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Comprehensive Stability - Learning Outcomes

Comp. Stab - Learning outcomes

Comprehensive Stability - Learning Outcomes


I. Knowledge of and ability to apply relevant international and national standards.

1. Basic Units and Definitions

  • Systems of Measurement (Metric, Imperial and US Customary units)

  • Quantities and Measurements for Stability Calculations

  • Definitions


II. Use of loading/stability information from trim and stability diagrams and marine operations manual.

1. Hydrostatic properties

  • Hydrostatic Property Information

  • Draft

  • Displacement

  • Height of the Centre of Buoyancy (KB) or Vertical Centre of Buoyancy (VCB)

  • Longitudinal Centre of Buoyancy (LCB) and Transverse Centre of Buoyancy (TCB)

  • The Waterplane Area (WPA)

  • Tons Per Inch (TPI)-Tonne per cm (TPC)

  • Longitudinal Centre of Flotation (LCF) and Transverse Centre of Flotation (TCF)

  • The Height of the Longitudinal Metacentre (KMI) and Transverse Metacentre. (KMt)

  • Moment to Heel or Trim 1° (MH1°-MT1°). Moment to Trim or Heel 1 cm (MCT-MCH)


2. Free surface effect

  • The Free Surface Effect on Stability

  • Calculation of the Loss of GM caused by the Free Surface Effect

  • The effect of added bulkheads in tanks on the Free Surface Effect

  • The Tank Tables with Free Surface Moment

  • Wet and Dry GM


3. Stability calculations on board

  • Loading Conditions

  • The Mooring System Correction

  • The Maximum Allowable Area Loading

  • The Stability Calculations on Daily Report Forms

  • Tank Capacity Tables and Curves


III. Understanding of fundamental principles-theories-factors affecting trim and stability to preserve trim and stability and measures to preserve trim and stability.

1. The centre of gravity, the centre of buoyancy, and the metacentre

  • The Centre of Gravity (G)

  • The Centre of Buoyancy (B)

  • The Metacentre (M)

  • The Height of the Metacentre (KM)

  • The Stability Couple

  • The Metacentric Height (GM)

  • The Righting Arm (GZ)

  • The Righting Moment

  • Heeling and Lolling

  • Hog and Sag

  • Stable Equilibrium

  • Neutral Equilibrium

  • Unstable Equilibrium

  • Stiff and Tender

  • Rolling Period

  • Transverse Versus Longitudinal Stability

  • Categories of Stability


2. Change of draft, heel, and trim

  • Mean Draft (MD)

  • True Mean Draft (TMD)

  • Change of Draft (COD)

  • Change of Trim (COT)-Change of Heel (COH)


IV. Static and dynamic stability criteria for MOUs, environmental limits, and criteria for survival conditions.

1. The calculations for Centre of Gravity (G), Centre of Buoyancy (B) and Metacentre (M)

  • The Effect of Weight Shifts on the Centre of Gravity (G)

  • Recapitulation of Shift of Centre of Gravity

  • The Position of the Centre of Buoyancy (B) and the Metacentre (M) in Relation to K

  • The Effect of Draft on the Centre of Buoyancy (KB)

  • Inertia

  • Calculation for BM

  • Calculation for GM

  • Calculation for List and Trim in Degrees

  • Summary of Static Stability for Small Angles


2. Stability at large angles-stability curves

  • Intact Statical Stability Large Angles

  • The Curve of Statical Stability

  • The Cross Curves of Stability

  • Use of Cross Curve of Stability

  • The Curve of Righting Moments

  • Dynamic Stability

  • Damage Stability

  • Basic Damage Stability Procedures

  • The Down-Flooding Angle

  • The Maximum Allowable Vertical Centre of Gravity (VCG)


V. Understanding of inclining experiment, deadweight, and their use

1. The Inclining Experiment

  • The Preparation of the Inclining Experiment

  • The Principle of the Inclining Experiment

  • The Inclining Experiment Calculation

  • Lightship and variable loading

  • Tracking cumulative changes to lightship condition.


VI. Use of daily loading calculations.


VII. Knowledge of the Effect of:

1. Trim and stability of MOUs in event of damage and consequent flooding and countermeasures.

  • Intact Statical Stability Large Angles

  • Basic Damage Stability Procedures

  • The Down-Flooding Angle

  • Effects of tanks or spaces open to the sea and free communication between tanks or spaces within the unit


2. Movement or off loading supplies or equipment and ballasting of MOUs in order to keep the unit's stress within the acceptable limits. Should include basic discussion/explanation of the following:

  • The Maximum Allowable Area Loading

  • Forces Working on the Floating Unit

  • Stress, Strain, and Yield

  • Fatigue

  • Shear Stress

  • Sagging and Hogging

  • Design Loading Conditions

  • Steel Quality and High Strength Steel

  • Member Loading and Stress

  • Fatigue in Members and Connections

  • Load Curves on Drilling Vessels


Preloading and leg stresses on Jackups

3. Mooring system.

  • Mooring System Components & Purpose

  • The Anchor System Correction

  • Use of Catenary Curve Tables

  • Vertical Component of Line Tension

  • Lightweight Correction for Deployed Chain

  • Environmental Forces & Offset

  • Effects of Line Failures


4. Loss of buoyancy

  • Definition of Damage Stability

  • Causes of Damage Stability

  • Consequences of Damage Stability

  • Permeability

  • Reserve Buoyancy and Damage Stability

  • Watertight Integrity

  • Calculation of Damage Stability

  • The Added Weight Method

  • The Lost Buoyancy Method

  • Comparison Between Added Weight and Lost Buoyancy Methods

  • The Stability Curve for Damage Stability

  • Damage Control Procedure

  • Damage Stability Calculation on Board


VIII. Knowledge of:

1. The emergency response for flooding due to damage, fire fighting, loss of buoyancy, and the effect on trim and stability.

  • Basic Damage Stability Procedures

  • Hazards Associated with Counter Flooding

  • The Down-Flooding Angle.


2. Countermeasures for damage stability

  • Basic Damage Stability Procedures

  • The Down-Flooding Angle


3. Effectively communicate stability-related information.

  • Loading Conditions

  • The Anchor System Correction

  • The Maximum Allowable Area Loading

  • The Stability Calculations on Daily Report Forms


4. Environmental Considerations - Pollution Prevention

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