Intro

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Intro
Only training and  hands-on  experience take
the mystery out of
shiphandling
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Intro

• Manoeuvring characteristics of ships
•  Course keeping ability  and  Dynamic
  stability 
• Dynamically stable ship after small disturbance
  move along a new straight course without using
  rudder
• Dynamically unstable ship performs turning circle
  with rudder amidships
• Dynamically unstable ships are more difficult to
  handle
•  Turning ability 
• Measure of ability to turn the ship with
  hard-over rudder
• Obtained by performing a  turning circle 
  manuvre
•  Initial turning ability  is defined by the
  amount of heading deviation per unit of distance
  travelled

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Intro / Dynamic stability
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Intro/ Dynamic stability

• Dynamically stable
• - Fine line ships (cargoships, containerships,
  passengerships) tend to be directionally stable
• directionally stable ship will move on a straight
  course if rudder is kept amidships
• When during a turn, rudder is put amidships rate
  of turn reduce to zero and vessel continues on
  straight course
• Directionally unstable
• ship deviates with the smallest disturbing cause
• If rudder put amidships during turn reduction of
  rate of turn but vessel keeps turning on a track
  with larger diameter

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Turning Ability
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Intro / Inertia - Momentum
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Intro / Inertia - Momentum
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Intro / Inertia - Momentum
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Intro / Inertia - Momentum
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Intro / Qualities of a good shiphandler

• Patience
• Anticipation be  proactive 
• instead of  reactive 
• Quietness
• Experience
• Steadfastness
• Concentration
• Knowledge / Know-how
• The  Art  of shiphandling

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You will see Fast captains, You will
see Old captains, Very seldom will You
see Old and fast Captains
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Chapter One

• 
  Various factors
• influencing the manoeuvring of the
  ship

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Ch1. Effect of Fixed Factors on shiphandling

• Fixed factors of the ship
• Design and dimensions of the ship
• Propulsion unit
• Propellers
• Rudders

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Ch1. Effect of Variable Factors on shiphandling

• Variable factors inherent to the ship
• - Draft
• Trim
• Displacement
• Fouling

• Variable factors outside ship
• Wind, Sea, Swell
• Current
• Interaction Depth of water / Shallow waters
• Interaction Proximity of other ships

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Ch1. Factors influencing the shiphandling

• Size of the ship
• Ships are designed to make speed , not to stop
• Engine power does not increase in proportion to
  ships size
• Large ships
• Difficult to judge speed from the bridge
• When swinging in port large swinging room
  required
• Estimation of distances to berth difficult
• Bridge is isolated from forecastle or poop
• Large ship causes more damage when colliding with
  berth

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Ch1. Factors influencing the shiphandling

• What is a large ship?
• In 1952 biggest tanker in the world was 45000DWT
• Lenght is a more relevant criterion than tonnage
• Below 100m small ship
• Longer than 200m large ship
• Between medium size
• Size of ship versus available space gives degree
  of difficulty
• For small ports 5000DWT ship is big
• A 5000 DWT ship does not present same problems of
  dimensions, mass, inertia and momentum as a
  50.000DWT.

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Ch1. Design of ship / Bridge amidships
Bridge amidships Advantages Shiphandler near the
pivoting point when swinging Best position in a
small ship Close to forecastle and poop / visual
communication Good indication of rate of
swing Disadvantages On large vessels each
end far from the bridge
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Ch1. Design of the ship / Bridge forward
Bridge forward Advantages Shiphandler has
excellent view of berth on arrival Close to
anchor when anchoring / easy communication with
anchor party Close to entrance of locks good
visual communication with the
shore Disadvantages Difficult to assess the
ships heading without looking aft From the
wings objects on one bow may appear on the other
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Ch1. Design of the ship / Bridge after
Bridge after Advantages Easy to judge rate of
swing / start and end of swing All ship is seen
when looking ahead / ships heading visualized If
bridge is near stern astern clearance easy to
assess Disadvantages Shiphandler far from
forecastle visual communication impossible when
mooring, anchoring, approaching lock or
berth Difficult to select precise spot for
anchoring Vessel passing ahead from bridge may
still collide with foredeck With restricted
visibility
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Ch1. Design of the ship

• Ratio Lenght/Breadth (L/B)
• Big L/B bad turning / good course keeping
  (dynamically stable ship) / good speed
• Ratio Lenght/Draft (L/D)
• Big L/D bad dynamical stability (example
  bulkcarrier or tanker in ballast)
• Ratio Block coefficient (Cb V/LBT)
• Big Cb bad dynamical stability, easy turning

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Ch1. Effect of ship parameters on manoeuvring
perf.
Good turning
Bad Bad
course keeping ability Good

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Ch1. Effect of the bulb on performance
Reduce the water resistance Increase of speed
one knot / depending on draft/trim Consumption
reduced Better course keeping ability Worse
turning ability
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Ch1. Vorm achtersteven / Forme de la poupe
Design of the stern influences the flow of the
water striking the propeller and the rudder
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Ch1. Design of the Hull
New hulls are designed to improve the quantity of
water passing through the propeller/rudder area.
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Ch1. Design of the Hull
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Ch1. Propulsion of the Ship / Diesel motor

• Manoeuvrability is function of type of propulsion
  
• Most common diesel engine fixed pitch
  propeller
• Ship is called m/s (for motorship) or m/v
  (for motor vessel)
• advantages
• Can be instantly stopped
• Can be quickly reverted
• During a stop manuvre engines can be stopped at
  the moment that the ship is stopped / propulsion
  ceases immediately.
• Can be quickly accelerated for emergency or kick
  ahead
• Disadvantages
• Compressed air quantity limited / Nof
  cons.starts.
• Big engines cannot run slowly / deadslow 9 or
  10knots
• Difficult to start astern when speed ahead to
  high

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Ch1. Propulsion of the Ship / Diesel motor
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Ch1. Propulsion of the Ship / Steam turbine

• Second most common Steam turbine. Ship is called
  s/s for steamship.
• Disadvantages
• Stern power only 40 to 50 of ahead power
  (smaller turbine used for astern)
• Problems to stop the vessel mostly in emergency
• Turbines can keep turning slowly ahead when
  supposed stopped.

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Ch1. Propulsion of the Ship / Steam turbine
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Ch1. Propellers

• Fixed right handed propeller
• Variable pitch propellers
• Twin propellers
• Outturning
• Inturning
• Kort Nozzle
• Azimuth stern drive (ASD)
• Voith Schneider

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Ch1. Variable Pitch propeller
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Ch1. Kort Nozzle / Tuyère Kort
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Ch1. Propulsion  Voith Schneider 
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Ch1. Rudders
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Ch1. Effect of Variable Factors on shiphandling

• Variable factors inherent to the ship
• - Draft
• Trim
• Displacement
• Fouling

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Ch1. Effect of Draft / Fully loaded ULCC
Difficult to stop and to bring in a turn
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Ch1. Effect of draft / Ship in ballast
Ship heavily affected by wind
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Ch1. Effect of Trim

• Trim by the head
• will turn into the wind
• difficult to steer
• rudder and propeller come out of the water when
  ship is pitching

Trim by the stern vessel tends to fall off
with side wind
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Ch1. Fouling / Salissure de coque
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Ch1. Effect of Fixed Factors on shiphandling

• Variable factors outside ship
• Wind, Sea, Swell
• Current
• Interaction Depth of water / Shallow waters
• Interaction Proximity of other ships

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Ch1. Effect of the wind
Loefgierig schip
Lijgierig schip
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Ch1. Effect of waves on the ship
The stability of the ship is affected by stern
waves
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Ch1. Effect of current
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Ch1. Effect of current
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Ch1. Interaction between ship and shore
Closeness of obstacles like shore, berth, etc
will modify the pressure fields around the ship
and provoke changes of heading, uncontrollable
swings, due to suction and repulsion forces.
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Ch1. Interaction between ships
Close quarters
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Ch1. Interaction between ships

• Overtaking ships

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Ch1. Interaction between ship and assisting
tugboat

• The tug is affected by the closeness of the ship
• Dangerous position when close to the bow

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Ch1. Comparison between ratios mass/power

• Airplane 4 to 6 kg/Pk
• Car 25 kg/Pk
• Coaster 50 kg/Pk
• Sea ship 2000 to 3000 kg/Pk