four
MacElrevey 169 About 200 feet The correct answer is: Number 2 two
Ship’s lie at anchor on their final heading. I. lying to the strong force, wind or current, affecting the ship. II. lying to the resultant of all forces acting on the ship. III. lying into the current 1. I only 2. II only 3. both I and II 4. all of the above 5. none of the above
MacElrevey 173-174 The correct answer is: Number 2 II only
List three reasons it is important to have a ship on her final heading before letting go.
MacElrevey 174 1. The chain will lead clear of the hull as it is slacked out. 2. Wear and strain on the chain, stem, windlass, and the mate’s paint budget. 3. The chain is laid out along teh bottom neatly and quickly 4. The chip can be positioned among other ships and obstructions with our concern about swinging clear after the anchor fetches up since your vessel is already on the same heading as those ships.
The major difference between the apparent motion of closer ships or objects and farther objects or the shoreline can be used to accurately detect lateral motion and motion ahead and astern.
MacElrevey 176-177 The correct answer is: True
Go astern to estimate ship’s speed through the water ____ the final anchoring location, when anchoring ____. 1. when at/at night 2. before reaching/at night 3. when at/at all times 4. before reaching/at all times
MacElrevey 179 The correct answer is: Number 4 before reaching/at all times
Ships at anchor always appear ______ your ship than they are actually lying. 1. closer to 2. farther from
MacElrevey 183 The correct answer is: Number 1 closer to
It’s important to use the proper amount of chain when handling a ship with her anchor. Used correctly, the anchor will drag along with conciderable resistance, but it won’t dig in and hold.
MacElrevey 194 The correct answer is: True
The offshore anchor is recommended when docking a ship because… I. There is more chance of the anchor digging in and holding. II. There is less chance of damaging the hull and chain. III. The offshore anchor may be used later to heave off the berth and undock with minimum damage to hull and chain. 1. I only 2. II only 3. both II and III 4. all of the above 5. none of the above
MacElrevey 192-193 The correct answer is: Number 3 both II and III
Static friction (when the wildcat is not turning) between the asbestos brake band and the windlass’s brake drum is approximately ____ times as great as dynamic friction 1. two 2. three 3. five 4. ten
MacElrevey 194 The correct answer is: Number 2 three
The best heading for approaching a single-point mooring is indicated by the heading of anchored ships and the reciprocal of the direction which the floating hoses trail from the buoy.
MacElrevey 212 The correct answer is: False
The wind has little effect on VLCCs, so these ships approach single-point moorings directly into the current.
MacElrevey 212 The correct answer is: False
The safest, most expedient approach to a single-point mooring is made by… I. heading directly at the mooring, keeping the buoy dead ahead as ship’s engine goes astern and stopping near the pickup buoy. II. making a significant course change, preferably to port, to come to the final approach heading, and then keeping the buoy fine on the port bow as the ship approached the SPM. 1. I only 2. II only 3. either I or II 4. neither I or II
MacElrevey 213-214 The correct answer is: Number 1 I only
When making a Mediterranean moor, the ship should back with her engines until in position, close up to the berth, before running any lines.
MacElrevey 230 The correct answer is: False
Departing a multiple-buoy mooring or Mediterranean moor, it’s usually best to… I. heave the weather anchor short. II. steam on the weather anchor as required while heaving home the lee anchor. III. steam away from the mooring as soon as the lee anchor breaks free, heaving on and dragging both anchors until well clear of the buoys or the berth. 1. I only 2. II and III only 3. all of the above 4. none of the above
MacElrevey 230 The correct answer is: Number 3 all of the above
Twin-screw ships fitted with single rudders are generally more responsive at slow speeds through the water when the engines are stopped.
MacElrevey 235 The correct answer is: True
Twin-screw ships can be moved laterally towards a berth by pushing the bow with a tug or bow thruster and backing the ____ engine while coming ahead on the other engine. 1. offshore 2. inshore
MacElrevey 235-236 The correct answer is: Number 1 offshore
VLCCs usually go astern to avoid close quarters situations.
MacElrevey 244 The correct answer is: False
Safe speed” is the same for all sizes of ships.”
MacElrevey 244 The correct answer is: False
Hydrodynamic effects are different for VLCCs.
MacElrevey 247 The correct answer is: False
Longer ships are more difficult to bring flat alongside because perspective makes the farther end appear much closer to the berth than the closer end (the ‘railroad track’ effect).
MacElrevey 247-248 The correct answer is: True
It is essential that the master be a competent shiphandler because, under certain circumstances, he has a responsibility to relieve a pilot in a timely and effective manner.
MacElrevey 293 The correct answer is: True
