Ship Manoeuvering Principles and Pilotage

Question 1

The speed at which you can safely go astern on the engines is generally?

Answer 1

5 kts on a fully laden ship

Question 2

What rules of thumb should you use to judge speed?

Answer 2

1 knot = approx. 100 FT per minute or 30 Meters per minute (0.017 NM per minute when using a VRM)

Question 3

When going astern and the ships head does not swing in the direction you expect due to the transverse thrust, this could be caused by the follow?

Answer 3

Wind effects or tidal stream effects.

Question 4

How can you create maximum transverse thrust effect?

Answer 4

By using Full ahead or Full astern, to create confused water around the propeller

Question 5

How can one minimize transverse thrust effect?

Answer 5

Build engine speed slowly by stages, so as to build up water through the propeller, so that it can gain maximum grip of the water

Question 6

How much rudder is generally used to counter the transverse thrust effects?

Answer 6

Generally pretty negligible, only will need 1 or 2 degrees to counter its effect.

Question 7

If there is not enough room to turn a ship round in one single maneuver, then the ship will have to be turned__________.

Answer 7

Short Round

Question 8

Which direction should a right handed propeller ship be turned to when turning short round?

Answer 8

Starboard

Question 9

Which direction should a left handed propeller ship be turned to when turning short round?

Answer 9

Port

Question 10

Where will the center of turn be positioned when the ship is on an even keel

Answer 10

approximately midships

Question 11

Where will the center of turn be positioned when the ship is down by the stern?

Answer 11

move further aft

Question 12

Where will the center of turn be positioned when the ship is down by the head?

Answer 12

Move further forward

Question 13

Do thrusters if fitted affect the center of turn?

Answer 13

NO

Question 14

Do the rudder and propeller effect the center of turn?

Answer 14

Only if there is a change in ships speed

Question 15

Will weight on a mooring line or anchor chain, alter the position of the center of turn?

Answer 15

Yes

Question 16

Do tugs pushing and pulling alter the position of the center of turn?

Answer 16

Yes

Question 17

When the portion of the weight of the ships inertia and the power of the tug approaches being equal, then the ships center of turn will__________________

Answer 17

virtually be at the point where the tugs force is positioned

Question 18

Define “drifting moment, and movement element”

Answer 18

Consisting of the moment between the point of balance of the wind force, and the point of balance of the under water resistance, which is mainly determined by the ships trim; combined with the leeward movement of the ship

Question 19

Define “wind force moment”

Answer 19

Between the point of balance of the wind force, and the ships center of turn, which varies according to the ships speed through the water

Question 20

Define “drifting movement”

Answer 20

the movement of the whole ship to leeward

Question 21

Define “ wind force point”

Answer 21

Is the point where the force of wind blowing on the ships side, including the superstructure and any deck cargo, is balanced or centered and will be somewhere on the ships surface. The wind force point will change or move if the relative direction of the wind changes, due to a change of the ships speed and or an alteration of course.

Question 22

Define “ wind resistance point”

Answer 22

of a ship, resisting the drifting movement due to the wind, is the point on the leeward side of the underwater section of the ship, at which all resistance moments balance. Only if the relative direction of the wind changes, so will the wind resistance point, resisting the force of the wind change.

Question 23

Define “ drifting moment lever”

Answer 23

the distance between the wind force point and the wind resistance point, measured at right angles to the direction of the wind.

Question 24

Define “Drifting Moment”

Answer 24

is the product of multiplying the drifting moment lever, by the force of the wind. It is the moment that turns a ship, when drifting, onto the heading with the wind force point and the wind resistance point in line with the direction of the wind, it is when effect of the wind force, against the resistance of the underwater part of the ship is balanced.

Question 25

Define “ wind force lever”

Answer 25

is the distance between the wind force point and the ships center of turn and if it is the initial center of turn, then it will be the “initial wind force lever”

Question 26

When the wind is from abaft the beam, as the ship slows down, then the relative wind strength __________

Answer 26

Increases

Question 27

When the ship is trying to turn due to the combined effects of ‘drifting moment’ and the ‘wind force moment’ how can this be assessed?

Answer 27

By how much port or starboard rudder is being used to carry the ships current heading.

Question 28

When making an approach with a following wind you should?

Answer 28

start reducing speed in plenty of time, reduce speed slowly as to keep as much thrust from the propeller onto the rudder as possible.

Question 29

What are the two ways you can change the relative direction of the wind on a ship and the effect of the wind?

Answer 29

altering ships speed or course, or a combination of both

Question 30

When berthing stern to tide what should you make the fore and aft officers aware of?

Answer 30

You will want the stern to come alongside first and not to heave on any lines forward until so instructed.

Question 31

As you gather stern way, what effect does that have on center of turn and transverse thrust effect.

Answer 31

center of turn will move aft, reducing the transverse thrust effect.

Question 32

Using an anchor on loaded Ships up to __________ Gross or empty ships up to ____________ Gross, providing the nature of the bottom is suitable like soft mud and sand is pretty routine nowadays

Answer 32

10,000 and 15,000. anything above that size runs the risk of breaking the anchor chain if there is current or a strong wind blowing.

Question 33

If there is no current or wind, then with care, an anchor can be used safely on ships ____________ gross

Answer 33

30-40,000 Gross tons

Question 34

When can anchors not be used?

Answer 34

bottom is unsuitable, restrictions due to pipes cables etc, entering lock gates.

Question 35

How can you check there is enough weight on the anchor?

Answer 35

by stopping the engines, if the ship starts turning towards the anchor, and also if the ship starts to loose way

Question 36

When using a radar VRM to measure distance off the berth to drop the anchor, what must you take into account?

Answer 36

Allowances for the distance between the anchor and the ships radar scanner.

Question 37

If a tug is towing on the starboard bow and you want it to tow on the port bow, to get from the starboard bow to the port bow the tug will apply some force in the _______

Answer 37

opposite direction that you want, so that it can make it to the port bow.

Question 38

In order of precedence which tug would you place forward on a towline? Conventional- Voith- Z drive

Answer 38

1. Conventional
2. Voith
3. Z drive ( only use forward if you have no other type available)

Question 39

In order of precedence which tug would you place aft on a towline? Conventional- Voith- Z drive

Answer 39

1. Z Drive
2. Voith
3. Conventional.

Question 40

Gob lines are used on assist tugs to?

Answer 40

help reduce the chance of girting, however they can also make the tug virtually impossible to steer.

Question 41

A major draw back to thrusters is?

Answer 41

they only supply their maximum effect when the ship is stopped.

Question 42

When maneuvering a ship using a thruster it is important to keep in mind where the _______________

Answer 42

center of turn is

Question 43

When maneuvering by radar and making your final approach it can be hard to judge?

Answer 43

ships speed over the ground, and any set or drift

Question 44

When anchoring a ship accurately use a radar that is?

Answer 44

Gyro stabilized and in North Up relative display

Question 45

To make a basic passage plan for a deep draft ship first you have to?

Answer 45

identify all the shallow points on the route, then decide on the amount of underwater clearance for the speed of the ship.

Question 46

When experiencing a set and/ or drift across a channel, while navigating or approaching relatively narrow channels, when making course changes you should?

Answer 46

Make larger alterations of course then necessary to just balance for the set and drift, so that you not only maintain your required course but get back onto your original track.

Question 47

When trying to identify a ship via VHF what is the very least information you should give to identify the ship.

Answer 47

ships position and what direction it is heading.

Question 48

Using the rudder hard over in ether direction back and forth to slow a ship down is sometimes referred as?

Answer 48

rudder cycling

Question 49

A fairly average modern ocean going ship today will have a length ___ to ___ times its beam and a loaded draft about ______ to _______ of its beam

Answer 49

6 to 7 times

1/2 to 1/3 of its beam

Question 50

True or False: Spring tides are bigger than neap tides?

Answer 50

True

Question 51

When navigating through estuary channels, more care is needed during spring tides because?

Answer 51

Any tidal set across channels will tend to be more pronounced, especially at high water when there is more room for the water to flow over the banks.

Question 52

As a rule of thumb spring tides start?

Answer 52

about 2 days before a new or full moon, and last until about 5 days after a new or full moon.

Question 53

If you are berthing a ship at the time of H.W or L.W, but especially at H.W and the berth is not a solid wharf, but a berth built on piles, so that the water is allowed to flow freely underneath it, then there is a risk you will be set?

Answer 53

off the berth unless there is a special geographic reasons, like a bend in the river.

Question 54

How much a ship squats depends on?

Answer 54

the lines of the ships underwater hull, her draft and speed, the depth of the water under the keel.

Question 55

What are the four indications that a ship is steaming to fast and squatting and that there is insufficient under keel clearance?

Answer 55

1. the ships starts sheering off course unexpectedly
2. increased vibration from the propeller
3. stern waves getting steeper and the tops of the waves breaking
4. a reduction in the propeller revolutions, with the consequent reduction in speed.

Question 56

Drag is?

Answer 56

the accumulation of all the different forces acting on a ship in shallow water.

Question 57

If you are maneuvering a ship with very little UKC then the ships behavior will be unpredictable because?

Answer 57

of the pressures that build up between the ship and the bottom.

Question 58

If you go aground on a falling tide and cannot get off, then make sure to remember to?

Answer 58

Drop the anchor to stop the following rising tide carrying the ship further onto the bank, take soundings all around the ship to find out what effect that falling tide might have on the ship .

Question 59

It is always a good policy to check?

Answer 59

the ships heading against the gyro compass before leaving a berth.