TMR 4220 Naval Hydrodynamics Manoeuvring and Ship Handling

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TMR 4220 Naval HydrodynamicsManoeuvring and
Ship Handling

• In this part of the course the items
• IMO requirements on ship manoeuvrability
• Ship design and dynamic stability
• Linear and non linear equations of motion
• Finding hydrodynamic coefficients
• Ship handling simulators
• Ship handling in confined waters
• will be presented through lectures, in-class
  discussions, web
• based material and written exercises

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TMR 4220 Lecture 2005.04.04

• Administrative matters
• Changes in lecture schedule
• Visit to SMSC?
• Lecture notes
• Learning material
• Lecture notes (at Institute office, cost NOK 100)
• Lecture foils
• Written exercises (2)

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Revised lecture plan
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TMR 4220 Lecture 2005.04.04

• Topics
• IMO and manoeuvring characteristics
• Examples of documentation of standard tests
• Linear equations of motion for surface vessels
• Stability types for ship manoeuvring studies
• Geometric ship characteristics and dynamic
  stability

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TMR 4220 Naval Hydrodynamics

• Learning objectives
• Explain characteristics of standard manoeuvres
  defined in IMO resolution
• State how standard manoeuvres shall be performed
• Describe selected other standard manoeuvres used
  for evaluation of a ships manoeuvring
  characteristics

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TMR 4220 Naval Hydrodynamics

• Learning objectives
• Show how to develop the combined sway yaw
  linear motion equations
• Describe conditions to be fulfilled when linear
  equations can be used
• Demonstrate steps taken to develop the
  characteristic equation for study of dynamic
  stability
• Show how to find necessary and sufficient
  conditions for dynamic stability
• Demonstrate use of Rouths method for stability
  investigation

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TMR 4220 Naval Hydrodynamics

• Learning objectives
• Demonstrate calculation of initial acceleration
  when the rudder angle is changed
• Demonstrate calculation of steady state values
  after a rudder angle change
• Show how to calculate steady state turning radius
  from yaw speed
• Explain applications of Nomotos equation

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Design spiral

• Manoeuvring performance is one item to check
  during the ship design process
• This is the only course in the marine technology
  MSc study where manoeuvring performance is
  discussed

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Why is manoeuvring performance important?

• Space requirements for different types of
  manoeuvres
• Control of own vessel in confined waters
• Control of own vessel in complex ship to ship
  operations

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Example Lightering operations

• Transfer of liquids between vessels steaming at
  slow speed (Louisianna Offshore Oil Port LOOP)
• Increased use of storage and export tankers,
  example Belokamenka

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IMO and manoeuvring documentation

• Resolution MSC.137(76)
• Standards for ship manoeuvrability
• Ships constructed on or after 1 January 2004
• Methods are either scale model tests and/or
  computer predictions using mathematical models
  (at design stage) or full scale tests
• All vessels of 100m in length, and chemical
  tankers and gas carrier regardless of length

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IMO and manoeuvring documentation

• Resolution MSC.137(76) Criteria
• Turning ability (advance and tactical diameter)
• Initial turning ability (distance covered before
  course change of 10 degrees when 10 degrees of
  rudder is applied)
• Yaw-checking and course keeping abilities
  (overshoot angles)
• Stopping ability (distance)

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IMO MSC Res. 137(76) - Highlights

• Section 1
• Invitation to Governments to encourage those
  responsible for design, construction and repair
  and operation of ships to apply the Standars to
  ship constructed on or after 1. January 2004

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IMO MSC Res. 137(76) - Highlights

• Section 2 General
• Standards are based on the understanding that the
  manoeuvrability of ships can be evaluated from
  the characteristics of conventional trial
  manoeuvres
• Two methods can be applied to demonstrate
  compliance with these Standards
• Scale model tests and/or computer predictions at
  the design stage (full-scale trials should be
  conducted to validate these results)
• Demonstrate compliance based on results of full
  scale trials

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IMO MSC Res. 137(76) - Highlights

• Section 3 Application
• Ships of all rudder and propeller types when
  length is greater or equal to 100 m
• Chemical tankers and Gas carriers regardless of
  length
• Ship undergoing repairs, alterations and
  modifications based on an evaluation by
  Administration

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IMO MSC Res. 137(76) - Highlights

• Test requirements
• Test speed used in the Standards is a speed of at
  least 90 of ships speed corresponding to 85 of
  the maximum engine output
• Conditions when running tests should be
• Deep, unrestricted water
• Calm environment
• Full load, even keel condition
• Steady approach at test speed when initiating the
  tests

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Manoeuvring Standards Criteria

• Turning ability (turning circle, rudder angle 35
  degrees (or equivalent))
• Advance should not exceed 4.5 ship lengths
• Tactical diameter should not exceed 5 ship
  lengths
• Initial turning ability
• Using 10 degree rudder, the vessel should not
  travel more than 2.5 ship lengths by the time the
  heading has changed 10 degrees from the original
  heading

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Manoeuvring Standards Criteria

• Yaw checking and course keeping abilities - 10/10
  degrees Zig-Zag test
• First overshoot angle should not exceed
• 10 degrees if L/U is less than 10 seconds
• 20 degrees if L/U is 30 seconds or more
• (5 0.5L/U) degrees if 10 seconds lt L/U lt 30
  seconds
• Second overshoot angle should not exceed
• 25 degrees if L/U is less than 10 seconds
• 40 degrees if L/U is 30 seconds or more
• (17.5 0.75L/U) degrees if 10 seconds lt L/U lt
  30 seconds

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Manoeuvring Standards Criteria

• Yaw checking and course keeping abilities - 20/20
  degrees Zig-Zag test
• First overshoot angle should not exceed 25
  degrees

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IMO check of PROBO vessel

• Lpp 163 m
• B 32.2 m Lpp/B
  5.06
• Tsc 11.27m
• Td 9.14m B/Td
  3.52
• CB 0.823
• 10/10 zig zag test, U 7.5 m/s
• 3 different aft body design tested

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Probo 10/10 Z test, results
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Manoeuvring Standards Criteria

• Stopping ability
• Track reach in the full astern stopping test
  should not exceed 15 ship lengths
• Value may be modified by Administration where
  ships of large displacement makes this criteria
  impracticable, but should in no case exceed 20
  ship lengths

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Buzz group no. 1

• Which of the IMO Manoeuvring Standards criteria
  will be most difficult to fulfill for
• A modern VLCC
• A modern container vessel
• Present your arguments for the rest of the
  students

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IMO MSC Circ. 1053 (see Annex 3)

• Explanatory Notes to the Standards for Ship
• Manoeuvrability
• Additional manoeuvres
• Spiral manoeuvres
• Direct spiral manoeuvre
• Reverse spiral manoeuvre
• Simplified spiral manoeuvre
• Pull out manoeuvre
• Very small zig-zag manoeuvre (0/5, 1/5), 20
  overshoots

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Additional standard tests

• Pull-out test
• After completed turning circle test, put rudder
  amidship and observe yaw speed
• Test can be used to check if a vessel is
  dynamically stable
• Spiral tests
• Direct spiral test, select rudder angle and keep
  it constant until yaw speed is constant
• Reversed spiral tests, select yaw speed and use
  rudder to obtain the selected yaw speed
• Plot yaw speed as a function of rudder angle

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Comments to IMO Standards - Dand

• For deep water and service/design speed only
• Give no indication of the handling
  characteristics in wind, waves and current
• Do not look at manoeuvres normally carried out by
  most merchant ships
• Full astern stopping test results in extreme
  termal loads on the engine
• Criteria derived from databases heavily biased
  towards (old) tankers and bulk carriers

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Comments to IMO Standards - Qaudvlieg and van
Coevorden

• From operational aspects additional requirements
  should be developed
• Manoeuvrability in shallow water
• Low speed manoeuvring capabilities
• Maximum tolerable wind forces in harbour
  manoeuvres
• Limited heel angles
• Steering in waves
• Steering with special devices

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Summary

• Manoeuvring characteristics are important for
  safe and efficient ship handling in confined
  waters and harbours
• IMO has approved a Manoeuvring Standards
  Criteria
• Criteria should be expanded to account for often
  used manoeuvres for merchant ships
• New propulsion and control systems change
  manoeuvring performance significantly